Pipes are used in many different applications, such as for example transporting gasses and fluids and protecting cables. The applications for pipes can result in diverse pipe sizes and technical requirements. Factors, such as for example pressure, corrosion resistance and drinking water compatibility result in pipes manufactured from varying materials. Examples of pipe materials include steel, cast iron, concrete, glass reinforced plastics and plastic. Plastic pipes are generally manufactured from thermoset resins and thermoplastic resins.
Pipes made of thermoset resins can be reinforced by glass fibres. Thermoset resins for pipes can be unsaturated polyester or vinylester or epoxy. These resins can be brittle, and are customarily reinforced by glass fibres. Typically, these resins have a low viscosity before polymerization. The low viscosity of the resins provides a good impregnation of the glass fibers, and a good quality and mechanical behavior of the final thermoset composite pipe.
Examples of thermoplastic resins include polyvinyl chloride (PVC), high density polyethylene (HDPE) and polypropylene (PP). In some instances, thermoplastic resins can be too viscous to ensure good impregnation of glass fibres and the mechanical properties of thermoplastic pipes can be below those of other pipe materials, such as for example steel and concrete. Thermoplastic pipes can be used in applications where the internal pipe pressure is low and the pipe diameter less than about 300 mm. Use of thermoplastic pipe in diameters larger than about 300 mm can result in larger wall thicknesses, high cost and low manufacturing productivity. However, pipes made of thermoplastic resins can have good chemical and corrosion resistance, excellent drinking water compatibility and can be easily connected by processes such as welding. It would be advantageous to provide pipes made of thermoplastic resins having pipe diameters larger than 300 mm. It would also be advantageous to provide pipe made of thermoplastic resins having improved mechanical resistance.
In accordance with embodiments of this invention there are provided apparatus and methods of manufacturing a continuous pipe from thermoplastic materials. The methods include the steps of providing an endless mandrel having a releasable surface, the endless mandrel configured for rotation, forming an inner liner layer on the releasable surface of the endless mandrel, forming an intermediate layer on the inner liner layer, forming an outer layer on the intermediate layer, thereby forming a continuous pipe and cutting the continuous pipe into segments. The method is characterized in that the inner liner layer is made of a thermoplastic material, the intermediate layer is made of commingled thermoplastic material and glass fiber reinforcement material, and the outer layer is made of a thermoplastic material.
Various advantages of this invention will become apparent to those skilled in the art from the following detailed description of the invention, when read in light of the accompanying drawings.
The present invention will now be described with occasional reference to the specific embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
Unless otherwise indicated, all numbers expressing quantities of dimensions such as length, width, height, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements.
In accordance with embodiments of the present invention, continuous thermoplastic pipe made from commingled fibers and methods of making same are provided. The term “pipe” as used herein, is defined to mean a hollow structure configured to convey materials or for use as a structural member. The term “thermoset”, as used herein, is defined to mean materials that irreversibly cure. The term “thermoplastic”, as used herein, is defined to mean materials that substantially “melt” at certain temperatures thereby forming a soft, flexible and elastic material, and freeze below the certain temperatures.
The description and figures disclose apparatus and methods for manufacturing continuous thermoplastic pipe. Generally, the disclosed and illustrated thermoplastic pipe has a relatively small wall thickness and a minimum outer diameter of approximately 300 mm. The thermoplastic pipe can be provided in various outer diameter sizes and is suitable for a variety of uses including as a conduit for drinking water.
Referring now to
The mandrel 12 includes a face plate 14, a plurality of rods 16 and tape 18. The face plate 14 is configured for retention of the rods 16 in a spaced apart orientation. In the illustrated embodiment, the face plate 14 is made of a metallic material and has a circular cross-sectional shape. Alternatively, the face plate 14 can be made of other desired materials and can have other desired cross-sectional shapes.
Referring again to
The outer perimeter of the rods 16 is covered by a tape 18. The tape 18 is configured to form a tape layer 19 having releasable surface upon which various subsequent layers forming a continuous pipe can be applied. In the illustrated embodiment, the tape 18 is made of a metallic material, such as for example steel. However, the tape 18 can be made of other desired materials. The tape 18 can have any desired thickness and width, and can be applied to the rods 16 in any desired manner sufficient to form a tape layer 19 having a releasable surface.
Optionally, a first cooling mechanism 17 can be configured to cool the tape layer 19. The first cooling mechanism 17 can be configured to cool the tape layer 19 to any desired temperature. The first cooling mechanism 17 can be any desired structure, mechanism or device, such as a blower.
Referring again to
The inner liner ribbon 20 is made of a resin-based material. Examples of resin-based inner liner ribbon 20 materials include polyvinyl chloride (PVC), polypropylene (PP) and polyethylene (PE), and combinations of these materials. However, other resin-based materials can be used. Optionally, the resin-based material for the inner liner ribbon 20 can be reinforced with chopped fibers, such as for example glass fibers.
The inner liner ribbon 20 has a width WIL and a thickness TIL. In the illustrated embodiment, the width WIL is in a range of from about 40.0 mm to about 400.0 mm and the thickness TIL is in a range of from about 0.5 mm to about 50.0 mm. Alternatively, the width WIL can be less than about 40.0 mm or more than about 400.0 mm and the thickness TIL can be less than about 0.5 mm or more than about 50.0 mm.
The inner liner ribbon 20 is applied to the tape layer 19 with the thermoplastic resin in a heated, semi-molten condition. The heated, semi-molten condition of the inner liner ribbon 20 is configured to facilitate adhesion to subsequent layers by providing a hot and sticky adhesive surface. In the illustrated embodiment, the inner liner ribbon 20 is heated to a temperature in a range of from about 130° C. to about 230° C. However, the inner liner ribbon 20 can be heated to temperatures less than about 130° C. or more than about 230° C.
Optionally, to maintain the inner liner layer 21 in a heated, semi-molten condition prior to the application of subsequent layers, a heater 24 can be directed to the inner liner layer 21. The heater 24 can be any desired structure, mechanism or device and can be configured to maintain inner liner layer 21 at any desired temperature. Optionally, the temperature of the inner liner layer 21 can be monitored by a sensor (not shown). The sensor can be any desired sensing mechanism or device.
The first extruder 22 is configured to provide the inner liner ribbon 20 in a continuous wrapped manner. The first extruder 22 can be any desired structure, mechanism or device sufficient and can include any desired structure or device, such as for example a flat die, to provide the inner liner ribbon 20. One example of a first extruder is an Alpa 45/60 single screw extruder provided by Cincinnati Extrusion GmbH headquartered in Vienna, Austria. However, other first extruders 22 can be used. The first extruder 22 is provided material for the inner liner ribbon 20 by a supply system (not shown). The supply system can be any desired structure or mechanism.
The inner liner ribbon 20 can be wrapped on the tape layer 19 in several manners. In the illustrated embodiment, the inner liner ribbon 20 is wrapped on the tape layer 19 in a manner such that successive applications of the inner liner ribbon 20 overlap previously installed applications of the inner liner ribbon 20. The overlap can be any desired amount. Alternatively, the inner liner ribbon 20 can be wrapped on the tape layer 19 in a manner such that an edge of successive applications of the inner liner ribbon 20 aligns with an edge of previously installed applications of the inner liner ribbon 20, resulting in no overlap of the wrapped inner liner ribbons 20.
Referring again to
The intermediate ribbon 30 can be made of a resin-based commingled thermoplastic and glass fiber reinforcement material. One example of a resin-based commingled thermoplastic and glass fiber reinforcement material is Twintex® reinforcement material marketed by Owens Corning headquartered in Toledo, Ohio. An intermediate ribbon 30 made of the Twintex® reinforcement material provides longitudinally oriented thermoplastic fibers commingled with longitudinally oriented glass fibers. However, other resin-based commingled thermoplastic and fiber reinforcement materials can be formed into the intermediate ribbon 30. Non-limiting examples of other fiber reinforcement materials include aramid fibers, carbon fibers and metallic fibers.
The intermediate ribbon 30 has a width WIR and a thickness TIR. In the illustrated embodiment, the width WIR is in a range of from about 40.0 mm to about 400.0 mm and the thickness TIR is in a range of from about 0.3 mm to about 5.0 mm. Alternatively, the width WIR can be less than about 40.0 mm or more than about 400.0 mm and the thickness TIR can be less than about 0.3 mm or more than about 5.0 mm.
The intermediate ribbon 30 is applied to the inner liner layer 21 with the thermoplastic resin in a heated, semi-molten condition. The heated, semi-molten condition of the intermediate ribbon 30 is configured to facilitate adhesion to subsequent layers by providing a hot and sticky adhesive surface. In the illustrated embodiment, the intermediate ribbon 30 is heated to a temperature in a range of from about 130° C. to about 230° C. However, the intermediate ribbon 30 can be heated to temperatures less than about 130° C. or more than about 230° C.
Optionally, to maintain the intermediate layer 34 in a heated, semi-molten condition prior to the application of subsequent layers, a heater 37 can be directed to the intermediate layer 34. The heater 37 can be any desired structure, mechanism or device and can be configured to maintain intermediate layer 34 at any desired temperature. Optionally, the temperature of the intermediate layer 34 can be monitored by a sensor (not shown). The sensor can be any desired sensing mechanism or device.
The applicator 32 is configured to provide the intermediate ribbon 30 in a continuous wrapped manner. The applicator 32 can be any desired structure, mechanism or device or combination of structures, mechanisms or devices sufficient to provide the intermediate ribbon 30. The applicator 32 is provided material for the intermediate ribbon by a supply system (not shown). The supply system can be any desired structure or mechanism.
The intermediate ribbon 30 can be wrapped on the inner liner layer 21 in several manners. In the illustrated embodiment, the intermediate ribbon 30 is wrapped on the inner liner layer 21 in a manner such that successive applications of the intermediate ribbon 30 overlap previously installed applications of the intermediate ribbon 30. The overlap can be any desired amount. Alternatively, the intermediate ribbon 30 can be wrapped on the inner liner layer 21 in a manner such that an edge of successive applications of the intermediate ribbon 30 aligns with an edge of previously installed applications of the intermediate ribbon 30 resulting in no overlap of the wrapped intermediate ribbons 30.
The use of a resin-based commingled thermoplastic and glass fiber reinforcement material for the intermediate ribbon 30 advantageously allows the intermediate layer 34 to provide circumferential reinforcement to the continuous pipe 50. Additionally, as the intermediate ribbon 30 is applied on all portions of the continuous pipe 50, including irregular portions as will be discussed in detail below, the resin-based commingled thermoplastic and glass fiber reinforcement material provides structural support for all of the portions continuous pipe 50.
Optionally, the resin-based longitudinally oriented and commingled thermoplastic and glass fiber reinforcement material used for the intermediate ribbon 30 can be further reinforced by the introduction of a layer or layers of cross-directionally oriented reinforcement fibers (not shown) prior to or subsequent to the application of the intermediate ribbon 30 to the inner liner layer 21. The cross-directionally oriented reinforcement fibers can be oriented relative to the longitudinally oriented and commingled thermoplastic and glass fiber reinforcement material in any desired manner. In some embodiments, the cross-directionally oriented reinforcement fibers can have a generally aligned, closely spaced substantially parallel orientation. In other embodiments, the cross-directionally oriented reinforcement fibers can have a random orientation. The cross-directionally oriented reinforcement fibers can have any desired length. In some embodiments, the cross-directionally oriented reinforcement fibers can have a diameter in a range of from about 8 microns to about 30 microns and can be in a form of a strand that can have a weight within a range of from about 300 g/km to about 9600 g/km. Alternatively, the cross-directionally oriented reinforcement fibers can be in the form of a strand having a diameter less than about 8 microns or more than about 30 microns and a weight that is less than about 300 g/km or more than about 9600 g/km. The cross-directionally oriented reinforcement fibers can be made of any material sufficient for reinforcement purposes, such as for example glass fibers, mineral fibers and carbon fibers. The cross-directionally oriented reinforcement fibers can be a single filament or numerous filaments. The cross-directionally oriented reinforcement fibers can be introduced to the intermediate ribbon 30 in any desired manner including for example by nozzles using fluids to influence or control the orientation of the cross-directionally oriented reinforcement fibers. One example of a process for forming resin-based commingled thermoplastic and glass fiber reinforcement material having cross-directionally oriented reinforcement fibers is disclosed in PCT Publication number WO2008/027206, published Mar. 6, 2008, which is incorporated herein in its entirety.
In still further embodiments, the intermediate ribbon 30 can be formed from commingled resin-based thermoplastic and woven reinforcement fabrics. The woven reinforcement fabrics can be any desired woven reinforcement fabric suitable for commingling with resin-based thermoplastic and reinforcing the intermediate ribbon 30. One non-limiting example of a woven reinforcement fabric is woven Twintex® reinforcement material.
Referring again to
The outer ribbon 40 is made of a resin-based material. Examples of resin-based outer ribbon 40 materials include polyvinyl chloride (PVC), polypropylene (PP) and polyethylene (PE) and combinations of these materials. However, other thermoplastic resin-based materials can be used. Optionally, the resin-based material for the outer ribbon 40 can be reinforced with chopped fibers, such as for example glass fibers.
The outer ribbon 40 has a width WO and a thickness TO. In the illustrated embodiment, the width WO is in a range of from about 40.0 mm to about 400.0 mm and the thickness TO is in a range of from about 0.5 mm to about 50.0 mm. Alternatively, the width WO can be less than about 40.0 mm or more than about 400.0 mm and the thickness TO can be less than about 0.5 mm or more than about 50.0 mm.
The second extruder 44 is configured to provide the outer ribbon 40 in a continuous manner. In one embodiment, the second extruder 44 is the same as or similar to the first extruder 22. However, the second extruder 44 can be other structures, mechanisms or devices sufficient to provide the outer ribbon 40 in a continuous manner. The second extruder 44 is provided material for the outer ribbon 40 by a supply system. The supply system can be any desired structure or mechanism.
The outer ribbon 40 can be wrapped on the intermediate layer 34 in the same manner as described above for the inner liner ribbon 20.
Referring again to
Optionally, a roller 52 can apply pressure and/or heat to the surface 51 of the continuous pipe 50. The roller 52 is configured to simultaneously smooth the outer surface 51 of the continuous pipe 50 and consolidate the inner liner layer 21, intermediate layer 34 and outer layer 42 together. The roller 52 can be configured to apply any desired amount of pressure and/or any amount of heat to the outer surface 51 of the continuous pipe 50. The roller 52 can be any desired structure, mechanism or device.
Optionally, a second cooling mechanism 53 can be configured to cool the continuous pipe 50. The second cooling mechanism 53 can be configured to cool the continuous pipe 50 to any desired temperature. The second cooling mechanism 53 can be any desired structure, mechanism or device, such as a blower.
As shown in
Referring now to
The continuous pipe 50 has an outer diameter ODP. In the illustrated embodiment, the outer diameter ODP is in a range of from about 300 mm to about 3000 mm. In other embodiments, the outer diameter ODP can be less than about 300 mm or more than about 3000 mm.
The continuous pipe 50 has a wall thickness WT. In the illustrated embodiment, the wall thickness WT is in a range of from about 1.5 mm to about 55.0 mm. In other embodiments, the wall thickness WT can be less than about 1.5 mm or more than about 55.0 mm.
As discussed above, the passage 26 and inner liner layer 21 are configured for use with a variety of fluids. Non-limiting examples include drinking water, oil and sewage water.
The apparatus and methods discussed above can be used to manufacture continuous pipe having more than three layers. Referring now to
Referring again to
The third layer 142 is a layer of foam-based material. The third layer is configured to increase the thickness wall of the continuous pipe 150 while having minimal weight impact. In the illustrated embodiment, the third layer is made of polyurethane foam. However, other foam-based materials, such as for example polyvinyl chloride (PVC) or polyethylene (PE) can be used. In the illustrated embodiment, the third layer 142 has a thickness in a range of from about 2.0 mm to about 50.0 mm. In other embodiments, the third layer 142 can have a thickness of less than about 2.0 mm or more than about 50.0 mm.
While the embodiment shown in
Another embodiment of an apparatus configured for manufacturing continuous pipe is illustrated, generally at 210, in
Referring now to
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The continuous pipe 250 can be heated, pressured, cooled and segmented as described above for continuous pipe 50.
Composite ribbons can be formed and wrapped in other manners. In one embodiment, a composite ribbon can be formed with integral resin, reinforcing and hollow portions. Referring now to
As shown in
In the illustrated embodiment, the hollow core 380 has a rectangular cross-sectional shape. Alternatively, the hollow core 380 can have other cross-sectional shapes. The hollow core 380, base 372 and top 374 form a composite ribbon thickness TCR. In the illustrated embodiment, the thickness TCR is in a range of from about 2.0 mm to about 50.0 mm. However, the thickness TCR can be other desired dimensions. The thickness TCR of the hollow core 380, base 372 and top 374 advantageously provide the continuous pipe with high rigidity, strength and stiffness at low weight. The apparatus and method of forming a continuous pipe with the composite ribbon 370 will be discussed in detail below.
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The apparatus and methods described above can be used to make continuous pipe having irregularly shaped portions. Referring now to
In certain embodiments, the bell housing 594 can include the layers illustrated in
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The principle and mode of operation of this invention have been described in certain embodiments. However, it should be noted that this invention may be practiced otherwise than as specifically illustrated and described without departing from its scope.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB09/06326 | 6/23/2009 | WO | 00 | 10/31/2011 |