CN117730179A - Flame retardant fabric comprising cotton substitute - Google Patents

Abstract

The present disclosure relates to Flame Retardant (FR) treated fabrics comprising yarns formed from a mixture of natural and/or synthetic fibers, the fabrics further comprising FR treated lyocell fibers, wherein the FR treatment is a non-cellulose reactive FR treatment and the FR treated lyocell fibers have low fibrillation, e.g., whereby at least some of the hydroxyl groups are crosslinked with a reactive resin.

Description

Flame retardant fabric comprising cotton substitute

Technical Field

The invention relates to a flame-retardant fabric and a manufacturing method thereof. The fabric comprises a cellulose-based cotton substitute having heat and flame resistant properties.

Background

Many professions require individuals to risk exposure to extreme heat and/or flame. Typical examples are industrial workers, firefighters, police and military personnel. Where possible, to provide such personnel with appropriate fire protection clothing. These garments differ significantly from ordinary everyday garments in that they are made at least in part from flame retardant textiles.

The garment must pass minimum thermal performance requirements such as flame and/or heat resistance, resistance to fusion metals, arc resistance, low percentage of (estimated) body burns in thermal mannequin tests, limited burn-out times and high burn resilience, and radiation protection.

In addition to professional fire-resistant clothing, more general work clothes are often required to have improved fire-resistance, which can be certified according to one or more standards. Other important performance requirements are tensile and tear strength, elongation at break, abrasion resistance, resistance to crocking, and resistance to water and liquid chemical penetration.

In addition, it is considered important that the garment provide adequate comfort, for example by allowing vapor to be transported away from the body and ensuring that the garment is not too stiff. The garment must also be durable, i.e., the parameters disclosed above last at least the expected or certified life of the product. This may be defined by the number of wash cycles.

Furthermore, the garment must be printable or dyeable with durable results so that, for example, the garment may be dyed to increase visibility. A common standard for performance requirements of flame resistant garments made from flexible materials is ISO 11612.

For making celluloseKnown treatments for imparting flame retardancy to fibers or textile articles comprising cellulosic fibers areAnd (5) processing. This treatment comprises pad-dyeing the textile product with an aqueous solution comprising a tetrahydroxyalkyl phosphonium (THP) salt, which is pre-reacted with urea and the pH is adjusted to 5-8.

THP does not substantially react with cellulose fibres, nor with textile products comprising said fibres, but rather forms an enveloping network around and/or throughout the molecular structure of the cellulose fibres. Thus, the first and second substrates are bonded together,the treatment is a non-cellulose reactive treatment, which means that there is substantially no chemical reaction between THP and cellulose fibres. Alternative non-cellulose reactive treatments of Proban and THP can achieve the same effect.

An alternative flame retardant treatment is a treatment with an N-hydroxymethylphosphonate compound, such as N-hydroxymethyldialkylphosphonopropionamide. Commercially, such treatments are under the trademarkCP and->KWB supplies. In this case, the flame retardant compound is grafted onto the cellulose by reaction on the C (6) hydroxyl groups of the cellulose, thereby creating grafted protective phosphonopropionamide molecules on the outside of the cellulose fibers. Thus, this is an example of a cellulose reactive phosphorus-containing compound, as there is a reaction between cellulose and the phosphorus-containing compound. Thus, pyrovatex treatment has radically different chemistry and mechanism than Proban process.

Pyrovatex and Proban were developed to impart flame retardancy to cotton, but have many associated problems with the resulting fabric. US 3816068 A1 discloses a flame retardant for cellulosic fabrics and describes the disadvantages of the Pyrovatex process. Disadvantages of Pyrovatex treated fabrics include incompatibility with many other treatments and their propensity to hydrolyze over time. The Pyrovatex treated product requires at least one wash per year after production (whether or not in use) to prevent hydrolysis and the unpleasant odors associated therewith. In general, the degree of flame retardance achieved is more limited than THP treatment and the process is compatible with only up to 20% of synthetic fibers. EP 0709518 A1 discloses a Proban treated cotton fabric. This document aims at solving the problem of stiffness of Proban treated cotton.

There are also fibers that are inherently flame retardant in nature and do not require treatment to achieve such flame retardancy. Such fibers, including para-aramid and meta-aramid fibers, PPS, PBO, and PBI, may be referred to as flame retardant fibers. Other inherently flame retardant fibers include fibers extruded from fiber spinning dope to which flame retardant additives have been added prior to spinning, for example as a masterbatch. The resulting fibers include FR Lyocell, modacrylic, FR polyester, and FR polyamide FR. Hereinafter, the term Flame Retardant (FR) is used to refer to fibers that have been treated to render them flame retardant, rather than those fibers that have inherent flame retardant properties.

An increasing concern in the clothing manufacturing field is the selection of environmental options. While natural fibers such as cotton may be preferred over synthetic fibers in some respects, cotton is known to have a relatively high impact on its production requirements, particularly in terms of water usage. It is desirable to provide a cotton substitute to at least partially replace cotton or other natural fibers in flame retardant garments.

A cotton substitute made from source-reliable wood chip cellulose is lyocell. This is a material similar to rayon but without the disadvantages of the viscose process. It also has a significantly lower water footprint than cotton, with up to 95% reduction in water used. However, to date, it has not been possible to adequately replace cotton with lyocell in situations where flame retardancy is required in combination with durability and other coveralls requirements. In particular, the fibrillation tendency of lyocell has been regarded as a major drawback.

It is desirable to provide a substitute for conventional FR cotton that has a smaller environmental footprint but meets at least some of the quality requirements expected for protective clothing.

Disclosure of Invention

According to the present invention there is provided a Flame Retardant (FR) treated fabric comprising yarns formed from a mixture of natural and/or synthetic fibers, the fabric further comprising FR treated lyocell fibers, wherein the FR treatment is a non-cellulose reactive FR treatment and the FR treated lyocell fibers have low fibrillation. Hereinafter, the term "lyocell" is used to denote an artificial cellulose-based cotton substitute. In particular, these may represent cellulose fibers obtained by an organic solvent spinning process, although the invention may also be applied to some cellulose fibers obtained by a viscose process. Although lyocell is available as a material from laning AGThe product is well known, but other similar cellulose-based cotton alternatives are available and may be equally suitable. Lyocell may be present in the form of short fibres, long fibres or filaments or tapes. Furthermore, in this context, reference to natural and synthetic fibers is intended to exclude lyocell fibers, i.e. these fibers are other than lyocell. Any amount of lyocell may be present depending on the desired characteristics. In particular, 1 to 99wt% of lyocell, preferably 10 to 70wt%, more preferably 15 to 50wt% of lyocell or 20 to 35wt% of lyocell may be present.

It is well known that lyocell is susceptible to fibrillation. It is also understood that the tensile strength of lyocell decreases after it absorbs water, i.e. in the wet state of the fabric. As a result of the study in the context of the present invention, it was also revealed that fibrillation was further exacerbated by performing THP-type FR treatments. In the wet state, water can penetrate into the bundle of lyocell fibrils, resulting in exposure of the fibrils at the surface of the fibers. As experienced during conventional FR treatment, the rate of fibrillation increases with increasing pH and increasing temperature. Unlike cotton, lyocell does not crosslink naturally and it is therefore desirable to provide a finish that at least partially compensates for increased fibrillation. For lyocell-like materials, it is believed that the fibrils are at least partially bound together by hydrogen bonding between adjacent fibrils. A decrease in the degree of hydrogen bonding, for example in the presence of water or as a result of certain treatments, may lead to increased fibrillation.

The fabric may be subjected to an antigen fibrillating finish by application of suitable additives. Preferably, the additive is a substance that reacts with hydroxyl groups of cellulose to stabilize fibrils. This may be by increasing the presence of hydrogen bonds or by forming covalent bonds, thereby achieving improved crosslinking of the fibrils. Additives that crosslink by forming covalent bonds with hydroxyl groups of the cellulosic material may be referred to as reactive resins, thermosetting resins, or easy care finishes. Reactive resins include ethylene urea formaldehyde, propylene urea formaldehyde, methylated urea formaldehyde and dimethylol dihydroxy ethylene urea (DMDHEU) modified resins. The latter is a preferred option. It will be fully appreciated by those skilled in the art that the alternatives and equivalents described above may also be employed. In this context, hypofibrillation can be qualitatively determined by the presence of hydroxyl crosslinks with lyocell. Alternatively, it may be determined experimentally, for example by pilling, abrasion, color retention or other tests as defined below.

In one embodiment, the natural fibers comprise FR cotton. The fabric may have the general feel of a cotton fabric in which a portion of the cotton has been replaced with a lyocell substitute. Up to about 50% of the cotton can be replaced without significantly affecting the overall performance of the fabric. However, the softness of the fabric increases significantly and is generally perceived as very comfortable in use. However, in general, in the case of a cotton quilt lyocell replacement, a certain amount of stronger fibers, such as synthetic fibers, may be required to compensate for the loss of certain properties or to otherwise supplement the lyocell. In particular, lyocell generally has a slightly lower wet strength than cotton, but significantly reduced strength after THP treatment. Thus, polyester can be added to the fiber blend to compensate. However, it is not excluded that other natural fibres such as flax or wool may be present in greater or lesser amounts.

In an embodiment, the synthetic fibers comprise polyester. Other synthetic fibers such as polyamides or aramids are also contemplated and are not excluded from the possible inclusion of additionalA small amount of high performance synthetic fibers. In one embodiment, the synthetic fibers comprise recycled polyester. One preferred source of recycled polyester is from the company Messaging Yuhui (Unifi Inc)Which is a mechanically regenerated polyester. Chemically recycled polyesters may also be used. Recycled polyesters have a number of attractive advantages, such as 45% less energy consumption compared to virgin polyesters; the water consumption is reduced by nearly 20% compared with the virgin polyester; and the greenhouse gas emissions are reduced by more than 30% compared to virgin polyester. The recycled polyester has excellent strength characteristics and increased durability, although it is not reactive to many FR treatments. Synthetic fibers can exist in a variety of forms including short fibers, long fibers, and filaments.

It should be understood that a variety of possible fabrics are contemplated, including woven fabrics and knitted fabrics. Preferably a woven fabric. The woven fabric may have any suitable construction, formed from warp yarns and weft yarns in a selected weave or pattern. The yarns in both the warp and weft yarns may all be the same or may be different in terms of their composition, weight, etc. Each yarn may be a spun yarn. Spun yarn is understood to comprise an intimate blend of constituent fibers. The multiple yarn ends may be twisted together to form a strand. Strands may also be formed by twisting a spun yarn with one or more filaments.

In one embodiment, lyocell fibers may be present only in the warp yarns. This has been found to be most suitable in the case where the lyocell has been sufficiently stabilised by the finishing process to prevent fibrillation. In this case, lyocell may be enhanced by the presence of synthetic fibers that are also blended into the warp yarns. Where lyocell is still subject to fibrillation, it may be preferred to include it only in the weft yarn instead in order to reduce its exposure to the exterior of the fabric, for example in a twill weave.

In certain embodiments, the warp yarn comprises lyocell, synthetic and natural fibers. Thus, the blend may be lyocell, cotton and polyester staple fibers, which together comprise at least 95% of the warp yarns. In embodiments, up to 50% of the warp yarns may comprise lyocell, with the remainder being equal amounts of cotton and polyester. In one embodiment, they may preferably be present in the warp yarn in a weight% ratio of about 50/25/25, respectively.

It has been observed that there is a certain relationship between the different characteristics of the fabric, which leads to an optimized result. In particular, it can be noted that increasing the amount of lyocell requires a corresponding increase in the amount of stronger synthetic fibres required to compensate for the loss of lyocell strength (in particular after being subjected to FR treatment). The synthetic fibers then exist in the yarn direction corresponding to the increased lyocell. In the case where the synthetic fibers are neither inherently FR nor FR treatable, the total amount of synthetic fibers that can be incorporated will depend on the degree of FR treatment of the natural fibers and lyocell. For reasons explained further below, a limited degree of FR treatment may be preferred in order to avoid excessive fibrillation. Thus, the total amount of non-FR synthetic fibers that may be present in the mixture may be limited. For this reason, it has been found that the above 50/25/25 mixture in warp yarns is quite suitable and obvious variants thereof will achieve the same advantageous effect.

However, when synthetic fibers are introduced in one direction, the fabric may become unstable, such as shrinkage. For this reason, other weave directions may also require a limited amount of synthetic fibers, for example a 90/10 cotton/polyester blend may be suitable. An overall blend of cotton/lyocell/polyester of about 50/30/20 may occur. It should be noted that in general, a small amount of synthetic fibers may be preferred because its primary purpose is strength compensation and it has a negative impact on the FR level of the overall fabric. However, it is possible to achieve a synthetic fiber amount exceeding that achievable by Pyrovatex type treatment.

In the case of polyesters, up to 50wt% of polyester may be present in the overall fabric. For other fibers such as polyamides, up to 20wt% may be present. The proportion of substitute fibers that remain below the upper limit of THP FR treatment compatibility may be selected depending on the end use and are also within the scope of the present application. For example, to provide a desired strength, softness, and color retention ratio, or to contain a relatively large amount of green fibers.

In an embodiment, the weft thread may mainly comprise natural fibers, preferably between 70 and 95wt% natural fibers, in particular cotton.

Any suitable weave configuration is contemplated and the skilled artisan will fully appreciate the respective advantages of such a weave. In embodiments, the fabric may be woven in a twill weave, preferably 2/1 twill. Satin weave may also be used where it is desired to provide a particular draping feel or to ensure that certain yarns are specifically laid on one face or the other. The fabric may also be a double layer fabric, a double sided fabric or a fabric having two identical sides with different characteristics of the respective front and back fabrics.

According to an important aspect of the invention, the fabric comprises an anti-fibrillation finish to prevent lyocell fibrillation. As noted above, lyocell does not crosslink naturally and it is therefore desirable to provide a finish that at least partially compensates for increased fibrillation. Importantly, while it is well known to use finished lyocell fibers to prevent fibrillation, it has now been found that non-fibrillating finishing agents are detrimental to the application of flame retardant treatments to lyocell fibers. Improved application of FR treatment can be achieved by using untreated lyocell fibers, i.e. lyocell fibers that have not been subjected to an antigen fibrillation treatment. This has been found to be particularly true for Proban-Type (THP) treatment. Without wishing to be bound by theory, it is believed that the presence of a cross-linking resin such as formaldehyde prevents the operation of the THP mechanism, which requires the formation of an enveloping network around and/or throughout the molecular structure of the lyocell fibre.

According to the invention, an antigen-fibrillating resin finish may be applied after FR treatment. However, it has also been found that FR treatment itself may have a subsequent negative impact on the antigen fibrillation process. This is believed to be due to steric hindrance of the hydroxyl group caused by THP treatment. According to one aspect of the invention, the extent of FR treatment is kept to a minimum. In this context, the amount of phosphorus in the final fabric may be kept below 2.5wt%, preferably below 2.4wt% or even below 2.2wt%. The nitrogen values also reflect the extent of FR treatment and these can be kept below 1.7wt% or below 1.6wt% or even below 1.5wt%. These values were found to still ensure adequate FR compliance. However, as noted above, for those cases where the synthetic fibers are non-FR, the reduced degree of FR treatment limits the total amount of synthetic fibers that can be present in the blend.

In embodiments, the fabric further comprises a water and/or oil repellent finish. Suitable finishes include conventional PFAS (perfluoroalkylated species) finishes, such as PTFE,Etc. Alternatively, the fabrics of the present disclosure may also be made with PFAS-free finishes, thereby being more environmentally friendly.

As noted above, the fabric may also contain other fibers or yarns for specific technical purposes. For protective workwear, the antistatic fibers may be included as fibers in a blend or as individual antistatic yarns or filaments. In embodiments, the fabric may comprise antistatic fibers or filaments in an amount between 0.2wt% and 3 wt%. In the case of antistatic filaments, amounts of up to 5wt% may be required, depending on whether the antistatic fibers are distributed or localized.

An exemplary fabric according to the present invention may comprise: in warp yarns:

40-60wt%, preferably about 50wt% lyocell,

15-35wt%, preferably about 25wt% cotton; and

15 to 35wt%, preferably about 25wt% recycled polyester;

in the weft yarn:

70 to 99wt%, preferably about 90wt% cotton,

1 to 20wt%, preferably about 10wt% recycled polyester.

The fabric is desirably resistant to washing at least 50 times without losing its desired characteristics according to ISO 15797. These may include one or more of the following:

a color retention score greater than 2 or greater than 3 according to the gray scale comparison of ISO 105-a 02;

surface ignition requirements in excess of ISO 11612 according to the test procedure of ISO 15025 (2000);

the test procedure according to ISO 15025 (2000), exceeding the bottom edge ignition requirement of ISO 11612;

tear strength greater than 10N according to ISO 13937-2 (2000);

tensile strength greater than 300N according to ISO 13934-1 (2013).

The fabric should also preferably exhibit a fabric abrasion resistance of greater than 15 000 cycles, preferably greater than 20 000 cycles, and meet ISO 12947-2 for a 12KPa applied force according to the martindale method.

The non-cellulose reactive treatment may be any suitable such treatment, preferably based on THP salts, such asAnd (5) processing.

The invention also relates to a method for producing a flame resistant fabric comprising a mixture of natural and/or synthetic fibres and lyocell fibres having accessible hydroxyl groups, which method comprises first subjecting the fabric to a non-cellulose reactive FR treatment and subsequently finishing the fabric by applying a fibrillated resin for stabilizing lyocell.

In this context, the term "contactable hydroxyl groups" is intended to refer to the fact that the lyocell fibres have not been treated with an antigen-fibrillating additive such as a cross-linked resin. According to the invention, it has been shown that the presence of such additives prior to FR treatment can reduce the efficacy of the treatment. For this reason, it is desirable to subject the fabric to an FR treatment in which the lyocell fibers provided in the yarn have not been stabilized against fibrillation by a treatment that can occupy hydroxyl groups.

Prior to FR treatment, the fabric may be pretreated by one or more processes selected from the group consisting of: desizing, scouring, bleaching, mercerizing, dyeing, including reactive and non-reactive dyes.

The fabric may be any suitable fabric, including woven or knitted, and the method may include first constructing the fabric from individual yarns prior to FR treatment. In other words, the FR treatment is performed on the fabric, not on the yarn itself. Constructing the fabric may include weaving the yarns with warp and weft yarns, preferably in a twill weave. In an embodiment, lyocell is present in the yarn only in the warp direction.

Finishing the fabric by applying the resin may include using any suitable chemical to prevent fibrillation. Preferably, the resin is a substance that reacts with hydroxyl groups of cellulose to stabilize fibrils. Such resins may be referred to as reactive resins, thermosetting resins, or easy care finishes. Reactive resins include ethylene urea formaldehyde, propylene urea formaldehyde, methylated urea formaldehyde and dimethylol dihydroxy ethylene urea (DMDHEU) modified resins. The latter is a preferred option, although equivalents and alternatives may be equally applicable. The finishing step may be accomplished by crosslinking of the resin, for example by application of heat.

The finishing may further comprise a water and/or oil repellent treatment, preferably provided in a separate step after application of the resin to prevent fibrillation. Both treatments can be applied together, but for the existing treatments it has been found that better results are achieved by first performing an antigen fibrillation finishing and then applying a water/oil repellent finish. The heat treatment may be carried out together for both treatments, but it is preferable that the antigen-fibrillated resin is crosslinked by the heat treatment before the water/oil repellent finish is started. Suitable oil-and/or water-repellent finishes include conventional PFAS (perfluorinated alkylate) finishes, such as PTFE,Etc. Alternatively, the fabrics of the present disclosure may also be made with PFAS-free finishes, thereby being more environmentally friendly.

The invention also relates to a garment manufactured by the method as described above or below.

This combination of materials produces an eco-friendly fabric that is breathable, comfortable, durable (avoiding rapid fibrillation) and FR. The range of advantages of cotton provides sustainability and breathability to the fabric.

Several materials are particularly attractive in environmental protection products. Renewable materials, sustainable materials, and materials with low water starvation have less environmental impact.

Flame Retardant (FR) is thus defined in this application to mean flame and/or heat resistance imparted by treatment of filaments, fibers, yarns or fabrics. This may provide a fabric with a low percentage of (estimated) body burns in thermal mannequin tests, limited burn-up time and high burn resilience, as well as resistance to radiant heat, arc resistance and melting metallic. For example, the performance requirements of ISO 11612 for flame retardant garments made from flexible materials are met.

Detailed Description

By way of non-limiting example, the following process steps from source to product are described.

The steps of an exemplary manufacturing process are described below.

Initially, the staple fibers are spun into a yarn.

These yarns are then woven into a blank according to the desired optimum specifications.

Checking the grey cloth.

There is a pretreatment including desizing, scouring and bleaching.

In a further pretreatment step, cotton and lyocell are mercerized.

The fabric is then dyed in a continuous dyeing process comprising dyeing and fixing.

Then check if the cloth has color defects before entering the finishing line.

One or two FR treatment steps may be performed, including fabric impregnation and ammonia curing.

The fabric is mechanically softened in a pneumatic cylinder, becoming more flexible.

Stretching the product onto a tenter frame and treating with resin to prevent fibrillation.

The fabric is then heat treated to crosslink the applied resin.

Additional finishing agents are applied to obtain oil and water repellency.

Heat/anneal the product.

Preshrinking the fabric to reduce shrinkage.

Then quality control.

And then packaged and shipped to the garment manufacturer where it is shaped for a particular use, such as a particular workplace uniform.

Staple fibers forming the yarn include cotton, lyocell and recycled polyester. Cotton is a natural fiber that provides comfort and better moisture management than synthetic fibers. Cotton is a fiber traditionally used in FR treated fabrics.

Lyocell is a synthetic cellulosic fiber. There are other alternative Cellulose-based cotton substitutes, such as Livaeco supplied by Bola fiber company (Birla Cellulose) ^TM 、Birla Modal ^TM 、Birla Excel ^TM 、Birla Viscose ^TM And Birla spanshades ^TM . Lyocell is an industrial and washable fiber that loses strength in the wet state. In fact, lyocell has similar strength in wet state as cotton and is more sustainable than cotton. Compared with cotton, the water consumption of the lyocell is less than 95 percent. Lyocell is more comfortable than cotton, has better moisture management and is generally smoother to the skin. However, it is a fibrillated fiber; for example, in the wet state, water permeates into the interior of the fibril bundles, resulting in exposure of fibrils at the fiber surface. The rate of fibrillation increases with increasing pH and increasing temperature.

The (recycled) polyester may be mechanically or chemically recycled. Since polyester is a relatively high strength material, it is used in FR treated fabrics to improve durability, however it is also heavier than cellulose based fabrics. Polyesters cannot be made into flame retardants with Proban chemicals. Mechanically regenerated polyesters can be used to improve sustainability. The use of recycled polyester provides a 45% reduction in energy consumption compared to virgin polyester and a nearly 20% reduction in water consumption compared to virgin polyester. Compared with virgin polyester, the emission of greenhouse gases is reduced by more than 30 percent.

For the exemplary EG9600 fabric, the following staple fibers were used to weave the yarns:

cotton (Medium)

The number of the microRNA was 3.8 to 4.4

Length 27mm

Toughness 26-30cN/tex

Tencel lyocell standard

Count 1.25dtex

Length 38mm

Toughness 38cN/tex

Wet toughness 31cN/tex

Repreve recycled polyester

Count 1.3dtex

Length 38mm

Toughness 59cN/tex

P190

Count 39/6dtex

Length = filament

An exemplary formulation for the fabric yarn is:

warp yarn:

50% lyocell;

25% cotton; and

25% recycled polyester.

Weft yarns:

90% cotton; and

10% recycled polyester.

AS twist yarn:

75% cotton;

8% recycled polyester.

17% Negastat filaments.

The EC9600 fabric was woven with the warp and weft yarns described above in a 2/1 twill weave. An antistatic yarn is included at every 1:20 pitch in the weft direction. The total weight percent of each fiber in the final fabric is:

50% cotton;

30% lyocell;

19% recycled polyester.

1% Negastat filaments.

After a single THP treatment, the fabric was measured to have the following flame retardant characteristics:

the amount of THP was measured by P, N analysis with the following results:

EG 9600： P 2.1％ N 1.7％

traditional cotton products: p2.9% N1.9%.

The fabric is still susceptible to fibrillation after FR treatment. After FR treatment the fabric is finished with a suitable resin to prevent fibrillation of the lyocell in the product. The resin is applied in a pad dyeing (fouuard) process, and the application process includes removing moisture by pressing and heating, and then performing a heat treatment to crosslink the resin. The term "non-fibrillated" as used herein is understood to mean substantially non-fibrillated and interchangeable with low fibrillation. The application of the non-fibrillating resin provides a fabric that has reduced fibrillation compared to its as-spun state.

A second finish is required to make the fabric water and/or oil repellent by fluorocarbon resin (FC) to meet ISO 13034. The resin and FC may be combined in one bath or the resin and FC finish may be applied sequentially in a two-step process in order to improve fibrillation and prevent color loss. This two-step process reduces fibrillation after washing. A further improvement is to first crosslink the resin prior to application of the FC finish.

Washing is possible and results in reduced and uniform fibrillation according to standard ISO 15797, 75 ℃, j requirement. According to ISO 15797, 75 ℃, j, the fabric remains durable even after 50 severe washes.

The final product has the following advantages:

50% of the green material,

durable and sustainable in nature and is capable of being used,

compared to conventional FR treated fabrics, the water footprint is 28% lower,

compared to conventional FR treated fabrics, the CO2 footprint is 10% lower,

super soft and breathable due to lyocell,

low water vapor resistance (breathability) and good short-time vapor absorption,

better performance than traditional FR treated fabrics,

conventional FR treated cotton fabrics feel stiff and strong, EG9600 feel soft and soft to the skin,

FR performance comparable to conventional FR treated fabrics,

low pilling.

Three batches of improved FR fabrics were tested and the properties measured after final finishing showed repeatability and met technical specifications as follows:

the technical specifications of the fabric of the invention are in terms of characteristics with those of standard FR fabrics and are known as Modal/Tencel ^TM Is comparable and commensurate with alternative inherently flame retardant fabrics. The improved FR fabrics of the invention further have improved comfort and reduced carbon footprint. The technical specifications are compared as follows:

Claims (24)

1. a Flame Retardant (FR) treated fabric comprising a yarn formed from a mixture of natural and/or synthetic fibers, the fabric further comprising FR treated lyocell fibers, wherein the FR treatment is a non-cellulose reactive FR treatment and the FR treated lyocell fibers have low fibrillation.

2. The fabric of claim 1, wherein the fabric is a woven fabric comprising warp yarns and weft yarns.

3. The fabric of claim 1 or claim 2, wherein the natural fibers comprise cotton.

4. Fabric according to any one of the preceding claims, wherein the synthetic fibres comprise polyester, polyamide and/or aramid, preferably regenerated.

5. The fabric according to any one of claims 2 to 4, wherein lyocell fibers are present only in warp yarns.

6. The fabric according to claim 5, wherein the warp yarns comprise lyocell, synthetic and natural fibers, preferably in a weight% ratio of about 50/25/25.

7. A fabric according to claim 5 or claim 6, wherein the weft yarns comprise predominantly natural fibres, preferably between 70 and 95 wt%.

8. A fabric according to any preceding claim woven in a twill weave, preferably a 2/1 twill weave.

9. The fabric according to any one of the preceding claims, further comprising an antigen-fibrillating finish, preferably comprising an antigen-fibrillating additive, optionally a resin crosslinkable with the hydroxyl groups of FR lyocell, preferably a DMDHEU resin.

10. The fabric according to any one of the preceding claims, further comprising a water and/or oil repellent finish, preferably comprising a fluorocarbon.

11. The fabric according to any one of the preceding claims, further comprising antistatic fibers, preferably in an amount between 0.2wt% and 5wt%.

12. The fabric according to claim 2, comprising

In warp yarns:

40-60wt%, preferably about 50wt% lyocell,

15-35wt%, preferably about 25wt% cotton; and

15 to 35wt%, preferably about 25wt% recycled polyester; and

in the weft yarn:

70 to 99wt%, preferably about 90wt% cotton,

1 to 20wt%, preferably about 10wt% recycled polyester.

13. The fabric of any one of the preceding claims, wherein the fabric is washable at least 50 times and retains at least one or more of the following characteristics according to ISO 15797:

-a color retention score of greater than 2 or greater than 3 according to a gray scale comparison of ISO 105-a 02;

-surface ignition requirements in excess of ISO 11612 according to the test procedure of ISO 15025 (2000);

-a bottom edge ignition requirement in accordance with the test procedure of ISO 15025 (2000) exceeding ISO 11612;

-a tear strength of greater than 10N according to ISO 13937-2 (2000);

-a tensile strength according to ISO 13934-1 (2013) of more than 300N.

14. A fabric according to any one of the preceding claims, wherein the fabric has a abrasion resistance of greater than 15 000 cycles, preferably greater than 20 000 cycles, according to the martindale method, and which meets ISO 12947-2 for a force of 12 KPa.

15. A fabric according to any preceding claim, wherein the non-cellulose reactive treatment comprises THP salt and preferably the amount of phosphorus in the final fabric is less than 2.5wt% and/or the amount of nitrogen in the final fabric is less than 2.0wt%.

16. A method of producing a flame retardant fabric comprising yarns comprising a mixture of natural and/or synthetic fibers and lyocell fibers having accessible hydroxyl groups, the method comprising first subjecting the fabric to a non-cellulose reactive FR treatment and subsequently finishing the fabric by applying a fibrillated resin for stabilizing lyocell.

17. A method according to claim 16, which method comprises constructing the fabric by weaving, preferably twill weaving, the yarns with warp and weft yarns.

18. The method of claim 17, wherein lyocell is present only in warp yarns.

19. The method according to any one of claims 16 to 18, wherein the FR treatment is a THP-based process.

20. A method according to any one of claims 16 to 19, wherein finishing the fabric by applying a resin comprises crosslinking the resin, preferably a formaldehyde resin.

21. A method according to any one of claims 16 to 20, wherein the finishing further comprises a water and/or oil repellent treatment, preferably provided in a separate step after application of the resin to prevent fibrillation.

22. The method according to any one of claims 16 to 21, wherein the fabric is pre-treated by one or more processes selected from the group consisting of: desizing, scouring, bleaching, mercerizing, dyeing, including reactive and non-reactive dyes.

23. A method according to any one of claims 16 to 22, wherein the yarns are spun yarns comprising a homogeneous mixture of staple fibers.

24. A garment made from the fabric of any one of claims 1 to 15 or by the method of any one of claims 16 to 23.