Patent Application
20190284729
The present invention relates to a process and system for the production of apparel fabrics, and more particularly, the present invention relates to a process and system for providing a coloured apparel fabric.
Within the field of textile manufacture for apparel manufacturing, there exists several processes and methodologies for the dying of such apparel materials and fabrics.
Processes utilized for dying in the textile and apparel field according to the prior art, include the conventional batch dyeing procedure. This process is performed within pressurized high temperature dyeing equipment, and dyestuffs such as dispersion dyes including Dystar Dianix sized at 1 micron, are pre dispersed within water under liquor to an appropriate ratio of typically at around 1:8 of dye to water as a dispersion in the water. In such a high temperature dyeing process, the dispersed dye may be provided so as to include the ratio or percentage of dispersion dye on weight of the fabric under a pH buffering system formed from yarn or fibers.
In such a process, the dyeing process is commenced at room temperature and then raised to an elevated temperature of about 130° C. to 135° C. The temperature is raised under temperature control at approximately 1.5° C. per minute to a temperature of 90° C. and then being held at the said temperature of 90° C. for about 10 minutes to assist in dye leveling or evenness of the dyestuff distributed on a fabric surface. The temperature is then raised to the requisite temperature of about 130° C. to 135° C. for 30 minutes to 40 minutes so as to allow dyestuff penetration of the fabric sheet, for example fabric formed from Polyethylene terephthalate(polyester) polymer.
The dye bath in which the fabric resides is then dropped from as high a temperature as possible to avoid the residue oligomer being retained on the fabric, typically at a rapid cooling rate from 132 degrees Celsius to room temperature, often with an intermediate temperature of 80 degrees Celsius which assists in the reduction of the formation of creases in the fabric.
The fabric is subsequently washed off typically at room temperature which may consist of more than one wash off step in typically room temperature water. After the washing process step, the fabric is provided with a reduction clear (RC) processing step, whereby the fabric is washed off in a bath typically containing the equivalent of about two grams per liter of each 100% solid caustic soda (sodium hydroxide) and hydro (sodium hydrosulphite).
A neutralization step follows thereafter, whereby the fabric is treated in a neutralizing acidic solution, typically acetic acid for example 0.5 cc/litre for a time period of about 30 minutes at room temperature, in order to neutralize any residual alkaline materials utilized in the reduction clear process step.
A softening process is typically deployed thereafter, whereby the fabric is treated by a softening agent of about 4% for about a further 30 minutes such as a hydrophilic softener that provides a soft feel by hand such as Tubingal GSO from CHT.
Another dyeing process as utilized in the prior art for the dyeing of fabric as a textile material is the foam dying process. In this process, the fabric is preheated to a temperature of about 10 degrees Celsius to 20 degrees Celsius above room temperature to provide a softer fabric, and which is then drawn through a foam coloring agent.
The foam typically has a volume of about 10 times more than water which is provided as a dyestuff transport medium which, upon the fabric being drawn through a pair of opposing rollers, applies the dye to the fabric.
Subsequently, a drying process is required to dry the fabric. The foam dying process is typically used for the dying of carpet and for the dying of bulk fabric.
A further dying process utilized in the prior art for the dying of fabric by way of a cold pad batch process. This process is frequently deployed within the art for the dyeing of cellulosic materials and for the dying of cotton knit fabrics. Approximately ⅓ of cotton knit dying in Europe is prepared according to this process.
The cold patch dying process involves a technique or process whereby pad-batch dyeing starts with saturating first the prepared fabric with pre-mixed dye liquor, which is then passed through a set of rollers. The rollers, or otherwise known as paddlers, effectively forces the dyestuff into the fabric. In this cold patch process, excess dye solution is also removed. Following the removal of the excess dye stuff, the fabric is subsequently “batched”, whereby batching is done by either storing in rolls or in boxes, which typically takes a minimum of 4-12 hours. The batches are generally enclosed by plastic films which prevents absorption of carbon dioxide as well as water evaporation. Finally, upon the reaction being complete, the fabrics are washed typically by becks, beams, or any other washing device.
A further process utilized in the art of fabric colouring is carbon dioxide dyeing, which is also known within the art as vapour phase dyeing. This is a recent development in the art of textile and fabric dyeing, whereby a fabric is dyed under vapour without the necessity of water. The entire process is conducted in a closed environment so as to prevent contamination to and from the surroundings.
It is an object of the present invention to provide a process and system for providing an apparel fabric material, which overcomes or ameliorates at least some of the deficiencies as associated with the prior art.
The present invention may involve several broad forms. Embodiments of the present invention may include one or any combination of the different broad forms herein described.
In a first aspect, the present invention provides a process of forming an apparel fabric having a predetermined requisite optical colour and pattern effect and having predetermined physical fabric properties, said process comprising the steps of:
(i) providing a first plurality of n yarn, wherein the total denier of n yarn is equal to a first denier (D1);
(ii) providing at least one further plurality of m yarn, wherein the total of m yarn is equal to a further Denier (D2); and
(iii) knitting the first plurality of yarn with the at least one further plurality of yarn by way of a knitting process so as to form a multi-ply apparel fabric;
wherein each yarn is formed from a plurality of fibers formed from a polymeric material, wherein the fibers are formed from a dope dyeing process and wherein said fibers are colored during said dope dyeing process;
wherein upon knitting of said first plurality of n yarn with said at least one further plurality of m yarn to form said multi-ply apparel fabric, said apparel fabric is formed having said predetermined requisite optical colour and pattern effect devoid of optically detectable variants in said requisite optical colour and pattern effect; and
wherein the first plurality of n yarn and the at least one further plurality of m yarn are selected so as to provide said predetermined optical colour and pattern effect and said predetermined physical fabric properties.
Preferably the first denier (D1) and the further denier (D2) are in the range of from 45 denier to 200 denier.
Each yarn of the first plurality of n yarn and each yarn of the at least further plurality of m yarn preferably consists of p number of fibers whereby p is in the range of from 40 to 300, and wherein each fiber has a largest cross sectional diameter in the range of from 0.2 μm to 1.1 μm.
Preferably, the polymeric material each yarn of the first plurality of n yarn and each yarn of the at least further plurality of m yarn is formed selected from the group including Polyethylene Terephthalate, Polyester, Acrylic, Polyolefin, Nylon 6 and Nylon 66 and blends thereof.
Preferably, the polymeric material utilised in the dope dyeing process is of irregular form having a maximum dimension in the range of from 1.5 to 4 mm. The polymeric material may be provided in an irregular form, having dimensions of approximately 3.3 mm×3 mm×2.2 mm.
A master batch pigment is utilised in the dope dyeing process whereby the particle size of the master batch is less than the denier of the fibers from which the yarn is formed.
Preferably, the master batch pigment has a particle size in the range of from 20 nanometers to about 2 microns.
The dope dyeing process preferably includes the introduction of a softening agent, so as to provide a softening effect to the knitted apparel fabric.
Preferably, the dope dyeing process includes the introduction of a dulling agent in the range of approximately 0.4% to 1.5% by weight, so provide a requisite level of dullness to the knitted apparel fabric. Preferably, the dulling agent is TiO2.
The knitting process is preferably a commercial knitting process performed by an automatic knitting machine. Preferably, the knitting process is performed by a circular knitting machine.
Preferably, the first plurality of yarn and the at least a further plurality of yarn have the same number of yarn.
Preferably, wherein each yarn of the first plurality of n yarn has the same denier such that each yarn has a denier of (D1)/n, and wherein each yarn of the at least one further plurality of m yarn has the same denier such that each yarn has a denier of (D2)/m.
Preferably, the first denier (D1) is equal to the further Denier (D2).
Preferably, the first plurality of yarn and the at least one further plurality of yarn are formed from the same polymeric material.
The requisite optical colour and pattern effect may be a solid colour effect. Alternatively, the requisite optical colour and pattern effect is a regular pattern effect or an irregular pattern effect.
The requisite optical colour and pattern effect may be a pattern selected from the group including heather pattern, stripes, jacquard, motifs and the like.
In a second aspect, the present invention provides an apparel fabric formed from the process of the first aspect.
In a third aspect, the present invention provides an article of apparel formed from an apparel material formed from the process of the first aspect.
In a fourth aspect, the present invention provides process of forming a yarn consisting of dope dyed fibers for production of an apparel fabric having a predetermined requisite optical colour and pattern effect and having predetermined physical fabric properties, said process including the steps of:, said process including the steps of:
(i) mixing a master batch dye of a requisite colour with a molten polymeric material so as to form a molten polymeric material of said requisite colour;
(ii) extruding said molten polymeric material through a plurality of spinnerets so as to form a plurality of dope dyed fibers of said requisite colour, wherein said spinnerets having a size of approximately 2 to 3 times the requisite size of the fibers from which a yarn is to be formed; and
(iii) winding a plurality of said fibers so as to form a dope dyed yarn for subsequent forming of an apparel fabric.
Preferably the yarn has a denier is in the range of from 45 denier to 200 denier.
Each yarn preferably consists of a number of fibers in the range of from 40 to 300.
Each fiber of said yarn preferably has a largest cross sectional diameter in the range of from 0.2 μm to 1.1 μm.
Preferably, the polymeric materials is formed from materials from the group including Polyethylene Terephthalate, Polyester, Acrylic, Polyolefin and blends thereof.
The polymeric material utilised for forming the molten polymeric material is preferably provided in an irregular form having a maximum dimension in the range of from 1.5 to 4 mm. Preferably, the polymeric material is provided in an irregular form, having dimensions of approximately 3.3 mm×3 mm×2.2 mm.
The master batch pigment has particle size which is less than the denier of the fibers from which the yarn is formed.
Preferably, the master batch pigment has a particle size in the range of from 20 nanometers to about 2 microns.
The process may further include a step of introducing a softening agent into the molten polymeric material, so as to provide a softening effect to the knitted apparel fabric, prior to extrusion of the molten polymeric material.
The process may further include a step of introducing a dulling agent in the range of approximately 0.4% to 1.5% by weight into the molten polymeric material so provide a requisite level of dullness to the knitted apparel fabric, prior to extrusion of the molten polymeric material. Preferably, the dulling agent is TiO2.
In a fifth aspect, the present invention provides a system for forming a multi-ply apparel fabric having predetermined requisite optical colour and pattern effect and having predetermined physical fabric properties from a plurality of yarn having said requisite optical colour and pattern and being formed from a plurality of polymeric dope dyed fibers, said system comprising:
a knitting assembly for knitting a plurality of yarn so as to form a multi-ply knitted apparel fabric having predetermined requisite optical colour and pattern effect and having predetermined physical fabric properties;
a creel for carrying a plurality of bobbins; and
a plurality of guide members disposed for the guiding n yarn from n bobbins to the knitting assembly for the knitting with m yarn from m bobbins, wherein n and m are integers of two or greater;
wherein upon knitting of said yarn to form a multi-ply apparel fabric, said apparel fabric is formed having predetermined requisite optical colour and pattern effect and having predetermined physical fabric properties effect devoid of optically detectable variants in said requisite optical colour and pattern effect; and.
wherein the yarn of n yarn and the yarn of m yarn are selected so as to provide said predetermined optical colour and pattern effect and said predetermined fabric properties.
Preferably, the system is a commercial automatic knitting machine, and the system is preferably a circular knitting machine.
In order that a more precise understanding of the above-recited invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. The drawings presented herein may not be drawn to scale and any reference to dimensions in the drawings or the following description is specific to the embodiments disclosed.
Any variations of these dimensions that will allow the subject invention to function for its intended purpose are considered to be within the scope of the subject invention. Thus, it is important to understand that these drawings depict only the typical embodiments of the invention and are not therefore to be considered as limiting in scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
The present invention provides a process and system for the production of fibers and yarns for the production of fabrics for use in the commercial implementation within the apparel industry.
The present invention further provides a process for the knitting of such fibers and yarns for the formation of an apparel fabric for use in the commercial implementation within the apparel industry.
The apparel industry demands fabrics to meet requirements such as colour fastness, weight, softness, degree of dullness or shininess, and breathability or wicking, in order that such fabrics are suitable for the formation of apparel.
Further, in order to meet the requisite optical requirements, any such fabric for the use in apparel must be free from optically identifiable defects, such as berre' effect or “weft bars” effect, whereby bands or lines of a different colour can be observed by the naked eye which extend along or across a knitted fabric, which are unacceptable within the apparel industry. Within the field of dyeing and production processes of apparel fabrics, there exist numerous processes for providing coloration to such fabrics including the processes as referred to above in the prior art.
However, such processes exhibit deficiencies and drawbacks when utilized for the preparation of fabrics for apparel, including lack of colorfastness, lack of consistency and repeatability of colour, fading, ultraviolet degradation, cost of manufacture, hostile manufacturing process, excessive consumption of resources such as water, high electricity and power consumption, long processing cycle durations, use of toxic chemicals during processing and potential exposure of such toxic chemicals to persons engaged in manufacturing, excessive waste materials and disposal requirements thereof, and disposal of highly toxic and corrosive byproduct waste materials.
Of paramount importance in the manufacture of apparel, in respect of coloration, are the properties of colorfastness and repeatability and consistency of colour. Fading or change of colour of a apparel reduces the longevity of the apparel, as such effects are considered undesirable to users.
In particular, in commercial applications whereby the longevity of a particular colour is required, such as in work uniforms or sports teams uniforms whereby a particular colour is required and whereby team members are required to have the same coloured uniforms, lack of colorfastness renders an apparel to have a limited term of use. Furthermore, in such cases where a particular colour of a brand or whereby a colour is associated with a uniform, it is important that apparel have consistent coloring and as such, a high-level repeatability of manufacture of colour of materials to be used for apparel is required.
Materials as utilized for the production of apparel fabrics must have inherent physical properties which renders such materials applicable for the formation of apparel, and the specific properties of a fabric from which apparel is formed and the fibers thereof must have appropriate physical properties such as strength, flexibility, sizing such as denier. As such, materials to form apparel fabrics, in addition to colorfastness and repeatability must exhibit appropriate physical properties.
Knitting processes used in the apparel industry, must provide a fabric which is free from optical defects, and be of a consistent colour without variances or defects such as berre' effect or “weft bars” effect.
In order to provide such a fabric suitable for use in the production of apparel which meets the requirements of the apparel industry, the present invention provides the following:
(i) Dope dyed fibers for the formation of yarn for a knitting process which is suitable for use in the production of an apparel fabric; and
(ii) a yarn and a knitting process which provides an apparel fabric which is of a consistent colour and which is free from optically detectable defects such as berre' effect or “weft bars” effect such that the apparel fabric is suitable for use in the production of apparel and satisfies industry expectations of fabrics for such apparel
A dope dyed fiber and yarn for use in the production of apparel fabric in accordance with the present invention exhibits colorfastness and repeatability of colour, as well as obviating deficiencies associated with the prior art including those as recited above, as there are provided fibers and yarn which are coloured during the manufacturing process.
The present invention is realized by the provision of a process and system for the manufacture of an apparel fabric, whereby the apparel fabric is formed from dope dyed coloured fibers which have suitable physical and sizing parameters and properties, which are used to form an apparel fabric of a requisite colour for use in apparel.
Accordingly, and in accordance with the present invention, there is provided a process and system for the manufacture of apparel fabrics, whereby colored fibers are produced having a suitable size and material properties for use in production of apparel fabrics.
In order to provide such a suitable fabric for use as an apparel, the present invention provides a process and system, whereby the fibers from which a yarn is formed are formed having a requisite colour, prior to the formation of the yarn from which the apparel fabric is formed and prior to formation of the apparel fabric, which is in contrast to the prior art whereby fiber and/or yarn and/or fabric for apparel fabric are dyed after the fiber and/or yarn and/or fabric is formed.
By providing fibers which are dyed during the manufacture of the fibers, the fibers are formed so as to have a requisite colour during the manufacturing process, the fibers are provided with a uniform colour through the thickness of the fiber. This provides monofilaments with excellent colour fastness, and resistant to fading due to ultraviolet (“UV”) effects.
Furthermore and importantly, by using such a fiber for formation of a yarn for the preparation of apparel fabrics, ease of reproducibility of colour is achievable between batches.
In accordance with the present invention, so as to provide such a coloured fiber, a dope dyeing process is utilized so as to provide coloured fibers that are suitably sized for the preparation for apparel fabrics.
In order to utilise a dope dyeing process to provide a dope dyed apparel fabric, the present inventors have implemented a process whereby:
(i) Novel fibers having a denier as fine as in the range of from 0.4 to 2.2 denier are produced for use in the production of a yarn suitable for use, in accordance with the present invention, in the formation of an apparel fabric.
In accordance with the present invention, typical ranges of denier and diameter of fibers as utilized in the present invention are shown below, as well as the denier of yarn incorporating such fibers.
Unless a mono fiber is formed from a dope dyeing process according to the present invention having one single thread is utilized in a knitting process, yarns are formed from multiple fibers for the subsequent knitting thereof to form an apparel fabric.
By way of example, yarns having a Denier “D” and “f” number of fibers applicable for use in the present invention are as follows:
(ii) Coloration is provided during the dope dyeing process whereby a master batch pigment is utilised, whereby the particle size is appropriately sized for forming fibers of such a fine denier, where the master batch pigment being in the nanometer range of as low as 20 nanaometers, and as high as the micrometer range where applicable such as 1 micron for yellow colour dyes and 2 microns for turquoise colour dyes. Typically, particle size is less than the denier of the fiber from which the yarn is formed, for example wherein the size of the master batch is about 0.06 microns.
(iii) A polymeric material applicable for forming the apparel fabric is utilized.
In accordance with the present invention, synthetic materials that are suitable for use for the formation of coloured fibers include polymeric materials such as nylon, polyester, acrylic and polyolefin and blends thereof.
In order to further utilise a dope dyeing process to provide a dope dyed apparel fabric, the present inventors have identified that perceived optical colour variance of an apparel fabric is caused by barre' effect or “weft bars” effect, whereby optically there exists an optical variation of colour of the fabric, which is typically a banding effect, which may result in a fabric being unsuitable for use in the apparel industry due to market rejection of such materials in view of uniformity of colour, whereby colour uniformity is inherently a requirement for apparel fabrics.
Furthermore, the present inventors have identified parameters which are influential in causing any such barre' effect or “weft bars” effect, and still further the present inventors have identified a process which can substantially mitigate or alleviate such barre' effect or “weft bars” effect, such that a dope dyed fabric is produced which is an apparel fabric meeting the industrial and commercial requirements of a fabric for the apparel industry, as well as providing the above and below mentioned advantages as afforded by the production of dope dyed fibers and a fabric formed from yarn comprising of such dope dyed fibers.
Accordingly, the present invention provides a process and system for producing an apparel fabric formed from a yarn comprised of dope dyed fibers, which is suitable for the production of apparel.
Example of Dope Dyeing Process and System of Invention
Referring to
Step 1—Blending
A master batch pigment 110 is provided, having a particle size less than the denier of the fibers from which the yarn is formed. A polymeric material 120 from which the fibers are to be formed, for example Polyethylene Terephthalate (“PET”) for the formation of a nylon fiber, is provided in a chip form. Such chips as used are typically sized having a maximum dimension in the range of from 2 mm to 3 mm, and are provided in an irregular form, having dimensions such as 3.3 mm×3 mm×2.2 mm. In accordance with the present invention, a dope dyeing process has been utilized with a master batch pigment 110 of particle size in the range of 20 nanometres to 4 microns such that fibers/filaments having a size range of 0.4 to 2.2 denier can be produced, so as to be applicable for the production of a fabric having properties suitable for use for the manufacture of apparel. A maximum dye content of 4.2% by weight is typically introduced for use in the present invention.
A blending device 130 is provided for providing a blending step, which blends the master batch pigment 110 with the polymeric material 120 therein until a suitably blended mixture is provided.
Additives can also be introduced at this step, such as introduction of a softening agent.
Also, in order to provide a fiber for the formation of a yarn for the production of an apparel fabric having an appropriate luster, a dulling agent can be introduced into the mixture of the pigment and the PET chip, such as TiO2. By way of example, approximately 0.6% by weight TiO2 can be introduced so as provide a semi-dullness apparel fabric, and approximately 1.2% by weight TiO2 can be introduced so as to provide a full-dullness apparel fabric.
The mixing step is typically carried out at room temperature, or ambient temperature of the location in which the mixing is conducted.
Step 2—Melting
Following the mixing step 1, a melting step 2 is carried out which provides for the melting of the blend of master batch pigment 110 and the polymeric material 120 and the abovementioned additives, at a temperature of approximately 280 to 290 degree Celsius inside a reaction chamber 140, such that the polymeric material 120, which is then coloured due to the master batch pigment 110, is in a suitably melted and viscous form.
Some agitation by way of mechanical means, such as a stirring mechanism, is preferably utlised to provide for additional equal distribution and mixing, so as to result in an evenly coloured viscous material.
Step 3—Cooling
A cooling step is then provided, whereby the molten mixture is cooled to approximately 160 degrees Celsius, such that the mixture remains in a viscous state.
Step 4—Extrusion
Following the cooling step, the viscous material is then extruded through a plurality of spinnerets, which are of a plurality of apertures, whereby the spinnerets have a size approximately 2 to 3 times the requisite size of the fibers.
Examples of sizes of fibers applicable to the present invention are recited above in Table 1.
In accordance with the present invention, to ensure that the apparel fabric has suitable breathability by way of wicking effect, the spinnerets are provided with a cross-sectional geometry such that longitudinal recesses or rebates are formed along the length of the extruded fiber. An example of such a suitable cross-sectional geometry is shown in
With reference to
In the present example, the fiber 200 has a cross-sectional geometry having 4 lobes 210. As is depicted, the lobes 210 form between an adjacent lobe recesses or rebates 220. As will be understood and appreciated by those skilled in the art, when a plurality of fibers 200 are wound so as to form a yarn as described with reference to Step 5 below, the rebates cause interstices or vacancies to be formed within the yarn, which provides breathability by way of wicking effect for an article of apparel knitted from such yarn.
Step 5—Winding
In order to provide the requisite yarn for subsequent knitting to form an apparel fabric, the extruded fibers are wound onto a plurality of bobbins 150, whereby a number of fibers are wound onto each bobbin so as to form a yarn.
Examples of the number of fibers wound onto a bobbin to form a requisite yarn in accordance with the present invention are shown in Table 2 above. A typical number of fibers that are used in accordance with the present invention to form one yarn is 72 fibers.
During the winding process, the fibers forming the yarns are interlaced together, typically by localised fusion providing a cross-connection between fibers, which maintains the fibers together as a yarn and prevents the yarn from falling apart.
During the winding process, the fibers are cooled to approximately 140 degree Celsius to 150 degrees Celsius.
The wound yarn is a Pre-Oriented Yarn (“POY”) and at this stage in the process is not suitable for forming an apparel fabric by way of knitting.
Depending upon the type of yarn to be utilised, the yarn is then processed to form a (A) filament yarn or (B) a staple yarn by subsequent processing.
(A) Filament Yarn
In order to provide a filament yarn, a drawing step 160 is subsequently provided after Step 5 above, whereby the yarn is drawn which regulates the size or denier of the yarn. Included in the drawing step is a texturizing process, so as to provide characteristics to the yarn and rendering it suitable for apparel fabric formation, whereby the following attributes are imparted to the yarn:
(i) Functionality;
(ii) Optical impression as being a yarn for fabric production; and
(iii) Feel or tactile attributes, rending the yarn to have the suitable tactile attributes such that when knitted into an apparel fabric the fabric meets the requisite texture as appropriate for the apparel industry.
During the texturing process, the yarn may be treated so as to be, for example, Drawn Textured Yarn (“DTY”) or Air Textured Yarn (“ATY”).
In accordance with embodiments of the present invention, the yarn is preferably Drawn Textured Yarn, and including a “False Twist” by techniques as known in the art, so as to impart an elastic attribute to the yarn as a crinkle, as is known by those skilled in the art. In such a process, as is known by those skilled in the art, by the use, by way of example, of friction disks and heat setting.
Accordingly, the three above attributes at (i), (ii) and (iii) are imparted to the yarn, rendering it suitable for knitting of apparel fabric, which is wound onto a spindle 170.
After such processing of the yarn, an apparel fabric may be formed by way of a knitting process.
(B) Staple Yarn Formation
When a staple yarn is required, the POY yarn is cut into lengths, for example 2.5 cm in length, by a cutting process 180, and a spinning process 190, such as used in cotton spinning, is utilised.
A yarn having a high Turns Per Inch (“TPI”) can be formed by processes as known by those skilled in the art, with a high twist, in order to provide a yarn with the requisite properties suitable for the formation of an apparel fabric.
It is noted that whilst dope dyeing processes have been used for the production of large coloured fibers formed from materials such as acrylic, nylon/polyamide and polyester for other technical fields, such use is limited to the production of fibers for use for forming industrial products such as nylon or synthetic rope, fishing and safety nets and the like, with limited colours such as navy, red and black.
However, the fibers produced in such industries are not suitable for use in the apparel fabric technical field, due to the fibers having a cross section or denier excessively large so as to render the fibers non-applicable for use in the production of apparel fabrics.
Furthermore, the particle size of pigments utilized in dope dyeing processes according to the prior art cannot be used for the production of fibers suitably sized for the production of apparel fabrics which provide requisite colorfastness and repeatability of colour between batches.
Still further, such yarn of the prior art are also not suitable for the formation of apparel fabric due to such yarn not having the requisite breathability, texture, elastic properties or optical properties.
Example of Dope Dyeing Process of the Present Invention
By way of example, a general comparison between a traditional high temperature polyester dyeing process and dope dyed polyester process in accordance with the present invention is described.
Referring to Table 3, the parameters of a traditional high temperature polyester dyeing process and a dope dyeing process are shown.
By way of background, a traditional high temperature polyester dyeing process is described by referring to Table 3 below, the process and parameters of, whereby the dyestuffs that apply is disperse dye and the colour depth is a medium colour.
In this example, a 1000 kg batch under liquor to goods (i.e. fabric) ratio at 1:8 dark colour by use of a 4 tube high temperature dyeing machine with each tube having a loading at about 250 kg, is used.
A summary of parameters of the processes utilized for the two processes are shown in Table 3, whereby the work flow steps are as follows, showing step durations, chemicals used and amounts, temperatures and volumes of water:
1. A Pre-treatment process is applied for the removal of knitting oil and dirt during knitting process, as is represented by 1st bath,
2. A dyeing is applied, which is a colouring process to apply pre disperse, that is dissolved disperse dye with a pH and temperature dyeing curve as is represented by the 2nd bath,
3. A wash off process is subsequently applied, as is represented by the 3rd and 4th baths,
4. Reduction clearing is subsequently utilised so as to remove the unfixed dye under a reduction condition under a strong alkali bath, as represented by the 5th bath,
5. A Wash off process is subsequently applied as is represented by the 6th & 7th baths,
6. A neutralization step is subsequently utilised, including the application of acid to remove the strong alkali so as to provide a skin friendly pH, as represented by the 8th bath, and
7. A softening step is subsequently applied, whereby a softener is applied, as represented by the 9th bath.
Further referring to Table 3, the steps of a dope dyeing process and process parameters are shown for a dope dyed polyester, with the workflow and steps as follows:
1. a rinsing step is utilised, as represented by the 1st bath, whereby a rinsing step is applied, and
2. following the rinsing step, a softening step is applied as represented by the 2nd bath.
As will be noted, by comparison, the traditional high temperature polyester dyeing process utilizes 9 bath steps in comparison with the processing of a dope dyed material having just 2 steps, and uses significantly more water at higher temperatures.
With reference to Table 4 below, a parametric comparison between a traditional high temperature polyester dyeing process and the dope dyed process is provided as follows:
By way of example, for a factory producing 36 million articles of apparel per year, utilizing the present invention for the colouring of apparel in comparison to the typical high temperature polyester dyeing as utilized presently in the art, the following environmental and economic advantages are provided:
(i) A water saving of approximately 504,000,000 litres per year is provided, on the basis of 9 million kgs of fabric at 56 litres of water per kg of fabric;
(ii) A reduction of electricity consumption by 1,512,000 kW per year, at 168 kW per tonne×9,000 tonnes
(iii) A reduction of energy consumption due steam by 45.75 billion kJ, total 5,082,880 KJ per tonne×9,000 tonnes
(iv) Zero discharge of chemicals, as with the present invention, the only chemicals used are a softener and a detergent, and the present invention provides no toxic sludge and no chemicals are released into the environment.
Advantages of Dope Dyeing Process of the Present Invention
As is demonstrated by Table 3 and Table 4 and as discussed above, the process and system according to the present invention, provides significant advantages over the process of the prior art.
Such advantages include:
(a) Colorfastness, Stability and Reproducibility
Provides a fiber with high colorfastness suitable for use in textile fabric
Provides a fiber which has high colour stability, and resistance to UV degradation, suitable for use in textile fabric
Provides a process for providing a fiber suitable for use in textile fabric, whereby reproducibility of fiber colour is readily repeatable between manufacturing batches.
(b) Cost saving/Economic advantages:
Significant reduction in water consumption
Significant reduction in electricity consumption as consumed by prior art for pump, winches and the like, as well as reduced cycle time requiring less electricity
Significant energy consumption reduction due to lower thermal requirements and less steam required.
(c) Environmental Advantages:
Due to less number of cycles and elevated temperatures, and the obviation of a high dyeing temperature cycle and the reduction of clearance cycle, significantly reduced thermal loading is transferred to the environment from the system of the present invention.
Obviation of toxic waste and the release of such waste into the environment
(d) OHS (Occupational Health and Safety) attributes:
No usage of toxic chemicals, and hence less likelihood of exposure of toxic chemicals to production workers and the environment
Lower ambient temperatures in the workplace, providing preferable work conditions
Formation and Production of Knitted Apparel Fabric According to the Present Invention
As mentioned above, in addition to the breathability, texture and elastic properties as required of an apparel fabric, it is necessary that any such apparel fabric is free of any optical defects.
Such common optical defects are barre' effect or “weft bars” effect which may be introduced during the knitting process for the forming of a fabric from dope dyed yarn as provided by the present invention, so as to provide uniformity of colour for apparel fabrics for the apparel industry.
There exist several causes of the berre' effect within the fabric industry, which include:
(i) Periodic count variation in the weft yarn arising out of roller eccentricity or mechanical defects in the spinning preparatory processes.
(ii) Mixing of weft of different counts, different twist levels, different directions of doubling twist and different brightness levels especially in filaments.
(iii) Mixing of spun blended yarns produced from synthetic fibers of different merge numbers.
(iv) Manufacturing defect in filaments such as variation in denier.
(v) count difference in weft,
(vi) excessive tension in the weft feed package, especially in filaments,
(vii) variability in pick density and difference in twist,
(viii) colour or shade of adjacent group of picks,
(ix) difference in blend composition or in the cottons used.
It has been found that a knitted fabric utlising yarn as described above, in accordance with the present invention, has the presence of berre' effect.
One manner in which the berre' effect of knitted fabrics can be somewhat mitigated, is by providing a colour assessment process and knitting adjustment process. As is known by those in the art, an industrial knitting process comprises the interlacing of a plurality of yarns being introduced by a corresponding plurality of bobbins about which the yarns are wound. Various arrangements are used in the fabric industry, for example 102 or 114 bobbins, which carry the corresponding yarn to be knitted.
In order to assess the colour, a knitted sample is formed from each bobbin, and the colour parameters of the knitted fabric is then assessed, after which depending upon the colour assessment, a designated positon on the creel is assigned for a particular bobbin, which may be used to mask or overcome berre' or weft bar effect of a resultant knitted fabric caused by small alteration in denier of fibers and other contributing factors including those as recited above.
In such a technique of the prior art, there exist several colour parameters which may be assessed, and these may be either effected by eye, or by electronic image capture and subsequent computer analysis. Such parameters in clue darkness/lightness, hue, chroma or the like.
According to the prior art, the following process can be used:
a tubular knit down in the form of a tubular sock type article, whereby the sock is made to a predetermined diameter for each bobbin,
(ii) a testing panel of a predetermined size is inserted within the sock and the sock stretched thereover,
(iii) the colour parameters of the sock are assessed, whereby the colour parameters are assessed over a predetermined gauge length, and
(iv) depending upon the assessed colour properties, a bobbin is placed at a location on the creel of the knitting machine system in order to reduce the berre' effect.
For example, for a tubular sample stretched over a testing panel, the panel is of a requisite colour, such as a dark colour or white colour, depending upon the colour of the fabric being assessed. An optical assessment may be made, for example if the knitted fabric is “dark” or “light”, and a bobbin's position in a creel selected and altered accordingly.
In order to mask the berre' effect, various relocation assessments may be made and bobbins relocated, for example as a dark/light/dark light rearrangement criteria, or a dark/dark/light/light rearrangement criteria, or a dark/dark/light/dark/dark/light criteria.
However, whilst such a technique goes some way in reducing berre' effect, the present inventors have found that for knitted apparel fabric formed from dope dyed yarn according to the present invention, the berre' effect can only be sufficiently reduced by approximately 60% to 70% of the time.
The above technique takes approximately half a day to assess the yarn from the bobbins and provide an arrangement of the bobbins on the creel with a view to overcoming any berre' effect. However, due to the success rate of approximately 60% to 70%, once a knit down process has commenced and after which if the berre' effect present is detected, this will have a very large detrimental effect in that large runs of knitted fabric need to be disposed of if the berre' effect is indeed present.
Unlike non-dope dyed fabric of the prior art which can be somewhat reprocessed if a berre' effect is found, dope dyed knitted fabric can only be disposed of.
Accordingly, within the apparel fabric knitting process, for dope dyed yarn, the following detrimental and prohibitive attributes exist within the prior art:
(i) excessive set-up times for initial bobbin adjustment;
(ii) possible further adjustment and relocation of bobbins may be required after production has commenced;
(iii) particularly skilled and trained persons are required to effect such a bobbin relocation technique;
(iv) there exists inconsistency in such a technique due to human determination of bobbin placement based on experience where human assessment does affect repeatability;
(v) if berre' effect occurs during a production run, it is required that such skilled persons be present to effect remedial action, which is not always possible in the apparel industry as knit down runs often are effected 24 hours per day, and appropriately skilled staff are not always on-site on standby 24 hours per day;
(vi) using such a technique, which is reliant on human judgement, between manufacturing runs of knitting of apparel fabric, there may be inconsistency between runs depending upon the consistency of a person or between different persons;
(vii) other parameters such as yarn tension can also influence berre' effect, and as such, between different knitting machines, there can be different requirements in set-up and location of bobbins;
(viii) parameters outside the control of knitting machine operators can affect the results of reduction of berre' effect, and further result in unexpected berre' effect which can be difficult to correct;
(ix) the down time during initial set-up of bobbins to reduce berre' effect, as well as interruption of knitting to correct berre' effect, causes significant operational costs; and
(x) as dope dyed knitted fabric having berre' effect cannot be corrected, significant financial loss is incurred due to disposal of unusable fabric as well as disposal costs.
As is understood by those skilled in the art, any apparel fabric having berre' effect is unacceptable and will be immediately rejected by the apparel industry and the market.
It should be noted and as known and understood by those skilled in the art, it is not commercially viable or acceptable in the apparel industry to utilise a fabric which has a success rate of only 60% to 70% satisfying industry requirements, as the cost of loss and delay makes any such process not economically viable within the apparel industry.
Accordingly, although a dope dyed fabric has the above product, commercial, environmental, occupational health and safety, and manufacturing cost advantages, such a fabric having berre' effect, which cannot be obviated, cannot be commercially implemented.
Accordingly, the present inventors have provided a solution to obviate the presence or occurrence of berre' effect of knitted dope dyed fabrics which overcomes the above recited disadvantages, whilst still providing all product, commercial, environmental, occupational health and safety, and manufacturing cost advantages.
As such, the present inventors have overcome all deficiencies and impediments of fabrics and manufacturing techniques of the prior art, so as to provide a commercially viable and effective dope dyed apparel fabric which is acceptable by the apparel industry.
In order to provide such an apparel fabric which does not exhibit the berre' effect, the present invention provides a process as follows:
(i) the appropriate apparel requisite yarn denier for an apparel article is determined, which is the denier of the requisite yarn from which the fabric is knitted,
(ii) the requisite yarn denier is divided by an integer of two or greater,
(iii) a multi-ply yarn for knitting is provided by two or more yarn, whereby the denier of each yarn of the multi-ply yarn collectively provide the requisite yarn denier for the knitting process, and
(iv) knitting is performed using such multi-ply yarns.
For example, if the total denier of the yarn for a fabric is to be 150 denier, dividing 150 denier by two dictates that two yarn each of 75 denier are to be used as a “multi-ply” yarn. Alternatively and for example, if a 150 denier yarn is required for the fabric, then three yarn each of 50 denier may be used to form such a “multi-ply” yarn.
It has been found and demonstrated by the present inventors that the above process consistently provides an apparel fabric devoid of berre' effect, and which consistently provides an apparel fabric acceptable to the market in the apparel industry.
The above process has the advantages over the above-described berre' effect reduction technique of the prior art, including:
(i) 100% delivery of apparel fabric devoid of berre' effect;
(ii) no necessity for special pre-production colour assessment runs and analysis;
(iii) no necessity for specially trained technicians;
(iv) no inconsistency due to human error or human subjectivity;
(v) no exposure to large amounts of down time;
(vi) no large and excessive fabric loss costs, loss in production time, and costs for disposal; and
(vii) no reliance on arbitrary adjustment, or machine idiosyncrasies, or knitting machine parameter fluctuation.
Referring to
Whilst not depicted in the present diagram, those skilled in the art are aware that the plurality of bobbins can be circumferentially displaced in a circular type knitting machine 300 as depicted in the present example. In other and alternate knitting machine arrangements, the bobbins need not necessarily be circumferentially disposed, but may have the yarn guided to the knitting machine so as to be introduced at appropriate locations for the knitting thereof by a knitting machine, for the generation of a knitted fabric. Accordingly, no physical limitations are to be inferred by the use of the diagram of
As will also be appreciated by those skilled in the art, there exist numerous manners in which the various integers of knitting machines may be implemented for the knitting and subsequent winding of a knitted fabric, and that the schematic representation of
As will be seen from
Referring to
Referring to
With reference to
As described above, the berre' effect cannot be mitigated so as to meet the optical requirements of an apparel fabric formed from dope dyed yarn by processes or techniques of the prior art such as when using a system and arrangement as described in reference to
The present invention provides a knitting machine and process which allows for multi-ply yarn to be knitted so as to form a multi-ply knitted apparel fabric, such that no visually detectable berre' effect within the apparel is present.
In order to provide such a multi-ply yarn, the present inventors have found and proven that the knitting by the knitting assembly of a knitting machine, whereby multi-ply yarn is fed or delivered to the knitting assembly, provides such a kitted berre' effect free fabric suitable for the apparel industry.
As shown in the example of
In the present example, a plurality of guides or eyelets 375d is provided after the tensioners 370d and as such, multi-ply dope dyed yarn is fed to the knitting assembly such that the knitted fabric is a multi-ply dope dyed fabric.
Also, as mentioned above, if the total denier of the yarn for a fabric is to be 150 denier, dividing 150 denier by two dictates that two yarn each of 75 denier are to be used as a “multi-ply” yarn. Alternatively and for example, if a 150 denier yarn is required for the fabric, then three yarn each of 50 denier may be used to form such a “multi-ply” yarn.
In the present example, a two-ply yarn is utilised and as such, one guide or eyelet 375d is provided between a pair of adjacent tensioners 375d. Each bobbin 310d carries thereon a yarn 320d having half the denier of the requisite denier from which the fabric is to be formed, and yarn 320d from two tensioners is fed through each guide or eyelet 375d such that two yarn 320d each of half the requisite denier is received by each guide or eyelet 375d such that a multi-ply yarn, in this case a two-ply yarn 325d, is fed to the knitting assembly.
As will be appreciated by those skilled in the art, the above described example is one manner in which a multi-ply yarn may be provided to the knitting assembly, and numerous alternate or other embodiments which provide the same technical effect are considered to fall within the scope of the invention.
Whilst the present invention has been described above in examples as being implemented in a solid colour fabric formed from one polymeric material fabric is to have, those skilled in the art will appreciate and understand that in such an example, the colour of the fibers as extruded during the dope dyeing process may not necessarily be identical to the fabric as formed. As will be understood, the fabric will have a requisite or predetermined optical colour and pattern effect and predetermined physical fabric properties, and the colour of the yarn and fibers from which the yarn is formed is determined based on the desired predetermined optical colour effect of the fabric. As will also be appreciated, parameters such as dullness of the yarn and the manner in which the knitting is performed, also have influence on the optical colour and pattern effect and predetermined physical fabric properties of the fabric.
As will be understood by those skilled in the art, although various parameters determined the ultimate physical properties of a knitted fabric including density in knitting which is denoted in number of ends/picks per inch, the denier of the yarn is a predominant parameter influencing the density of the knitted fabric.
In other embodiments, the total denier of each multi-ply yarn need not necessarily be the same as each other, and using such different denier multi-ply yarn typically gives rise to a regular knit having a rugged surface. In such an embodiment, whereby thick and thin yarn are used, a jacquard knit may be produced.
Also, as will be appreciated by those skilled in the art, in other or alternate embodiments, the denier of the yarns forming a multi-ply yarn for knitting in the present invention need not necessarily be equal. For example, in embodiments as described above, 2 yarn each of 75 denier are used to form a multi-ply yarn for the knitting with another multiply yarn. However, in other embodiments, whereby the requisite denier of multi-ply yarn is 150 denier, the individual yarn may be for example 40 denier, 50 denier and 60 denier, without departing from the scope of the present invention.
Furthermore, although within the above embodiments the yarn are formed from the same material polymeric material, as will be appreciated and understood by those skilled in the art, one multi-ply yarn of one polymeric material may be knitted with another multi-ply yarn of a different polymeric material. In such a case, bobbins may carry yarn formed from different polymeric materials may be utilised. For example, a jacquared knit may be provided.
Also as will be understood, the yarn forming each multi-ply yarn for subsequent knitting need not necessarily be formed from the same polymeric material as the other yarn, and need not necessarily be formed of the same colour as the other yarn.
Still further, as will be appreciated by those skilled in the art, in other or alternate embodiments, the multi-ply yarn may have a different colour to that of another multi-ply yarn which it will be knitted with, so as to provide regular pattern effects, such as heather, stripes, motifs and the like.
Accordingly and as will be appreciated, the present invention is not limited to solid colour knits, and different bobbins may carry yarn of different colours. Further, the denier of one multi-ply yarn need to be the same as another multi-ply yarn which it is knitted with, and need not necessarily be of the same colour or polymeric material. Still further, the individual yarn which form each multi-ply yarn need not all necessarily have the same denier, and in some alternate embodiments need not necessarily be formed from the same colour or polymeric material.
The present invention, by implementation of a multi-ply knitting process utilising yarn formed from dope dyed fibers, obviates the commercially prohibitive berre' effect, which is demonstrated and described with reference to
Referring to
An enlarged photographic representation of the berre' effect of
Whilst techniques of the prior art as described above in reference to the manner in which the berre' effect can be reduced have been diligently pursued by the present inventors, it was not possible to repeatedly eliminate the presence of the berre' effect, and removal of the berre' effect could only be achieved 60% to 70% of the time, which as described above inherently precludes such a process and fabric material from applicability to the apparel industry.
By contrast and as shown and described in reference to
The present invention is shown and proven to obviate the berre' effect and referring to
As is clearly evident, there is no optically identifiable berre' effect present in the apparel article 400c, and the apparel fabric from which the apparel article 400c is formed satisfies the apparel industry requirements as recited above and below. A comparative scale of 40 mm is shown, evidencing no berre' effect within such a period.
An enlarged photographic representation of
As is shown, there exist no optically identifiable or discernable berre' effect in the apparel article 400c or 400d as a result of the implementation of multi-ply dope dyed yarn of the present invention, and any optically observable berre' effect has been obviated, resulting in a dope dyed knitted fabric suitable for the apparel industry.
The present inventors, through diligent and repeated trials and analysis, have found and proven that the implementation of multi-ply dope dyed yarn of the present invention in a knitting process and system according to the present invention, obviates the necessity of techniques of the prior art as described for reduction of berre' effect, and can provide an apparel fabric suitable for the apparel industry and meet such repeatability requirements as recited above.
As will be understood, whilst the optical assessment and obviation of berre' effect as described above is demonstrative that a dope dyed yarn formed from the dope dyeing process according to the present invention may be utilised for knitted fabrics satisfying the stringent requirements of the apparel industry, other manners in which the obviation of the berre' effect which have been identified by the present inventors to be caused by fluctuation of fiber and yarn denier and other above recited parameters are equally as applicable to the present invention and fall within the scope thereof.
The present invention provides a dope dyed fabric suitable for the apparel industry, which provides advantages over the prior art including:
(i) Colorfastness, stability and reproducibility,
(ii) Cost saving/economic advantages,
(iii) Environmental advantages, and
(iv) OHS (Occupational Health and Safety) attributes.
By implementation of a process for preparation of novel and suitably sized fibers for producing yarns applicable to the performance requirements of an apparel fabric, and utilization of a dope dyed process incorporating suitably and sufficiently small particular size master batch pigment particulates, a novel apparel fabric is provided by the present invention.
Further, by the identification of parameters causing optical defects unsuitable for apparel fabrics and determination of a process which obviates such optical defects by using a multi-ply dope dyed yarn, the present invention has provided an apparel fabric which has both functional and visual characteristics so as to render the novel fabric suitable to the apparel industry.
In view of the global demand for fabrics suitable for the apparel industry, the present invention by overcoming deficiencies of the prior art and providing advantages including those as recited above, provides a useful technical solution to such deficiencies.
Definitions
Apparel fabric is defined as fabric for the manufacture of apparel, whereby apparel include clothing and garments for the at least partial covering of the body of a person, and articles of apparel include fashion, non-fashion and sportswear such shirts, t-shirts, tops, singlets, jerseys, dresses, skirts, shorts, trousers, undergarments, coats, jackets, scarves, shawls, swimwear and the like.
Apparel industry is defined as the industry of apparel, including the manufacture of yarn for the formation of apparel fabric, the manufacture of items from apparel fabric, the wholesaling of items of apparel, the retain of items of apparel, supply of items of apparel, and all intermediate steps there between.
Apparel industry requirements are defined as strict, uncompromising and unforgiving in standards in quality, reproducibility, efficiency and cost, and items of apparel and manufactures and suppliers thereof who cannot consistently meet the Apparel Industry standards will either not be able to enter the industry or sustain a commercial position in the industry.
Cellulosic Fiber
Cellulose is a fibrous material of plant origin and the basis of all and man-made cellulosic fibers. The natural cellulosic fibers include cotton, flax, hemp, jute, and ramie. Cellulose is a polymeric sugar polysaccharide made up of repeating 1-4-8 hydro glucose units connected to each other 8 ether linkage.
Colorfastness
It is the term used in the dyeing of textile materials, meaning resistance of the color to fading or running.
Denier
Unit to define yarn thickness, it is defined as the mass in grams per 9,000 meters.
Disperse Dye
Water insoluble dyes that are engineered to color polyester under high temperature to allow dye penetration into the fiber.
Dope Dye
The mass coloration of synthetic fiber by mixing the master batch pigments with the synthetic material through spinnerets into air and water, forming a colored thread.
Foam Dye
The application by transporting the dyestuffs through foam instead of water. This application is particularly interested in pile fabric and bulky fabric, for example, carpet.
Lab Dips
The color formulation under a small scale to optimize colorants mixing percentage and condition that use as a reference to carry bulk dyeing.
Master Batch
A solid or liquid additives for coloring plastics, which allows a processor to colour raw polymer economically during the plastic manufacturing process. For polyester dope dyed, master batch is mixed with polyester chip and melt spun to provide the colour yarn.
Micro Fiber
The term to define synthetic fiber thickness, it is agreed in the market that yarn thickness that is finer than or equivalent to one denier or decitex per thread is termed as micro fiber.
Microns
The unit to express size of a tiny object, one micron is equivalent to 10−6 meter.
Oligomer
The short chain polymer that decomposes under chemical or temperature from chain breakage.
Polyester
A type of synthetic fiber that was obtained by reaction of dicarboxlic acids with dihydric alcohols commonly abbreviated PET, PETE with full name Polyethylene terephthalate. It entered the market in 1950′ from its outstanding winkle free performance. Dupont market their polyester fiber under the trademark Dacron and Terylene.
Synthetic Fiber
They are created by extruding fiber forming materials through spinnerets into air and water, forming a thread. Synthetic fibers are made from synthesized polymers or small molecules such as petroleum based chemicals or petrochemicals. These materials are polymerized into long, linear chemicals that bonds adjacent carbon atoms. Differing chemical compounds will be used to produce different types of fiber. Synthetic fibers account for about half of all fiber usage, with application in every field of fiber and textile technology. Although many classes of fibers base on synthetic polymers have been evaluated as potentially valuable commercial products, four of them—nylon, polyester, acrylic and polyolefin—dominate the market. These four products account for approximately 98 percent by volume of synthetic fiber production, with polyester alone accounting 60 percent.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2016/105753 | 11/14/2016 | WO | 00 |
