Patent Application
20130059495
The disclosure related to durable fabrics which are resistant to tearing and abrasion, which include synthetic yarns including a bulked and entangled yarn.
Polymer filaments, such as polyamide, polyolefin and polyester, are useful for a variety of textile products. When these filaments are textured and/or have a high tenacity/tensile strength, they are especially useful where durable yarns are needed. Examples of such products are useful for performance outdoor wear; contract, automotive/transportation and home upholstery; military apparel and gear; denim and sweaters; activewear; outdoor gear; backpacks; luggage; and footwear, among others.
These yarns are typically made through the process of air-jet texturing. The air-jet texturing process can provide both bulk and/or texture to the yarn in addition to entangling the yarn which provides a yarn that is capable of being incorporated into a fabric. However, this equipment required for this process and conducting this process can be cost-prohibitive.
Multiple filament polymer yarns can also be prepared as bulked continuous filaments. However, without further treatment, these filaments do not form an integrated yarn that can be knit or woven into a fabric.
One aspect provides an article including a yarn; where the yarn includes:
(a) a plurality of bulked continuous filaments;
(b) a denier of about 200 to about 2000, including about 300 to about 1200;
(c) a denier per filament of about 1 to 20, including about 1 to about 8; and including about 3 to about 6;
(d) a tenacity of about 2.0 to about 7.0 grams per denier, including about 4.0 to about 6.0;
where the yarn is interlaced.
In order to provide yarns with the tenacity required for durable fabrics, the yarn preparation includes specific drawing conditions, which increase the tenacity of the yarns. One suitable method for preparing the yarns includes:
(a) spinning a synthetic yarn;
(b) drawing the yarn;
(c) bulking the yarn in the absence of air jet texturing; and
(d) interlacing the yarn; and
(e) winding the yarn onto a package.
The method may be a coupled or in-line process which excludes the need for separately spinning the yarn and then subsequently providing the texturing or bulk to the yarn. Subsequent to the bulking of the yarn, which occurs in the absence of air jet texturing, the yarn is interlaced. By interlacing the yarn, the multiple filaments form an integrated yarn, which may be subsequently knit or woven into a fabric. The interlacing process also provides the yarn with a means for maintaining the bulk of the yarn, which may otherwise be removed under the tension of knitting or weaving processes.
Another aspect provides an article including the bulked and interlaced yarn. The article may also include a fabric prepared from the bulked and interlaced yarn. The bulked and interlaced yarn includes:
(a) a plurality of bulked continuous filaments;
(b) a denier of about 200 to about 2000;
(c) a denier per filament of about 1.0 to 8.0, and
(d) a tenacity of about 2.0 to about 7.0 grams per denier;
where the yarn is interlaced.
Another aspect provides an article including a fabric which is knit or woven from a bulked and interlaced polymer yarn. The yarn includes polyamide, such as nylon 6 or nylon 6,6, having a plurality of bulked continuous filaments. The yarn has a denier of about 200 to about 2000; including a denier of about 200 to about 1500 or about 500 to about 1500 or about 900 to about 1000; a denier per filament (dpf) of about 1 to 20, including about 1 to about 8, or including about 3 to about 6 and a tenacity of about 2.0 to about 7.0 grams per denier. The number of filaments may also vary such as about 50 to about 1000 filaments. This includes about 100 to about 500 filaments or about 140 to about 350 filaments or about 140 to 280 filaments.
For the purpose of this disclosure, the term “air jet texturing” is meant to include a method of providing texture to a yarn, where a yarn is led through the turbulent region of an air jet at a rate faster than it is drawn off on the far side of the jet. In the jet, the yarn structure is opened, loops are formed, and the structure is closed again. Some loops are locked inside and others are locked on the surface of the yarn. The yarn made by this process is characterized by its bulkiness and the presence of a multitude of filament loops irregularly spaced along the length of the yarn.
For the purposes of this invention, “a method of providing texture” means a process of introducing fine distortions along the length of a continuous filament yarn, where such distortions are limited to the introduction of crimp including edge crimping, gear crimping, and stuffer box crimping. Other methods that are sometimes referred to as texturing, but are specifically excluded from the definition for the purposes of this invention, include false twist texturing, knit-deknit texturing and air-jet texturing.
For the purposes of this invention, “bulking” means a process specifically intended to increase the specific volume of continuous filament yarn wherein said processes impart crimping (bending or folding) to the yarn and its constituent filaments so that the yarn and constituent filaments deviate from a linear path. Bulking, as used herein, specifically excludes air-jet texturing.
The term “bulked”, for purposes of this invention, refers to yarns of permanently crimped filaments; i.e. the filaments retain their crimp upon removal from the yarn.
“% Crimp”, for the purposes of this invention, is a property measured according to the method provided herein that provides a measure of the extent of crimp achieved. It is essentially the percentage elongation exhibited by a crimped yarn when tension is applied to the yarn. The specific volume or bulk of yarn (cm3/g) increases as of extent of crimp increases. The extent of crimp can therefore be used as a proxy for characterizing yarn bulk.
For the purposes of this invention, the term “edge crimp” method refers to a method of providing texture and/or bulk to a yarn, including but not limited to, where the yarn is heated and stretched over a crimping edge, then cooled.
For the purposes of this invention, the “gear crimp” method is meant to include, but is not limited to, a method for providing texture and/or bulk to a yarn where the yarn is fed through the meshing teeth of two gears, where the yarn takes the shape of the two gears.
For the purposes of this invention, the term “stuffer box” method is meant to include, but is not limited to, a method for providing bulk to a yarn where the crimping unit includes two feed rolls and a stuffer box. By compressing the yarn into the stuffer box, the individual filaments are caused to fold or bend at a sharp angle, while being optionally, simultaneously set by a heating device.
For the purposes of this invention, “interlacing” means a process by which the continuous filaments in the inventive multifilament yarn are entangled resulting in frequent periodic compact nodal regions of high filament entanglement being separated along the length of the of the yarn by bulkier, relatively open regions of the same crimped filaments which are largely non-entangled. The interlaced process conducted in this manner provides a cohesive yarn. This periodic node structure distinguishes interlaced yarn from air-jet textured yarn which includes a consistently high degree of yarn entanglement along the entire length of the air-jet textured yarn. For the purpose of the disclosures with respect to this invention, interlacing and entangling may be used interchangeably. The interlacing is observed as nodes along the length of the yarn prevent the separation of crimped filaments and is necessary for processing the yarn into fabric, such as by weaving or knitting.
The yarns of some aspects are useful for the preparation of bulked fabric. The yarns which are bulked and entangled are directly weaveable or knittable under tension to form a bulked fabric without the need for secondary processing of the yarns. For example, the yarns are spun, drawn, bulked, and interlaced in a single in-line or coupled process. The yarns produced from this process are then formed into bulked fabrics through either weaving or knitting and without any additional twisting, entangling or air jet texturing of the yarns.
The multifilament yarns of some aspects, which can be included into a fabric or other articles, are both bulked and interlaced, but also have a higher tenacity due to a specific drawing process. The tenacity of the yarns may be about 2.0 to about 7.0 grams per denier. Other suitable ranges for tenacity include about 3.0 to about 7.0 grams per denier; about 3.0 to about 6.0 grams per denier, about 3.5 to about 7.0 grams per denier about 3.5 to about 6.0 grams per denier and about 4.0 to about 6.0 grams per denier. Higher tenacities may also be useful. However, where the tenacity is under 2 grams per denier, a fabric made from such a yarn will likely lack the desired durability.
The tenacity of the yarns is increased by the drawing process. Suitable drawing methods include a single step or multiple step drawing method. In a suitable single step method, the yarn is drawn with a heated roll with a surface speed of about 2000 to about 4000 meters per minute (m/min) and a temperature of about 150° C. to about 220° C., or 150° C. to about 190° C.; including a surface speed of about 2000 to about 4000 meters per minute (m/min), or about 2500 to about 4000 m/min, and a temperature of about 160° C. to about 210° C. or about 180° C. to about 210° C. The draw ratio may be about 2.5 to about 4.0. Suitable draw ratio ranges include about 2.6 to about 4.0; about 2.8 to about 4.0; about 3.1 to about 4.0; and other ranges greater than about 4.0. Multiple step or multiple draw roll methods, as known in the art, are also suitable. Where a multiple step process is included, the final set of draw rolls may include the conditions described in this paragraph.
The bulking process includes providing bulk to the yarn in the absence of the costly air jet texturing method. Suitable bulking processes include, but are not limited to, stuffer box, edge crimping, gear crimping or combinations thereof.
The interlacing process can include any as known in the art. The interlaced yarns may include a degree of interlacing about 2 nodes/meter to about 60 nodes/meter; other suitable ranges include about 15 nodes/meter to about 55 nodes/meter and about 20 nodes/meter to about 40 nodes/meter. The yarns may be interlaced at any suitable pressure greater than zero such as greater than 0 to 150 psi. Suitable interlacing pressures also include 30 psi to 130 psi; and 40 psi to 90 psi, and 50 psi to about 110 psi. For a nylon 6,6 yarn of about 1000 denier and 3.0 to 3.5 denier per filament (dpf) one suitable interlacing pressure may be about 60 psi to about 80 psi.
The bulking process provides a yarn with a bulk from about 1.0 to about 12.0 cm3/g, including about 3 to about 12.0 cm3/g, including from about 3.0 to about 12 cm3/g and from about 6.0 cm3/g to about 12 cm3/g. Consistency of the level of bulk throughout the yarn is desired and is more important than the measured level of bulk. Accordingly, the bulk may be measured by any suitable process known in the art. One suitable process for measuring bulk is disclosed in U.S. Pat. No. 3,471,702. Bulk of the yarn is provided as cm3/g. Alternatively, bulk can be calculated from % crimp based on the following formula:
Bulk=2(% Crimp)+4.2
The bulk calculation takes advantage of the correlation between bulk and % crimp, which is substantially linear in the range of interest disclosed herein. The % crimp may be any suitable amount such as about 0.50 to about 3.0. Other suitable ranges for % crimp include about 0.75 to about 2.0 and about 0.5 to about 2.0.
Any of a variety of polymers in addition to nylon can be included in the yarns and fabrics as disclosed. The polymer may include polyolefins, polyesters, polyamides, copolymers thereof, and combinations thereof. Aramides and oxidized polyacrylonitrile may also be suitable. Specific examples, without limitation, of suitable polyolefins include polyethylene and polypropylene; polyesters include polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate; suitable polyamides include, nylon 6, nylon 6,6, nylon 11, nylon 12, nylon 6, nylon 10, nylon 6,12, and partially aromatic polyamides such as MXD6, among others. For example, polyamides such as nylon 6 and nylon 6,6 are useful either in blends, as copolymers or as homopolymers. The polymers may also be derived from post consumer and post-industrial recycle variations of these polymers.
A variety of cross-sections are useful for the multiple filament, bulked and interlaced yarns. In one aspect, the cross-section of the filaments is round. Useful cross-sections include round, hollow, tri-lobal, oval, scalloped oval, and combinations thereof, among others that are well-known in the art.
A variety of different additives are useful in the yarns, fabrics and articles described herein. A specific example of yarns with additives includes solution dyed nylon. An exemplary and non-limiting list is included. However, additional additives are well-known in the art. Examples include: anti-oxidants, UV stabilizers, colorants, pigments, cross-linking agents, phase change materials (paraffin wax), antimicrobials, minerals (i.e., copper), microencapsulated additives (i.e., vitamin E gel, aloe vera, sea kelp, nicotine, caffeine, scents or aromas), nanoparticles (i.e., silica or carbon), calcium carbonate, flame retardants, vitamins, medicines, fragrances, electrically conductive additives, dyeability and/or dye-assist agents (such as quaternary ammonium salts), optical brighteners, electroconductive additives, luminescent additives, lubricants, organic and inorganic fillers, preservatives, thermochromic additives, insect repellants, wetting agents, stabilizers (hindered phenols, zinc oxide, hindered amine), and combinations thereof.
The yarns of some aspects may be prepared as fabric. This includes knit or woven fabrics. Suitable woven fabrics include plain weave, twill, satin, basket, rip stop and an assortment of fancy dobby weaves, among others. Suitable knits include warp or circular knits. A specific knit fabric may be a single jersey knit such as tricot or raschel knit, among others.
The fabrics of some aspects have properties making them especially useful for durable products such as luggage, outdoor apparel, outdoor gear, denim, footwear and military apparel and gear, among others. The fabric may also be a narrow fabric, such as webbing, which can include a tightly woven fabric. The fabric properties include grab strength of about 80 to about 1200 pounds, depending on the yarn denier used. Fabrics also exhibit tear strength of about 8 to about 150 pounds, including about 40 to about 70 pounds as well as greater than 70 pounds, depending on the yarn denier used. Fabrics also exhibit Taber abrasion resistance of about 80 to about 4000 cycles; this includes about 400 to about 800 cycles, as well as greater than 800 cycles, depending on the yarn denier used.
The fabrics may also be coated as needed for specific articles where reduction in air or moisture permeability requires this modification. Suitable coatings include polyurethanes, acrylics, waterproof/breathable membranes, laminates, and an assortment of coatings specifically designed for upholstery and leisure fabrics.
The features and advantages of the present invention are more fully shown by the following examples which are provided for purposes of illustration, and are not to be construed as limiting the invention in any way.
Tables 1 and 2, below show the properties of several inventive (examples 5 to 24) and comparative yarns (examples 1 to 4), as indicated in the table. Averages were calculated as indicated. The yarns are spun from nylon 6,6 polymer and each include 280 filaments. The yarns are drawn at a draw ratio of about 3.1 with a hot roll temperature, measured at the first stage draw rolls, of about 160° C., are bulked via stuffer box at 180° C. measured at the stuffing jet and interlaced as indicated.
Interlace is measured according to ASTM standard method D4724-87 (reapproved 1992). This method covers common procedures for interlace measurement by needle insertion. The results are reported as interlace nodes per meter of interlaced yarn. A suitable apparatus to measure interlace nodes is the Rothschild R2071/72 automated interlace tester from Rothschild Measurement Instruments, Traubenstrasse 3, Zurich, Switzerland.
Denier is the linear density of a filament expressed as weight in grams of 9000 meters of filament. Denier can be measured on a Vibroscope from Textechno of Munich, Germany. Denier times (10/9) is equal to decitex (dtex). Denier per filament can be determined gravimetrically in accordance with ASTM D 1577.
Tenacity at break (T) is the maximum or breaking force of a filament expressed as force per unit cross-sectional area. The tenacity can be measured on an Instron model 1130 available from Instron of Canton, Mass. and is reported as grams per denier (grams per dtex). Filament tenacity at break (and elongation at break) can be measured according to ASTM D 885.
32a
aNote -
32a
aNote -
bMeasured at first stage draw rolls
cMeasured at stuffer jet
As noted earlier, % crimp is a measure of the elongation exhibited under tension. For Table 3B the % crimp was measured using the following method:
Crimp Measurement of Textured Yarns
1. Verify the mass of the 10.5 g wire weights
2. Specimens—Total of three (3) 100 wrap skeins/package
3. Lease all the skeins at top and bottom. Do not cut skeins.
4. Drop the bar on the skein winder and carefully remove first skein, carefully holding the top and bottom lease, to eliminate twisting of the skein upon itself.
5. Hang on top hook of shrinkage board, and while still holding bottom, carefully add the 10.5 g weight to the bottom of the skein (not the lease) & measure after 15 seconds. Record as the “Light Weight Length”. The 10 g weight will be left on during the entire test.
6. Hang a 300 g weight (along with the 10.5 g weight), and after 30 seconds measure the length of the skein and record as the “Heavy Weight Length”.
7. Repeat steps 6-8 for remaining skeins and repeat until 3 skeins from each package have been wound, and light/heavy lengths have been measured.
% Crimp=100% (Heavy Weight Length−Light Weight Length)/(Light Weight Length)
Several fabrics are woven from the yarns shown in tables 1 and 2. The fabrics that include comparative yarns 1-4 in either the warp or fill directions were not suitable as bulked fabrics. These comparative fabrics are observed to have a slick appearance. This is in contrast to the fabrics which are made with the inventive yarns 5 to 24 in both the warp and weft directions. The fabrics which include only inventive yarns show varying degrees of suitability for bulked fabrics. The yarn combinations that provide the most suitability for bulked fabrics were the fabrics yarns which are interlaced at about 40 to 90 psi in both the warp and the fill.
While there have been described what are presently believed to be the preferred embodiments of the invention, those skilled in the art will realize that changes and modifications may be made thereto without departing from the spirit of the invention, and it is intended to include all such changes and modifications as fall within the true scope of the invention.
| Number | Date | Country | |
|---|---|---|---|
| 61531726 | Sep 2011 | US |
