ES2436719T3 - Threads, fabrics of high wear resistance and objects made with these - Google Patents

Abstract

Thread consisting of an intimate mixture of two types of fibers, characterized by the fact that the first type of fibers is a discontinuous nylon fiber and the second type of fibers is a discontinuous cellulose fiber of artificial high tenacity that has a toughness in the break in the conditioned state of more than 32 cN / tex and the content of the discontinuous nylon fiber in the mixture is in the range of 10% to 75%.

Description

Threads, fabrics of high wear resistance and objects made with them.

[0001] This invention relates to threads and fabrics containing discontinuous nylon fiber and cellulose discontinuous fiber of high artificial tenacity, and objects such as garments, bedding or upholstery made therefrom, and refers in particular to fabrics that have a high resistance to wear, while maintaining a high level of comfort.

[0002] It has been found that certain types of work clothes, including those used in high abrasion conditions, wear out very quickly. This is particularly true for work clothes intended for use in sand conditions. It is known that cellulosic fibers such as cotton, viscose rayon or lyocell can be converted into garments that have a high level of comfort. This is because the garments absorb moisture and have a cool comfortable feel. However, pure cellulose garments do not have a high level of abrasion resistance.

[0003] Abrasion resistance in fabrics and garments is measured by the Martindale test and in this patent application the number of rubs is always given until 2 wires are broken. This is a standard tissue test whose details are set out in ASTM D4966-98 and ISO 12947.

[0004] 50% cotton / 50% polyester fabrics have a good level of comfort, but have an abrasion resistance of 20,000 to 50,000 rubs, depending for example on fabric construction, weight, etc. But even this is not enough for very demanding conditions, such as the desert. It is also known that the abrasion resistance of cotton-containing fabrics can be increased by producing a cotton / nylon fabric. The fabric used by the U.S. Army For the desert camouflage uniform it is a 50% cotton / 50% nylon fabric, known as NyCo, with a Martindale resistance exceeding 80,000 rubs.

[0005] In addition, the tissues must have adequate tear resistance. Tear resistance is the force necessary to start or continue a tear in a tissue under specific conditions. The details of the tear strength test are set out in ASTM D-2261, ASTM D-2262 and BS EN ISO 13937.

[0006] The specification is set for the required benefits. For example, for a 2x1 polyester / cotton twill field uniform according to UK specifications, a breaking strength of 28 N in the warp and 20 N in the weft is required. Tissues called ripstop may have different requirements, for example, 25 N warp and 60 N in the weft.

[0007] Lyocell is the generic name for a cellulosic artificial fiber produced without the formation of a derivative from a solution of cellulose in an aqueous organic compound, usually N-methylmorpholine-N-oxide (NMMO). Lyocell has a tenacity much higher than regular viscose. While the lyocell in the conditioned state normally shows a breaking toughness of approximately 37 cN / tex, regular viscose under the same conditions shows a breaking toughness of less than 25, but which depends strongly on the individual production process.

[0008] Nylon-6.6, for comparison, has a breaking toughness of about 56 cN / tex and cotton of about 25cN / tex.

[0009] In addition to the cotton and nylon fabrics used by the US Army, certain nylon / Lyocell fabrics have been produced experimentally. These nylon / lyocell fabrics were produced by weaving a Lyocell weft in a continuous filament nylon warp. Although Lyocell is produced as a cut fiber, and rolled in threads so that it can be woven or knitted to form garments, this is not the case for nylon. Much of the nylon is made as a continuous filament material composed of warp threads. A warp is effectively a set of threads that are wrapped around a cylinder and arranged on a loom before starting to weave. The weft thread is passed back and forth through the warp generally using a shuttle. The warp must be formed before starting and warps of continuous nylon filaments were already available. The experimental fabrics were made by weaving a Lyocell yarn as a weft through the continuous filament nylon warp threads. These tissues have not been used commercially at any scale and were made purely as an experiment. Nylon cut fibers, that is, fibers cut to a defined length after extrusion and rolled up as threads, were never used for this application.

[0010] Another artificial cellulosic fiber other than Lyocell is modal, which is produced by a modified viscous process. The Modal is another artificial fiber of high tenacity cellulose, since it shows a breaking strength of approximately 35 cN / tex in the conditioned state. According to the definition of BISFA, Modal fibers are cellulose fibers that have a high breaking strength and a high wet modulus. The breaking force (Bc) of a modal fiber in the conditioned state is Bc (cN); 1.3�T + 2T. The force (Bm) necessary to produce an elongation of 5% in the wet state of a modal fiber is Bm (cN); 0.5 * T. T is the average linear density in decitex.

[0011] Mixtures of lyocell and modal are also known in the market, but so far they have not been sold in large quantities.

[0012] It is an object of the present invention to provide a fabric that has a good balance between comfort for the wearer of clothing made from the fabric and good abrasion and tear resistance. Obtaining a good level of comfort or wear resistance and tearing is something that is easily done. However, it is much more difficult to obtain both since the properties of the tissues necessary for good comfort and the properties of the tissues required for good wear and tear resistance are usually mutually exclusive.

[0013] It is a preferred additional object to produce a fabric that can be dyed uniformly, especially with dyes commonly used in the dyeing of military uniforms, where said dyes have infrared reflectance (IR) characteristics that can be adapted to the nature of the camouflage applied to the uniform.

[0014] Known FR finishes often significantly reduce the mechanical properties of tissues containing cellulosic fibers. Therefore, it is another preferred additional object to produce a fabric that can be treated with a flame retardant ("FR" Flame retarding) finish, for example, Proban®, without losing too much strength and abrasion resistance.

[0015] A further object of the invention is to provide a thread that can be used to produce a fabric with the properties mentioned above.

[0016] By means of the present invention, a thread is provided consisting of an intimate mixture of discontinuous nylon fiber and a discontinuous fiber of high tenacity artificial cellulose and a fabric containing said yarn. Preferably, the high tenacity artificial cellulose discontinuous fiber shows a breakability in a conditioned state of more than 32 cN / tex.

[0017] The thread may contain 10 to 75% nylon and the fabric may contain 10% to 50% nylon. Preferably, the balance in each case is of cellulose fiber of high artificial toughness but in any case, the fabric made of yarn must contain at least 50% cellulose fiber of high artificial toughness.

[0018] The term nylon, as used herein, refers to the group of plastics known as polyamides. Nylons are characterized by amide groups (CONH) and cover a range of types of materials, for example, Nylon 4.6; Nylon 6; Nylon 6.6; Nylon 12; Nylon 6.12. All are suitable although nylon 6 and nylon 6,6 are preferred.

[0019] In addition, preferably the artificial high tenacity nylon and cellulose fiber both have a medium or very similar linear density ("title") in decitex (dtex). For example, a 1.7 dtex or 1.4 dtex lyocell fiber can be mixed with a 1.7 or 2.0 dtex nylon fiber. In general, similar mean linear densities mean a difference of no more than 50% between the two fibers.

[0020] The length of discontinuous nylon fiber and artificial high tenacity cellulose fiber is also the same or very similar. For example at 38 mm discontinuous fibers of Lyocell can be mixed with 35 to 40 mm of discontinuous nylon fibers, more preferably with 38 mm discontinuous fibers of nylon. In general, similar fiber lengths mean a difference of no more than 15% in length between the two fibers.

[0021] The artificial high tenacity cellulose fiber is preferably a Lyocell discontinuous fiber, a Modal discontinuous fiber or a mixture thereof.

[0022] Lyocell and modal have a higher breaking toughness than other cellulosic materials including cotton. They also have a high wet strength. Therefore, a significant effect on the tear resistance of the tissue can be expected. But since nylon has an even higher breaking toughness, the expert would expect that the breaking strength of a fabric containing both nylon and a high strength artificial cellulose fiber would decrease if the amount of nylon decreased. Therefore the expert would incorporate only the amount of cellulose fiber that is needed to create sufficient comfort for the user.

[0023] However, surprisingly, it has been found that by incorporating increasing amounts of artificial high tenacity cellulose fiber the tear resistance of the resulting tissue increases. Therefore, a fabric consisting of yarns mixed from high tenacity artificial cellulose discontinuous fiber and discontinuous nylon fiber have high tensile strength and gain strength from both nylon fibers and high cellulose fibers. artificial toughness.

[0024] Additionally, it has been found that to obtain the benefit of both the discontinuous nylon fiber and the high strength artificial cellulose discontinuous fiber, fibers must be used to make the yarn.

[0025] When the artificial high tenacity cellulose fiber is mixed with nylon, it does not provide an advantage of exceeding 20% nylon. Abrasion resistance, tensile strength and tear resistance have almost all reached a level suitable for high performance applications.

[0026] The artificial high tenacity cellulose fiber can be a dull fiber, that is to say an artificial cellulose fiber containing a matting agent, for example TiO2. This can give certain advantages such as improved sun protection for use in desert areas.

[0027] The artificial high tenacity cellulose fiber can be a bright fiber, that is to say a high artificial artificial toughness cellulose fiber that does not contain a matting agent.

[0028] By the present invention, a fabric is also provided which contains a thread as described above.

[0029] In addition, by means of the present invention, a fabric is also provided which contains a yarn consisting of an intimate mixture of discontinuous nylon fiber and high tenacity artificial cellulose discontinuous fiber. The fabric according to the invention may contain from 10% to 50% nylon. Preferably, said fabric is a woven fabric and contains said thread both in the warp and in the weft.

[0030] The fabric may have a basis weight in the area of 100 to 500 g / m2 preferably 120 to 300 g / m2, more preferably 180 to 250 g / m2.

[0031] The fabric may be a twill weave and may be a 2x1 twill. It could also be of another construction, for example, flat.

[0032] Preferably the fabric has a Martindale abrasion resistance of at least 60,000 rubs, preferably at least 100,000 rubs, and a tear resistance of at least 20 Newtons, preferably at least 30 Newtons.

[0033] As the fabrics according to the invention are mainly used for military applications and work clothes, which can be treated with various finishes, such as printing liquids, FR finishes or IR reflectance finishes. According to the general experience, the finishes can affect the original properties of the fibers or threads. But for example, if a FR® finish FR finish is applied on the upper part of the fabric according to the invention, the resistances are maintained quite well. Both tensile and tear strength decrease approximately 10-15% but abrasion resistance is still greater than 100,000.

[0034] The Proban® process is based on the application of THPC (Tetrakishidroxymethylphosphonium chloride) with urea to generate a pre-condensate. to generate a pre-condensed the tissue and the tissue is dried at ~ 15% moisture content. The tissue is then exposed to ammonia vapors in a special reaction chamber, and then an oxidation with hydrogen peroxide. This process is well known to the expert. Chemicals and instructions are available at Rhodia.

[0035] A suitable similar FR finish is the Pyrovatex ® finish which is also known to be applicable to cellulosic fibers such as modal or Lyocell. Pyrovatex® is a durable phosphorus-containing finish created by using dimethylphosphonopropionamide N-methylol in combination with trimethylolmelamine and phosphoric acid as a catalyst in a dry curing process. Chemicals and instructions are available at Huntsman.

[0036] Due to the intended use of the threads according to the invention they can also be used in knitted fabrics. The resulting knitted fabrics show a very high resistance to blowouts combined with superior comfort. The abrasion resistance of the knitted fabrics shows the same dependence on the proportion of the cellulosic / nylon mixture as the knitted fabrics. Due to the more open construction of a knitted fabric, the abrasion resistance as measured by the Martindale test is generally lower than that of the woven fabrics. However, for many applications a knit construction is needed, especially when the demand for comfort of use and elasticity is high, but it has to be combined with certain durability requirements, for example, wear for corporate clothing. For those applications an abrasion resistance of at least 25,000 rubs would be sufficient.

[0037] The fabrics according to the invention can be used for the manufacture of work clothes, business clothes or uniforms. Due to their good abrasion resistance they can also be used for the manufacture of upholstery fabrics for furniture, office chairs or seats in transport vehicles such as cars, buses, trains or airplanes. In upholstery fabrics according to the invention, FR finishes are also applicable. Non-durable FR chemicals are also applicable for these purposes, which are well known to those skilled in the art, such as a mixture of boric acid and borax or ammonium salts of strong acids, especially phosphoric acid, such as diammonium phosphate or sulfamate. ammonium or ammonium bromide. An additional field of use for fabrics according to the invention is the manufacture of hospital and hotel bedding, especially when

5 use industrial laundries for washing.

[0038] A possibility to further increase the positive properties of the products according to the invention is the use of lyocell fibers with incorporated chitosan, which is already known from WO 2004/007818 and the Austrian utility model AT 008 388 U2. This will give the tissues an anti function

10 bacterial, as well as better comfort to the skin.

[0039] It is also possible to combine lyocell fibers with incorporated chitosan with finishes such as those described above, especially with FR finishes such as Proban® or Pyrovatex®. It will be carried out especially in applications where a fabric should have both advantageous properties.

[0040] However, another object of the present invention is a garment, which contains a fabric as described above. This garment is preferably work clothes, business clothes or a uniform, although it can also be any other type of garment, for which the typical properties of said fabric are advantageous.

[0041] Another object of the present invention is upholstery or bedding, which contains this fabric as well as a piece of furniture containing said upholstery.

[0042] The invention will now be illustrated by way of examples. These examples are not limiting the scope of the invention in any way.

25 Examples 1 to 6

[0043] Commercially available PA-6.6 discontinuous fibers with a 2.0 dtex titer and 38 mm cut length were mixed according to the ratios described in Table 1 with commercially TENCEL® discontinuous fibers

30 available with a title of 1.4 dtex and cut length of 38 mm and rolled in a thread of Nm 1/26 (Ne 1/15). The threads were further processed by weaving 2x1 twill with a weight of 249 g / m2 and 32 ends and 24 tips. The warped fabrics were sewn, scorched, seasoned, dried, heated to 205 ° C, printed to meet the army's IR reflectance specifications and finished with an FC water repellent. These procedures are well known to any person skilled in the art. Tear resistance was measured

35 in the warp as well as in the weft direction and the Martindale test was applied to each fabric thus finished.

Table 1

Example

Tencel / PA ratio 6.6 [p / p] Thread tenacity [cN / tex] Tear resistance of the warp [N] Tear resistance of the weft [N] Martindale [rubs]

1 Comparison

100/0 25.4 18 30 20,000

2

90/10 24.0 25 32 65,000

3

80/20 23.3 26 42 > 100,000

4

70/30 22.0 28 40 > 100,000

5

60/40 20.9 28 42 > 100,000

6

50/50 20.4 29 Four. Five > 100,000

[0044] It can be clearly derived from Table 1 that the highest improvement in the mechanical properties of the tissue

40 appears when the nylon content is increased from zero to 20%. Next, practically important values are obtained and the increase in more quantities of Nylon only translates into slight improvements. Martindale tests were halted for economic reasons when a level of 100,000 rubs was reached.

[0045] In the tissues of examples 1, 3, 4 and 5 the GATS test was applied, which gives an impression on speed

45 to which sweat will move away from the user's body. The graphs are shown in figure 1. The tendency to point out is that in general the higher the content of TENCEL, the faster the water absorption (slope of the graph), and the greater the volume that can be maintained (height of the graph). Speed is the key point.

Examples 7 to 9:

50 [0046] 2x1 twill were made from 1/15 Ne wire containing a Tencel / PA-6.6 70% / 30% (but / weight) fiber blend according to example 1. The weight and finish varied according to Table 2, but the process steps were the same as in Examples 1 to 6. In Example 8 a Proban® treatment was then applied. In example 9 a different construction of the

55 woven, but using the same threads as in example 7.

Table 2

Example

Construction [ends / tips] Fabric weight [g / m2] Tear resistance of the warp [N] Tear resistance of the weft [N] Martindale [Rubs] Note

7

39/22 205 35 27 > 100,000 -

8

39/22 205 27 twenty-one > 100,000 FR Proban finish

9

39/20 179 36 31 > 100,000 Lower weight

[0047] It can be seen that the three structures according to the invention comply with the United Kingdom military specification of 28 cN (warp), 20 cN (weft) and 45,000 Martindale rubs. The fabric of Example 8 also passed the flame retardant test of EN 532.

Example 10:

[0048] A 2x1 ripstop twill with 30 ends / 22 tips and 180 g / m2 was made from 70/30 thread of Example 4 10 but with a 350f / 136 nylon filament ripstop thread each ninth tip. Table 3 shows the comparison with the United Kingdom military specification for ripstop fabric.

Table 3

Example

Tear warp resistance [N] to the Tear resistance of the weft [N] Martindale [rubs] Air permeability [l / m2s]

Specification

25 60 30,000 200

10

39 > 50 unable to tear > 100,000 415

15 Examples 11 to 13:

[0049] A single jersey was knitted with a Nm50 / 1 ring thread containing the same fibers as those used in Examples 2 through 6 with the various compositions listed in Table 4. The knitted fabrics were dyed with a common reactive dye.

20 Table 4

Example

Tencel / PA ratio 6.6 [p / p] Martindale [rubs]

11 Comparison

100/0 13,000

12

95/5 18,000

13

90/10 28,500

[0050] As in the manufactured fabrics, a strong increase in abrasion resistance was observed by adding small amounts of nylon.

25 Example 14:

[0051] A yarn was made as in Example 3, but using a 1.4 dtex lyocell fiber containing chitosan ("Tencel C" by Lenzing AG, containing 0.5% (w / w) Chitosan in the fiber) instead of regular fiber

30 Tencel The Tencel C: PA 6.6 ratio was 80% / 20% (w / w). This thread was processed in a 2x1 twill with a weight of 203 g / m2. The measured properties are indicated in table 5.

Example 15:

[0052] A yarn was made as in Example 3, but using a 1, 4 dtex modal fiber produced by Lenzing AG instead of the Tencel fiber. The modal ratio: PA 6.6 was 80% / 20% (w / w). This thread was processed in a 2x1 twill with a weight of 212 g / m2. The measured properties are indicated in table 5.

Table 5

Example

Tear warp resistance [N] to the Tear resistance of the weft [N] Martindale [rubs] Air permeability [l / m2s]

14

Four. Five Four. Five 84,000 326

fifteen

39 30 75,000 352

Claims (21)

one.

Thread consisting of an intimate mixture of two types of fibers, characterized by the fact that the first type of fibers is a discontinuous nylon fiber and the second type of fibers is a discontinuous cellulose fiber of artificial high tenacity that has a toughness in the break in the conditioned state of more than 32 cN / tex and the content of the discontinuous nylon fiber in the mixture is in the range of 10% to 75%.

2.

Thread according to claim 1, wherein the length of discontinuous fiber of the nylon and cellulose fibers is the same or very similar.

3.

Thread according to claim 1, wherein the discontinuous cellulose fiber is a Lyocell discontinuous fiber, a Modal discontinuous fiber or a mixture thereof.

Four.

Thread according to claim 1, wherein the nylon material is selected from the group consisting of Nylon-4,6, Nylon-6, Nylon-6,6, Nylon-12 and Nylon-6,12.

5.

Thread according to claim 1, wherein the nylon material is Nylon-6 or Nylon-6.6.

6.

Use of the yarn according to any of the preceding claims for the manufacture of a fabric, characterized in that said fabric contains at least 50% of a discontinuous cellulose fiber of high artificial toughness.

7.

Fabric, which contains a thread according to any of the preceding claims.

8.

Fabric according to any of the preceding claims, wherein the fabric contains between 10% and 50% nylon.

9.

Fabric according to claim 7, wherein the fabric is a woven fabric that contains this thread both in the warp and in the weft

10.

Fabric according to any of claims 7 to 9, which has a Martindale abrasion resistance of at least 60,000 rubs.

eleven.

Fabric according to any one of claims 7 to 10, showing a tear strength of at least 20 Newtons.

12.

Fabric according to any one of claims 7 to 11, wherein the fabric has a basis weight of 100 to 500 g / m2.

13.

Fabric according to any one of claims 7 to 8, wherein the fabric is a knitted fabric.

14.

Fabric according to claim 13, showing a Martindale abrasion resistance of at least 25,000 rubs.

fifteen.

Fabric according to any of the preceding claims, containing a FR finish.

16.

Use of the fabric according to any of the preceding claims for the manufacture of work clothes, business clothes or uniforms.

17.

Use of the fabric according to any of the preceding claims for the manufacture of upholstery fabric for furniture, office chairs or seats of cars, trains or airplanes.

18.

Use of the fabric according to any of the preceding claims for the manufacture of bedclothes for hospitals and hotels.

19.

Garment, which contains a fabric according to any of the preceding claims.

twenty.

Bedding, containing a fabric according to any of the preceding claims.

twenty-one.

Furniture, office chairs or seats for use in transport vehicles containing upholstery containing a fabric according to any of the preceding claims as upholstery fabric.