Heat resistant outershell fabric

Abstract

The present invention relates to a thermally-resistant woven fabric and/or multiple ply fabric sheet for use as single or outer layer of protective garments, of the type comprising an inside fabric layer and an outside fabric layer joined together by an array of connecting lines. The woven fabric and/or multiple ply fabric sheet comprise yarns, wherein said yarn comprises i) meta-aramid ii) from about 5 to 10 weight % of polyamide and iii) at least 2 weight % of antistatic fibers, the weight % being based on the total weight of the yarn.

Claims

1. A yarn for a thermally resistant fabric sheet, wherein said yarn comprises i) meta-aramid ii) from about 5 to 10 weight % of polyamide and iii) at least 2 weight % of antistatic fibers, the weight % being based on the total weight of the yarn, wherein the polyamide is either an aliphatic or semi-aromatic polyamide.

2. The yarn according to claim 1, wherein said yarn comprises approximately i) 91 weight % meta-aramid ii) 7 weight % polyamide iii) 2 weight % antistatic fibers, the weight % being based on the total weight of the yarn.

3. The yarn according to claim 1 or 2, wherein the linear density Nm of the yarn is from about 40/2 to about 140/2.

4. The yarn of claim 3, wherein the linear density Nm of the yarn is about 80/2.

5. A woven fabric sheet comprising the yarn of claim 1 or 2.

6. The woven fabric according to claim 5, wherein warp and weft are made from the same yarn.

7. The woven fabric according to claim 5, wherein the fabric is a plain weave.

8. A multiple ply fabric sheet comprising at least one ply made of the woven fabric of claim 5.

9. The multiple ply fabric sheet according to claim 8, wherein said fabric is a two-ply fabric and wherein the other ply is made of a 100% para-aramid yarn.

10. The fabric sheet according to claim 8, wherein said fabric is a two-ply fabric and wherein the two plies are formed by an inside fabric layer (B) and an outside fabric layer (A) joined together by an array of connecting lines (10).

11. The fabric sheet of claim 10, wherein the inside fabric layer (B) and outside fabric layer (A) are both woven fabrics and are joined together by an array of woven connecting lines (10) formed by interwoven threads making up the fabrics.

12. The fabric sheet according to claim 10, wherein the array of connecting lines (10) is constituted by a plurality of connecting lines being arranged in an isolated group (30) of a generally Y-shaped configuration with three lines extending from a convergence point (40), the lines being connected together at their convergence point and wherein each isolated group is spaced apart from one another.

13. A garment, in particular a garment for exposure to high temperature environments, comprising the woven fabric sheet of claim 5.

14. A garment, in particular a garment for exposure to high temperature environments, comprising the woven fabric sheet of claim 10, wherein the outside fabric layer (A) of the fabric sheet is disposed on the outside of the garment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a picture of the outside fabric layer (A) of a multiple ply fabric sheet according to the invention, with an array of Y-shaped connecting lines.

(2) FIG. 2 is a picture of the outside fabric layer (A) of a multiple ply fabric sheet according to comparative example 1.

(3) FIG. 3 is a picture of the outside fabric layer (A) of a multiple ply fabric sheet according to comparative example 2.

(4) FIG. 4 is the weaving construction of a multiple ply fabric sheet according to example 1 of the invention.

DETAILED DESCRIPTION

(5) Disclosed herein is a yarn for a thermally resistant fabric sheet, wherein said yarn comprises:

(6) i) meta-aramid

(7) ii) from about 5 to 10 weight % of polyamide and

(8) iii) at least 2 weight % of antistatic fibers, the weight % being based on the total weight of the yarn.

(9) In a preferred embodiment, the yarn of the present invention comprises approximately

(10) i) 91 weight % meta-aramid

(11) ii) 7 weight % polyamide

(12) iii) 2 weight % antistatic fibers, the weight % being based on the total weight of the yarn.

(13) The polyamide used in the yarns of the present invention is selected from the group of aliphatic and semi-aromatic polyamide, preferably aliphatic polyamide. Particularly preferred is a polyamide 66.

(14) Antistatic fibers are selected from the group consisting of carbon core polyamide sheath or metal core polyamide sheath.

(15) In a preferred embodiment, the count of the yarns of the invention has a linear density Nm from about 40/2 to about 140/2, more preferably about 80/2.

(16) A woven fabric according to the present invention can be made with the yarns disclosed above. In particular, the same yarns could be used for both the warp and weft of the fabric.

(17) In a preferred embodiment, the woven fabric is a plain weave.

(18) In another embodiment, multiple ply fabric sheets comprising at least one ply made of the woven fabric described above are provided.

(19) Multiple ply fabric sheets of the present invention can be made of two plies wherein one ply is formed by an inside fabric layer (B) and the other ply by an outside fabric layer (A) joined together by an array of connecting lines (10).

(20) Preferably, the two plies are interwoven together, by known techniques, and the connecting lines (10) are made with the yarns of the inside fabric layer (B) and/or outside fabric layer (A). Preferably, the connecting lines (10) are made with the yarns of the inside fabric layer (B).

(21) Preferably, the multiple ply fabric sheet of the present invention is a two-ply fabric wherein one ply, the outside fabric layer (A), is made with the woven fabric of the present invention and the other ply, the inside fabric layer (B), is made of a yarn that is both heat resistant and has low thermal shrinkage, such as polyparaphenylene terephtalamide (para-aramid), polyamideimide, and copolyimide. Particularly preferred is multiple ply fabric sheet wherein the inside fabric layer (B) is made of a yarn 100% para-aramid yarn. The yarn count of the inside fabric layer (B) can be the same or different than the yarn count of the outside fabric layer (A). Particularly preferred is a two-ply fabric wherein the inside fabric layer (B) and the outside fabric layer (A) have a plain weave construction with the same yarn count and the same number of yarns per centimeter in both warp and weft directions.

(22) When exposed to intense heat, the outside layer (A) is caused to shrink and because of the connecting lines (10) the inside layer (B) is buckling leading to an increased thickness of the multiple ply fabric sheet wherein air is entrapped between the plies.

(23) As shown in FIG. 1, the array is made up of a plurality of connecting lines being arranged in an isolated group (30), each group being composed of three connecting lines (10) arranged in a Y shape.

(24) In on preferred embodiment, two of the three connecting lines (10) of each Y are of substantially equal length and extend at substantially equal angles (of) 120° from a convergence point (40) where the connecting lines (10) are connected together.

(25) In the example of FIG. 1, the three connecting lines (10) of each Y are all parallel to corresponding lines (10) of the other Y-shaped groups. Moreover the parallel lines (10) of different groups are all exactly or approximately aligned with and parallel to lines (10) of the other groups. So, the vertical stems of the Ys are aligned in vertical rows, and the inclined arms of the Ys are also aligned along rows. The Y-shapes of every alternate vertical row of the Y shapes are aligned both vertically and horizontally, as can be seen for the left and right vertical rows in FIG. 1.

(26) Each Y-shaped group (30) of connecting lines (10) is isolated from the other groups. The connecting lines (10) are arranged at different angles and are spaced apart from one another to leave, between the isolated Y-shaped groups of connecting lines (10), gaps (50) where the two layers (A), (B) are not connected to one another.

(27) Other shapes of grouped connecting lines are possible, for example L-shapes, T-shapes, H-shapes, X-shapes, Z-shapes and so on (with or without gaps in the shapes), and it is also possible to include a plurality of curved connecting lines as individual lines in say C-shape or S-shape, or grouped lines where two straight lines are connected by a curved section for example to form a U-shape. Various shapes and patterns can also be composed from an array of individual isolated connecting lines.

(28) A two ply fabric is one specific embodiment but other configurations are envisaged with more layers than only two.

(29) The woven fabric and/or the multiple ply fabric sheet of the present invention are also suitable to make garments, in particular garments for exposure to high temperature environments. In particular, the woven fabric and/or the multiple ply fabric sheet of the present invention can be used as the outer layer of such garments. In the case of multiple ply fabric sheet, the outside fabric layer (A) of the fabric sheet is disposed on the outside of the garment. Optionally, the woven fabric and/or the multiple ply fabric sheet of the present invention can be used in association with breathable membrane and/or lining to make a garment.

(30) The garment according to the present invention can be manufactured in any possible way. The garment can be made from a multilayer structure. Such multilayer structure preferably comprises, but is not limited to, an internal layer (lining), optionally an intermediate layer made of a breathable waterproof material, and an outer layer made of the multiple ply fabric sheet according to the invention. The most internal layer directly faces the wearer's skin or the wearer's underwear.

(31) The garment according to the present invention can be of any kind including, but not limited to, jackets, coats, trousers, gloves, overalls and wraps

EXAMPLES

Example 1 of the Invention

(32) A two-ply woven fabric sheet (layer A and layer B) was prepared with the following two yarn combination.

(33) A blend of fibers consisting of: 91 weight % of meta-aramid having a cut length of approximately 100 mm; 7 weight % of polyamide 66 and 2 weight % of antistatic fibers made of carbon core polyamide sheath spun into one type of single long staple yarns Y-A1 using long staple processing equipment.

(34) Single Yarn Y-A1 had a linear density of Nm 80/1 and a twist of 850 Turns Per Meter (TPM) in the Z direction. Two single Y-A1 yarns were then plied and twisted together. The resulting plied and twisted yarn (TY-A1) had a linear density of Nm 80/2 and a twist of 760 TPM in the S direction. TY-A1 was subsequently treated with steam to stabilize its tendency to wrinkle

(35) TY-A1 yarns were used as warp yarn and weft yarn for forming the first ply (layer A).

(36) For the second ply, the weft and warp Y-B1 yarns were prepared as follows: 100 weight % para-aramid stretch broken fibers were ring spun into a single staple yarn Y-B1 using a long staple processing equipment.

(37) Single yarn Y-B1 had a linear density of Nm 80/1 and a twist of 700 TPM in the Z direction. Two single Y-B1 yarns were then plied and twisted together. The resulting plied yarn (TY-B1) had a linear density of Nm 80/2 and a twist of 700 TPM in the S direction. TY-B1 was subsequently treated with steam to stabilize its tendency to wrinkle TY-B1 was used as warp yarn and weft yarn for the second ply.

(38) A fabric weave having an array of Y-shaped connecting lines like in FIG. 1 was prepared. This weave fabric had 45 yarns/cm (warp) (22.5 yarns/cm for each ply), 45 ends/cm (weft) (22.5 ends/cm for each ply) and a specific weight of 240 g/m2.

(39) The performance of the multiple ply fabric sheet is given hereunder in table 1.

Comparative Examples 1 and 2

(40) Comparative examples 1 and 2 were made with different yarns and weaving construction than example 1. However, the weight of the multiple ply fabric sheet is substantially the same for Example 1, comparative example 1 and comparative example 2.

(41) Specific yarn and construction are given in table 1 for comparative examples 1 and 2.

(42) The examples confirm the superior performance of the multiple ply fabric sheet according to the invention.

(43) As shown in table 1, multiple ply fabric sheet of example 1 shows high mechanical, thermal and electric arc performances, very good abrasion resistance, very good durability (no fibrillation of para-aramid, good color retention), soft hand, while the multiple ply fabric sheets of comparative examples 1 and 2 show lower abrasion and snagging resistance. In addition the comparative examples show poor durability when washed several times compared to the example of the invention.

(44) Properties measurements were made according to standards (ISO, ASTM etc. . . . ) and are given in table 1.

(45) ATPV stands for Arc Thermal Performance Value.

(46) FFF stands Fabric Failure Factor.

(47) TABLE-US-00001 TABLE 1 EXAMPLE 1 COMPARATIVE EXAMPLE 1 COMPARATIVE EXAMPLE 2 warp yarn 80/2 91% meta-aramid 70/2 93% meta-aramid 100/2 93% meta-aramid 1 7% polyamide 66 5% para-aramid 5% para-aramid 2% antistatic fibers 2% antistatic fibers 2% antistatic fibers Long staple Short staple Short staple yarn 80/2 100% para-aramid 70/2 100% para-aramid 100/2 100% para-aramid 2 Stretch broken weft yarn 80/2 91% meta-aramid 70/2 93% meta-aramid 100/2 93% meta-aramid 1 7% polyamide 66 5% para-aramid 5% para-aramid 2% antistatic fibers 2% antistatic fibers 2% antistatic fibers Long staple Short staple Short staple yarn 80/2 100% para-aramid 70/2 100% para-aramid 100/2 100% para-aramid 2 Stretch broken weight (g/m2) 240 239 232 ratio face (A):face (B) 1:1 1:1 1:1 construction (yarns/cm) 45 × 45 41 × 41 56 × 56 weave Plain weave Twill 2/1 Plain weave See FIG. 1 See FIG. 2 See FIG. 3 tensile strengths (N) 2600 2770 2280 ISO 13934-1 2900 2780 2830 tear strengths (N) 240 284 117 ISO 13934-2 260 329 165 abrasion (cycles) 72000 48000 18000 ISO 12947-2 air permeability (l/m2/s) 245 317 184 ISO 9237 FFF = (TPP/weight) * 100 6.8 6.98 6.72 84 kW/m2, spacer ISO 17492 snagging 3 3 ASTM D3939-2 4 3-4 pilling (4000 cycles) 4 3-4 3-4 ISO 12945-2 ATPV (cal/cm2) 16 24 12 EN 61482-1-1