CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No.

62/311,562, filed March 22, 2016, which is incorporated by reference herein.

TECHNICAL FIELD

[0002] The present application relates generally to nylon based filaments, yams, and fabrics, and relates more specifically to nylon based filaments containing a base nylon and a secondary nylon, and yarns and fabrics formed therefrom.

BACKGROUND

[0003] Polyester fabrics currently dominate the activewear market and are becoming popular in mainstream clothing fabrics because of their resistance to wrinkling and low-moisture uptake. Meanwhile, relative to polyester fabrics, nylon fabrics offer lower coefficient of friction, dramatically reduced wear (i.e., loss of material over time), lower propensity to generate static, and improved feel, but suffer from wrinkling and dimensional changes when wet.

[0004] Thus, there is a need for filaments, yarns, and fabrics having the beneficial properties of nylon with improved properties such as improved resistance to wrinkling and dimensional changes.

SUMMARY

[0005] In one aspect, a multifilament is provided that includes a filament that contains a composite material formed from (i) a main structural component containing a mixture of one or more aliphatic nylons and one or more semiaromatic nylons, and optionally (ii) an additive component mixed with the main structural component.

[0006] In another aspect, a multifilament is provided that includes a filament that contains a composite material formed from (i) a main structural component containing a mixture of one or more base nylons and one or more secondary nylons, and optionally (ii) an additive component mixed with the main structural component, wherein the one or more base nylons and the one or more secondary nylons are present in amounts such that the filament has a greater tenacity than an otherwise equivalent filament having a main structural component formed only of the one or more base nylons. [0007] In yet another aspect, a fabric is provided that contains a multifilament that includes a plurality of filaments containing a composite material formed from (i) a main structural component containing a mixture of one or more base nylons and one or more secondary nylons, and optionally (ii) an additive component mixed with the main structural component, wherein the one or more base nylons and the one or more secondary nylons are present in the filaments in amounts such that each filament has a greater tenacity than an otherwise equivalent filament having a main structural component formed only of the one or more base nylons. DETAILED DESCRIPTION

[0008] Nylon based filaments and yarns and fabrics made therefrom are disclosed herein. The nylon based filaments possess one or more improved properties as compared to known nylon filaments. In particular, embodiments of the nylon filaments and yarns disclosed herein may display one or more of: improved tenacity, resistance to wrinkling, and resistance to dimensional changes when wet as compared to otherwise equivalent nylon filaments formed from conventional nylon materials.

[0009] As used herein, the term "filament" is used broadly to refer to a thread or fiber-like structure. For example, the filaments may be made in a typical extrusion process or other known process. As used herein, the term "multifilament" refers broadly to multifilament yams or fibers in which a plurality of filaments are combined, such as in a typical yam spinning process.

[0010] In certain embodiments, the nylon based filaments disclosed herein are formed from a composite material. The composite material is a mixture of a main structural component containing one or more base nylons and one or more secondary nylons, and optionally an additive component.

[0011] As used herein, the phrase "main structural component" refers to the polymer mixture (e.g., the mixture of one or more base nylons and one or more secondary nylons) that forms the bulk of the filament and provides the structural properties thereto. That is, any additive component, coating or finish, or other supplemental material (e.g., filament core) combined with the main structural component to form the filament, does not significantly alter the structural properties of the filament imparted by the main structural component.

[0012] As used herein, the phrase "an additive component" refers to one or more suitable additive materials that are distinct from the polymers forming the main structural component and that do not significantly alter the structural properties of the filament as imparted by the main structural component. The additive component is optional. For example, the additive component may be present in the composite material in an amount of up to about 3 percent, by weight. For example, the additive component may be present in the composite material in an amount of from about 0.1 percent, by weight, to about 3 percent, by weight. In certain embodiments, the additive component is present in the composite material in an amount of from about 0.1 percent, by weight, to about 1.5 percent, by weight. As used herein, the term "about" is used to refer to plus or minus 5 percent of the numerical value of the number with which it is being used.

[0013] The one or more materials of the additive component may be premixed with one or more of the nylon components or may be combined with the nylon components as a separate ingredient. For example, the additive component may include one or more additive materials selected from dyes, pigments, optical brighteners, stabilizers, anti-static agents, antimicrobial agents, and mixtures thereof. For example, the additive materials may be selected from agents containing fumed silica, activated carbon or other species which are difficult to incorporate in filaments. Additionally, functional additives such as remediation or catalytic materials may be used. Other suitable additives are known in the filament processing industry and may also be used.

[0014] Thus, the filaments described herein are formed of a composite mixture, or blend, of the base nylon(s), the secondary nylon(s), and any additive component. The additive materials of the additive component may be present as a component of one or more of the nylon(s) prior to mixing or may be introduced as a separate component into the mixing process. Suitable coatings and/or finishes may be applied to the filaments described herein.

[0015] In certain embodiments, the one or more base nylons and the one or more secondary nylons are present in the composite mixture in amounts such that the filament has a greater tenacity than an otherwise equivalent filament having a main structural component formed only of the one or more base nylons. For example, the filament may have a tenacity that is from about 40% to about 60% higher than the tenacity of an otherwise equivalent filament having a main structural component formed only of the one or more base nylons (i.e., with the one or more secondary nylons).

[0016] As used herein, the phrase "otherwise equivalent filament" when used to define one or more relative properties of the filaments, yarns, or fabrics disclosed herein, refers to filaments, yarns, or fabrics that have been manufactured in identical processes to have identical dimensions, filament count, etc., but in which the composite material differs in the main structural component containing only the one or more base nylons. That is, the "otherwise equivalent filament" refers to a filament that is identical to the relevant filament of the present disclosure other than the composition of the main structural component, which includes no secondary nylons.

[0017] It has been discovered that improved properties such as increased strength and improved resistance to wrinkling and dimensional changes can be achieved in filaments, and the yams and fabrics formed therefrom, through the use of particular base nylons and secondary nylons. In some embodiments, the one or more base nylons are one or more aliphatic nylons and the one or more secondary nylons are one or more amorphous nylons.

[0018] For example, suitable aliphatic nylons include nylon 6,6, nylon 6, nylon 6,69, nylon 6,66, nylon 66,6, nylon 6,12, nylon 6,10, nylon 11, nylon 12, other aliphatic nylon copolymers, and mixtures thereof. In certain embodiments, the one or more base nylons are selected such that they have a glass transition temperature of less than 80°C, such as in the range of about 15°C to about 75°C, or in the range of about 20°C to about 70°C. For example, nylon 6 (wet or in high humidity) has a glass transition temperature of about 20°C, nylon 6,6 (wet or in high humidity) has a glass transition temperature of about 25°C, nylon 6 (with less than 0.1% moisture in nylon) has a glass transition temperature of 47°C, and nylon 6,6 (with less than 0.1% moisture in nylon) has a glass transition temperature of 70°C.

[0019] For example, suitable amorphous nylons include those that are semiaromatic, such as those with a phenyl ring. In certain embodiments, the one or more secondary nylons are amorphous semiaromatic nylons selected from MXD6, 6I/6T, 6T/6I, DT/DI, DI/DT,

6I/6T/DI/DT, 6I/DI, 6T/DT, Dicycan-I, Dimetyldicycan-I, Dimethyldicycan-T, and Dicycan- T, nylon copolymers containing 61, 6T, DI, DT or Dicycan, and mixtures thereof. In certain embodiments, the one or more secondary nylons are selected such that they have a glass transition temperature of at least 80°C, such as in the range of about 80°C to about 150°C, or in the range of about 110°C to about 140°C. For example, nylon 6I/6T having a weight ratio of 2: 1 has a glass transition temperature of about 130°C.

[0020] As used herein, the following nomenclature is used in accordance with usage in the industry, as indicated. I: isophthalic acid; T: terephthalic acid; 6I/6T: copolymer made of hexamethylene diamine, isophthalic acid, and terephthalic acid; 61: hexamethylene diamine- isophthalic acid; 6T: hexamethylene diamine-terephthalic acid; 612: hexamethylene diamine- dodecanedioic acid; 610: hexamethylene diamine-sebacic acid; D: 2-

Methylpentamethylenediamine; MXD6: poly amide produced by poly condensation of MXDA with adipic acid. [0021] It has surprisingly been discovered that incorporation of even a small amount of the secondary nylon(s) into a filament composite containing the base nylon(s) results in a shift in various material properties of the filament that impact performance and wrinkling of a multifilament yarn manufactured therefrom. In particular, the glass transition temperature and crystallization behavior, moisture uptake behavior, and tenacity of the filament, and the yams formed therefrom, may be impacted by incorporating at least 2 percent, by weight, of the secondary nylon(s) into the composite material.

[0022] In some embodiments, the secondary nylon(s) are present in the composite material in an amount of from about 2 percent, by weight, to about 6 percent, by weight. In certain embodiments, the secondary nylon(s) are present in the composite material in an amount of from about 2 percent, by weight, to about 5.5 percent, by weight. In certain embodiments, the secondary nylon(s) are present in the composite material in an amount of from about 3 percent, by weight, to about 5 percent, by weight. In one embodiment, the secondary nylon(s) are present in the composite material in an amount of about 4 percent, by weight. For example, in filaments having a size of from 1 to 3.4 dpf, the secondary nylon(s) may be present in the range of about 2 percent, by weight, to about 6 percent, by weight, such as about 4 percent, by weight.

[0023] It was previously believed that an amount of greater than 6 percent, by weight, of a secondary nylon was required to achieve any shift in base nylon properties in monofilament applications (i.e., in significantly larger diameter filaments), such as described in U. S. Patent Application Publication No. 2017/0009384. However, it has now been discovered that such composites may be used in multifilament applications in which the filaments have much smaller size. However, the upper limit of secondary nylon(s) loading for filaments in the multifilament range is surprisingly smaller than was previously thought. In fact, as demonstrated by the Examples herein, a particularly useful loading range of the secondary nylon(s) is from about 2 percent, by weight, to about 6 percent, by weight. The ability to decrease the amount of secondary nylon(s) and still attain the improved performance properties of these multifilaments was not expected based on prior testing. For example, in filaments having a size of from 10 to 20 dpf, the secondary nylon(s) may be present in the range of about 2 percent, by weight, to about 6 percent, by weight.

[0024] It has surprisingly been discovered that incorporation of even a small amount of the secondary nylon(s) into a filament composite containing the base nylon(s) results in a shift in the crystallization behavior of the material with minimized phase separation of the material. In particular, the filaments and yams of the present disclosure may have a higher temperature of onset of crystallization than an otherwise equivalent filament having a main structural component formed only of the one or more base nylons. This shift in crystallization behavior results in the composite material being able to be drawn to a higher degree during processing, as is discussed in greater detail below and in the Examples. This beneficially enables processing of the filaments at an increased speed, and therefore at an increased output. For example, yams manufactured in a fully drawn yam process using the presently disclosed filaments may be able to be drawn at a draw ratio that is at least 20% greater than an otherwise equivalent filament having a main structural component formed only of the one or more base nylons, on the same equipment, with no operability loss. For example, an increase in draw ratio of about 40% over an otherwise equivalent filament having a main structural component formed only of the one or more base nylons has been observed.

[0025] Furthermore, without intending to be bound by a particular theory, it is believed that the increased glass transition temperature provides improved wrinkle resistance to the disclosed filaments, yams, and fabrics. For example, it is suspected that these composites provide wrinkle resistance because of a rise in glass transition temperature of the formulation. As mentioned above, nylon 6 and nylon 6,6 have glass transition temperatures around the room temperature when exposed to high humidity or water. Having a glass transition temperature near room temperature allows the molecules of nylon mobility which results in a molecule able to adapt newer configuration which results in wrinkles. Meanwhile, polyester has a glass transition temperature much higher than room temperature leading to locked molecules at room temperature and thus no changes in molecular configuration leading to natural wrinkle resistance.

[0026] Prior to the present discovery, it was understood that combining a small amount of a secondary polymer having distinct crystallization properties with a majority component of another polymer having a faster crystallization time resulted in phase separation due to the majority component crystallizing faster. Thus, it was previously believed that the secondary polymers described herein were effective to split or shear filaments containing the base polymers described herein. Thus, it was unexpected that uniform filaments formed of the composite mixtures described herein could even be achieved, let alone that the filaments would display the improved wrinkle resistance and strength properties that have been observed. For example, it is believed that, for the presently disclosed filaments, the phase separation of the main structural component is minimized and/or the base and secondary nylons are partially miscible. Specifically, a 3 dpf filament having a diameter of 20 micron has been manufactured. Due to the observed draw characteristics and tenacity, it has been determined that the domains (i.e., volumes of inclusion of the materials) must be much smaller than the diameter of the filament (i.e., less than a micron). Otherwise, breakage and decreased strength would be observed.

[0027] It is also believed that improved wrinkle resistance of the disclosed filaments, yams, and fabrics is achieved though providing the secondary nylon(s) in the composite in an amount such that the moisture uptake properties of the filaments are altered. Because wrinkling of fabrics is also caused by uneven filament and yam drying (e.g., when a portion of the filament or yam is wet and other portions are dry a wrinkle forms due to the difference in dimensions caused by moisture presence), reducing the propensity of the filaments to take on moisture improves the wrinkle resistance of a fabric made therefrom.

[0028] In particular, the moisture uptake by nylon 6 and nylon 66 are known to be significant. For example, a wet nylon 6 yam can absorb more than 5% of its weight in water within the molecular structure. As demonstrated by the Examples below, it was surprisingly found that incorporation of even a small amount of the secondary nylon(s) into a filament composite containing the base nylon(s) results in a decrease in overall moisture absorption and absorption rate. In addition, dimensional changes of the wet filaments were less than observed in otherwise equivalent filaments having a main structural component containing only the base nylon. In particular, the filaments and yarns disclosed herein may have a smaller relative length change when soaked in water than an otherwise equivalent filament having a main structural component containing only the base nylon. Moreover, the filaments and yarns disclosed herein may have a smaller enthalpy of drying than otherwise equivalent filaments having a main structural component containing only the base nylon.

[0029] Moreover, it has been discovered that incorporation of even a small amount of the secondary nylon(s) into a filament composite containing the base nylon(s) results in filaments and yarns having a greater tenacity (i.e., strength) for the same weight filament. In particular, as described in the Examples, the filament may have a tenacity that is from about 40% to about 60% higher than the tenacity of an otherwise equivalent filament having a main structural component formed only of the one or more base nylons. Thus, a fabric may beneficially be formed of the same weight of the presently disclosed yarn and may display increased strength characteristics. Alternatively, a fabric having identical strength characteristics may be lighter weight than a fabric formed of otherwise equivalent yarn. For example, if the yarn's tenacity is 30% higher than an otherwise equivalent yarn, then a fabric formed from the high tenacity yam can be reduced in weight by 30%. Such lightweight high strength fabrics formed from nylon are particularly desirable in activewear applications (e.g., athletic jerseys). The tenacity of the filaments and yams disclosed herein may range from about 3 to about 11 grams per denier with higher tenacity reached with multiple draw zones.

[0030] The filaments described herein may be formed to have any suitable dimensions and cross-sectional shape. For example, the filaments may have a round, trilobal, or any other suitable cross-sectional shape. For example, the filaments may have a denier per fiber of from about 0.1 dpf to about 3.5 dpf, such as from about 0.8 to about 3.5 dpf For example, such filaments may be suitable for use in apparel fabrics. Other filaments may have a denier per fiber of from about 3.5 dpf to about 11 dpf. For example, such filaments may be suitable for use in seat belts or other harnesses.

[0031] In certain embodiments, a fabric is provided that is formed from a multifilament (i.e., yam) formed from one or more of the filaments described herein. The fabric may be constructed by any suitable means, including weaving or knitting. It is believed that fabrics formed from the filaments described herein may be manufactured to have a denier that is lower than previously achievable with conventional nylon based filaments. For example, the fabrics formed from the filaments described herein may have a denier of as low as 40 denier. As described above and the Examples, the filaments and yams described herein beneficially impart improved wrinkle resistance and strength properties to a fabric formed therefrom. Moreover, such fabrics also maintain the reduced wear, lower coefficient of friction, and lower propensity to generate static that are associated with traditional nylon fabrics.

[0032] The fabrics and yams described herein may be formed exclusively from the filaments described herein or may contain a combination of the filaments described herein and other nylon or other synthetic or natural filaments.

[0033] As discussed further herein, the filaments, yams, and fabrics described herein may be made by any suitable process or apparatus known in the industry. For example, any known filament extrusion, melt spinning process know in the art may be used. For example, a multifilament yam may be made by a standard fully drawn yam process, such as one that forms a continuous 34 filament 100 denier yam, as described in the Examples. For example, a standard one-step bulked continuous filament process may be used to produce the yams described herein, such as a 20 dpf, 1000 denier yam that may be suitable for carpet applications.

[0034] The filaments, yams, and fabrics described herein may be textured or crimped, as desired for the particular application. This textured yam is knitted, tufted, or woven into a fabric. It can be dyed in yam form or in a fabric form. Beneficially, the dye wash fastness and flexibility of coloration for nylon materials, such as the filaments described herein, is much greater than polyester.

[0035] The filaments and yarns described herein can also be used in applications other than fabrics, including narrow gauge bands (such as for seat belts and other harnesses), tire cords, carpets, and ropes.

[0036] Accordingly, the presently described filaments provide improved properties such as increased strength and improved resistance to wrinkling and dimensional changes can be achieved in filaments, and the yarns and fabrics formed therefrom, through the use of particular base nylons and secondary nylons. This technology allows the addition of wrinkle resistance to nylon fabrics with minimal change to fiber spinning, dyeing, or fabric construction. Moreover, the improved processability as well as the improved filament uniformity and tenacity observed is crucial to many types of fibers produced with nylon including seat belts, filtration fabrics, tire reinforcement cords, sewing filaments, and high performance luggage fabrics. Additionally, certain applications of nylon yams and filaments, in particular sail fabrics and seat belt/harnesses benefit greatly from the reduced dimensional change when wet that has been observed.

[0037] Thus, the present disclosure allows for the manufacture of nylon based yams and fabrics that display one or more of the beneficial properties of traditional nylon materials (e.g., lower coefficient of friction, reduced wear, lower propensity to generate static, and improved feel) while also displaying a resistance to wrinkling and moisture uptake that is typical of polyester based materials.

[0038] The foregoing disclosure may be further understood and illustrated by the following non-limiting Examples. In particular, while the Examples generally disclose base nylons of nylon 6 and nylon 6,6 in combination with secondary nylon 6I/6T, the present disclosure is not intended to be limited to such combinations. Rather, these Examples are meant to be representative of the improved properties that may be attained with each of the various combinations of base and secondary nylons disclosed throughout the present application.

[0039] Examples

[0040] For Examples 1-5, bright trilobal 34 filament 100 denier continuous multifilament yams were manufactured using nylon 6,6 (having a relative viscosity of either 40 (standard) or a relative viscosity of 60 (high molecular weight (HMW)) as the base nylon and nylon 6I/6T (commercially available as SVPX-115 from Shakespeare Company, LLC) as the secondary nylon, according to an embodiment of the disclosure. A comparative reference yarn was prepared with 34 filament 100 denier continuous filament yarn using nylon 6,6 (standard) as the base nylon without any secondary nylon.

[0041] The yams were manufactured in a standard fully drawn yarn (FDY) process in which polymer pellets were weighed and blended into a feeder and an extruder melted the polymer and mixed the polymers and any additives. Next, an extruder head, melt pipe, and static mixer were used to equilibrate the melt at a uniform temperature and increase mixing, and a spin beam was used to divide the polymer flow into different streams. A meter pump and spinneret were used to produce dozens or hundreds of molten filaments with uniform shear history and temperature and then a quench delay and air quench were used to cool the filaments. Next a finish applicator system was used to add lubricant to the filaments and the filaments were combined to form a filament bundle or yam. A feed roller then fed the yam to three or four (although other numbers may be used) pairs of Godet rolls, of which one or more pairs (typically two) were heated. The yam then traveled through an interlace jet and a take-up winder.

[0042] In the industry, the "draw ratio" is understood to be the ratio of linear speed between the feed roller and the last Godet roll pair. The draw ratio that may be used on a particular filament yarn is dictated by the properties of the filament yam, including the rate of crystallization of the material. It is desirable to increase the draw ratio to process the filaments at an increased speed, and therefore at an increased output; however, increasing the draw ratio to in excess of what the filament material can withstand results in breakage of the yarn.

[0043] The comparative sample of nylon 6,6 yam was able to be drawn at a draw ratio of 4.8, whereas the samples containing 4% of the secondary nylon surprisingly were able to be drawn at a draw ratio of 6.7 on the same equipment, with no operability loss. This increase in draw ratio was surprising and indicates that significant improvements in output may be achieved with the filaments of the present disclosure.

[0044] Example 1

[0045] The comparative nylon 6,6 and 4% secondary nylon yarns were then exposed to heat at 350°F for 50 seconds and subsequently conditioned at room temperature for 24 hours. Each of the yarns was then elongated until its breaking point, according to ASTM D2256, and the percent elongation at break and tenacity were measured for each of the yarns. The percent enhancement in tenacity over yam made using the nylon 6,6 as the base nylon without any secondary nylon was calculated, as shown in Table 1 below. Nylon 6,6 Nylon 6,6 with 4% HMW Nylon 6,6

Nylon 6I/6T with 4% Nylon

6I/6T

Tenacity (gpd) 4.4 6.3 7.1

% enhancement 100% 143% 161%

% elongation at 37% 25% 22%

break

Table 1: Tenacity, % Enhancement over Control, and % Elongation at Break of Dry Conditioned Yarns

[0046] The yarns were then immersed in water for 1 hour, blotted dry, and each of the yams was then elongated until its breaking point, according to ASTM D2256, and the percent elongation at break and tenacity were measured for each of the yams. The percent enhancement in tenacity over yam made using the nylon 6,6 as the base nylon without any secondary nylon was calculated, as shown in Table 2 below.

[0047] Surprisingly, as shown in the tables above, the nylon 6,6 containing just 4% of the 6I/6T secondary nylon exhibited dramatically improved properties. These yams showed higher tenacity and a smaller change in properties when wet than the control nylon 6,6 filament without any secondary nylon.

[0048] This combination of higher tenacity and smaller change when wet in tenacity and elongation of the yams containing the secondary nylon beneficially enables that use of lower weight yams/filaments to achieve the same strength (i.e., tenacity) of a fabric. For example, with a tenacity of 6.9 gpd versus 4.1 gpd, it is estimated that one would require about 1/3 lower fabric weight to achieve similar weight bearing properties with the 6.9 gpd tenacity yams. Thus, lightweight, but high strength filaments, yams, and fabrics may be

manufactured. Alternatively, if a similar weight of fabric is desired, the overall weight bearing properties of that fabric will increase for the higher tenacity yams or filaments.

[0049] Example 2

[0050] 4 to 5 mg samples of the yam, as described above, were heated to 300°C at a rate of about 20°C/min, until each of the yams became a flowable melt, and then cooled from 300°C to 25°C at a rate of about 20°C/min. The polymer melts were observed to determine the temperature at which crystallization began, and the enthalpy change upon crystallization was measured. The results are shown in Table 3 below.

[0051] Surprisingly, the temperature of the onset of crystallization of the yams containing just 4% of the secondary nylon was notably higher than that of the unmodified nylon 6,6 yams, and the enthalpy upon crystallization of the yam containing just 4% of the secondary nylon was significantly lower than that of the nylon 6, 6 yam. The higher crystallization temperature and lower enthalpy of the modified yams indicates that these modified yams crystallize slower than the unmodified nylon 6,6 yams without the secondary nylon. It is theorized that this slower crystallization rate may allow for the modified filaments to be produced and drawn at faster rates, as explained above.

[0052] Differential scanning calorimetry (DSC) crystallization curves for the experimental samples unexpectedly showed a shift in baseline at ~130°C, which is consistent with the glass transition temperature of nylon 6I/6T. Moreover, each sample containing nylon 6I/6T surprisingly showed a similar glass transition temperature peak, indicating that the secondary nylon is well mixed in the polymer, which was not expected given the phase separation that typically occurs in polymer mixtures in which the majority component is known to crystallize faster than the minority component.

[0053] Example 3

[0054] Yarn samples as described above were conditioned in a lab at 23°C and 50% relative humidity for over 24 hours and then weighed, vacuum dried, and weighed again once dried. The percent change in weight between the conditioned yarns and the vacuum dried yams is shown in Table 4 below.

[0055] Surprisingly, the weight change upon drying of the nylon 6,6 yarns containing 4% of the 6I/6T secondary nylon was significantly less than that of the unmodified nylon 6,6 yam without any secondary nylon. In other words, the modified nylon 6,6 yarns containing 4% 6I/6T absorbed less water than the unmodified nylon 6,6 yams. The lower water absorption of the modified yarns will beneficially make fabrics made from these filaments less likely to wrinkle than fabrics made of unmodified nylon 6,6 filaments without the secondary nylon.

[0056] Example 4

[0057] The yams described above were immersed in water for 24 hours in a controlled lab condition of 23°C. They were then removed from the water, blotted dry, and their lengths were measured. The yarns were then conditioned in the lab maintained at 23°C and 50% relative humidity for 24 hours, where they were allowed to dry out, and then the lengths of the yams were measured again. The length of the conditioned sample was then calculated as a percentage of the wet sample, as shown in Table 5 below. Nylon 6,6 Nylon 6,6 with 4% HMW Nylon 6,6 with

Nylon 6I/6T 4% Nylon 6I/6T

Length of 97.9% 98.6% 98.7%

Conditioned Sample

as % of Wet Sample

Table 5: Length of Conditioned Sample as % of Wet Sample of Yarns

[0058] Surprisingly, the nylon 6,6 with 4% 6I/6T yarns exhibited much less of a change in length between their wet and conditioned states than the unmodified nylon 6,6 filaments without any secondary nylon. This smaller change in length between wet and conditioned states would contribute to wrinkle resistance of fabrics made from filaments comprising nylon 6,6 with 4% 6I/6T.

[0059] Example 5

[0060] The yams described above were washed to remove finish, then soaked in water for 24 hours, blotted dry, and held in a conditioned lab (23°C and 50% relative humidity) for 24 hours. DSC was used to measure heat flow in each sample as it was raised from 25°C to

300°C at 20°C/min. During the initial heating process, a temperature peak was observed that can be correlated to moisture loss. The area under the peak is reported as the enthalpy required to dry the yarns, as shown below in Table 6.

[0061] Surprisingly, the modified yams made from nylon 6, 6 with 4% 6I/6T had significantly lower peak temperatures during drying and thereby required less energy to dry than yarns made from nylon 6,6 without any secondary nylon. This means that fabrics made from these modified yams containing secondary nylons beneficially would require less energy to dry than unmodified nylons without any secondary nylons. [0062] Example 6

[0063] A standard one-step bulked continuous filament (BCF) process was used to produce 20 dpf, 600 denier yarn. The standard BCF machine (i.e., one-step process) includes weighing and blending polymer pellets into a feeder, after which an extruder melts the polymer and mixes the polymers and any additives. An extruder head, melt pipe, and static mixer are used to equilibrate the melt at a uniform temperature and increase mixing, and a spin beam is used to divide the polymer flow into different streams. A meter pump and spinneret are used to produce dozens or hundreds of molten filaments with uniform shear history and temperature. Next a quench delay and quench are used to cool the filaments. The filaments then travel through an interlace jet. Next a finish applicator system is used to add lubricant to the filaments. A feed roller then feeds the yam to two (although other numbers may be used) pairs of Godet rolls, of which one or more pairs (typically one) are heated. The yam then travels along a bulking jet and cooling roll, followed by a take-up roll, and winder.

[0064] In the industry, the "draw ratio" is understood to be the ratio of linear speed between the feed roller and the last pair of Godet rolls. The draw ratio that may be used on a particular filament is dictated by the properties of the filament, including the rate of crystallization of the material. It is desirable to increase the draw ratio to process the filaments at an increased speed, and therefore increased output; however, increasing the draw ratio to in excess of what the filament material can withstand results in breakage of the filament.

[0065] A comparative sample yarn was made using standard nylon 6 and an experimental yam was made using standard nylon 6 with 6% nylon 6I/6T. A second experimental sample was made using standard nylon 6 with 8% nylon 6I/6T. The comparative sample of nylon 6 yam was able to be drawn at a draw ratio of 2.75, whereas the sample containing 6% of the secondary nylon surprisingly was able to be drawn at a draw ratio of 3.75 on the same equipment, with no operability loss. This increase in draw ratio was surprising and indicates that significant improvements in output may be achieved with the filaments of the present disclosure.

[0066] In the industry, the "linear speed" of the process is understood to be the speed at which the winder is running, which represents the output of the process (i.e., the length of yam being wound per duration). On typical BCF machines, the upper limit of the output (i.e., linear speed), like the draw ratio, is dictated by the speed that the filaments can withstand without breakage. The linear speed varies significantly based on the polymer being used. For example, polypropylene based yams typically run approximately 60 to 70% faster than nylon 6,6 based yarns, while nylon 6 and polyethylene terephthalate (PET) run somewhere in between. It is theorized that the crystallization rate of the polymer being processed impacts the maximum linear speed attainable.

[0067] Using the above described BCF machine, the sample containing 6% of the secondary nylon allowed for an increase of linear speed of about 20% over the maximum linear speed attainable with the comparative sample of nylon 6 yarn, with no operability loss. Moreover, the sample containing 8% of the secondary nylon was able to be run at even higher speeds.

[0068] It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the invention. Thus, it is intended that the present disclosure cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.