The present disclosure relates to unitary polymer composite articles and to methods and/or systems for producing polymer/resin composites made with matting and particles, for example, Silicon carbide particles and glass fiber matting via resin infusion. Certain embodiments are to articles for use in pumps, pump components and other mechanical parts. Certain embodiments are directed methods and/or systems for producing composites for use in pumps, pump components and other mechanical parts. These composites have uses in the mining industry, the chemical industry, flue gas desulphurization, for example in power generation, desalination and/or other fields of use.
Methods for producing machine components for use in corrosion and/or wear-resistant environments from cast mineral compositions are known in the art. Machine components such as pumps and pump components have applications in several industrial areas. Typically, the methods used for producing such cast mineral components involve premixing of a resin composition with a wear resistant filler, and then adding the resultant slurry to a casting tool and thereafter curing the slurry with heat to produce a mineral cast component.
One known method for producing mineral cast components involves premixing a resin/filler system slurry in a heatable, evacuated positive mixer at a temperature of higher than 20° C. and at a pressure of under 80 mbar. The casting is then carried out in a preheated casting mould. In the first curing step, the cast piece is slightly cured at a temperature of over 60° C. in an annealing furnace. After the first step of curing, the piece is removed from the mould in a mould removal station, and, if needed, the cast piece may be mechanically reworked and cleaned. Thereafter, the cast piece is transferred back into the annealing furnace and completely cured at a temperature over 120° C.
Another manufacturing process involves casting mineral composite pieces that are made up of multi-shell structure layers and, if need be, pre-stressed reinforcements. However, these methods have high manufacturing costs due to the successive casting of the individual shells.
However, the existing methods for casting polymer/resin composite pieces have several disadvantages. For example, the amount of resin/filler mixed for traditional slurry casting requires mixing of excess materials in a batch process to ensure that the mould tool is completely filled. This often results in waste and additional cost to the manufacturer. Existing systems require the handling of potentially harmful resins and solvent and exposing these chemicals to the atmosphere. This impacts on worker safety and air quality controls issues. The equipment used for mixing and pumping the resin/filler slurry is subject to significant wear over time. This again increases cost to the manufacturer. Furthermore, slurry casting, due the higher viscosity of the slurry mixture, is less useful for producing composites with moulds that have complex shapes, acute angles, corners, and/or turns in the mould shape. Slurry casting also requires the use of an excess of resin in the mixing and filling step which is then removed either after curing or skimmed off in the liquid form as the solid filler settles in the tool. In the case of an ambient cure system, this excess resin cannot be recycled. In the case of a heat cured system, the resin can be reused but this is not an ideal solution since the slurry has to be continually mixed and may be negatively impacted if kept for too long. Slurry casting also tends to introduce excessive and unwanted air pockets into the final cured product. With slurry casting it is commercially not possible to substantially infuse the slurry into glass fiber mats or carbon fiber mats that are often used in the moulding process.
The present disclosure is directed to overcome and/or ameliorate at least one or more of the disadvantages of the prior art, as will become apparent from the discussion herein. The present disclosure also provides other advantages and/or improvements as discussed herein.
Certain embodiments are directed to methods and systems that may be used for producing matting/polymer/filler composites using resins that are infused into a particle matrix and into matting, and then cured to produce components. These unitary polymer composite articles may be used in highly corrosion and wear-resistant environments.
Certain embodiments are directed to a method for producing a moulded composite article including the steps of: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles; and c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite.
Certain embodiments are directed to a method for producing a moulded composite article including the steps of: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite, wherein the composite comprises between 20% to 80% by weight of the resin composition and between 80% to 20% by weight of the particles; and d) curing the composite to form the moulded composite article, wherein the article is substantially void of air pockets.
Certain embodiments are to a unitary polymer composite article comprising: 50% to 90% by weight of particles; 10% to 50% by weight of resin; and at least one layer of matting integrally incorporated in the unitary polymer composite.
Certain embodiments are to a unitary polymer composite article comprising: 20% to 80% by weight of particles; 20% to 80% by weight of resin; and at least one layer of matting integrally incorporated in the unitary polymer composite. Certain embodiments are to a unitary polymer composite article comprising: 50% to 90% by weight of particles; 10% to 50% by weight of resin; and at least one layer of substantially continuous matting integrally incorporated in the unitary polymer composite article.
Certain embodiments are to a unitary polymer composite article comprising: 20% to 80% by weight of particles, wherein at least 20% of the particles have a Mohs hardness of greater than 6.5, 6.8, or 7; 20% to 80% by weight of resin; and at least one layer of matting integrally incorporated in the unitary polymer composite article.
Certain embodiments are to a unitary polymer composite article comprising: 20% to 80% by weight of particles, wherein at least 20% of the particles have a have a Mohs hardness of greater than 6.5, 6.8, or 7; 20% to 80% by weight of resin; and at least one layer of substantially continuous matting integrally incorporated in the unitary polymer composite article.
Certain embodiments are directed to methods and/or systems that may be used for producing resin/filler/matting composites. For example, certain methods and/or systems are directed to infusing a resin composition into a mould tool that is already filled to a predetermined level with particles and already has matting placed in the mould tool, wherein a substantial portion of the particles have a suitable hardness. After infusing the resin composition and ensuring that the formed composite has been sufficiently mixed and has a suitable distribution of the resin composition and the particles, then the composite may be cured to form a moulded composite article. Vibration of the mould tool and/or other suitable techniques may be used to ensure an acceptable level of mixing and suitable distribution the resin composition and the particles. Uniform distribution, or substantial uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. The resins used herein may be thermal setting resins as well as non-thermal setting resins. One exemplary particle type that may be used is Silicon carbide. However, other types of particles, or combinations of particles, may also be used. These particles may be treated to increase their wetting and/or bonding characteristics. Other fillers, matting, liners or combinations thereof may also be used. In addition to resin infusion methods and/or systems other methods and/or systems are disclosed herein. These moulded composite articles may be used in pumps, pump components and other mechanical parts and have uses in the mining industry, the chemical industry, flue gas desulphurization, desalination and/or other fields of use.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) adding at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles, wherein a substantial portion of the particles have a Mohs hardness of 7 or greater; c) infusing a resin composition into the at least one layer of matting and the particles that are in the mould tool in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles; and d) curing the composite to form the moulded composite article.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles; c) infusing a resin composition into the at least one layer of matting and the particles that are in the mould tool in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 80% by weight of the resin composition and between 20% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling the mould tool with particles; c) infusing a resin composition into the at least one layer of matting and the particles that are in the mould tool in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; and e) curing the composite to form the moulded composite article.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling the mould tool with particles; c) infusing a resin composition into the at least one layer of matting and the particles that are in the mould tool in order to form a composite; d) vibrating the at least one layer of matting and the particles in the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; and e) curing the composite to form the moulded composite article.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusion of the resin composition; wherein the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles, wherein at least 20%, 30%, 40%, 50%, 60%, 70%, or 85% by weight of the particles have a Mohs hardness of 7 or greater; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles, wherein at least 20%, 30%, 40%, 50%, 60%, 70%, or 85% by weight of the particles have a Mohs hardness of 7 or greater; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 80% by weight of the resin composition and between 20% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
Certain embodiments are directed to a method for producing a moulded polymer ceramic composite article comprising: a) providing at least one layer of matting to a mould tool interior; b) substantially filling the mould tool interior with treated silicon carbide particles, wherein the mould tool is vibrated during at least a portion of the filling process; c) placing the mould tool filled with the treated particles and the at least one layer of matting under a vacuum of less than 100 mbar; d) infusing a resin composition into the mould tool interior substantially filled with the treated particles and the at least one layer of matting under a vacuum of less than 100 mbar and forming a composite, wherein the composite comprises between 15% to 30% by weight of the resin composition and between 70% to 85% by weight of the treated particles; and e) curing the composite by heating until cured.
Certain embodiments are directed to a method for producing a moulded polymer ceramic composite article comprising: a) providing at least one layer of matting to a mould tool interior; b) substantially filling the mould tool interior with a blend of silane treated silicon carbide particles, wherein a substantial portion of the blended particles is between 50 μm to 1 mm in size and the mould tool is vibrated during at least a portion of the filling process; c) continuing to vibrate the mould tool after filling in order to facilitate a packing of the blended particles; d) placing the mould tool filled with the blended particles and the at least one layer of matting under a vacuum of less than 100 mbar; e) infusing a resin composition into the mould tool interior substantially filled with the blended particles and the at least one layer of matting under a vacuum of less than 100 mbar and forming a composite; f) vibrating the mould tool substantially filled with the composite in order to facilitate densification; g) curing the mould tool substantially filled with the composite by heating until cured, wherein a portion of the resin composition is bonded to a substantial portion of the blended particles via a silane coupling agent that is coated on a substantial portion of the blended particles; and h) removing the cured moulded polymer ceramic composite article from the mould tool, wherein the article comprises between 15% to 30% by weight of the resin composition and between 70% to 85% by weight of the blend particles.
Certain embodiments are directed to a method for producing a moulded polymer ceramic composite article comprising: a) providing at least one layer of matting to a mould tool interior; b) substantially filling the mould tool interior with a blend comprising two or more grades of silane treated silicon carbide particles, wherein a substantial portion of the blended particles is between 50 μm to 1 mm in size and the mould tool is vibrated during at least a portion of the filling process at one or more vibration rates between 100 to 10,000 Hz; c) continuing to vibrate the mould tool after filling at one or more vibration rates between 100 to 10,000 Hz in order to facilitate a packing of the blended particles and to facilitate a substantially even flow of the blended particles into interior geometries of the mould tool; d) placing the mould tool filled with the blended particles and the at least one layer of matting under a vacuum of less than 100 mbar; e) infusing a resin composition into the mould tool interior substantially filled with the blended particles and the at least one layer of matting under a vacuum of less than 100 mbar to form a composite; f) vibrating the mould tool substantially filled with the composite at one or more vibration rates of between 100 to 10,000 Hz for a time period of between 1 minute to 45 minutes in order to facilitate densification and to mitigate against resin wash; g) curing the mould tool substantially filled with the composite and the at least one layer of matting by heating until cured, wherein a portion of the resin composition is bonded to a substantial portion of the blended particles via a silane coupling agent coated on a substantial portion of the blended particles; and h) removing the cured moulded polymer ceramic composite article from the mould tool, wherein the article comprises between 15% to 30% by weight of the resin composition and between 70 to 85% by weight of the blended particles.
Certain embodiments are directed to a method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool interior; b) filling to a predetermined level the mould tool with particles, wherein a substantial portion of the particles have a Mohs hardness of greater than 7; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite, wherein at least a portion of the mould tool is subjected to a vacuum and at least a portion of the mould tool is subject to a positive pressure during at least a portion of the infusing of the resin composition; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
This summary is not intended to be limiting as to the embodiments disclosed herein and other embodiments are disclosed in this specification. In addition, limitations of one embodiment may be combined with limitations of other embodiments to form additional embodiments.
For a better understanding of the disclosure, and to show more clearly how it may be carried into effect according to one or more embodiments thereof, reference will now be made, by way of example, to the accompanying figures.
The following description is provided in relation to several embodiments that may share common characteristics and features. It is to be understood that one or more features of one embodiment may be combined with one or more features of other embodiments. In addition, a single feature or combination of features in certain of the embodiments may constitute additional embodiments. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the disclosed embodiments and variations of those embodiments.
The subject headings used in the detailed description are included only for the ease of reference of the reader and should not be used to limit the subject matter found throughout the disclosure or the claims. The subject headings should not be used in construing the scope of the claims or the claim limitations.
The present disclosure is directed, at least in part, to methods and systems that use resin infusion and/or other methods in order to produce composite articles that are useful in certain environments. An exemplary embodiment is directed to a method where sufficiently hard particles are added to a mould tool to a predetermined level and then a resin composition is infused into the mould tool either via vacuum infusion or pressure infusion. Typically the mould tool will be vibrated during the addition of the particles in order to assure an even filling of the mould tool. Vibration may also be used at other stages of the method. Once the mould tool has been filled to the desired level with the particles and the resin composition, the formed composite is then cured in the mould tool, in order to produce the composite article.
One or more of the following advantages is found in many of the disclosed methods and/or systems and the articles produced.
A. The amount of resin composition mixed and particles used can be close to exactly what is required to fill the mould. Comparatively, the known slurry casting methods require mixing of excess resin/particles, in a batch process, to ensure that the mould is filled. The known slurry casting methods thus can result in waste and additional cost.
B. By directly infusing a resin composition into a matting/particle-filled tool in a closed system, the need to handle harsh resins and/or solvent is reduced and exposure of such resins and/or solvents to the atmosphere is reduced. Such closed systems facilitate improved worker safety and/or air quality controls.
C. Wear and tear mixing and pumping equipment is known to be a problem when mixing and pouring abrasive slurries. Certain disclosed embodiments eliminate, or substantially reduce, the process of wet mixing a resin/particulate slurry. This saves on wear and tear on the equipment and reduces the cost of manufacturing and/or the cost of replacing equipment.
D. Known slurry casting processes require the use of an excess of resin in the mixing and filling step which is then removed either after curing or is skimmed off in the liquid form as the solid filler settles in the mould tool. In the case of an ambient cure system, this excess resin typically cannot be recycled. In the case of a heat-cured system the resin can often be reused, but this is an additional intervention that is not required by the many of the disclosed embodiments.
E. The disclosed processes tend to introduce less air pockets into the final cured articles.
F. A mould can be used in casting which has more complex shapes, sharp corners, acute angles or combinations thereof.
G. In many of the disclosed embodiments, glass fiber mats and/or carbon mats that are set into the mould can be infused with the resin composition, as compared with traditional slurry casting methods where this is commercially impossible/impractical.
The particles may be selected from a variety of types of materials. For example, one or more of the following types of materials may be used: Silicon carbide, Alumina carbide, Tungsten carbide, Titanium carbide, Corundum, Quartz, Silicon dioxide, Silica, Silica sand, sand and other suitable non-absorbent particles. Silicon carbide particles are used in certain embodiments. Blends of different size grade Silicon carbide particles are used in certain embodiments.
The aspect ratio of a substantial portion of the particles used may vary. In certain applications, a substantial portion of the particles have an aspect ratio of between 0.7 to 1.3. Other suitable ranges of aspect ratios may also be used, for example, an aspect ratio of between 0.5 to 2, 0.7 to 2, 0.5 to 1.8, 0.8 to 1.2, or 0.5 to 1. A certain percentage of the particles used may fall outside of these aspect ratios. For example, in certain applications the weight percentage of particles that fall outside of one or more of these aspect ratio ranges may be less than 1%, 3%, 5%, 7% or 10%.
Different size ranges of the particles may be used. In certain applications, a substantial portion of the particles are between 50 μm to 1 mm in size. Other suitable size ranges may also be used, for example, between 25 μm to 3 mm, 100 μm to 1.5 mm, 75 μm to 0.8 mm, 500 μm to 1.2 mm, 750 μm to 1.5 mm, 1 mm to 2 mm, or 750 μm to 1.2 mm. A certain weight percentage of the particles used may fall outside these size ranges. For example, in certain applications the weight percentage of particles that fall outside of one or more of these size ranges may be less than 1%, 3%, 5%, 7% or 10%.
Different size grades of particles may also be blended to form the particles used. In certain applications, the particles comprise a blend of two or more different size grades of particles. In certain embodiment, the particles comprise a blend of at least 1, 2, 3, 4, 5 or 6 different size grades of particles. In certain embodiments, 2 to 4, 1 to 5, 2 to 5 or 3 to 6 different size grades of particles may be used.
Different ratios of different size grades of particles may also be used. For example, the particles may comprise about a 70:30 weight ratio blend of about 750 μm graded silicon carbide particles and about 200 μm graded silicon carbide particles. Another example is wherein the particles comprises a 65 to 75:25 to 35 weight ratio blend of 725 to 775 μm graded silicon carbide particles and 175 to 225 μm graded silicon carbide particles. Another example is wherein the particles comprise a blend of at least 3 different grades of particles comprising about one part 1 mm particles, about one part 750 μm particles, and about one part 100 μm particles. Another example is wherein the particles comprise a blend of at least 5 different grades of particles comprising about one part 1 mm particles, about one part 750 μm particles, about one part 500 μm particles, about one part 250 μm particles and about one part 100 μm particles. Another example is wherein the particles comprise a blend of at least 5 different grades of particles comprising about 15 to 25 weight parts of 0.9 to 1.1 mm particles, 15 to 25 weight parts 730 to 770 μm particles, 15 to 25 weight parts 480 to 520 μm particles, 15 to 25 weight parts 230 to 270 μm particles and 15 to 25 weight parts 90 to 110 μm particles. Other suitable weight ratios may also be used. For example, for a two-blend of different size grades of particles, the weight ratio may be 75:25, 85:15; 90:10; 95:5, 65:35, 60:40, 50:50, 40:60, 35:65, 5:95, 10:90, 15:85, 25:75 or other suitable weight ratios. Similar ranges of weight ratios may be used with blends of 3, 4, 5, or 6 different size grades of particles. A certain percentage of the particles used may fall outside these different size grades. For example, in certain applications the weight percentage of particles that fall outside of these different size grades may be less than 1%, 3%, 5%, 7%, 10%, 15% or 20%.
Different types of particles may also be combined, for example, wherein the particles comprise a blend of at least two different types of particles. Another example is wherein the particles comprise a blend of at least two to four different types of particles. The number of different types of particles that are used may be related to the particular application. Silicon carbide particles in one or more sizes can be combined with, for example, tungsten carbide particles in one or more sizes, and in the ratios disclosed herein. Furthermore, hollow microspheres can be beneficially added to produce a lightweight and/or wear resistant component, in certain embodiments up to 50% of the silicon carbide by volume can be replaced with hollow microspheres with a density of 0.125, 0.15, 0.20, 0.35 or 0.38 g/cc to produce a finished part with substantially reduced weight and/or density. In certain embodiments up to 50% of the silicon carbide by volume can be replaced with hollow microspheres with a density range of between 0.125 to 0.38 g/cc, 0.15 to 0.35 g/cc, 0.15 to 0.20 g/cc, 0.25 to 0.38 g/cc or other suitable ranges to produce a finished part with substantially reduced weight and/or density. In certain embodiments, microspheres can be added to produce a moulded component wherein up to 60%, 50%, 40%, 30% or 20% of the other particles by volume can be replaced with microspheres. In certain embodiments, the microspheres may be made up of natural and/or synthetic materials, for example glass microspheres, polymer microspheres, ceramic microspheres or combinations thereof. Solid and/or hollow microspheres may be used in certain applications. In certain aspects, hollow microspheres may be used to lower the density of the final material.
Different levels of hardness in the particles may also be used. One example is wherein a substantial portion of the particles have a Mohs hardness of between 8.8 and 9.2. Another example is wherein a substantial portion of the particles have a Mohs hardness of greater than 9 and are substantially inert. Other suitable ranges of Mohs hardness may also be used, for example, between 8 to 9.5, 7.5 to 9.5, 8.5 to 9.5, 6 to 7.5, 7 to 8.5, 6 to 8 or 9 to 9.5. In certain embodiments, at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99% or 99.5% by weight of the particles may have a Mohs hardness of between 6.8 to 7.5, 7 to 8, 8 to 9.5, 7.5 to 9.5, 8.5 to 9.5, 6 to 7.5, 7 to 8.5, 6 to 8 or 9 to 9.5. In certain embodiments, a substantial portion of the particles will have a Mohs hardness of at least 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.2, 8.5, 8.8, 9, or 9.5. In certain embodiments, at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99% or 99.5% by weight of the particles may have a Mohs hardness of at least 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.2, 8.5, 8.8, 9, or 9.5. A certain percentage of the particles used may fall outside these Mohs hardness values. For example, in certain applications the weight percentage of particles that fall outside of these Mohr hardness values may be less than 1%, 3%, 5%, 7% or 10%. In certain embodiments, a substantial portion of the particles used will be inert or substantially inert.
The particles used may be treated to enhance their ability to mix and/or combine with the resin composition used, in order to form a composite and/or a cured article. The treatment applied to the particles may be related in part to the types of particles used and/or to the make-up of the resin composition used. Various wetting agents and/or coupling agents may be used to enhance the interaction of the particles with the resin composition. Coupling agents tend to enhance the adhesion between a solid surface (e.g., particles) and a curable resin composition. Useful examples of suitable coupling agents include organo-silanes, zircoaluminates, and/or titanates. With respect to the organo-silanes, in certain embodiments coating a portion of the surface of a substantial portion of the silicon carbide particles with one or more alkyl-silane agents before infusion of the resin composition have been found to work well for enhancing the wetting and/or bonding between the particles and the resin. The coupling agent may be selected from a variety of coupling agents. In certain embodiments, the coupling agent comprises a plurality of molecules, each having a first end adapted to bond to the particles and a second end adapted to bond to the resin when cured. Exemplary coupling agents are Alpha Silanes produced by Power Chemical Corporation of South Korea. Other exemplary silanes are Dow Z-6032, and Z-6075 (vinyl triacetoxy silane) and similar coupling agents available from DeGussa and Crompton, for example, Dynasylan. Other exemplary coupling agents are one or more of the following: OCTEO (Octyltriethoxysilane), DOW Z6341 (octyltriethoxysilane), Dynasylan GLYMO (3-glycidyloxypropyltrimethoxysilane), DOW Z6040 (glycidoxypropyltrimethoxysilane), Dynasylan IBTEO (isobutyltriethoxysilane), Dynasylan 9116 (hexadecyltrimethoxysilane), DOW Z2306 (i-butyltrimethoxysilane), Dynasylan AMEO (3-aminopropyltriethoxysilane), DOW Z6020 (aminoethylaminopropyltrimethoxysilane), Dynasylan MEMO (3-methacryloxypropyltrimethoxysilane), DOW Z6030, DOW Z6032 (vinylbenzylaminoethylaminopropyltrimethoxysilane), DOW Z6172 (vinyl-tris-(2-methoxyethoxy) silane), DOW Z6300 (vinyltrimethoxysilane), DOW Z6011 (aminopropyltriethoxysilane) and DOW Z6075 (vinyl triacetoxy silane). Other exemplary coupling agents are titanates and other organo-metal ligands. Other coupling agents are also contemplated. Typically the choice of the coupling agent will be based at least in part on compatibility with the resin reactive groups and surface chemical groups on the proposed filler. The amount of coupling agent used may vary. For example, in certain embodiments, the Silicon carbide particles are treated with an organo-silane coupling agent composition that is capable of bonding to a portion of the resin composition during curing of the composite. In certain embodiments, the Silicon carbide particles are treated with an alkyl silane that is capable of bonding to a portion of the resin composition during curing of the composite. In certain embodiments, the coupling agent composition is present between 0.5 to 5 wt. % of the weight of particles. In other embodiments, the coupling agent composition is present between 0.5 to 1.5 wt. %, 1 to 3 wt. %, and 0.5 to 2 wt. % or in other suitable weight percentage ranges of the weight of particles used. In certain applications, combinations of the various coupling agents may also be used.
Wetting agents, or surfactants may also be used and tend to impact the rheology of the composition during processing. In general, various types of wetting agents, i.e., anionic, cationic, nonionic, amphoteric, zwitterionic, organic, and so on, can be employed in certain embodiments disclosed herein. Useful examples of wetting agents include INTERWET 33 from Chemie America Interstab Chemicals, New Brunswick, N.J.; FLUORAD from 3M Co. St. Paul, Minn. or AEROSOL OT from Rohm Haas, Philadelphia, Pa. Other suitable surfactant additives include the BYK range of additives produced by BYK-Chemie of the ALTANA group such as BYK-500, BYK-501, BYK-515, BYK-550, BYK-506, BYK-535, BYK-555, BYK-560, BYK-920, BYK-966, BYK-980, BYK-909, BYK-969 & BYK-985. Certain of these agents may also assist with preventing foaming during resin infusion under vacuum conditions in addition to their wetting behavior. In certain embodiments, the wetting agent composition is present between 0.5 to 2.5 wt. % of the weight of particles. In other embodiments, the wetting agent composition is present between 0.5 to 1.5 wt. %, 1 to 3 wt. %, 0.5 to 2 wt. %, 3 to 5 wt. %, 1 to 5 wt. % or in other suitable weight percentage ranges of the weight of particles used. In certain applications, combinations of the various wetting agents may also be used.
Flow agents may also be used in certain applications in preparing the particles to be used herein. Flow agents tend to prevent or reduce “caking” of powders during processing. For example, a flow agent may be used in certain embodiments to prevent the particles from caking during the blending step. Useful examples of flowing agents include condensates of ethylene oxide and unsaturated fatty acids. In certain embodiments, the flow agent composition is present between 0.5 to 2.5 wt. % of the weight of particles. In other embodiments, the flow agent composition is present between 0.5 to 1.5 wt. %, 1 to 3 wt. %, and 0.5 to 2 wt. % or in other suitable weight percentage ranges of the weight of particles used.
In certain applications, one or more of the following may be used: coupling agents, wetting agents, flow agents or combinations thereof.
Various infusion grade resins may be used with the present disclosure. Some examples are vinyl ester resins, vinyl ester urethane hybrid based resins, epoxy based resins, polyester resins or combinations thereof. Resins that may be utilized may include non-thermoset resins and thermoset resins, such as thermoset polyester resins and thermoset vinyl ester resins, or combinations thereof. Generally, resins may be in liquid form, and when mixed with a catalyst and/or subjected to heat, a chemical reaction occurs forming a solid. However, the present disclosure also contemplates the use of liquid, solid, semi-solid resin compositions or combinations thereof.
Thermoset molecules will crosslink with each other during curing. Advantageous features of thermoset resins may include: ease in use for processing, do not necessarily need pressure to form, are generally inexpensive, usually are stronger than thermoplastics, and can be better suited to higher temperatures then thermoplastics. Some types of thermoset resins include, but are not limited to, epoxy thermoset resins, polyester thermoset resins, vinylester thermoset resins, polyurethane thermoset resins, phenolic thermoset resins or combinations thereof. Resins that may be utilized may include polyester resins and vinyl ester resins, which can be chemically tailored to be flexible or rigid, and can be reinforced, pigmented, and filled. These resins may be cured at ambient temperature, or in an oven up to 400° F. In general, polyesters may be formed from combining dicarboxylic acids and polyols (such as diols and glycols), and may also include additional monomers/diluents. In general, vinyl ester polymers may be formed from combining diepoxides and monocarboxylic acids, such as unsaturated monocarboxylic acids, and may also include additional monomers/diluents. The prepared vinyl ester may then be dissolved in a reactive solvent, such as styrene. Generally, vinyl ester resins have lower resin viscosities (approx 200 cps), than polyester resins (approx 500 cps) and epoxy resins (approx 900 cps). To cross-link the polymer molecules, an initiator, such as a peroxide initiator (catalyst), may be added. A particular type of thermosetting resin is the so-called turane resin, which is a thermosetting urethane or vinyl ester urethane hybrid resin, such as Daron 45 supplied by DSM. The thermosetting urethane combines during curing the chemistry of radical polymerization with polyurethanes. This 2-component resin system delivers at least two useful properties: (1) the curing reaction can be controlled from very fast to slow reacting systems and (2) the cured turane products have desired physical and chemical properties for use in many of the applications disclosed herein. The Daron 45 turane resin system consists of 2 components, i.e., Daron 45 and Lupranate M20R. Lupranate M20R is a polymeric methylene phenylisocyanate resin supplied by Elastogran GmbH other polymeric methylene phenylisocyanates may be used for example PAPI-27 supplied by Dow Chemical. Mixing both components, in the presence of catalysts and radical initiators, results in two curing reactions. Fully cured turane resin system based on Daron 45 results in reinforced composite with suitable chemical and/or thermal resistance combined with suitable mechanical properties. Composite construction produced with turane resin system based on Daron 45 turane exhibit suitable long-term heat resistance and suitable resistance to long-term mechanical loading and/or wear. Turane resin systems based on Daron 45 are applicable for open and closed mould techniques. Properties of cast unfilled resin systems may include, but are not limited to: a density of 1,180 kg/m3 at 23° C., volume shrinkage of 6.0%, heat deflection temperature (HDT) of 210° C., glass transition temperature (Tg) of 200° C., tensile strength of 70 MPa, modulation of elasticity in tension of 3.2 GPa, elongation at break of 2.5%, flexural strength of 140 MPa, modulation of elasticity in bending of 3.4 GPa, impact resistance (unnotched) of 15 kJ/m2, fracture toughness of 0.5 MPa, water absorption at 80° C. of 1.2 wt. %. Unsaturated polyester or vinyl ester resins, generally, are cured by use of initiation systems. For example, unsaturated polyester or vinyl ester resin systems may be cured under the influence of peroxides and may be accelerated by the presence of metal compounds, such as cobalt salts as accelerators, for example, cobalt naphthenate and/or cobalt octanoate. In addition to accelerators, the polyester resins may also contain inhibitors and/or stabilizers so that the resin system does not gel prematurely. Polymerization initiation of unsaturated polyester resins, for example, by redox reactions involving peroxides, may be accelerated or pre-accelerated by a cobalt compound in combination with another accelerator. The unsaturated polyester resin or vinyl ester resin may suitably be selected from: (1) Ortho-resins which are based on phthalic anhydride, maleic anhydride, or fumaric acid and glycols, such as 1,2-propylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol or hydrogenated bisphenol-A. Commonly the ones derived from 1,2-propylene glycol are used in combination with a reactive diluent such as styrene. (2) Iso-resins: these are prepared from isophthalic acid, maleic anhydride or fumaric acid, and glycols. These resins may contain higher proportions of reactive diluent than the ortho resins. (3) Bisphenol-A-fumarates: these are based on ethoxylated bisphenol-A and fumaric acid. (4) Chlorendics: are resins prepared from chlorine/bromine containing anhydrides or phenols in the preparation of the UP resins. (5) Vinyl ester resins: these are resins, which are often used because of their hydrolytic resistance and suitable mechanical properties, as well as for their low styrene emission; these resins have unsaturated sites in the terminal position, introduced by reaction of epoxy resins (e.g. diglycidyl ether of bisphenol-A, epoxies of the phenol-novolac type, or epoxies based on tetrabromobisphenol-A) with (meth)acrylic acid. Instead of (meth)acrylic acid also (meth)acrylamide may be used. Examples of suitable vinyl ester resins may include Derakane 470-300, Derakane Momentum 470-300, Derakane 411-350 produced by Ashland. Reactive groups curable by reaction with peroxides may be present in the resins, for instance, reactive groups derived from itaconic acid, citraconic acid and/or allylic groups. The unsaturated polyester resins may contain solvents, such as solvents inert to the resin system or that may be reactive therewith during the curing step. Examples of suitable reactive solvents include styrene, α-methylstyrene, (meth)acrylates, N-vinylpyrrolidone and N-vinylcaprolactam. The unsaturated polyester resins may contain approximately 1 wt. %, 3 wt. %, 5 wt. %, 7 wt. %, or 10 wt. % of a reactive solvent. Vinyl esters are processable by a range of moulding methods including infusion techniques such as resin transfer moulding (RTM), vacuum-assisted RTM, and the Seemann Composites Resin Infusion Moulding Process (RTM, VARTM, SCRIMP). Reinforced vinyl esters offer high strength, toughness, tensile elongation, heat resistance, chemical resistance, wear resistance or combinations thereof. Vinyl esters have the advantages of both unsaturated polyester and epoxy chemistries. The polymer backbone is formed by reacting unsaturated monocarboxylic acids (such as methacrylic acid) with high molecular weight bisphenol A and novolac epoxides. Unsaturated ester functional groups or linkages at the end of each vinyl ester linear molecular chain serve as sites for chain growth and crosslinking. Styrene, for example, serves as a diluent or thinner and coreactant in vinyl ester curing, and induces hydrophobicity or resistance to water absorption during polymerization. Vinyl esters can also have suitable mechanical properties to epoxies, while also decreasing processing time, such as eliminating the need for post cure. For example, urethane-modified DION 9800 vinyl ester, much like high-performance resins such as epoxy, provides suitable toughness and wet out properties in carbon fibre composites processed through infusion and other processes. Another example includes Reichhold's DION 9500 rubber-modified vinyl ester, which promotes surface adhesion in composites, along with suitable strength, toughness and elongation, and high viscosity at the end of the cure cycle. EPOVIA vinyl esters, such as isocyanate-modified EPOVIA RF 5000 vinyl ester, may provide high heat resistance, or EPOVIA RF 2000 SEHA, which provides suitable mechanical properties. Applications that need high levels of toughness, elongation and fatigue properties may use EPOVIA KRF-3200. In addition, EPOVIA KAYAK KRF-1001 vinyl ester, may be employed with silicone carbide filler, such as silicon carbide particles, or alumina/silicon carbide particles.
In certain embodiments, the viscosity of the resin/filler composition may have a viscosity at the processing temperature of less than 1500 cps, less than 1000 cps, less than 500 cps, or less than 300 cps. In certain embodiments, the viscosity of the resin/filler composition may have a viscosity at the processing temperature of between 150 cps to 1500 cps, 150 cps to 300 cps, 200 cps to 1000 cps, or 200 cps to 500 cps.
In certain embodiments, the resin mixture may be formulated to allow at least 30 minutes at room temperature without significant viscosity increase (due to reaction). In certain embodiments, the resin mixture may be formulated to allow at least 20, 40, 60, 90 minutes at room temperature without significant viscosity increase (due to reaction).
In certain embodiments, the cured composite article may have one or more of the following properties: an elongation at break of between 0.5 to 8%, a density of between 1 to 1.3 kg/m3, a hardness of between 70 to 95 Shore D, a volume shrinkage of less than 8%, a flexural strength above 120 MPa, and a tensile strength above 25 MPa. In certain embodiments, the cured composite article may have a volume shrinkage of less than 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7% or 8%. In certain embodiments, the cured composite article may have a volume shrinkage of between 0.5% to 2%, 0.25% to 1%, 1% to 4%, or 5% to 9%.
In certain embodiments, the resin composition is a thermosetting infusion grade resin. Non-thermal setting resins may also be used in certain applications.
In many of the disclosed applications, the viscosity of the resin and/or the resin composition is one factor in selected a suitable resin. In general, lower viscosities upon infusion are desirable to assist in the infusion process. In certain applications, the viscosity of the resin and/or resin composition is less than 1500 cPs at 25° C., 1000 cPs at 25° C., 800 cPs at 25° C., 500 cPs at 25° C., 400 cPs at 25° C., 200 cPs at 25° C., 100 cPs at 25° C., 80 cPs at 25° C., 60 cPs at 25° C., 30 cPs at 25° C., or 10 cPs at 25° C. In certain embodiments, the viscosity of the resin and/or the resin composition is in the range of between 10 cPs to 500 cPs at 25° C., 10 cPs to 250 cPs at 25° C., 20 cPs to 600 cPs at 25° C., 30 cPs to 400 cPs at 25° C. degrees C., 100 cPs to 800 cPs at 25° C., or 50 cPs to 500 cPs at 25° C. In certain embodiments, the viscosity of the resin and/or the resin composition is in the range of between 10 cPs to 500 cPs at 45° C., 10 cPs to 250 cPs at 45° C., 20 cPs to 600 cPs at 45° C., 30 cPs to 400 cPs at 45° C., 100 cPs to 800 cPs at 45° C., or 50 cPs to 500 cPs at 45° C. Other suitable viscosities are also contemplated. For example, where a portion of the resin composition is mixed with the particles before adding the resin/particles composition to the moulding tool. Here the viscosity may higher than those viscosities provide herein. Another example would be use of a resin and/or resin composition that is thixotropic.
Certain embodiments are directed to mould articles wherein matting or other liner materials are used as an outer lining and/or in building up the cured article. The matting may be made from a number of different materials, for example, glass, glass fibers, carbon, carbon fibers, polymers, polymers fibers, minerals (such as wollastonite, clay particles, micas), mineral fibres (such as wollastonite, clay particles, micas), or combinations thereof. In addition, the terms “fibre” and “fibres” are to be taken to also include platelet and platelets, respectively. Fibre should also be construed to incorporate spherical glassy components, such as cenospheres, zenospheres, plerospheres or combinations thereof. Other spherical additives are glass beads and/or micro-balloons (hollow microscopic glass beads), which may be sourced from commercial manufacturers or from fly ash and/or bottom ash may also be used. Fibres can also be treated sizing agents or other chemical treatment to improve compatibility with resin mixtures, wetting of the fibres or other desirable properties. Combination of the above types of fibres and/or materials may also be used. In certain applications, glass and/or carbon fibres may be particularly suitable fibres. Cellulose fibres may also be used but these fibres are heat labile. In certain applications where weight is a factor, then cellulose fibres may be useful. The terms “fibre” and “filament” may be used interchangeably herein and includes chopped bundles of fibres and individualized filaments. In certain applications, the type of fibre, or combinations of fibre, selected may depend, at least in part, on its ability to be woven into appropriate cloth like materials. For example, one or more of the following: ceramic fibres, glass fibres, carbon fibres, polymer fibres (eg aramid fibre), wool fibres, cotton fibres, nylon fibres etc. In certain applications, the fibres with very high strength to weight ratios such as carbon, glass, certain polymer fibres or combinations thereof may be used. For example, in certain applications, the carbon fibre density may be at least 1.25 g/cc, 1.5 g/cc, 1.75 g/cc, 2 g/cc, 2.25 g/cc, 2.5 g/cc or other values. In certain applications, the carbon fibre density may be between 1.25 g/cc to 2.5 g/cc, 1.75 g/cc to 1.95 g/cc, 1.5 g/cc to 2.5 g/cc, 1.75 g/cc to 2.25 g/cc or other values. In certain applications, the carbon fibre may have an elongation at break of at least 0.2%, 0.3%, 0.5%, 1%, 2%, 4%, or other values. In certain applications, the carbon fibre may have an elongation at break of between 0.2% to 4%, 0.3% to 2.5% 0.5% to 2% or other values. In certain applications, the carbon fibre may have a tensile strength of at least 1000 MPa, 2500 MPa, 4000 MPa, 5000 MPa, 6000 MPa, 7000 MPa, 8000 MPa or other values. In certain applications, the carbon fibre may have a tensile strength of between 1000 MPa to 8000 MPa, 2500 MPa to 6000 MPa, 3000 MPa to 7000 MPa, or other values. In certain applications, the glass fibre density may be at least 1.25 g/cc, 1.5 g/cc, 1.75 g/cc, 2 g/cc, 2.5 g/cc, 3 g/cc or other values. In certain applications, the glass fibre density may be between 2 g/cc to 3 g/cc, 1 g/cc to 4 g/cc, or other values. In certain applications, the glass fibre may have a tensile strength of at least 1000 MPa, 1500 MPa, 2000 MPa, 2500 MPa, 3000 MPa, 3500 MPa, 4000 MPa or other values. In certain applications, the glass fibre may have a tensile strength of between 1000 MPa to 4000 MPa, 2000 MPa to 3500 MPa, 2000 MPa to 4000 MPa, or other values. In certain applications, the glass fibre may have an elongation at break of at least 3%, 4%, 5%, 6%, 7%, or other values. In certain applications, the glass fibre may have an elongation at break of between 4% to 7%, 4.53% to 6%, 5% to 8% or other values.
In certain applications, matting may be defined as a woven, non-woven, or a combination of woven and non-woven fabric type material comprised at least in part of individual fibres to form a sufficiently continuous, substantially continuous, or continuous cloth like material. In certain applications, matting may be defined as a woven, non-woven, or a combination of woven and non-woven type material, a liner, a cloth, a cloth like material, a matting like material, at least 1, 2, 3, 4, 5, 6, 7 or 8 layers of cloth, at least 1, 2, 3, 4, 5, 6, 7 or 8 layers of cloth like material, preforms, etc. The material may be cut to the desired size and shape to produce a preform 2 dimensional shape. In certain applications, multiple layers of the material can be stacked up or combined to produce a multilayer piece of matting. In certain applications, the matting may contain other additives.
If the matting material is a woven material, then the properties of the final composite may vary depending on the style of weaving that has been used. For example, some carbon and/or glass fibre matting may either be a bidirectional weave in which fibres are oriented at typically 90° to one another or a unidirectional weave in which the individual fibres are oriented substantially parallel to one another. Another example is some carbon and/or glass fibre matting may have a twill weave. In certain applications, twill weaves may have better “drape” and conformability than other types of weaves. Typically a twill weave is a bidirectional weave due to how the weave is produced. There are also other types of bidirectional weaves. Matting may also be produced in other weave types such as fish weave, satin weave, harness weave, or combinations thereof. The type of weave or combinations of weaves that are used may depend at least in part on the particular application.
If the matting is a non-woven material, then the properties of the final composite may vary depending on the thickness of the non-woven fibre and properties of the non-woven fibre. For example, thinner non-woven material may produce a lesser amount of reinforcement in the final moulding. Non-woven materials may produce a composite with reduced properties compared to an appropriately selected woven fabric reinforced composite, due at least in part to the less regular orientation of the reinforcing fibres in the non-woven. The reduction may manifest itself in reduced tensile and/or flexural strength, but non-wovens do have the advantage of often being more cost effective choices than woven mattings.
The particles and resin composition may be defined in terms of weight %, whereas matting may be defined at least in part by the thickness of the matting used either before infusion and/or after infusion. In certain applications, the at least one matting layer may have a thickness of at least 0.1 mm, 0.5 mm, 1 mm, 2 mm, 4 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm 50 mm, 75 mm or 100 mm. In certain applications, the at least one matting layer may have a thickness of between 0.1 mm to 50 mm. 0.1 mm to 2 mm, 0.5 mm to 10 mm, 2 mm to 10 mm, 5 mm to 30 mm, 20 mm to 50 mm, 1 mm to 75 mm, 20 mm to 100 mm or other ranges. In certain applications, the at least one preform may have a thickness of at least 0.1 mm, 0.5 mm, 1 mm, 2 mm, 4 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm 50 mm, 75 mm, or 100 mm. In certain applications, the at preform may have a thickness of between 0.1 mm to 50 mm. 0.1 mm to 2 mm, 0.5 mm to 10 mm, 2 mm to 10 mm, 5 mm to 30 mm, 20 mm to 50 mm, 1 mm to 75 mm, 20 mm to 100 mm or other ranges.
In certain applications, where multiple layers of fabric are stacked up to form the matting, a layer of adhesive may be used to hold the separate fabric layers together. Multiple layers of fabric may be held sufficiently together in various ways, for example using one of more of the following: adhesive sprays; adhesive coatings; stitched together; mechanically attached, for example using staples; and a multilayer fabric may be produced by folding a large section of single layer cloth. For example, an adhesive such as 3M Spray 77 can be applied in a light layer, with the aim of making the cloth slightly tacky such that the next layer may be lightly adhered and not become dislodged during handling or lay up in the mould. The same or a similar process may be used when the matting is to be positioned on an outside surface of the mould, in this case, the fibre matting will have a light spray of adhesive applied to the surface intended to be against the mould wall then be positioned on the mould surface. In certain applications, the layer of adhesive need only be heavy enough to produce the slight tackiness desired to hold the matting in place, this is a much smaller amount than would be used if true bonding of the surfaces were desired.
In certain applications, for example, where a complex shape is desired, and/or production processes demand speed in mould preparation, a preform may be used instead of laying up individual or multiple layers of matting. Preforms may also be used in other situations as well. Such a preform may be made using a separate mould or blank and is prepared by applying the cloth to the mould or blank and using a slightly heavier coat of adhesive between each layer of cloth. In this case the adhesive provides bonding between the layers and stiffness to hold the shape of the preform during handling and installing in the final mould. In certain applications, it may be desirable to apply sufficient adhesive to maintain, or substantially maintain, the integrity of the preform but at the same time avoid using too much adhesive such that the fabric becomes saturated with adhesive as this may impede resin flow during the subsequent infusion step. Also the type of adhesive selected may be influenced by the resin system being used. Alternatively the fabric may be soaked in a liquid solution of adhesive and/or starch-like material and then applied to the mould or blank and allowed to dry to form the stiffened preform. In this case it is desirable to ensure that the water or solvent is sufficiently, or substantially, removed from the preform prior to using the preform.
In the situation where the matting is to be included as an internal matting element, different techniques may be used to hold the matting in the desired position. In certain applications, it may be possible to include attachment points on a metal internal reinforcement to support the matting in the desired position. Alternatively, dowels or shims may be used. In certain applications, these dowels or shims may be formed using the resin that is used for the infusion and/or a similar resin type. The shims may then be attached to the preform. The shims or dowels permit the preform to be situated at a distance from the surface of the moulding. That distance may be controlled by the length and placement of the shims or dowels. Typically the shims and/or dowels are of a length sufficient to extend from the preform to one or more of the following: the interior surface of the mould, supporting reinforcement and other mould inserts. The shims and/or dowels also hold the preform in place as a result of contact with the one or more of the following: the mould, supporting reinforcement and other mould inserts.
In certain applications, fibre matting may also be used advantageously to distribute the resin from the injection port. For example, the matting is positioned covering the infusion port and a continuous area of the tool where rapid resin distribution is desired. When the resin enters the port, it will rapidly infuse into the matting before continuing to fill the adjacent particulate filler. This happens because the weave of the fabric provides a path of lower resistance to resin flow than the densely packed filler.
In certain embodiments, it may be desirable to alternatively fill the mould with solid filler and fibre matting to produce a multiple layer composite where layers of wear resisting media are interspersed with regions of reinforcing fibre matting. In certain embodiments, at least 2, 3, 4, 5, 6, 7, 8 or 9 layers may be used. This type of composite may be produced by applying matting to at least a portion of the mould surface (if desired), assembling the mould and adding particles to a predetermined level, vibrating to compact the particles, placing a stiffened fibre preform on top of the particles followed by filling with more particles and vibrocompacting. These steps could be repeated as many times as required until the mould is filled to the desired level, at which point it would undergo one or more of the infusion processes disclosed herein, for example, vacuum infusion, vacuum/positive pressure infusion, positive pressure infusion, gravitationally assisted infusion, etc.
Various types of articles may be produced using the embodiments disclosed herein. For example, an article than can beneficially be produced with one or more of the methods disclosed herein is a hydrocyclone (see
Addition of matting to the articles disclosed herein may provide benefits to the final performance of the moulding. Depending on component geometry and the alignment of the matting within the component this could include substantial increases in tensile strength and/or flexural strength and significant changes to the modulus of the material. In certain applications such as the hydrocyclone described above or a pump, it may be possible to replace an existing metal casing using this composite arrangement by judicious selection and positioning of matting without compromising the strength of the finished article. This would produce a strong and lightweight finished article which has the added advantage of being produced in a single or reduced manufacturing steps.
Certain embodiments are directed to mould articles and methods of making such mould articles wherein a first portion of the mould article is prepared using the embodiments disclosed herein or other casting methods, for example, slurry casting. This first portion of the moulded article is at least partially cured or cured. And a second portion of the moulded article is prepared using embodiments disclosed herein and the second portion is at least partially cured or cured. The first portion and the second portion may then be combined and affixed or bonded together in a suitable manner. For example, a first portion is produced using slurry casting. A second portion is produced wherein matting or other liner materials are used as an outer lining and/or in building up the second portion. The matting may be made from a number of different materials, for example, glass fibers, carbon fibers or combinations thereof including all previously discussed fibre types. Where matting or other liner materials are used these materials typically need to be infused with the resin composition. Certain embodiments disclosed herein make it possible to infuse, or to substantially infuse, the matting or other liner materials that are being used with the second portion with the resin composition during the casting process. Certain of the casting techniques disclosed herein make it commercially possible to infuse and cast the second portion and thereafter combine the first portion and the second portion to produce a composite article.
Various fillers may also be used in certain embodiments. Fillers tend to affect properties of the composite and/or the articles produced. For example, fillers may impact on the hardness, porosity level, wear behavior, ease of machining, density, etc. Examples of filler materials include metal carbonates (such as calcium carbonate, chalk, calcite, marl, travertine, marble, limestone, calcium magnesium carbonate, sodium carbonate, magnesium carbonate), silicas (such as amorphous silica, quartz, glass beads, glass powder, glass bubbles, and glass fibers), silicates (such as talc, clays (montmorillonite), feldspar, mica, calcium silicate, calcium metasilicate, sodium aluminosilicate, sodium silicate), metal sulfates (such as calcium sulfate, barium sulfate, sodium sulfate, aluminum sodium sulfate, aluminum sulfate), aluminum trihydrate, metal oxides (such as calcium oxide (lime), aluminum oxide, titanium dioxide), metal sulfites (such as calcium sulfite), greystone, marble, gypsum, Na2SiF6, cryolite, vermiculite, carbide ceramics (such as tungsten carbides, silicon carbides, zirconium carbides, chromium carbide and other metal carbides) and combinations thereof.
Various methods and/or systems are contemplated for infusing the resin into the mould tool once the particles have been added to the mould tool. Some exemplary arrangements are schematically shown in
After the mould is assembled, some dry particulate filler (4) may be added to the mould. This is illustrated in
Next a resin pot (7) is attached to the mould (1) via a resin infusion line and to the pot is added the premixed resin (8). This is illustrated in
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Various designs of moulds and infusion ports may be used with certain disclosed embodiments. For example,
As discussed herein, the mould tool is filled to a predetermined level with the selected particles and matting may be positioned in the mould tool as discussed herein. The particles may be added in various manners that results in appropriate packing and filling of the tool. These particles may, or may not, have been treated with wetting agents, coupling agents, flow agents, other suitable additives or combinations thereof. Vibration of the mould tool and/or other suitable addition techniques such as compressed air to fluidize the particles being added may be used. In certain embodiments, during particle addition, the mould tool (and/or at other stages in the process) is vibrated in order to facilitate packing and addition of the particles to the tool. This is useful where the geometry of the mould tool is complex. The vibration rate is typically between 1 to 10,000 Hz. Other ranges of vibration may also be used, for example, 1 to 100 Hz, 1 to 1000 HZ, 100 to 1500 Hz, 500 to 2000 Hz, 1000 to 5000 Hz, 3000 to 7000 Hz or 5000 to 10,000 Hz. The vibration may be turned on and off in various time periods such as between 1 minute to 3 minutes, 2 minutes to 10 minutes or 5 minutes to 10 minutes. Other time periods may also be used, such as between 30 second to 1 hour, 15 minutes to 30 minutes or 30 minutes to 90 minutes. In certain applications, compressed air may also be used to fluidize the granular material during addition to the mould tool. Compressed air may be useful when filling complex geometries. Use of compressed air and other suitable technique may be combined with vibration in order to facilitate the process. Uniform distribution, or substantial uniform distribution, of the particles in the mould too is desired to the extent it can be achieved.
In certain embodiments, the vibration is continued for a period of time after filling to the predetermined level is completed to facilitate packing of the particles and even flow of the particles into geometries of the mould. In certain embodiments, during particle filling, the mould is vibrated at a vibration rate of between 100 to 10,000 Hz and vibration continues for up to one minute after filling is completed to facilitate packing of the particles and even flow of the particles into geometries of the mould. Infusion of the resin composition into the mould tool is carried out using a variety of different suitable techniques. For example, vacuum infusion, infusion under pressure and/or infusion at atmospheric pressure.
With respect to vacuum infusion, one technique is to attach a resin infusion port to the mould at one or several filling points. Typically this is carried out from the bottom portion or the lower region of the mould tool. Other locations may also be used. The tool with matting and filled particles is then sealed and placed under a vacuum of less than 100 mbar. Other vacuums may also be used or pulled. For example, a vacuum of less than 15 mbar, 20 mbar, 25 mbar, 50 mbar, 100 mbar, 150 mbar or 500 mbar. Ranges of vacuums and/or variation in the amount of vacuum pulled may also be used. For example, a vacuum of between 75 to 150 mbar, 50 to 200 mbar, 25 to 125 mbar or 50 to 150 mbar. Different methods may be used as to how the vacuum is applied to the mould tool or a portion of the mould tool. For example, the mould tool can either be a vacuum sealable tool itself or placed in a vacuum chamber or even a sealed bag attached to vacuum which is commonly known in the composite industry as “vacuum bagging.” Vacuum filling allows for faster infusion of the resin composition into the tool and/or also reduces the likelihood of air entrapment during infusion. An exemplary schematic for vacuum infusion is illustrated in
Vacuum leakage may be an issue in certain equipment. This can be dealt with in a number of ways as long as a suitable vacuum is applied to facilitate the infusion. For example, as shown in
In order to add the resin composition, in certain embodiments, the resin composition is then mixed through a static mixer and dispensed into a resin pot attached to the other end of the infusion hose. A tap is opened on the infusion hose to allow resin to be induced into the tool under the pull of the vacuum. The resin is allowed to infuse through the particles and matting to fill the tool to the desired level. After filling, in certain embodiments, the tool is again vibro-compacted for a period of up to 5, 10, 20 or 30 minutes to ensure maximum densification and to mitigate against “resin wash” where particles are washed away from the injection port by resin flow resulting in a resin rich zone. Another option is to rotate the tool at least one time by at least 20% and vibrate the tool again to further densify the resin, matting and filler composite.
In certain embodiment, the methods using vacuum infusion may reduce the amount of wastage in resin and/or particles that has to be used as compared with traditional methods that premix the resin and particles before adding to the tool. In certain embodiments, the wasted resin and/or particles may be less than 20%, 15%, 10%, 8%, 5%, 3%, 2%, 1% or 0.5% by weight of the materials used for a particular manufacture. Such savings in waste and disposal costs may be advantages in this manufacturing process.
With respect to infusion of the resin composition into the mould tool under pressure, one technique is to attach a resin infusion port to the mould at one or several filling points. Typically this is carried out from the bottom, or the lower region of the mould tool. Other locations may also be used. The tool filled to the desired level with particles and matting is then subject to a pressure of approximately 10 psi or less. Other pressures may also be used. For example, a pressure of approximately 20 psi, 15 psi, 10 psi, 8 psi, 6 psi, 5 psi or less or the tool can be left open to atmospheric pressure. Ranges of pressure and/or variation in the amount of pressure applied may also be used. In addition, different pressures may be applied from different ports. For example, a pressure of between 5 psi to 25 psi, 5 psi to 15 psi, 8 psi to 20 psi or 5 psi to 10 psi may be applied to one or more ports. Different methods may be used as to how the pressure is applied to the mould tool or a portion of the mould tool, as long as a suitable pressure is applied in order to facilitate the infusion. An exemplary schematic for pressure infusion is illustrated in
Alternatively, the infusion step can be performed at atmospheric pressure. However, extended vibration times up to 30 minutes, 45 minutes, 60 minutes, 90 minutes, 2 hours, 3 hours, or 5 hours may be required after infusion under atmospheric pressure. In certain applications, longer infusion times may be needed. In certain embodiments, the infusion times may be a time period that is sufficient to ensuring that the formed composite has been sufficiently mixed. One advantage of atmospheric filing is that it requires significantly reduced investment in vacuum tooling and plant equipment, and the resin can be injected directly into the mould by a static mixing system without the need for an intervening resin pot. This allows for almost exact resin volumes to be used with minimal waste. In certain embodiments, the waste may be less than 10%, 8%, 5%, 3%, 2%, 1% or 0.5% by weight of the materials used for a particular manufacture. Such savings in waste and disposal costs are useful in this manufacturing process. An alternative method of practicing atmospheric infusion involves the use of a resin pot that is held at a height sufficiently above the tool to create a sufficient pressure differential, based on the use of gravity, to provide the force to infuse the resin into the interior of the mould tool.
With respect to infusing the resin composition into the mould, this may be accomplished via at least one, two, three or four port(s). This may also be accomplished using a progressive feeding system wherein a first port is used to feed the resin composition into the mould from one position on the mould to fill a first portion of the mould and then a second port is opened to feed the resin composition into a second portion of the mould. Variations on how the resin composition is feed into the mould are contemplated.
In certain embodiments, when placing matting in the mould tool and filling the mould tool with the particles and/or the resin composition or after placing the matting in the mould tool and filling the mould tool with the particles and/or the resin composition, it is desirable to apply mechanical and/or physical forces ensure that one or more of the following have occurred: the tool has been sufficiently filled, air pockets in the materials added have been sufficiently eliminated, the particles and resin composition have been sufficient mixed, the resin composition has sufficiently infused the matting, and complex geometries of the tool have been sufficiently filled. The mould tool may also contain other fillers and/or other materials as disclosed herein. Various techniques may be used to ensure that this occurs. For example vibration may be used. In certain embodiments, it is useful to vibrate the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition. In certain applications, after the mould tool with matting is filled with the particles and the resin composition, the mould tool is vibrated at one or more vibration rates of between 1 to 10,000 Hz for a time period of between 1 minute to 45 minutes. In certain applications, after the mould tool with matting is filled with the particles and the resin composition, the mould tool is vibrated at one or more vibration rates of between 1 to 10,000 Hz for a time period of between 1 minute to 75 minutes in order to facilitate one or more of the following: densification and to mitigate against resin wash; to achieve uniform distribution, or substantially uniform, distribution of the resin composition and the particles to the extent it can be achieved; infusion of the resin composition into the matting; infusion of the resin composition into at least a portion of the matting; substantial infusion of the resin composition into the matting; substantial infusion of the resin composition into at least a portion of the matting; sufficient infusion of the resin composition into the matting; and sufficient infusion of the resin composition into at least a portion of the matting. Other ranges of vibration may also be used to vibrate the mould tool containing matting, particles and the resin composition and optionally other fillers, for example, 1 to 100 Hz, 1 to 1000 HZ, 100 to 1500 Hz, 500 to 2000 Hz, 1000 to 5000 Hz, 3000 to 7000 Hz or 5000 to 10,000 Hz. The vibration may be turned on and off in various time periods such as between 1 minute to 3 minutes, 2 minutes to 10 minutes or 5 minutes to 10 minutes. Other time periods for vibration may also be used, such as between 30 second to 1 hour, 15 minutes to 30 minutes, 30 minutes to 90 minutes or 1 hour to 4 hours. These time periods may be applied to, in certain applications, to one or more of the stages where vibration is desired. Another option, in certain embodiments, is to rotate the tool at least one time by at least 20% and vibrate the tool again to in order to further facilitate one or more of the following: densification and to mitigate against resin wash; to achieve uniform distribution, or substantially uniform, distribution of the resin composition and the particles to the extent it can be achieved; infusion of the resin composition into the matting; infusion of the resin composition into at least a portion of the matting; substantial infusion of the resin composition into the matting; substantial infusion of the resin composition into at least a portion of the matting; sufficient infusion of the resin composition into the matting; and sufficient infusion of the resin composition into at least a portion of the matting. In certain embodiments, the filled mould tool may be rotated at least 1, 2, 3, 4 or 5 times by at least 10%, 20%, 30%, 50% or 60% and vibrated tool again to in order to further facilitate one or more of the following: densification and to mitigate against resin wash; to achieve uniform distribution, or substantial uniform distribution, of the resin composition and the particles to the extent it can be achieved; infusion of the resin composition into the matting; infusion of the resin composition into at least a portion of the matting; substantial infusion of the resin composition into the matting; substantial infusion of the resin composition into at least a portion of the matting; sufficient infusion of the resin composition into the matting; and sufficient infusion of the resin composition into at least a portion of the matting.
The percentages of the particles and the resin composition that may be found in the composite may vary. The amount and/or volume of matting that may be found in the composite may also vary. In certain embodiments, the composite comprises: between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles. In other embodiments, the composite comprises: between 20% to 30% by weight of the resin composition and between 70% to 80% by weight of the particles. In certain embodiments, the resin composition comprises approximately 10% to 50%, 20% to 25%, 20% to 30%, 25% to 35%, 30% to 45%, 40% to 55% or 50% to 80%, by weight of the total weight of the composite. In certain embodiments, the particles comprise approximately 90% to 50%, 80% to 75%, 80% to 70%, 75% to 65%, 70% to 55%, 60% to 45% or 20% to 50% by weight of the total weight of the composite. In certain embodiments, the resin composition comprises at least 10%, 20%, 30%, 40%, 50%, 60%, 70% or 80% by weight of the total weight of the composite. In certain embodiments, the particles comprises at least 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% by weight of the total weight of the composite. In addition, other components may be present in the composite. For example, chopped glass fibre, chopped or milled carbon fibre, microspheres, or combinations thereof can be used up to 3%, 5%, 7% or 10% by weight. Hollow microspheres can be used up to 30%, 40%, 50% or 60% by volume (the by weight will change based on density of microspheres). These materials may be used to displace the filler, but typically not the resin.
Following infusion and after the composite is sufficiently formed, the tool is removed from the vacuum, pressure and/or vibration source and is placed in an oven to cure. Various curing time periods and temperatures may be used to achieve the desired properties of the cured moulded composite article. For example, curing can be achieved by simply heating to 80° C. and holding for 4 hours. Alternatively, certain embodiments include a temperature ramp in the process whereby the filled tool is first heated to a lower temperature of for example 50° C. for two hours followed by increasing to for example 60° C. and finally to for example 80° C. for a minimum of one hour hold at each of these temperatures. Other temperatures may also be used in the ramp curing. In certain embodiments, the filled tool is subjected to 1, 2, 3, 4 or 5 different curing temperatures. For example, the filled tool is subject to curing between 40° C. to 60° C. for a time period of between 30 minutes to 3 hours and between 70° C. to 90° C. for a time period of between 1 hour to 3 hours. Another example is the filled tool is subject to curing between 40° C. to 60° C. for a time period of between 30 minutes to 3 hours, and then subjected to curing temperature of 50° C. to 70° C. for a time period of between 30 minutes to 2 hours and finally subject to a curing temperature of between 70° C. to 90° C. for a time period of between 1 hour to 3 hours.
In certain embodiments, the method comprises the mould tool being substantially filled with the silicon carbide particles and the resin composition is cured in a temperature range between 70° C. and 90° C. for between 3 hours to 6 hours.
In certain embodiments, the method comprises the mould tool being substantially filled with the silicon carbide particles and the resin composition is cured using a temperature ramp of at least one, two, three or four different temperatures wherein the silicon carbide particles and the resin composition is held at each temperature for between 30 minutes to 3 hours.
Other methods and/or variations on resin infusion are also contemplated in the present disclosure. In certain embodiments, at least one layer of matting may be positioned in a mould tool, the mould tool may be partially filled with a first portion of a resin composition and then a first portion of the particles may be added. Vibration and/or other suitable techniques may be used to mix and distribute the resin composition and the particles at one or more stages in this process. Uniform distribution, or substantial uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. Thereafter, the mould tool may be partially filled with a second portion of a resin composition and then a second portion of the particles may be added. Alternatively, at least one second layer of matting may be positioned in the mould either before or after the second portion of a resin composition and/or a second portion of the particles has been added. Vibration and/or other suitable techniques may be used again to mix and suitably distribute the resin composition and the particles at one or more stages in this process. These steps can be repeated until the mould tool is filled to a predetermined level and the composite is formed. The composite may then be cured to form a moulded composite article. Other fillers may also be used in forming the product to be cured.
In certain embodiments, the mould tool may be partially filled with a first portion of particles and then a first portion of a resin composition may be added. Vibration and/or other suitable techniques may be used to mix and suitably distribute the resin composition and the particles at one or more stages in this process. Uniform distribution, or substantially uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. Thereafter, the mould tool may be partially filled with a second portion of particles and then a second portion of the resin composition. Vibration and/or other suitable techniques may be used again to mix and suitably distribute the resin composition and the particles at one or more stages in this process. These steps can be repeated until the mould tool is filled to a predetermined level and the composite is formed. Other fillers and/or matting or liners may also be used in forming the product to be cured. The composite may then be cured to form a moulded composite article.
In certain embodiments, at least one layer of matting may be positioned in a mould tool, the particles may be premixed with a powdered resin composition and this mixture of powdered resin composition and particles may be added to the mould tool to a predetermined level. Vibration and/or other suitable techniques may be used to mix and suitably distribute the resin composition and the particles at one or more stages in this process. Uniform distribution, or substantially uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. Other fillers may also be used in forming the product to be cured. The filled tool is then evacuated with a vacuum of less than 100 mbar and heated to effect fusion and curing and yield the consolidated composite article.
In certain embodiments, at least one layer of matting may be positioned in a mould tool, the particles may be premixed with a resin composition that has a higher viscosity at a first temperature and the resin/particles composition added to a mould tool to a predetermined level. And thereafter, the resin/particles composition may be heated to a second temperature such that the viscosity of the resin composition is reduced to a suitable level. Vibration and/or other suitable techniques may be then used to mix and suitably distribute the resin composition and the particles at one or more stages in this process. Uniform distribution, or substantially uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. Other fillers may also be used in forming the product to be cured. Once the composite is formed it may be cured to form a moulded composite article.
In certain embodiments, at least one layer of matting may be positioned in a mould tool, the particles may be added to a predetermined level in the mould tool. Thereafter a resin composition that has a higher viscosity at a first temperature may be infused into the mould tool. And the resin/particles composition may be heated to a second temperature such that the viscosity of the resin composition is reduced to a suitable level. Vibration and/or other suitable techniques may be then used to mix and suitably distribute the resin composition and the particles. Uniform distribution, or substantially uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. Once the composite is formed it may be cured to form a moulded composite article. Other fillers may also be used in forming the product to be cured.
In certain embodiments, at least one layer of matting may be positioned in a mould tool, the particles may be premixed with a first resin composition that has a higher viscosity and the resin/particles composition added to a mould tool to a predetermined level. And thereafter, a second resin composition may be added such that the viscosity of the combined first and second resin composition is reduced to a suitable level. Vibration and/or other suitable techniques may be then used to mix and suitably distribute the resin composition and the particles at one or more stages in this process. Uniform distribution, or substantially uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. Once the composite is formed it may be cured to form a moulded composite article. Other fillers may also be used in forming the product to be cured.
In certain embodiments, at least one layer of matting may be positioned in a mould tool, the particles may be added to a predetermined level in the mould tool. Thereafter, a resin composition that has a higher viscosity may be infused into the mould tool. Vibration and/or other suitable techniques may be then used to mix and suitably distribute the resin composition and the particles. Thereafter, a second resin composition may be added via infusion or using other suitable ways of addition or combinations thereof. Vibration and/or other suitable techniques may be then used to mix and suitably distribute the resin composition and the particles. Uniform distribution, or substantially uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. Once the composite is formed it may be cured to form a moulded composite article. Other fillers and/or matting or liners may also be used in forming the product to be cured.
In certain embodiments, at least one layer of matting may be positioned in a mould tool, the particles may be premixed with a thixotropic resin composition that has a higher viscosity than desired and the resin/particles composition added to a mould tool to a predetermined level. And thereafter, the resin/particles composition may be vibrated such that the viscosity of the resin composition is reduced to a suitable level. Vibration and/or other suitable techniques may be used to reduce the viscosity to an acceptable level, mix and suitably distribute the resin composition and the particles. Uniform distribution, or substantially uniform distribution, of the resin composition and the particles is desired to the extent it can be achieved. Once the composite is formed it may be cured to form a moulded composite article. Other fillers may also be used in forming the product to be cured.
In a variation of the process described in
As illustrated in
As illustrated in
As illustrated in
As shown in
As shown in
As shown in
In certain positive pressure and vacuum embodiments, the resin pot can advantageously be complemented with a piece of equipment designed for injecting resins or other liquid under elevated pressures. For example, a piston injection pump can be installed in the injection line between the tool and the resin pot to apply a positive pressure to the resin injection. Such a piston pump can either be pneumatically fed resin through pumps and tubing from resin storage and/or fed directly from a resin pot either under gravity feed or using a small positive pressure in the resin pot. This advantageously allows the creation of a sealed system of resin transfer from resin storage to infusion. In certain embodiments, the piston pump and resin pot can be replaced with a multi-component static mixer incorporated into a piston injection system. In this system, a multitude of piston pumps transport the resin through the static mixer at suitable injection pressures and from the static mixer, the mixed resin may be introduced either directly and/or indirectly into the tool.
The pressures and vacuum levels used for a combined vacuum/positive pressure system may vary. In certain embodiments, the mould may be placed under a vacuum of at least 150 mbar or at least 50 mbar and the resin infusion may begin solely under the force of vacuum to mitigate the amount of resin wash that occurs. After a small amount of resin has been introduced, the pressure can be increased gradually during the infusion to facilitate a continuous resin infusion speed. In certain applications, the final injection pressure will reach at least 20 psi, but at least 35 psi may also be used. In certain applications, final injection pressures of at least 100 psi may be used. In certain embodiments the resin infusion may begin solely under one or more of the following: vacuum, pressure, and vacuum and pressure. In certain embodiments, the mould may be placed under a vacuum of at least 150 mbar or at least 50 mbar and the resin infusion will begin solely under the force of vacuum to mitigate the amount of resin wash that occurs.
In certain embodiments, for at least a portion of the resin infusion process the mould tool may be placed under a vacuum of between 15 mbar to 500 mbar, 50 mbar to 150 mbar, 100 mbar to 400 mbar, 75 mbar to 175 mbar, 20 mbar to 60 mbar 150 mbar or 200 mbar to 800 mbar and the injection pressure may be one or more of the following: kept substantial constant, increased gradually, increased in steps, increased and decreased gradually, and increased and decreased in steps to pressures of between 1 psi to 2000 psi, 5 psi to 20 psi, 5 psi to 35 psi, 5 psi to 100 psi, 5 psi to 100 psi, 15 psi to 25 psi, 30 psi to 40 psi, 5 psi to 1000 psi, 5 psi to 500 psi or other suitable pressure ranges. In certain embodiments, the infusion of the resin composition into the mould tool under pressure may be carried out by using at least 1, 2, 3, 4, 5 or 6 resin infusion ports or infusion points to the mould, wherein during at least a portion of the resin infusion process the mould may be placed under a vacuum of between 15 mbar to 500 mbar, 50 mbar to 150 mbar, 100 mbar to 400 mbar, 75 mbar to 175 mbar, 20 mbar to 60 mbar 150 mbar, or 200 mbar to 800 mbar and the injection pressure may one or more of the following: be kept substantial constant, increased gradually, increased in steps, increased and decreased gradually, or increased and decreased in steps to pressures of between 1 psi to 2000 psi, 5 psi to 20 psi, 5 psi to 35 psi, 5 psi to 100 psi, 5 psi to 100 psi, 15 psi to 25 psi, 30 psi to 40 psi, 5 psi to 1000 psi, 5 psi to 500 psi or other suitable pressure ranges.
After the mould is assembled, some dry particulate filler (141) may be added to the mould. This is illustrated in
As illustrated in
When the filling step is deemed complete, the resin infusion is stopped by either closing the infusion line tap if one is in use, or clamping the infusion line (9). As illustrated in FIG. 18JG, after resin infusion is completed and the infusion line is clamped, the tool can optionally be vibrated again to further densify the resin, matting and filler composite. After vibration is removed, the vacuum on the tool is released and the resin composition is allowed to cure in the tool. As illustrated in
In certain embodiments where the matting is to be included as an internal matting element in the article, different techniques can be used to hold the matting in the desired position.
The methods, method steps and/or systems disclosed herein are not intended to be limiting as to the embodiments disclosed. In addition, limitations of one embodiment may be combined with limitations of other embodiments to form additional embodiments.
In certain embodiments, post cure touch up and reworking may also be performed if desired and/or required. Additional curing may also be performed, if needed, by placing the cured item in an oven and curing at a suitable temperature for a period of time. For example, additional curing may be performed in an oven at a temperature of between 90° C. to 140° C. over a time period of between 2 hours to 6 hours. Other suitable temperatures and time periods may also be used. The temperature and/or time period selected may depend on the components used to form the article and/or its proposed use.
In certain embodiments, a moulded composite article comprising a substantial portion of the Silicon carbide particles having a Mohs hardness of greater than 7 and matting and the article comprising at least between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the Silicon carbide particles can be further cured in an oven at 120° C. for approximately 4 hours. The percentages of the particles and resin composition that may be found in the composite may vary. In certain embodiments, the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles. In other embodiments, the composite comprises between 20% to 30% by weight of the resin composition and between 70% to 80% by weight of the particles. In certain embodiments, the resin composition comprises approximately 10% to 50%, 20% to 25%, 20% to 30%, 25% to 35%, 30% to 45% or 40% to 55% by weight of the total weight of the composite. In certain embodiments, the particles comprise approximately 90% to 50%, 80% to 75%, 80% to 70%, 75% to 65%, 70% to 55% or 60% to 45% by weight of the total weight of the composite. In addition, other components may be present in the composite. For example, chopped glass fibre, chopped or milled carbon fibre, microspheres, or combinations thereof can be used up to 3%, 5%, 7% or 10% by weight. Hollow microspheres can be used up to 30%, 40%, 50% or 60% by volume (the by weight will change based on density of microspheres). These materials may be used to displace the filler, but typically not the resin.
The percentages of the particles and the resin composition that may be found in the moulded composite article may vary. In certain embodiments, the moulded composite article comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles. In other embodiments, the moulded composite article comprises between 20% to 30% by weight of the resin composition and between 70% to 80% by weight of the particles. In certain embodiments, the resin composition comprises approximately 10% to 50%, 20% to 25%, 20% to 30%, 25% to 35%, 30% to 45% or 40% to 55% by weight of the total weight of the moulded composite article. In certain embodiments, the particles comprise approximately 90% to 50%, 80% to 75%, 80% to 70%, 75% to 65%, 70% to 55% or 60% to 45% by weight of the total weight of the moulded composite article. In addition, other components may be present in the composite article. For example, chopped glass fibre, chopped or milled carbon fibre, microspheres, or combinations thereof can be used up to 3%, 5%, 7% or 10% by weight. Hollow microspheres can be used up to 30%, 40%, 50% or 60% by volume (the by weight will change based on density of microspheres). These materials may be used to displace the filler, but typically not the resin. In certain embodiments, the composite comprises between 15 to 30% by weight of the resin composition and between 70 to 85% by weight of the silicon carbide particles. In certain embodiments the moulded composite article comprises between 15 to 30% by weight of the resin composition and between 70 to 85% by weight of the silicon carbide particles. The weight percentages of the particles and resin composition disclosed herein may be combined with other physical properties of the composite articles disclosed herein.
In certain embodiments, the at least one layer of matting is at least 0.1%, 0.5%, 1%, 5%, 10%, 20%, or 30% by volume of the total volume of the unitary polymer composite article. In certain embodiments, the at least one layer of matting is between 0.1% to 30%, 0.5% to 30%, 1% to 20%, or 5% to 20% by volume of the total volume of the unitary polymer composite article. Other % volume amounts may also be used. In certain embodiments, the at least one layer of matting is at least 0.1%, 0.5%, 1%, 5%, 10%, or 20% by weight of the total weight of the unitary polymer composite article. In certain embodiments, the at least one layer of matting is between 0.1% to 20%, 0.5% to 20%, 1% to 10%, 5% to 20%, or 10% to 20% by weight of the total weight of the unitary polymer composite. Other % weights amounts may also be used. The amount of matting that may be present in the composite article may vary; the % weights and the % volumes disclosed herein may be combined with the other properties of the composite articles disclosed herein.
Various moulded composite articles are produced using the methods and/or systems disclosed herein. In certain applications, these unitary polymer composite articles are suitable for use either alone or in combination with other components in mechanical equipment, for example, pumps, and are particular useful in highly corrosion and/or wear-resistant environments. Some non-limiting examples are ceramic type pumps, components of ceramic type pumps, other mechanical equipment, and/or parts for mechanical equipment. In certain applications, the unitary polymer composite articles produced may be pumps, pump components, preforms and/or other components, these articles may be combined with, or used in conjunction with, other pumps, pump components, and/or parts produced using other methods, for example, slurry casting to produce the desired equipment. The unitary polymer composites disclosed herein may be used in the mining industry, the chemical industry, flue gas desulphurization, for example in power generation, desalination and/or other fields of use and are particular are useful for highly corrosion and/or wear-resistant environments.
As used herein, a unitary polymer composite article may have several different definitions. In certain embodiments, a unitary polymer composite article may be defined as an article comprising: resin, particles and matting, wherein the matting is infused, substantially infused or sufficiently infused with the resin and the unitary article is formed during in the mould process. This may include, in certain applications, a portion of the matting being only substantially infused or sufficiently infused with the resin. In certain applications, the unitary polymer composite article produced may be sufficiently void, substantially void or void of air pockets. This is in contrast to a manufacturing process where, for example, slurry casting is used to form a portion of the article and another portion of the article, such as the matting, is formed separately and the two portions of the article are combined together by, for example gluing. In certain embodiments, a unitary polymer composite article may be defined as an article comprising: resin, particles and matting, a mould tool containing the polymer/matting/resin composite is vibrated for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusion of the resin composition. In certain applications, the unitary polymer composite article produced may be sufficiently void, substantially void or void of air pockets. In certain embodiments, a unitary polymer composite article may be defined as an article comprising: resin, particles and matting, wherein the article is produced in a single moulding or casting process.
The composite articles have applications in a variety of fields such as mining, chemical industry, flue gas desulphurization, desalination or other fields. In certain embodiments, the physical and chemical properties disclosed herein may be combined in various combinations.
In certain embodiments, the unitary polymer composite article produced has a flexural strength of at least 20, 25, 30, 40, 50, 55 or 60 MPa. In certain embodiments, the flexural strength of the articles produced is between 25 to 60 MPa, 30 to 55 MPa, 40 to 55 MPa, 50 to 60 MPa or other suitable flexural strengths. In certain embodiments, the cured resin composite has a flexural strength of at least 20, 25, 30, 40, 50, 55 or 60 MPa. In certain embodiments, the flexural strength of the cured resin composition is between 30 to 55 MPa, 25 to 40 MPa, 30 to 50 MPa, 25 to 60 MPa or other suitable flexural strengths.
In certain embodiments, the unitary polymer composite article produced has a tensile strength of at least 5, 10, 15, 20 or 30 MPa. In certain embodiments, the tensile strength of the article produced is between 5 to 15 MPa, 10 to 30 MPa, 5 to 25 MPa, 15 to 30 MPa or other suitable tensile strengths. In certain embodiments, the cured resin composition has a tensile strength of at least 15, 30, 50, 70 or 100 MPa. In certain embodiments, the tensile strength of the cured resin composition is between 15 to 100 MPa, 30 to 100 MPa, 15 to 70 MPa, 50 to 100 MPa or other suitable tensile strengths.
In certain embodiments, the unitary polymer composite article produced has a glass transition temperature of at least 90° C., 100° C., 110° C., 115° C., or 120° C. In certain embodiments, the cured resin composition has a glass transition temperature of at least 90° C., 100° C., 110° C., 115° C., or 120° C.
In certain embodiments, the unitary polymer composite article produced is substantially uniform in dispersion of the particles within the resin matrix. Air pockets are substantially eliminated. The distribution of particles is substantially uniform and resin rich zones are substantially eliminated. This results in a substantially consistent density in the cured product. Density of the cured composite article may be between 2 to 3 g/cc, 2.2 to 2.8 g/cc or 2.4 to 2.7 g/cc. Other densities ranges and/or some density variation may be found in the cured product of certain embodiments.
In certain embodiments, the article produced is sufficiently void, substantially void or void free of air pockets. In certain applications, void free of air pockets may be determined by cutting open a portion of the article produced and visually inspecting for air pockets or holes. If the upon visually inspecting without magnification a 5 cm squared surface area of the cut open article has less than 10%, 8%, 6%, 5%, 3%, 2% or 1% of that surface area made up of air pockets, then in certain applications the article produced may be considered void free. In certain embodiments, sufficiently void of air pockets may be determined by cutting open a portion of the article produced and visually inspecting for air pockets or holes. If the upon visually inspecting without magnification a 5 cm squared surface area of the cut open article has less than 40%, 35%, 25%, or 20%, of that surface area made up of air pockets, then in certain applications the article produced may be considered sufficiently void free. Reducing the number of air pockets is one advantage of certain embodiments.
In certain embodiments, the unitary polymer composite article produced has a suitable wear resistance. In certain applications, wear resistance may be defined by performance is the flue gas desulfurization application, where this material would be considered erosion and/or corrosion resistant. Typical application life span may be above 15,000 hours of use and as high at 100,000 hours of use or higher. In certain embodiments, wear resistance may be defined as wherein the material produced has a life span of between 10,000 to 200,000 hours of use, 15,000 to 100,000 hours of use, 15,000 to 60,000 hours of use, 25,000 to 100,000 hours of use or 40,000 to 80,000 hours of use. Typical lifespan for rubber or metals may be 5000 to 30,000 hours under normal conditions. In certain embodiments, wear resistance may be defined as wherein the material produced has a life span of between 3,000 to 40,000 hours of use, 5,000 to 30,000 hours of use, 10,000 to 30,000 hours of use or 15,000 to 25,000 hours of use. In certain embodiments, the article produced has a suitable acid resistance. In certain embodiments, the article produced has a suitable chemical resistance. In certain embodiments, the article produced has one or more of the following properties: a suitable wear resistance, a suitable acid resistance, and a suitable chemical resistance. In certain embodiments, the article produced has a suitable wear resistance, a suitable acid resistance, and/or a suitable chemical resistance wherein the material produced has a life span of between 5,000 to 30,000 hours of use, 15,000 to 200,000 hours of use, 5,000 to 20,000 hours of use, 15,000 to 100,000 hours of use, 25,000 to 100,000 hours of use or 40,000 to 80,000 hours of use.
It is to be understood that the physical property ranges disclosed herein can be combined in various combinations. For example, certain disclosed embodiments are directed methods and systems that produce a unitary polymer composite article that has a flexural strength of between 30 to 150 MPa, a tensile strength of between 15 and 120 MPa and a glass transition temperate of at least 110° C. Certain disclosed embodiments are directed methods and systems that produce a unitary polymer composite article that has one or more of the following properties: a flexural strength of at least 30 MPa, a tensile strength of between 20 and 50 MPa and a glass transition temperate of at least 110° C. Another example is a method and/or system that produces a moulded composite article comprising a substantial portion of the Silicon carbide particles have a Mohs hardness of greater than 7 and the article comprising at least between 10% to 50% by weight of the resin composition and between 50% to 90% of the Silicon carbide particles, wherein the article produced has one or more of the following properties: a flexural strength of between 50 to 80 MPa, a tensile strength of between 20 and 50 MPa, a glass transition temperate of at least 110° C., suitable wear resistance, suitable acid resistance, and suitable chemical resistance.
For example, certain disclosed embodiments are directed to a unitary polymer composite article that has a flexural strength of at least 100 MPa, a tensile strength of between 20 and 80 MPa and a glass transition temperate of at least 110° C. For example, certain disclosed embodiments are directed to an article that has a flexural strength of between 30 to 55 MPa, a tensile strength of between 20 and 50 MPa and a glass transition temperate of at least 110° C.
Example 1, two SiC blend, vacuum infusion and 80° C. curing: In the following example a moulded composite article is prepared using Silicon carbide particles. The final articles contained approximately 75% by weight Silicon carbide particles and approximately 25% by weight Polymer. The polymer/resin composition contains:
100 parts by weight Daron 45 vinyl ester urethane hybrid polymer;
35 parts by weight polymeric methylene diphenyl isocyanate (MDI);
2 parts by weight peroxide catalyst; and
5 parts by weight zeolite molecular sieve.
The process of manufacture involves the following steps (see
1. Resin: Part A and Part B resin mixtures are prepared:
Part A contains the 100 parts of a vinylester hybrid polymer and 5 parts zeolites sieves and
Part B contains 35 parts of polymeric methylene diphenyl isocyanate and 2 parts of peroxide catalyst. Part A and Part B resin mixtures were carried out in a flask fitted with a mechanical stirrer. Approximately 1 kg is prepared for this example.
2. Silane treated Silicon carbide preparation: In this example, the Silicon carbide used is a mixture of two different grade sizes (between 50 μm and 1 mm) and is prepared as follows. One kilogram of Silicon carbide (24 mesh) was added to a solution of 30 grams of an alkyl silane in 450 mL absolute Ethanol. The 24 mesh screened Silicone carbide is made up particles that are around 750 μm in size or smaller. The alkyl silane is selected so that it will be reactive with the above resin composition. Here the alkyl silane is 3-methacryloxypropyltrimethoxysilane (3-MPS). The mixture is stirred to ensure particles are fully wetted and then allowed to stand at room temperature for about one hour. The mixture is filtered using a vacuum filter flask and Buchner funnel and the residue was washed with ethanol, and then dried under a vacuum of around 20 mbar to yield the final silane treated SiC. This procedure was repeated for 46 mesh screened Silicon carbide particles to provide a similar amount of 200 μm size SiC particles.
3. The selected grades of silane treated Silicon carbide are dry blended prior to use. In this example the blend is a 70:30 mix of 750 μm:200 μm.
4. A piece of matting approximately 0.75 mm thick in total and 20 cm×8 cm in size consisting of 3 layers of carbon fibre twill woven fabric bonded together with spray adhesive is positioned in the mould. The matting used here is a carbon fibre twill woven fabric and contains carbon fiber. The matting is placed in the desired position within a mould tool and secured as needed.
5. The mould tool is filled with the above blend of the treated Silicon carbide grains. During particle filling the mould is vibrated at a vibration rate of between 100 to 10,000 Hz and vibration continues for up to one minute after filling is completed to facilitate packing of the particles and even flow of the particles into geometries of the mould. Compressed air may is also used, if needed, to fluidize the granular material during filling, particularly when filling complex geometries.
6. A resin infusion hose is attached to the mould at one or several filling points on the bottom of the tool and the particle filled and vibro-compacted mould is then sealed and placed under a vacuum of less than 100 mbar. The mould tool is either a vacuum sealable tool itself or is placed in a vacuum chamber or even a sealed bag attached to vacuum as is commonly known in the composite industry as “vacuum bagging.” Vacuum filling allows for resin faster filling of the tool and also reduces the likelihood of air entrapment during infusion.
7. A heat curable, two component resin material is then mixed through a static mixer and dispensed into a resin pot attached to the other end of the infusion hose. A tap is opened on the infusion hose to allow resin to be induced into the tool under the pull of the vacuum. The resin is allowed to infuse through the matting and particles and fill the tool. After filling, the tool is again vibro-compacted for a period of up to 5 minutes to ensure maximum densification and to mitigate against any “resin wash” where particles are washed away from the injection port by resin flow resulting in a resin rich zone.
8. Following this the mould tool is removed from vibration and vacuum and placed in an oven to cure the unitary polymer composite. Here in this example curing is achieved by simply heating to 80° C. and holding for 4 hours. After curing, the unitary polymer composite article is removed from the tool.
9. Post cure touch up and reworking of the article is performed as needed.
10. Additional annealing of the article is performed, if needed, by placing the cured item in an oven and curing at a temperature of over 120° C. for 4 hours with no vacuum.
The resulting unitary polymer composite article had the following properties: flexural strength of 110 MPa, flexural modulus of 15000 MPa, and tensile strength of 25 MPa.
Example 2, five particles size SiC blend, vacuum infusion and 80° C. curing: In the following example a moulded composite article is prepared using five different sizes of Silicon carbide particles. The final articles contained approximately 75% by weight Silicon carbide particles and approximately 25% by weight Polymer as well as a portion of matting. The polymer/resin composition contains
100 parts by weight Daron 45 vinyl ester urethane hybrid polymer
35 parts by weight polymeric methylene diphenyl isocyanate (MDI)
2 parts by weight peroxide catalyst
5 parts by weight zeolite molecular sieve
The process of manufacture involves the following steps (see
1. Resin: Part A and Part B resin mixtures are prepared:
Part A contains the 100 parts of a vinylester hybrid polymer and 5 parts zeolites sieves and
Part B contains 35 parts of polymeric methylene diphenyl isocyanate and 2 parts of peroxide catalyst. Part A and Part B resin mixtures were carried out in a flask fitted with a mechanical stirrer. Approximately 1 kg is prepared for this example.
2. Silane treated Silicon carbide preparation: In this example, the Silicon carbide used is a mixture of five different grade sizes and is prepared as follows. One kilogram of Silicon carbide (24 mesh) was added to a solution of 30 grams of an alkyl silane in 450 mL absolute Ethanol. The 24 mesh screened Silicone carbide is made up particles that are around 750 μm in size or smaller. The alkyl silane is selected so that it will be reactive with the above resin composition. Here the alkyl silane is 3-methacryloxypropyltrimethoxysilane (3-MPS). The mixture is stirred to ensure particles are fully wetted and then allowed to stand at room temperature for about one hour. The mixture is filtered using a vacuum flask and filter funnel and the residue was washed with ethanol, and then dried under a vacuum of around 20 mbar to yield the final silane treated SiC. This procedure was repeated for other sizes of screened Silicon carbide particles to provide a similar amount of 1 mm, 750 μm, 500 μm, 250 μm and 100 μm grade size SiC particles. For the 100 mesh (150 μm grade size) material, the suspension was stirred mechanically for one hour rather than allowed to stand, to ensure that the particles were fully wetted and able to react with the silane due to the reduced ability of the solvent the permeate the mass.
3. The five grades of silane treated Silicon carbide are dry blended prior to use. Here the a blend of treated SiC grades is one part by weight 1 mm, one part by weight 750 μm, one part by weight 500 μm, one part by weight 250 μm and one part by weight 100 μm.
4. A layer of matting approximately 0.25 mm thick in total and 20 cm×8 cm in size consisting of 1 layer of non-woven E glass fibre fabric is positioned in a mould tool. The matting used here is a non-woven E glass fibre and contains glass fiber. The matting is placed in the desired position within the mould tool and secured as needed.
5. The mould tool is filled with the above blend of the treated Silicon carbide grains. During particle filling the mould is vibrated at a vibration rate of between 100 to 10,000 Hz and vibration continues for up to one minute after filling is completed to facilitate packing of the particles and even flow of the particles into geometries of the mould. Compressed air may is also used, if needed, to fluidize the granular material during filling, particularly when filling complex geometries.
6. A resin infusion hose is attached to the mould at one or several filling points on the bottom of the tool and the particle filled and vibro-compacted mould is then sealed and placed under a vacuum of less than 100 mbar. The mould tool is either be a vacuum sealable tool itself or is placed in a vacuum chamber or even a sealed bag attached to vacuum as is commonly known in the composite industry as “vacuum bagging.” Vacuum filling allows for resin faster filling of the tool and also reduces the likelihood of air entrapment during infusion.
7. A heat curable, two component resin material is then mixed through a static mixer and dispensed into a resin pot attached to the other end of the infusion hose. A tap is opened on the infusion hose to allow resin to be induced into the tool under the pull of the vacuum. The resin is allowed to infuse through the particles and matting and fill the tool. After filling, the tool is again vibro-compacted for a period of up to 5 minutes to ensure maximum densification and to mitigate against any “resin wash” where particles are washed away from the injection port by resin flow resulting in a resin rich zone.
8. Following this, the tool is removed from vibration and vacuum and placed in an oven to cure the unitary polymer composite or the single casted polymer composite. Here in this example curing is achieved by simply heating to 80° C. and holding for 4 hours. After curing, the unitary polymer composite article or the single casted polymer composite article is removed from the tool.
9. Post cure touch up and reworking of the article is performed as needed.
10. Additional annealing of the article is performed, if needed, by placing the cured item in an oven and curing at a temperature of over 120° C. for about 4 hours with no vacuum.
The resulting unitary polymer composite article had the following properties: flexural strength of 65 MPa, flexural modulus of 12500 MPa, and tensile strength of 22 MPa.
Example 3, two SiC blend, matting, vacuum infusion and Ramp curing: Here the polymer composite is prepared as in Example 1, however was curing was carried using a temperature ramp in the process. The filled mould tool is first heated to a lower temperature of 50° C. for two hours followed by increasing to 60° C. and finally 80° C. for a minimum of one hour hold at each of these temperatures. The resulting unitary polymer composite article had the following properties: flexural strength of 58 MPa, flexural modulus of 14000 MPa, and tensile strength of 34 MPa.
Example 4 five particles size SiC blend, vacuum infusion and Ramp curing: Here the polymer composite is prepared as in Example 2, however, firing was curing was carried using a temperature ramp in the process. The filled tool is first heated to a lower temperature of 50° C. for two hours followed by increasing to 60° C. and finally 80° C. for a minimum of one hour hold at each of these temperatures. The resulting unitary polymer composite article had the following properties: flexural strength of 122 MPa, flexural modulus of 12700 MPa, and tensile strength of 29 MPa.
Example 5, two particle size SiC blend, matting, vacuum infusion and 80° C. curing: In this example, the Siliconcarbide blend used was the same as that in Example 1, however, in this case the Silicon carbide had been treated with the silane Silquest® A1100, gamma-aminopropyltriethoxysilane according to the method described in example 1. And the article was made up of approximately 75% by weight Silicon carbide particles and approximately 25% by weight Polymer, as well as a portion of matting. However, the polymer/resin composition used in this example was a two part infusion grade epoxy resin and hardener system Epolam 2035, with a viscosity preferably less than 1000 cps, and optimally less than 500 cps. To prepare the resin compositions Part A and Part B resin mixtures are prepared as follows: Part A contains the 100 parts of a vinylester hybrid polymer and 5 parts zeolites sieves and Part B contains 35 parts of polymeric methylene diphenyl isocyanate and 2 parts of peroxide catalyst. Part A and Part B are commercially available materials. Part A contains 100 parts of an infusion grade epoxy resin with glass transition temperature above 120° C. Parts B contains an amine hardener matched to the epoxy resin in Part A. The resulting unitary polymer composite article had the following properties: flexural strength of 135 MPa, flexural modulus of 8000 MPa, and tensile strength of 35 MPa.
Example 6, five particle size SiC blend, matting vacuum infusion and 80° C. curing: In this example, the Silicon Carbide blend used was the same as that in Example 2. And the article was made up of approximately 75% by weight Silicon Carbide particles and approximately 25% by weight Polymer in this case the silicon carbide grains we not treated with a silane coupling agent and were used as received. However, the polymer/resin composition used in this example was a two part infusion grade epoxy resin and hardener system Epolam 2035, with a viscosity preferably less than 1000 cps, and optimally less than 500 cps. To prepare the resin compositions, Part A and Part B resin mixtures are prepared as follows: Part A contains the 100 parts of a vinylester hybrid polymer and 5 parts zeolites sieves and Part B contains 35 parts of polymeric methylene diphenyl isocyanate and 2 parts of peroxide catalyst. Part A and Part B are commercially available materials. Part A contains 100 parts of an infusion grade epoxy resin with glass transition temperature above 120° C. Parts B contains an amine hardener matched to the epoxy resin in Part A. The resulting unitary polymer composite article had the following properties: flexural strength of 85 MPa, flexural modulus of 3000 MPa, and tensile strength of 26 MPa.
Example 7, Two particle size SiC blend, matting, pressure infusion and 80° C. curing: The SiC particles and the resin composition used are prepared as in Example one. However, here pressure infusion was used. A resin infusion hose is attached to the mould at one or several filling points on the top of the tool and the particle filled and vibro-compacted mould is subject to a pressure of 1.1 bar. The resin infusion hose is attached to a pressurized resin pot which is subject to an internal pressure of 1.5 bar. The pressure differential is maintained until the tool is filled. Thereafter the tool was vibrated for an additional time period of 10 minutes. The resulting unitary polymer composite article had the following properties: flexural strength of 62 MPa, flexural modulus of 16000 MPa, and tensile strength of 33 MPa.
Example 8 Two particle size SiC blend, matting, atmosphere infusion and 80° C. curing: The SiC particles and the resin composition used are prepared as in Example one. However, here atmospheric infusion was used. A resin infusion hose is attached to the mould at one or several filling points on the top of the tool and the tool is infused with the resin composition. After infusion, the tool is vibrated around 30 minutes in order to eliminate air pockets and to ensure full densification of the Silicon carbide particles. The composition was then placed in an oven to cure and cured by heating the oven to 80° C. and holding the tool in the oven for 4 hours. One advantage of atmospheric infusion is that it significantly reduced investment in vacuum tooling and plant equipment, and resin can be injected directly into the mould by a static mixing system with no intervening resin pot. This allows for almost exact resin volumes to be used with minimal waste. The resulting unitary polymer composite article had the following properties flexural strength of 57 MPa, flexural modulus of 11000 MPa, and tensile strength of 30 MPa.
Example 9, two different type of particles, matting, vacuum infusion and 80° C. curing: In the following example a moulded composite article is prepared using Silicon carbide and alumina particles. The final unitary polymer composite article contained approximately 50% by weight Silicon carbide particles, approximately 25% by weight alumina particles, approximately a 1 mm thick layer of unidirectional carbon fibre matting consisting of 4 layers of unidirectional weave carbon fibre fabric bonded together with spray adhesive and approximately 25% by weight Polymer. The polymer/resin composition contains
100 parts by weight Daron 45 vinyl ester urethane hybrid polymer
35 parts by weight polymeric methylene diphenyl isocyanate (MDI)
2 parts by weight peroxide catalyst
5 parts by weight zeolite molecular sieve
The process of manufacture involves the following steps (see
1. Resin: Part A and Part B resin mixtures are prepared:
Part A contains the 100 parts of a vinylester hybrid polymer and 5 parts zeolites sieves and
Part B contains 35 parts of polymeric methylene diphenyl isocyanate and 2 parts of peroxide catalyst. Part A and Part B resin mixtures were carried out in a flask fitted with a mechanical stirrer. Approximately 1 kg is prepared for this example.
2. Silane treated Silicon carbide preparation: In this example, the Silicon carbide used is a mixture of two different grade sizes (between 50 μm and 1 mm) and is prepared as follows. One kilogram of silicon carbide (24 mesh) was added to a solution of 30 grams of an alkyl silane in 450 mL absolute Ethanol. The 24 mesh screened Silicone carbide is made up particles that are around 750 μm in size or smaller. The alkyl silane is selected so that it will be reactive with the above resin composition. Here the alkyl silane is 3-methacryloxypropyltrimethoxysilane (3-MPS). The mixture is stirred to ensure particles are fully wetted and then allowed to stand at room temperature for about one hour. The mixture is filtered using a vacuum filter flask and Buchner funnel and the residue was washed with ethanol, and then dried under a vacuum of around 20 mbar to yield the final silane treated SiC. This procedure was repeated for 46 mesh screened Silicon carbide particles to provide a similar amount of 200 μm size SiC particles.
3. The alumina particles are similarly treated with 3-methacryloxypropyltrimethoxysilane (3-MPS), using alumina particles of between 50 μm and 1 mm in size.
4. The selected grades of silane treated silicon carbide & alumina are dry blended prior to use. In this example the blend is a 70:30 mix of 750 μm:200 μm of each silicon carbide and alumina.
5. The carbon fibre matting is positioned on the surface of a mould tool and held in place using a light coat of spray adhesive.
6. The mould tool is filled with the above blend of the treated Silicon carbide and treated alumina grains. During particle filling the mould tool is vibrated at a vibration rate of between 100 to 10,000 Hz and vibration continues for up to one minute after filling is completed to facilitate packing of the particles and even flow of the particles into geometries of the mould. Compressed air may is also used, if needed, to fluidize the granular material during filling, particularly when filling complex geometries.
7. A resin infusion hose is attached to the mould tool at one or several filling points on the bottom of the tool and the particle filled and vibro-compacted mould is then sealed and placed under a vacuum of less than 100 mbar. The mould is either be a vacuum sealable tool itself or is placed in a vacuum chamber or even a sealed bag attached to vacuum as is commonly known in the composite industry as “vacuum bagging.” Vacuum filling allows for resin faster filling of the tool and also reduces the likelihood of air entrapment during infusion.
8. A heat curable, two component resin material is then mixed through a static mixer and dispensed into a resin pot attached to the other end of the infusion hose. A tap is opened on the infusion hose to allow resin to be induced in to the tool under the pull of the vacuum. The resin is allowed to infuse through the particles and fill the tool. After filling, the tool is again vibro-compacted for a period of up to 5 minutes to ensure maximum densification and to mitigate against any “resin wash” where particles are washed away from the injection port by resin flow resulting in a resin rich zone.
9. Following this the mould tool is removed from vibration and vacuum and placed in an oven to cure. In this example curing is achieved by simply heating to 80° C. and holding for 4 hours.
10. Post cure touch up and reworking is performed as needed.
11. Additional annealing is performed, if needed, by placing the cured item in an oven and curing at a temperature of over 120° C. for about 4 hours with no vacuum.
The resulting unitary polymer composite article had the following properties: flexural strength of 140 MPa in the direction of the unidirectional carbon fibre weave, flexural modulus of 13000 MPa, and tensile strength of 27 MPa.
Example 10, combine positive pressure and vacuum infusion: The Silicon carbide particles and the resin composition used may be prepared as disclosed herein. A pump liner is made using an appropriate tool to form the desired shape. A series of bidirectional carbon fibre twill weave fabric layers are placed across the surface of the mould in order to produce matting with an average thickness of approximately 12.5 mm (5 layers of fabric). The mould tool is sealed and utilizes a double vacuum seal arrangement as disclosed herein. Other suitable vacuum arrangements may also be used. The resin infusion line is attached to the mould tool and clamped to seal, then connected to the piston infusion pump. About 8150 grams of suitable Silicon carbide powder is added via the vertical pump discharge neck and the assembly is vibrated at about 20 Hz during filling with Silicon carbide. Filling is continued until the mould tool is sufficiently full of compacted Silicon carbide. The discharge is then covered with a sealed mould cap and the mould is placed under vacuum at about 50 mbars. Prime™ 20 LV epoxy resin and Prime 20LV slow hardener (manufactured by Gurit Holding AG) are mixed and placed in a resin pot supported above a piston infusion pump. The pump is primed with resin and the infusion line clamp is removed allowing resin to enter the filled mould through the piston pump, under vacuum suction. After about 2 minutes, a positive pressure of about 5 psi is applied to the resin through the piston pump and each subsequent 2 minute period the pressure is increased by about 5 psi. After 12 minutes the resin injection pressure is about 30 psi while in-tool vacuum is held at about 50 mbar. These conditions are retained for around a further 15 minutes, or when resin is observed entered the vacuum line which has been positioned in the discharge neck sealing cap. The total mass of resin infused is about 2770 grams. The vacuum line and infusion line are both clamped shut and disconnected from the respective pumps. The tool is then vibrated again at about 20 Hz−1 for around 10 minutes. Vibration is ceased and the component is allowed to cure for about 12 hours at ambient temperature at which time the mould is opened and the cured liner demoulded. The moulding is then post cured for around 12 hours at 80° C. and trimmed as needed of flash using suitable machining techniques. The article produced is unitary polymer composite article.
In the following, further embodiments are explained with the help of subsequent examples. Example A1. A unitary polymer composite article comprising: 50% to 90% by weight of particles; 10% to 50% by weight of resin; and at least one layer of matting integrally incorporated in the unitary polymer composite.
A unitary polymer composite article comprising: 50% to 90% by weight of particles; 10% to 50% by weight of resin; and at least one layer of substantially continuous matting integrally incorporated in the unitary polymer composite article
A unitary polymer composite article comprising: 20% to 80% by weight of particles, wherein at least 20% of the particles have a have a Mohs hardness of greater than 6.5, 6.8 or 7; 20% to 80% by weight of resin; and at least one layer of matting integrally incorporated in the unitary polymer composite article.
A unitary polymer composite article comprising: 20% to 80% by weight of particles, wherein at least 20% of the particles have a have a Mohs hardness of greater than 6.5, 6.8 or 7; 20% to 80% by weight of resin; and at least one layer of substantially continuous matting integrally incorporated in the unitary polymer composite article.
The article of one or more of the A Examples, wherein a substantial portion of the particles have a Mohs hardness of greater than 7.
The article of one or more of the A Examples, wherein the at least one layer of matting is at least 0.1%, 0.5%, 1%, 5%, 10%, 20% or 30% by volume of the total volume of the article.
The article of one or more of the A Examples, wherein the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least one layer of matting is at least 0.1%, 0.5%, 1%, 5%, 10% or 20% by weight of the total weight of the article.
The article of one or more of the A Examples, wherein the at least one layer of matting is comprised of one or more of the following materials: glass, glass fibers, carbon, carbon fibers, ceramics, ceramic fibers, polymers, polymer fibers, minerals and mineral fibres.
The article of one or more of the A Examples, wherein the article comprises at least two, three, four, five, six or seven layers of matting.
The article of one or more of the A Examples, wherein the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least one layer of matting of the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of A Examples, wherein the at least two, three, four, five, six or seven layers of matting of the article are void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least one layer of matting is at least 5 mm, 10 mm, or 20 mm, thick and the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least one layer of matting is between 5 mm to 25 mm, 1 mm to 10 mm, or 10 mm to 20 mm thick and the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least one layer of matting is made with glass fibre and the at least one second layer is made with carbon fiber and the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least one layer of matting is made with glass fibre and the at least one second layer is made with carbon fiber and the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least two, three, four, five, six or seven layers of matting are alternating layers made of one or more of the following: glass fibre, carbon fibre, ceramic fibre and cellulose fibre, and the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least two, three, four, five, six or seven layers of matting are made of one or more of the following: glass fibre, carbon fibre, ceramic fibre and cellulose fibre, and the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least two, three, four, five, six or seven layers of matting are made of one or more of the following: glass, carbon, ceramic and cellulose, and the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein the at least two, three, four, five, six or seven layers of matting are made of at least two, three or four different materials and the article is void, substantially void or sufficiently void of air pockets.
The article of one or more of the A Examples, wherein at least 20%, 30%, 40%, 50%, 60%, 70% or 85% by weight of the particles have a Mohs hardness of 7 or greater.
The article of one or more of the A Examples, wherein a substantial portion of the particles have an aspect ratio of between 0.5 to 2.
The article of one or more of A Examples, wherein at least 20%, 30%, 40%, 50%, 60%, 70% or 85% by weight of the particles have an aspect ratio of between 0.5 to 2.
The article of one or more of A Examples, wherein a substantial portion of the particles have an aspect ratio of between 0.7 to 1.3.
The article of one or more of A Examples, wherein at least 20%, 30%, 40%, 50%, 60%, 70% or 85% by weight of the particles have an aspect ratio of between 0.7 to 1.3.
The article of one or more of the A Examples, wherein a substantial portion of the particles are between 50 μm to 1 mm in size.
The article of one or more of the A Examples, wherein at least 20%, 30%, 40%, 50%, 60%, 70% or 85% by weight of the particles are between 50 μm to 1 mm in size.
The article of one or more of A Examples, wherein the particles comprises a blend of two or more different size grades of particles.
The article of one or more of the A Examples, wherein the particles comprises a blend of at least 1, 2, 3, 4, 5 or 6 different size grades of particles.
The article of one or more of the A Examples, wherein the particles comprises about a 70:30 weight ratio blend of about 750 μm graded Silicon carbide particles and about 200 μm graded Silicon carbide particles.
The article of one or more of the A Examples, wherein the particles comprises a 65 to 75:25 to 35 weight ratio blend of 725 to 775 μm graded Silicon carbide particles and 175 to 225 μm graded Silicon carbide particles.
The article of one or more of the A Examples, wherein the particles comprises a blend of at least 5 different grades of particles comprising about one part 1 mm particles, about one part 750 μm particles, about one part 500 μm particles, about one part 250 μm particles and about one part 100 μm particles.
The article of one or more of the A Examples, wherein the particles comprises a blend of at least 5 different grades of particles comprising about 15 to 25 parts of 0.9 to 1.1 mm particles, 15 to 25 parts 730 to 770 μm particles, 15 to 25 parts 480 to 520 μm particles, 15 to 25 parts 230 to 270 μm particles and 15 to 25 parts 90 to 110 μm particles.
The article of one or more of the A Examples, wherein the particles comprises a blend of at least two different types of particles.
The article of one or more of the A Examples, wherein the particles comprises a blend of at least two to four different types of particles.
The article of one or more of the A Examples, wherein a substantial portion of the particles have a Mohs hardness of between 8.8 and 9.2.
The article of one or more of the A Examples, wherein a substantial portion of the particles have a Mohs hardness of greater than 9 and are substantially inert.
The article of one or more of the A Examples, wherein at least 20%, 30%, 40%, 50%, 60%, 70% or 85% by weight of the particles have a Mohs hardness of greater than 9 and are substantially inert.
The article of one or more of the A Examples, wherein the particles are selected from one or of the following: Silicon carbide, Alumina carbide, Tungsten carbide, Titanium carbide, Corundum, Quartz, Silicon dioxide, Silica, Silica sand, and other suitable non-absorbent particles.
The article of one or more of the A Examples, wherein the particles are Silicon carbide particles.
The article of one or more of the A Examples, wherein the resin composition is an infusion grade resin.
The article of one or more of the A Examples, wherein the resin composition comprises one or more of the following: a vinyl ester urethane resin and an epoxy resin.
The article of one or more of the A Examples, wherein the resin composition comprises a thermosetting infusion grade resin.
The article of one or more of the A Examples, wherein the article has a complex geometry and there is a substantial uniform distribution of the resin composition and the particles.
The article of one or more of the A Examples, wherein the article has a substantial uniform distribution of the resin composition and the particles.
The article of one or more of the A Examples, wherein the article comprises between 15% to 30% by weight of the resin composition and between 70% to 85% by weight of the particles; the particles are a blend comprising two or more grades of silane treated Silicon carbide particles; and a substantial portion of the blended particles are between 50 μm to 1 mm in size.
The article of the A Examples, wherein the at least one matting is a fibre matting comprising: glass fibre, carbon fibre, other reinforcing fibre material or combinations thereof.
The article of the A Examples, wherein the at least one layer of matting is continuous, substantially continuous or sufficiently continuous.
The article of the A Examples, wherein the at least one layer of matting is at least 30%, 40%, 50%, 60%, 70%, 80% or 90% continuous.
The article of the A Examples, wherein the at least one layer of matting is at least 30%, 40%, 50%, 60%, 70%, 80% or 90% by length continuous.
The article of the A Examples, wherein the at least one layer of matting is made up at least 1, 2, 3, 4, 5, 6, 7, 8 or 9 discontinuous portions and the discontinuous portions are continuous, substantially continuous or sufficiently continuous.
The article of the A Examples, wherein the article comprises at least two, three, four, five, six or seven layers of matting and the matting is a fibre matting comprising: glass fibre, carbon fibre, other reinforcing fibre material or combinations thereof.
The article of the A Examples, wherein the article comprises at least two, three, four, five, six or seven layers of matting and at least one of the layers is continuous, substantially continuous or sufficiently continuous.
The article of the A Examples, wherein the article comprises at least two, three, four, five, six or seven layers of matting and at least two, three or four of the layer are continuous, substantially continuous or sufficiently continuous.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level the mould tool with particles, wherein a substantial portion of the particles have a Mohs hardness of greater than 7; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite, wherein at least a portion of the mould tool is subjected to a vacuum and at least a portion of the mould tool is subject to a positive pressure during at least a portion of the infusing of the resin composition; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level a mould tool with particles; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level a mould tool with particles, wherein at least 20%, 30%, 40%, 50%, 60%, 70% or 85% by weight of the particles have a Mohs hardness of 7 or greater; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 50% by weight of the resin composition and between 50% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) filling to a predetermined level a mould tool with particles, wherein at least 20%, 30%, 40%, 50%, 60%, 70% or 85% by weight of the particles have a Mohs hardness of 7 or greater; c) infusing a resin composition into the mould tool filled with the particles and the at least one layer of matting in order to form a composite; d) vibrating the mould tool for a portion of time at one or more of the following stages: during the filling with the particles, after the filling with particles, during the infusing of the resin composition and after the infusions of the resin composition; wherein the composite comprises between 10% to 80% by weight of the resin composition and between 20% to 90% by weight of the particles; and e) curing the composite to form the moulded composite article.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) substantially filling a mould tool interior with a blend comprising two or more grades of silane treated Silicon carbide particles, wherein a substantial portion of the blended particles is between 50 μm to 1 mm in size and the mould tool is vibrated during at least a portion of the filling process at one or more vibration rates between 100 to 10,000 Hz; c) continuing to vibrate the mould tool after filling at one or more vibration rates between 100 to 10,000 Hz in order to facilitate a packing of the blended particles and to facilitate a substantially even flow of the blended particles into interior geometries of the mould tool; d) placing the mould tool filled with the blended particles under a vacuum of less than 100 mbar; e) infusing a resin composition into the mould tool interior substantially filled with the blended particles and the at least one layer of matting under a vacuum of less than 100 mbar; f) vibrating the mould tool substantially filled with the blended particles, the at least one layer of matting and the resin composition at one or more vibration rates of between 100 to 10,000 Hz for a time period of between 1 minute to 45 minutes in order to facilitate densification and to mitigate against resin wash; g) curing the mould tool substantially filled with the blended particles, the at least one layer of matting and the resin composition by heating until cured, wherein a portion of the resin composition is bonded to a substantial portion of the blended particles via a silane coupling agent coated on a substantial portion of the blended particles; and h) removing the cured moulded composite article from the mould tool, wherein the article comprises between 15% to 30% by weight of the resin composition and between 70% to 85% by weight of the blend particles.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) substantially filling a mould tool interior with a blend of silane treated Silicon carbide particles, wherein a substantial portion of the blended particles is between 50 μm to 1 mm in size and the mould tool is vibrated during at least a portion of the filling process; c) continuing to vibrate the mould tool after filling in order to facilitate a packing of the blended particles; d) placing the mould tool filled with the blended particles under a vacuum of less than 100 mbar; e) infusing a resin composition into the mould tool interior substantially filled with the blended particles and the at least one layer of matting under a vacuum of less than 100 mbar; f) vibrating the mould tool substantially filled with the blended particles, the at least one layer of matting and the resin composition in order to facilitate densification; g) curing the mould tool substantially filled with the blended particles, the at least one layer of matting and the resin composition by heating until cured, wherein a portion of the resin composition is bonded to a substantial portion of the blended particles via a silane coupling agent coated on a substantial portion of the blended particles; and h) removing the cured composite article from the mould tool, wherein the article comprises between 15% to 30% by weight of the resin composition and between 70% to 85% by weight of the blend particles.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) substantially filling a mould tool interior with treated Silicon carbide particles, wherein the mould tool is vibrated during at least a portion of the filling process; c) continuing to vibrate the mould tool after filling in order to facilitate a packing of the treated particles; d) placing the mould tool filled with the treated particles under a vacuum of less than 100 mbar; e) infusing a resin composition into the mould tool interior substantially filled with the treated particles and the at least one layer of matting under a vacuum of less than 100 mbar; f) vibrating the mould tool substantially filled with the treated particles, the at least one layer of matting and the resin composition in order to facilitate densification, wherein the treated particles and the resin composition comprises between 15 to 30% by weight of the resin composition and between 70 to 85% by weight of the treated particles; and g) curing the mould tool substantially filled with the treated particles and the resin composition by heating until cured.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) substantially filling a mould tool interior with a blend comprising two or more grades of silane treated silicon carbide particles, wherein a substantial portion of the blended particles is between 50 μm to 1 mm in size and the mould tool is vibrated during at least a portion of the filling process at one or more vibration rates between 100 to 10,000 Hz; c) continuing to vibrate the mould tool after filling at one or more vibration rates between 100 to 10,000 Hz in order to facilitate a packing of the blended particles and to facilitate a substantially even flow of the blended particles into interior geometries of the mould tool; d) infusing a resin composition into the mould tool interior substantially filled with the blended particles and the at least one layer of matting at atmospheric pressure; e) vibrating the mould tool substantially filled with the blended particles, the at least one layer of matting and the resin composition at one or more vibration rates of between 100 to 10,000 Hz for a time period of between 15 minutes to 75 minutes in order to facilitate densification and to mitigate against resin wash; f) curing the mould tool substantially filled with the blended particles, the at least one layer of matting and the resin composition by heating until cured, wherein a portion of the resin composition is bonded to a substantial portion of the blended particles via a silane coupling agent coated on a substantial portion of the blended particles; and g) removing the cured composite article from the mould tool, wherein the article comprises between 15 to 30% by weight of the resin composition and between 70 to 85% by weight of the blend particles.
A method for producing a moulded composite article comprising: a) providing at least one layer of matting to a mould tool; b) substantially filling a mould tool interior with a blend of silane treated Silicon carbide particles, wherein a substantial portion of the blended particles is between 50 μm to 1 mm in size and the mould tool is vibrated during at least a portion of the filling process; c) continuing to vibrate the mould tool after filling in order to facilitate a packing of the blended particles; d) infusing a resin composition into the mould tool interior substantially filled with the blended particles and the at least one layer of matting at atmospheric pressure; e) vibrating the mould tool substantially filled with the blended particles, the at least one layer of matting and the resin composition in order to facilitate densification; f) curing the mould tool substantially filled with the blended particles, the at least one layer of matting and the resin composition by heating until cured, wherein a portion of the resin composition is bonded to a substantial portion of the blended particles via a silane coupling agent coated on a substantial portion of the blended particles; and g) removing the cured composite article from the mould tool, wherein the article comprises between 15% to 30% by weight of the resin composition and between 70% to 85% by weight of the blend particles.
A method for producing a composite article comprising: a) providing at least one layer of matting to a mould tool; b) substantially filling a mould tool interior with treated Silicon carbide particles, and the mould tool is vibrated during at least a portion of the filling process; c) continuing to vibrate the mould tool after filling in order to facilitate a packing of the treated particles; d) infusing a resin composition into the mould tool interior substantially filled with the treated particles and the at least one layer of matting at atmospheric pressure; e) vibrating the mould tool substantially filled with the treated particles, the at least one layer of matting and the resin composition in order to facilitate densification, wherein the treated particles and the resin composition comprises between 15% to 30% by weight of the resin composition and between 70% to 85% by weight of the treated particles; and f) curing the mould tool substantially filled with the treated particles and the resin composition by heating until cured.
The method of one or more of the B Examples, wherein a substantial portion of the particles have an aspect ratio of between 0.5 to 2.
The method of one or more of the B Examples, wherein a substantial portion of the particles have an aspect ratio of between 0.7 to 1.3.
The method of one or more of B Examples, wherein a substantial portion of the particles are between 50 μm to 1 mm in size.
The method of one or more of the B Examples, wherein the particles comprises a blend of two or more different size grades of particles.
The method of one or more of the B Examples, wherein the particles comprises a blend of at least 1, 2, 3, 4, 5 or 6 different size grades of particles.
The method of one or more of the B Examples, wherein the particles comprises about a 70:30 weight ratio blend of about 750 μm graded Silicon carbide particles and about 200 μm graded Silicon carbide particles.
The method of one or more of the B Examples, wherein the particles comprises a 65 to 75:25 to 35 weight ratio blend of 725 to 775 μm graded Silicon carbide particles and 175 to 225 μm graded Silicon carbide particles.
The method of one or more of the B Examples, wherein the particles comprises a blend of at least 5 different grades of particles comprising about one part 1 mm particles, about one part 750 μm particles, about one part 500 μm particles, about one part 250 μm particles and about one part 100 μm particles.
The method of one or more of the B Examples, wherein the particles comprises a blend of at least 5 different grades of particles comprising about 15 to 25 parts of 0.9 to 1.1 mm particles, 15 to 25 parts 730 to 770 μm particles, 15 to 25 parts 480 to 520 μm particles, 15 to 25 parts 230 to 270 μm particles and 15 to 25 parts 90 to 110 μm particles.
The method of one or more of the B Examples, wherein the particles comprises a blend of at least two different types of particles.
The method of one or more of the B Examples, wherein the particles comprises a blend of at least two to four different types of particles.
The method of one or more of the B Examples, wherein a substantial portion of the particles have a Mohs hardness of between 8.8 and 9.2.
The method of one or more of the B Examples, wherein a substantial portion of the particles have a Mohs hardness of greater than 9 and are substantially inert.
The method of one or more of the B Examples, wherein the particles are selected from one or of the following: Silicon carbide, Alumina carbide, Tungsten carbide, Titanium carbide, Corundum, Quartz, Silicon dioxide, Silica, Silica sand, and other suitable non-absorbent particles.
The method of one or more of the B Examples, wherein the particles are Silicon carbide particles.
The method of one or more of the B Examples, wherein the particles are treated to enhance their wetting during the infusion of the resin composition.
The method of one or more of the B Examples, wherein the Silicon carbide particles are treated with a organo-silane coupling agent composition that is capable of bonding to a portion of the resin composition during curing of the composite.
The method of one or more of the B Examples, wherein the Silicon carbide particles are treated with an alkyl silane.
The method of one or more of the B Examples, wherein the resin composition is an infusion grade resin.
The method of one or more of the B Examples, wherein the resin composition comprises one or more of the following: a vinyl ester urethane resin and an epoxy resin.
The method of one or more of the B Examples, wherein the resin composition comprises a thermosetting infusion grade resin.
The method of one or more of the B Examples, wherein the resin composition has a viscosity of less than 1000 cps.
The method of one or more of the B Examples, wherein the resin composition has a viscosity of less than 500 cPs at 25 degrees C.
The method of one or more of the B Examples, wherein the resin composition has a viscosity of less than 60 cPs at 25 degrees C.
The method of one or more of the B Examples, wherein the resin composition has a viscosity of between 10 cPs to 500 cPs at 25 degrees C.
The method of one or more of the B Examples, wherein the resin composition has a viscosity of between 10 cPs to 500 cPs at 45 degrees C.
The method of one or more of the B Examples, wherein the resin composition is thixotropic.
The method of one or more of the B Examples, wherein and the mould tool is vibrated during at least a portion of the particle filling process at one or more vibration rates of between 100 to 10,000 Hz.
The method of one or more of the B Examples, wherein and the mould tool is vibrated after the particle filling process at one or more vibration rates of between 100 to 10,000 Hz in order to facilitate one or more of the following: a packing of the particles and a substantially even flow of the particles into interior geometries of the mould tool.
The method of one or more of the B Examples, wherein after the mould tool is filled with the particles and the resin composition the mould tool is vibrated at one or more vibration rates of between 100 to 10,000 Hz for a time period of between 1 minute to 45 minutes.
The method of one or more of the B Examples, wherein after the mould tool is filled with the particles and the resin composition the mould tool is vibrated at one or more vibration rates of between 100 to 10,000 Hz for a time period of between 1 minute to 75 minutes in order to facilitate one or more of the following: densification and to mitigate against resin wash.
The method of one or more of the B Examples, wherein infusing of the resin composition into the mould tool interior filled to the predetermined level with the particles is carried out in part at atmospheric pressure.
The method of one or more of the B Examples, wherein at least a portion of the mould tool after filling with the particles is subjected to a vacuum of less than 100 mbar and the resin composition is infused into the mould tool interior under vacuum.
The method of one or more of the B Examples, wherein the resin is infused into of the mould tool after filling with the particles.
The method of one or more of the B Examples, wherein the interior of the mould tool after filling with the particles is subjected to a vacuum of less than 100 mbar and the resin composition is infused into the mould tool interior under vacuum.
The method of one or more of the B Examples, wherein, during curing a portion of the resin composition is bonded to a substantial portion of the particles via a silane coupling agent coated on a substantial portion of the particles.
The method of one or more of the B Examples, wherein the mould tool substantially filled with the silicon carbide particles and the resin composition is cured at one temperature range between 70° C. and 90° C. for between 3 to 6 hours.
The method of one or more of the B Examples, wherein the mould tool substantially filled with the Silicon carbide particles and the resin composition is cured using a temperature ramp of at least one, two, three or four different temperatures wherein the Silicon carbide particles and the resin composition is held at each temperature for between 30 minutes to 3 hours.
The method of one or more of the B Examples, wherein the amount of the resin composition prepared is only what is needed to fill the mould tool.
The method of one or more of the B Examples, wherein the method is a closed system that reduces the need of personal to handle the resin composition.
The method of one or more of the B Examples, wherein the method is a closed system that reduces the exposure of the resin composition to the atmosphere.
The method of one or more of the B Examples, wherein the method is a closed system that improves worker safety and air quality controls.
The method of one or more of the B Examples, wherein the method results in a resin/particles composition with reduced air pockets in the composition.
The method of one or more of the B Examples, wherein the method produces composites in a complex geometry mould tool that have a substantial uniform distribution of the resin composition and the particles.
The method of one or more of the B Examples, wherein the method produces a complex geometry cured article that is substantial uniform in distribution of the resin composition and the particles.
The method of one or more of the B Examples, wherein the method produces composites that have a substantial uniform distribution of the resin composition and the particles.
The method of one or more of the B Examples, wherein the method produces a cured article that is substantial uniform in distribution of the resin composition and the particles.
The method of one or more of the B Examples, wherein at least a portion of the mould tool is subjected to one or more of the following: atmospheric pressure, vacuum and positive pressure during at least a portion of the infusing of the resin composition.
The method of one or more of the B Examples, wherein at least a portion of the mould tool is subjected to vacuum during at least a portion of the infusing of the resin composition and at least a portion of the mould tool is subject to positive pressure during at least a portion of the infusing of the resin composition.
The method of one or more of the B Examples, wherein the at least one layer of matting is comprised of one or more of the following materials: glass, glass fibers, carbon, carbon fibers, ceramics, ceramic fibers, polymers, polymer fibers, minerals and mineral fibres.
The method of one or more of the B Examples, wherein at least two, three, four, five, six or seven layers of matting are positioned in the mould tool.
The method of one or more of the B Examples, wherein the method produces an article that is void, substantially void or sufficiently void of air pockets.
The method article of one or more of the B Examples, wherein the at least one layer of matting of the article is void, substantially void or sufficiently void of air pockets.
The method of one or more of the B Examples, wherein the at least two, three, four, five, six or seven layers of matting of the article are void, substantially void or sufficiently void of air pockets.
The method of one or more of the B Examples, wherein the article produced has a substantial uniform distribution of the resin composition and the particles.
The method of one or more of the B Examples, wherein the at least one matting is a fibre matting comprising: glass fibre, carbon fibre, other reinforcing fibre material or combinations thereof.
The method of one or more of the B Examples, wherein the at least one layer of matting is continuous, substantially continuous or sufficiently continuous.
The method of one or more of the B Examples, wherein the at least one layer of matting is at least 30%, 40%, 50%, 60%, 70%, 80% or 90% by length continuous.
The method of one or more of the B Examples, wherein at least a portion of the mould tool is subjected to one or more of the following: atmospheric pressure, vacuum and positive pressure during at least a portion of the infusing of the resin composition.
The method of one or more of the B Examples, wherein at least a portion of the mould is subjected to vacuum during at least a portion of the infusing of the resin composition and at least a portion of the mould tool is subject to positive pressure during at least a portion of the infusing of the resin composition.
The method of one or more of the B Examples, wherein the moulded composite article is a unitary polymer composite article.
A system for producing a unitary polymer composite article that uses one or more of the methods of the B Examples.
While the present disclosure has been described in connection with certain embodiments, it is to be understood that the present disclosure is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements. Also, the various embodiments described herein may be implemented in conjunction with other embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realize yet other embodiments. Further, each independent feature or component of any given embodiment may constitute an additional embodiment.
In this specification, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of”. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear.
In addition, the foregoing describes only some embodiments of the invention(s), and alterations, modifications, additions and/or changes can be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and not restrictive.
Number | Date | Country | Kind |
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2012901819 | May 2012 | AU | national |
This application claims priority to U.S. Provisional Application No. 61/591,126, to Humphries et al., entitled “Polymer Composites” filed on Jan. 26, 2012, and to Australian Provisional Application No. 2012901819, to Humphries et al., entitled “Polymer Composites” filed on May 4, 2012, each of these applications is incorporated herein by reference in their entirety. This application is also related to an International PCT application to Humphries et al., entitled “Polymer Composites” to be filed on or before Jan. 26, 2012. This PCT application is also incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/AU2013/000067 | 1/25/2013 | WO | 00 | 12/20/2013 |
Number | Date | Country | |
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61591126 | Jan 2012 | US |