AU2014291849A1

AU2014291849A1 - Fire resistant textile material

Info

Publication number: AU2014291849A1
Application number: AU2014291849A
Authority: AU
Inventors: Robert BEADLE; Charlotte Brandt; Simon Callum BURNETT-BOOTHROYD; Thomas Hainsworth; Derek Walker
Original assignee: Hainsworth AW and Sons Ltd
Current assignee: Hainsworth AW and Sons Ltd
Priority date: 2013-07-19
Filing date: 2014-07-04
Publication date: 2016-01-21
Anticipated expiration: 2034-07-04
Also published as: AU2014291849B2; EP3022343A1; WO2015008030A1

Abstract

A fire resistant textile material is composed of woven fabric having a face surface and a back surface, the fabric comprising polyparaphenylene isophthalamide (meta-aramid) fibres or a blend of meta-aramid with polyparaphenylene terephthalamade (para-aramid) fibres; and a blend of cellulose fibres and wool fibres; wherein the meta-aramid fibres are predominantly located on the face surface and the blend of cellulose fibres and wool fibres is predominantly located on the back surface.

Description

WO 2015/008030 PCT/GB2014/052051 FIRE RESISTANT TEXTILE MATERIAL This invention relates to fire resistant textile materials and garments made from these materials. The invention relates particularly but not exclusively to articles 5 of clothing for use by fire fighters and for textiles for manufacture of such clothing. European legislation requires employers to provide garments which protect their employees against hazards to which they may be exposed. Clothing for protection against heat and flame must pass minimum performance requirements for 10 flame, radiant heat, heat resistance, tensile and tear strength, abrasion resistance and penetration by water and liquid chemicals. The assembled garments must achieve levels of resistance to heat transfer by both flame and radiant heat. One of the most effective ways to reduce second and third degree bums is to 15 make sure that the barrier of protective clothing between the heat source and the skin remains intact during exposure. This is referred to as the break open resistance or non-break open protection. US 6699802 discloses a fire resistant textile material comprising a woven 20 face fabric composed of meta-aramid fibres including a woven mesh of low thermal shrinkage fibres, for example para-aramid fibres. An object of the present invention is to provide a fire resistant textile material with reduced weight, increased drape and improved comfort in use. 25 According to the present invention a fire resistant textile material is composed of woven fabric having a face surface and a back surface, the fabric comprising: polyparaphenylene isophthalamide (meta-aramid) fibres; and 30 a blend of cellulose fibres and wool fibres. wherein the meta-aramid fibres are predominantly located on the face surface and the blend of cellulose fibres and wool fibres is predominantly located on the back surface.

WO 2015/008030 PCT/GB2014/052051 2 The term "predominantly" refers to an amount of 60% or more, preferably 75% or more, by yam count. A preferred polyparaphenylene isophthalamide (meta-aramid) is Nomex 5 (Registered Trade Mark). A particularly preferred fibre comprises 95% Nomex, 3% Keviar (Registered Trade Mark) and 2% antistatic (P 140) fibres. Alternatively, meta/para aramid blends such as TypeT450 (DuPont) may be employed. A preferred polyparaphenylene isophthalamide (meta-aramid) fibre may 10 comprise Nomex (Registered Trade Mark). Alternative fibres may comprise polybenzimidazole (PBI), poly(paraphenylenbenzobisoxazole) (PBO) or blends thereof. A preferred cellulose fibre is a fire retardant viscose fibre. This may be 15 manufactured from wood pulp treated with a fire retardant. Lenzing FR. 2.2 Decitex fibres are preferred. Preferred wool fibres are shrink resistant wool fibres preferably with a thickness about 15.5 pm to about 29.5 ptm, more preferably 20.8 pm. The blend may 20 comprise from 25% wool and 75% cellulose to 75% wool and 25% cellulose, preferably about 50% wool and about 50% cellulose. Preferred fabric materials consist of a face and a back, wherein the face of the fabric consists of meta-aramid and optional further fibres and the back of the 25 fabric consists of cellulose fibres and wool fibres and optional meta-aramid fibres. The fabric is preferably a woven twill ripstop. A preferred fabric may be a 2 x 1 twill ripstop, a 3 x 1 twill ripstop or a 4 x 1 30 twill ripstop. Alternatively, a satin fabric, having the warp on the surface, may be employed.

WO 2015/008030 PCT/GB2014/052051 3 A fabric in accordance with this invention is particularly suited for use in a single layer or in direct contact with a wearer's skin in a multilayer garment, that is in garments wherein a lining is not present. 5 The use of meta-aramid, generally having thicker yams on the back, raises the fabric structure from the skin to provide an air layer, thereby increasing comfort and thermal protection for a wearer. The fabric creates a microclimate utilising the benefits of the hygrophilic properties of wool to help regulate temperature and humidity against a wearer's skin. 10 Preferred fabrics have more than 50% meta-aramid fibres on the face, more preferably more than 75% on the face. The number of threads or the weight of the warped yarns in relation to the 15 weft yams may be adjusted to achieve a desired percentage of meta-aramid on the face surface. Either the warp or weft may predominate, as convenient. In a preferred embodiment, the fabric may comprise a ripstop, preferably a 2 x 1 ripstop twill having a warp comprising meta-aramid or a blend thereof with other 20 fibres, for example Nomex T450 with a warp count of Nm 60/2. In a preferred fabric the weft may comprise a wool-cellulose blend with a weft count of Nm 60/2 (that is, two 60 Nm yarns twisted together) and Nm 40/2/2 (two 40 Nm yams twisted together and two of the resultant yams twisted together) 25 Nomex, with maximum weft mixing. Use of such a yam affords minimal contact with a wearer's skin. Use of a 2 x 1 twill allows an excess of meta-aramid, for example Nomex or blends thereof, in the warp to be provided on the fabric face. A ripstop is provided in 30 the warp & weft combination. Use of a ripstop affords good tear resistance and reduced surface contact in comparison to other fabrics. Dimensional stability is enhanced. Increased durability to washing may also be obtained.

WO 2015/008030 PCT/GB2014/052051 4 Double twisted yarns may be employed. The warp may have a yam count in the range of Nm 20/2 to 100/2, preferably Nm 30/2 to 80/2, more preferably Nm 40/2 to 60/2, especially Nm 60/2. When using Nm 60/2 the number of warp ends may be 4500 to 5600, typically 5168. 5 2 A preferred fabric weight may be 200 to 300, typically 240g/m2 A fabric in accordance with the present invention confers several advantages. The water absorbing or hydrophilic properties of wool combined with excellent 10 working properties of the cellulose fibres ensures efficient transfer of moisture away from a wearer's skin. The moisture is retained by the buffering effect of the wool by absorption and desorption before evaporation to maintain cool and dry wearing conditions during use. Lenzing (FR) and wool affords excellent thermal protection by absorption of heat energy with break open protection provided by the meta-aramid 15 fibres. Wool also provides inherent antimicrobial and antistatic properties to make the garment comfortable even after prolonged wearing or repeated washing or laundering. Water is released during thermal decomposition of a meta-aramid surface 20 layer upon exposure to high heat energy. This water may be absorbed by the underlying wool fibres. Evaporation of this moisture may enhance thermal protection of a user's skin. Thermal regulation is improved in warm dry conditions due to the unique 25 blend of wool / Lenzing and para-aramid fibres. The natural hydrophilic properties of wool facilitate vapour or moisture absorption and desorption in low relative humidity climates. The hygrophilic properties of Lenzing fibres serve to push moisture away. The fabric therefore serves as a heat exchanger and regulator. 30 The unique blend of the fibres and yams gives the fabric breathable buffer and thermal barrier properties which assist in keeping the wearer comfortable and avoids a liability to suffer from heat fatigue as commonly encountered with previously used products..

WO 2015/008030 PCT/GB2014/052051 5 The primary use of the fabric is a moisture management system coupled with a barrier to both radiant and convective heat extremes. These fabrics are particularly suited for use during wildland fire fighting. Other uses include Level 1 stationware and high voltage electrical engineering applications. 5 Tear Strength is increased due to the unique network of meta aramid fibres (which may be referred to as "tram lines") acting as strengthening support beams in the fabric structure and making it more durable and stable dimensionally. 10 When the face of the fabric is exposed to extreme heat and a consolidation occurs due to the nature of the aromatic fibres the heavier weft yarns (tram lines) act as a support to the fabric not only in providing dimensional stability but assists in the crimping effect of the structure thus getting volume into the structure. This property creates an increase in the thermal barrier protection by absorbing some of the energy 15 on exposure and has less surface contact with the wearer. The invention is further described by means of example, but not in any limitative sense, with reference to the accompanying drawings, of which: Figure 1 is a weaving plan of a fabric in accordance with this invention; and 20 Figure 2 is a plan view of the fabric in accordance with this invention. Example 1 The fabric comprises warp A consisting of meta-aramid (Nomex)/para aramid (Kevlar) yam). Weft A is a wool/Lenzing yam and Weft B is a meta-aramid 25 (Nomex) yam. The Weft A (Kevlar) yarns are each located between two Weft B (Nomex) yams. The Weft B yams are separated by 6 Weft A wool/Lenzing yarns to form a 2x1 twill ripstop fabric. Example 2 30 The fabric comprises warp A consisting of a PBI/para-aramid blend yam. Weft A is a wool/Lenzing yam and Weft B is a meta-aramid (Nomex) yam. The construction is the same as for Example 1.

WO 2015/008030 PCT/GB2014/052051 6 Example 3 The fabric comprises warp A consisting of a PBI/para-aramid blend yarn. Weft A is a wool/Lenzing yarn and Weft B is a meta-aramid (Nomex) yarn. The construction is the same as for Example 1. Warp A consists of PBO/para-aramid 5 blend yarns. Example 4 The fabric comprises warp A consisting of meta-aramid (Nomex)/para aramid (Kevlar) yarn). Weft A is a wool/Lenzing yarn and Weft B is a meta-aramid 10 (Nomex) yarn. The Weft A (Kevlar) yams are each located between two Weft B (Nomex) yarns. The Weft B yarns are separated by 6 Weft A wool/Lenzing yarns to form a 2x 1 twill ripstop fabric. Warp A consists of a meta-aramid/para-aramid blend including 2% of anti-static carbon fibre. 15

Claims

1. A fire resistant textile material is composed of woven fabric having a face surface and a back surface, the fabric comprising: 5 polyparaphenylene isophthalamide (meta-aramid) fibres or a blend of meta aramid with polyparaphenylene terephthalamade (para-aramid) fibres.; and a blend of cellulose fibres and wool fibres; wherein the meta-aramid fibres are predominantly located on the face surface and the blend of cellulose fibres and wool fibres is predominantly located on the back 10 surface.

2. A fire resistant textile material as claimed in claim 1, wherein the cellulose/wool blend is predominantly located on a back surface of the fabric. 15

3. A fire resistant textile material as claimed in claim 1 or 2, wherein the polyparaphenylene isophthalamide fibres comprise polyparaphenylene isophthalamide (meta aramid) fibres selected from polybenzimidazole (PBI) or poly(paraphenylenbenzobisoxazole) (PBO) or blends thereof. 20

4. A fire resistant textile material as claimed in any preceding claim, wherein the cellulose fibre is a fire retardant viscose fibre.

5. A fire resistant textile material as claimed in claim 4, wherein the cellulose fibre manufactured from wood pulp treated with a fire retardant. 25

6. A fire resistant textile material as claimed in any preceding claim, wherein the wool fibres are 20.8 ptm shrink resistant wool fibres.

7. A fire resistant textile material as claimed in any preceding claim wherein the 30 blend of cellulose fibres and wool fibres comprises by weight, from 25% wool and 75% cellulose to 75% wool and 25% cellulose.

8. A fire resistant textile material as claimed in claim 7, wherein the blend comprises 50% wool and 50% cellulose. 35 WO 2015/008030 PCT/GB2014/052051 8

9. A fire resistant textile material as claimed in any preceding claim comprising a 2 x 1 ripstop twill.

10. A fire resistant textile material as claimed in any preceding claim wherein the 5 weft comprises a wool-cellulose blend with a weft count of Nm 60/2 and a meta aramid with a weft count of Nm 40/2/2.

11. A fire resistant textile material as claimed in any preceding claim wherein the weft comprises a wool-cellulose blend with a warp count of Nm 60/2 and a meta 10 aramid with a warp count of Nm 40/2/2.

12. A fire resistant textile material as claimed in any preceding claim comprising double twisted yams. 15

13. A fire resistant textile material as claimed in claim 12, wherein the warp has a yarn count in the range of Nm 20/2 to 100/2.

14. A fire resistant textile material as claimed in claim 13, wherein the warp has a yarn count in the range of Nm 30/2 to 80/2. 20

15. A fire resistant textile material as claimed in claim 14, wherein the warp has a yarn count in the range of Nm 40/2 to 60/2.

16. A fire resistant textile material as claimed in claim 15, wherein the warp has a 25 yarn count is Nm 60/2.

17. A fire resistant textile material as claimed in claim 16, wherein the number of warp ends is 4500 to 5600. 30

18. A fire resistant textile material as claimed in any preceding claim, wherein the fabric weight is 200 to 300g/m 2 .

19. A fire resistant textile material further comprising a proportion of anti-static fibres. 35

20. A fire resistant textile material having a weaving plan as shown in Figure 1. WO 2015/008030 PCT/GB2014/052051 9

21. A fire resistant textile material substantially as hereinbefore described with reference to the accompanying drawings.