In the production of textiles, garments are often made by the interplacement of yarns in the fabric, often called the warp yarn and the fill yarn. By interweaving these yarns, a fabric is produced and from this fabric are cut the panels of fabric which are used to produce the finished garments. Color effects are important in the production of textiles, and dyeing machinery has been developed which is intended to efficiently and quickly dye the yarns and/or the fabrics prior to construction of the garment.

In one particularly important aspect of the industry, dye application, specialized machinery has been developed to rapidly, efficiently and economically facilitate the dyeing of yarns. These apparatus are generally based on one of three concepts: the dye liquor is moved as the material is held stationary, the textile material is moved without mechanical movement of the liquor, or both the dye liquor and the textile material move. These methods are generally known in the art and are described in the Kirk-Othmer Encyclopedia of Chemical Technology, Volume 8, pp. 722 et seq. (4th ed., 1993). An example of the first method utilizes a large stainless steel kier which is capable of withstanding sufficient pressure to reach a certain maximum operating temperature. The kier has one or more perforated spindles through which the dye liquor is pumped. Around this spindle the textile yarn is packed tightly in the form of a cake in a perforated basket. The dye liquor is pumped through the textile yarn, then flows to the bottom of the machine and into the return side of the pump.

Generally, the second type of dye application machinery involves moving the textile into a vat comprising dye and is then moving it out. One example of this type of machinery is chain warp dyeing wherein several yarn ropes are pulled through a series of tubs containing the dye liquor and gradually dyed to the desired shade.

Another example of this type of dye machinery comprises winch or beck dyeing. In winch or beck dyeing, the machine consists of a shallow U-shaped box which has a gradual low curvature in the back and a rather high vertical rise in the front. Yarn

rope is passed over the top of this reel and the first end of the fabric or yarn rope sewed to the back end to form an endless loop. A tub is filled with dye and the yarn rope immersed into it. The action of the turning elliptical reel lifts the fabric from the front of the dye bath, over the top of the reel and then slowly back into the dye liquor where it moves through the dye liquor.

In the third type of dye application, machines such as the Klauder-Weldon skein dye machine are used which not only turn the skeins of yarn through the dye liquor, but also move the liquor in small streams over the yarn as the threads pass over the spindles. Other machines based on winch type machines can include a jet for moving the dye over the moving fabric as well as subjecting the moving fabric to the tub of dye at the bottom of the winch.

In the processing of textile, enzymes have become common in the industry.

For example, lipases and/or pectinases are commonly known as scouring agents, lipase is useful in improving the wettability of polyester fibers, oxido-reductase enzymes are useful in the bleaching of fibers, cellulases are useful for biopolishing, depilling, stonewashing and improving the feel and/or appearance of fabrics and proteases are useful in the treatment of wool and silk to remove hairyness and improve their appearance and feel. Additionally, enzyme like compounds such as swolienins and expansins have application in the treatment and modification of cellulose containing fibers.

In particular, cellulases have found many uses in the textile industry.

Cellulases are enzymes which hydrolyze cellulose (ß-1, 4-D-glucan linkages) and produce as primary products glucose, cellobiose and cellooligosaccharides.

Cellulases are produced by a number of microorganisms and comprise several different enzyme classifications including those identified as exo-cellobiohydrolases (CBH), endoglucanases (EG) and ß-glucosidases (BG) (M. Schulein, Methods in Enzymology, vol. 160, pp. 235-242 (1988)). Current theory holds that the enzymes within these classifications can be separated into individual components. For example, microbial cellulase compositions may consist of one or more CBH components, one or more EG components and possibly ß-glucosidase. The complete cellulase system comprising CBH, EG and BG components synergistically act to convert crystalline cellulose to glucose. The exo-cellobiohydrolases and the endoglucanases act together to hydrolyze cellulose to small cello-oligosaccharides.

The oligosaccharides (mainly cellobioses) are subsequently hydrolyzed to glucose by a major p-glucosidase.

Cellulases and components thereof, used either singularly or in combination, are known to be useful in detergent compositions and for treating textiles. In the textile industry, during or shortly after the manufacture of cotton-containing fabrics, it is known to treat such fabrics with cellulase to impart desirable properties to the fabric. One purpose of this treatment is to remove fuzz, i. e., untangled fiber ends that protrude from the surface of a yarn or fabric, and pills, i. e., bunches or balls of tangled fibers that are held to the surface of a fabric by one or more fibers.

Accordingly, in the textile industry, cellulase has been used to improve the feel and/or appearance of cotton-containing fabrics, to remove surface fibers from cotton-containing knits, and also for imparting a stone washed appearance to cotton-containing denims. In particular, Japanese Patent Application Nos. 58-36217 and 58-54032 as well as Ohishi et al.,"Reformation of Cotton Fabric by Cellulase" and"What's New--Weight Loss Treatment to Soften the Touch of Cotton Fabric" Japan Textile News, (December 1988) each disclose that treatment of cotton- containing fabrics with cellulase results in an improved feel forthe fabric. It is generally believed that this cellulase treatment removes cotton fuzzing and/or surface fibers which reduces the weight of the fabric. The combination of these effects imparts improved feel to the fabric.

Clothing made from cellulose fabric, such as cotton denim, is stiff in texture due to the presence of sizing compositions used to ease manufacturing, handling and assembling of clothing items and typically has a fresh dark dyed appearance.

One desirable characteristic of indigo-dyed denim cloth is the alteration of dyed threads with white threads, which gives denim a white on blue appearance. For example, after a period of extended wear and laundering, the clothing items, particularly denim, can develop in the panels and seams localized areas of variation in the form of a lightening in the depth or density of color. In addition, a general fading of the clothes, some pucker in seams and some wrinkling in the fabric panels can often appear. In recent years such a distressed or"stonewashed"look, particularly in denim clothing, has become very desirable to a substantial proportion of the public.

Previous methods for producing the distressed look included stonewashing of a clothing item or items in a large tub with pumice stones having a particle size of about 1 to 10 inches and with smaller pumice particles generated by the abrasive nature of the process. Typically the clothing item is tumbled with the pumice while wet for a sufficient period such that the pumice abrades the fabric to produce in the

fabric panels localized abraded areas of lighter color and similar lightened areas in the seams. Additionally, the pumice softens the fabric and produces a fuzzy surface similar to that produced by the extended wear and laundering of the fabric.

The use of the pumice stones has several disadvantages, including overload damage to the machine motors, mechanical damage to transport mechanisms and washing drums, environmental waste problems from the grit produced and high labor costs associated with the manual removal of the stones from the pockets of the garments. In view of the problems associated with pumice stones in stonewashing, cellulase solutions are used as a replacement for the pumice stones under agitating and cascading conditions, i. e., in a rotary drum washing machine, to impart a"stonewashed"appearance to the denim (U. S. Patent No. 4,832,864).

Despite intensive research related to the use of cellulases in the textile industry, the industry continues to look for better methods of applying cellulase which result in less fabric damage while continuing to achieve the sought after effect, whether it be stonewashing, improved appearance, improved feel or other known advantages from the use of cellulase. Further, there exists a need for a method of applying cellulase and obtaining such benefits, which application methods work efficiently within existing capital framework used in the textile industry.

SUMMARY OF THE INVENTION It is an object of the invention to provide for an improved method of manufacturing textiles which have advantages achieved from the use of cellulase, but which are less prone to fabric damage or reduced strength.

It is a further object of the present invention to provide for a cellulase treatment process which is compatible with current textile production processes, is faster, more efficient and consequently less expensive than current garment treatment processes.

According to the invention, a method of producing a treated fabric is provided, which fabric comprises a warp and a fill yarn, wherein prior to the manufacture of the fabric, either the warp or the fill yarn is treated with an enzyme solution. Suitable enzymes for treatment include amylase for removing starch based sizing compositions from the fibers, protease enzymes for wool dehairing, pectinases and/or lipases for scouring of fibers generally, lipases for treatment of polyester fibers to, for example, improve their wettability, oxido-reductase enzymes for bleaching and expansins or swollenins for achieving modifications of the fibers.

In another embodiment of the invention, a method of producing a cellulose containing fabric is provided, which fabric comprises a warp and a fill yarn, wherein prior to the manufacture of the fabric, either or both the warp or the fill yarn is treated with a cellulase solution, provided however that if both yarns are treated they are treated to effect different degrees of cellulolytic cleavage. Preferably, the warp yarn is treated with a cellulase solution and the fill yarn is treated with cellulase to a lesser extent than the warp yarn or is not treated with a cellulase solution prior the manufacture of the garment. Further preferably, the fill yarn is substantially untreated with a cellulase solution prior to the manufacture of the garment. In an alternative embodiment, the fill yarn is treated with a cellulase solution and the warp yarn is treated with a cellulase to a lesser extent than the fill yarn or is not treated with a cellulase solution prior to the manufacture of the garment, and preferably the warp yarn is substantially untreated with a cellulase prior to the manufacture of the garment.

In another embodiment of the invention, the method according to the invention comprises a treatment range comprising a plurality of separate vats, wherein at least one of the vats is used for cellulase treatment and the other vats may be used to perform scouring, wetting, dyeing and/or rinsing steps, together or

as distinct steps. Preferably, the process of this embodiment comprises a continuous process for the production of yarn.

In another embodiment of the invention, a method is provided for the continuous treatment of yarn comprising the steps of: (a) contacting the yarn with a solution for scouring and/or wetting the yarn; (b) contacting the yarn with a solution for rinsing the yarn; (c) contacting the yarn with a solution for dyeing the yarn; and (c) contacting the yarn with a solution comprising a cellulase, wherein the yarn is used as a warp yarn in the production of a fabric.

In another embodiment of the invention, the fabric produced with the yarns of the invention is used to produce a garment. In a preferred embodiment of the invention, the garment or fabric made with the yarns of the invention is further treated with cellulase to produce a stonewashed effect, to biopolish, to remove pills or to otherwise improve the feel and/or appearance of the fabric or garment.

As discussed below, the inventors herein have discovered that by treating yarns used to produce garments and fabrics with cellulase, it is possible to produce garments which have the surprising advantage of being more resistant to strength loss than prior art garments and fabrics when treated with cellulase or other abrasive. This surprising result, i. e., that garments produced according to the present invention have greater strength while maintaining nearly identical characteristics in terms of stonewashed appearance, depilling, biopolishing or otherwise improving the appearance and/or feel of the garment, is not suggested by the prior art.

Thus, an advantage of the present invention is that the fabrics and garments treated according to the methods provided herein have reduced strength loss at equivalent stonewashing and/or biopolishing levels compared to prior art fabrics which are not treated in accordance with the invention.

BRIEF DESCRIPTION OF THE DRAWING Fig. 1 illustrates an example of a dye range which may be used in the process of the invention.

Fig. 2 illustrates the tensile strength loss after stonewashing of a garment made with the yarns according to the present invention compared to a garment made according to the prior art.

DETAILED DESCRIPTION OF THE INVENTION

"Cotton-containing yarn"means yarns or fibers made of pure cotton or cotton blends. When cotton blends are employed, the amount of cotton in the fabric is preferably at least about 35 percent by weight cotton. When employed as blends, the companion material employed in the yarn can include one or more non-cotton fibers including cellulosic or synthetic fibers such as polyamide fibers (for example, nylon 6 and nylon 66), acrylic fibers (for example, polyacrylonitrile fibers), and polyester fibers (for example, polyethylene terephthalate), polyvinyl alcohol fibers (for example, Vinylon), polyvinyl chloride fibers, polyvinylidene chloride fibers, polyurethane fibers, polyurea fibers and aramid fibers.

"Cellulose containing yarn"means yarns or fibers made of cotton or non- cotton containing cellulose or cotton or non-cotton containing cellulose blends including natural cellulosics and manmade cellulosics (such as jute, flax, ramie, rayon, and lyocell). Included under the heading of manmade cellulose containing fabrics are regenerated fabrics that are well known in the art such as rayon. Other manmade cellulose containing fabrics include chemically modified cellulose fibers (e. g, cellulose derivatized by acetate) and solvent-spun cellulose fibers (e. g. lyocell).

"Treatment range"means a machine or apparatus for the wet processing of a cotton or cellulose containing yarn. Generally, a treatment range will comprise a mechanism or mechanisms which provide for moving the yarn and/or the liquid so that a continuous or batchwise allotment of yarn is placed in contact with an aqueous solution containing agents for wet processing, such as, caustic, desize, dye, cellulase, and rinse liquor. Examples of apparatus for processing yarns include vertical spindle dye machines, dye ranges, chain warp dye apparatus, winch and beck systems, or any other apparatus useable for contacting a yarn with a cellulase solution, including those that pass yarn through a cellulase solution and those which pass a cellulase solution over a yarn. In one embodiment, an apparatus useful for the application of a dye, rinsing, scouring, wetting or otherwise applying aqueous finishes to a yarn is modified for use in the invention by using a cellulase in conjunction with any other wet processing being used. In a particularly preferred embodiment of the invention, an apparatus similar to an indigo dye range, wherein the yarn undergoes multiple passes through the cellulase liquor, i. e., skying and dipping of the yarns in cellulase is used. This preferred embodiment has the advantages that the skying time allows sufficient residence time for the cellulase to facilitate hydrolysis and also that the process is continuous. Cellulase is conveniently inactivated during the yarn drying process.

"Warp yarn"means the yarn which is used in a fabric which runs lengthwise in the finished garment. The warp yarn is generally crossed at right angles by the fill yarn.

"Fi ! ! yarn"means the yarn which is used in a fabric which runs cross-wise in the finished garment. The fill yarn is generally crossed at right angles by the warp yarn.

According to the invention, a method of producing a treated fabric is provided, which fabric comprises a warp and a fill yarn, wherein prior to the manufacture of the fabric, either or both the warp or the fill yarn is treated with an enzyme solution. Suitable enzymes for treatment include amylase for removing starch based sizing compositions from the fibers, protease enzymes for wool dehairing, pectinases and/or lipases for scouring of fibers generally, lipases for treatment of polyester fibers to, for example, improve their wettability, oxido- reductase enzymes for bleaching and expansins or swollenins for achieving modifications of the fibers. According to this embodiment of the invention, it is preferred that the enzyme solution be in a vat in a treatment range, and the yarn is passed through the vat in a continuous manner. In this way, it is possible to obtain significantly improved effects on the fibers in a continuous process wherein the enzyme treatment is efficiently interposed in a continuous process for the production of fabric.

According to another embodiment of the present invention, a method of producing a cellulose containing fabric or garment is provided, which fabric or garment comprises a warp and a fill yarn, wherein prior to the manufacture of the fabric, either or both the warp or the fill yarn is treated with a cellulase solution.

Preferably, the warp yarn is treated with a cellulase solution and the fill yarn is treated with cellulase to a lesser extent than the warp yarn or is not treated with a cellulase solution prior the manufacture of the garment. Further preferably, the fill yarn is substantially untreated with a cellulase solution prior to the manufacture of the garment. In an alternative embodiment, the fill yarn is treated with a cellulase solution and the warp yarn is treated with a cellulase to a lesser extent than the fill yarn or is not treated with a cellulase solution prior to the manufacture of the garment, and preferably the warp yarn is substantially untreated with a cellulase prior to the manufacture of the garment.

In another embodiment of the invention, the method according to the invention comprises a treatment range comprising a plurality of separate vats,

wherein at least one of the vats is used for cellulase treatment and the other vats may be used to perform scouring, wetting, dyeing and/or rinsing steps, together or as distinct steps. Preferably, the process of this embodiment comprises a continuous process for the production of yarn.

In another embodiment of the invention, a method is provided for the continuous treatment of yarn comprising the steps of: (a) contacting the yarn with a solution for scouring and/or wetting the yarn; (b) contacting the yarn with a solution for rinsing the yarn; (c) contacting the yarn with a solution for dyeing the yarn; and (c) contacting the yarn with a solution comprising a cellulase, wherein the yarn is used as a warp yarn in the production of a fabric.

In another embodiment of the invention, the fabric produced with the yarns of the invention is used to produce a garment. In a preferred embodiment of the invention, the garment or fabric made with the yarns of the invention is further treated with cellulase to produce a stonewashed effect, to biopolish, to remove pills or to otherwise improve the feel and/or appearance of the fabric or garment.

The yarn used in the process according to the invention is a cellulose containing yarn, preferably a cotton containing yarn, for which it is desirable to modify its characteristics with a cellulase. Generally, where it is desired to subject a yarn to cellulolytic cleavage, the yarn will lack any composition thereon which would be problematic to the activity or action of cellulase during the cellulase treatment step such as sizing, resins, chemical coatings, ionic charge or other chemicals adverse to cellulase activity. However, it is also possible to intentionally treat a yarn with size or chemical adverse to cellulase activity if it is desirable to shield certain yarns from cellulase activity. Thus, for convenience, it would be possible to use both, for example, sized yarns and unsized yarns in the same dye range without changing the solutions and obtain the benefits of the invention.

The method according to the invention is advantageously performed in a manner such that the cellulase treatment of the yarn is performed on a treatment range. It is thus possible to run a single process for the preparation of the yarn for the production of a fabric including such steps as, for example, scouring, rinsing, wetting, dyeing and other desirable wet processing steps, in addition to the cellulase treatment. This is especially desirable as it is unnecessary to outfit any special equipment solely for the cellulase treatment step. Thus, the treatment range may comprise a plurality of separate vats, wherein at least one of the vats is used for cellulase treatment and other vats are used for any one of the following steps:

scouring, wetting, dyeing and/or rinsing. It is thus possible to use a continuous process for the production of yarn in accordance with the present invention. One such continuous treatment comprises steps of (a) contacting the yarn with a solution for scouring and/or wetting the yarn; (b) contacting the yarn with a solution for rinsing the yarn; (c) contacting the yarn with a solution for dyeing the yarn; and (c) contacting the yarn with a solution comprising a cellulase.

Alternatively to multiple vats, it is possible to perform the process according to the invention in a single vat. A one vat treatment process which ensures appropriate residence time for the yarn in the cellulase vat, or a device which generates mechanical action such as a scuther or ultrasound vibrator, would be appropriate. Similarly, it may be possible to treat the yarns with a spray rather than a vat or any other appropriate method for treating the yarn prior to its incorporation into a fabric. Results can be significantly effected by increasing or decreasing the residence time and mechanical action of the yarns during the cellulase treatment and it is critical that these factors be optimized to ensure that the final product achieves the appropriate level of cellulase treatment. Nonetheless, such considerations are well within the skill of the ordinary worker in the field.

In accordance with the invention, after treatment of the yarn, the yarn is used to prepare the finished fabric from which the garment is made. Thereafter, in a preferred embodiment of the invention, the fabric or garment is treated with cellulase or an abrasive such as pumice, diatomaceous earth, or other methods of stonewashing, biopolishing, depilling or improving the feel and/or appearance through abrasive action.

As a particularly preferred embodiment, the fabric or garment made of the yarn is denim wherein the warp yarn is treated with cellulase and the fill yarn is not treated with cellulase prior to the manufacture of the garment or fabric. Garments or fabrics made from this yarn are then treated with cellulase according to methods well known in the art. For example, the garment or fabric may be incubated with an aqueous solution comprising cellulase under conditions effective to allow the enzymatic action to confer an improved or modified feel or appearance to the cellulose containing fabric. Where the fabric or garment is intended to display a stonewashed effect, it is especially preferable that the yarns be ring dyed, most preferably by an indigo or a sulfur based dye, in accordance with the methods known in the art for making denim fabrics and garments. The yarns may be dyed either before or after the cellulase treatment step for the yarn. Thereafter, the

completed denim fabric or garment made with the yarns is treated with cellulase or an abrasive as is generally known in the art to achieve the stonewashed effect. As is further described herein, at equal levels of stonewashing or biopolishing efficacy, fabrics and garments manufactured with yarns treated as provided herein surprisingly have reduced strength loss after cellulase or stonewashing treatment of the fabric or garment than prior art fabrics and garments.

The cellulase for treatment of the yarn may be selected from any source generally known in the industry as useful to obtain the effects for which cellulase is useful, e. g., biopolishing, depilling, stonewashing and otherwise improving the feel and/or apearance of cellulose containing fabrics or garments. Thus, the cellulase may be selected from a microbial source, e. g., a fungal or bacterial source.

Especially suitable for the present invention are cellulases obtained from a fungal source such as Trichoderma spp., Fusarium spp.,. or Humicola spp.

In one particularly useful method, the yarn is treated with cellulase by preparing an aqueous solution which contains an effective amount of cellulase together with other optional ingredients including, for example, a buffer, a surfactant, and a scouring agent. An effective amount of cellulase enzyme composition is a concentration of cellulase enzyme sufficient for its intended purpose, i. e., biopolishing, abrading, depilling or other known cellulase effects. In practice, it may not be preferable to define the exact end use of the yarn during the cellulase treatment stage. Thus, an"effective amount"of cellulase in the treatment composition according to the present invention is that amount which will provide the desired treatment. The amount of cellulase employed is also dependent on the equipment employed, the process parameters employed (the temperature of the cellulase treatment solution, the exposure time to the cellulase solution, and the like), the cellulase activity (e. g., a particular solution will require a lower concentration of cellulase where a more active cellulase composition is used as compared to a less active cellulase composition) and the type of effect desired. The exact concentration of cellulase in the aqueous treatment solution to which the yarn is subjected can be readiiy determined by the skilled artisan based on the above factors as well as the desired result. Preferably the cellulase is present in a concentration of from 1 to 5,000 ppm and most preferably 10 to 200 ppm total protein in the solution which is used to treat the yarn.

Optionally, a buffer is employed in the treatment composition such that the concentration of buffer is sufficient to maintain the pH of the solution within the

range wherein the employed cellulase exhibits activity which, in turn, depends on the nature of the cellulase employed. The exact concentration of buffer employed will depend on several factors which the skilled artisan can readily take into account.

For example, in a preferred embodiment, the buffer as well as the buffer concentration are selected so as to maintain the pH of the final cellulase solution within the pH range required for optimal cellulase activity.

In addition to cellulase and a buffer, the treatment composition may optionally contain a surfactant. Suitable surfactants include any surfactant compatible with the cellulase and the fabric including, for example, anionic, non- ionic and ampholytic surfactants. Suitable anionic surfactants for use herein include linear or branched alkylbenzenesulfonates; alkyl or alkenyl ether sulfates having linear or branched alkyl groups or alkenyl groups; alkyl or alkenyl sulfates; olefinsulfonates; alkanesulfonates and the like. Suitable counter ions for anionic surfactants include alkali metal ions such as sodium and potassium; alkaline earth metal ions such as calcium and magnesium; ammonium ion; and alkanolamines having 1 to 3 alkanol groups of carbon number 2 or 3. Ampholytic surfactants include quaternary ammonium salt sulfonates, and betaine-type ampholytic surfactants. Such ampholytic surfactants have both the positive and negative charged groups in the same molecule. Nonionic surfactants generally comprise polyoxyalkylene ethers, as well as higher fatty acid alkanolamides or alkylene oxide adduct thereof, and fatty acid glycerine monoesters. Mixtures of surfactants can also be employed in manners known to those skilled in the art.

Reaction temperatures during yarn treatment are governed by two competing factors. Firstly, higher temperatures generally correspond to enhanced reaction kinetics, i. e., faster reactions, which permit reduced reaction times as compared to reaction times required at lower temperatures. Accordingly, reaction temperatures are generally at least about 10°C and greater. Secondly, cellulase is a protein which loses activity beyond a given reaction temperature, which temperature is dependent on the nature of the cellulase used. Thus, if the reaction temperature is permitted to go too high, the cellulolytic activity is lost as a result of the denaturing of the cellulase. However, standard temperatures in the art are generally in the range of 35°C to 65°C.

Reaction times are dependent on the specific conditions under which the stonewashing occurs. For example, pH, temperature and concentration of cellulase will all effect the optimal reaction time. Generally, reaction times are from about 5

minutes to about 5 hours, and preferably from about 10 minutes to about 3 hours and, more preferably, from about 20 minutes to about 1 hour.

Preferably, the fabric comprising the yarn of the invention is used to produce a garment. The garment or fabric is preferably further treated with cellulase or abrasive agent to achieve a desired degree of abrasion for the entire fabric or garment, and to achieve benefits to the entire fabric or garment which are generally known to be produced from the application of cellulase or the abrasive, e. g., biopolishing, depilling, stonewashing and otherwise improving the feel and/or appearance of the garment or fabric.

In order to further illustrate the present invention and advantages thereof, the following specific examples are given with the understanding that they are being offered to illustrate the present invention and should not be construed in any way as limiting its scope.

EXAMPLE A pilot scale indigo dye range having the following particulars was used for the treatment of cotton yarn with cellulase: Total number of vats: 17 Capacity of each vat: 13 L Speed: 4.1 yards/min.

Skying time/vat: min./vat Dipping time/vat:-45 sec./vat A yarn rope having a yarn count of 6 s, and which was standard yarn as used for the production of denim was used. The yarn rope consisted of 334 ends.

The Processing Steps were as follows: Caustic Treatment: Caustic and sequestering agent was applied near at around 80 C to swell the cotton and get remove cotton impurities and promote indigo ring dyeing.

Indigo Dyeing:

Indigo was applied in 3 vats under conditions conducive for the application of the dye.

Cellulase Treatment: Cellulase treatment was done in 5 vats which were interconnected and their liquor circulated by recirculation pump. Diluted acetic acid was continuously fed to the vats by a peristaltic pump. to achieve ~ pu 4.5.

Residence time per vat was 45 seconds and"skying"time per vat was 1 minute.

At the start of the run, the range was"charged"by adding 30 g/l of IndiAge Super L cellulase product (available from Genencor International, Rochester N. Y.) per vat.

Cellulase enzyme was also fed continuously by a peristaltic pump. Pump flow was regulated to achieve continuously fed rate of 60 ml/min.

Temperature of the enzyme liquor was maintained at 50 °C. During"skying", the yarn was cooled to the ambient temperature.

Rinsing: Thorough rinsing was achieved by passing the yarn through several over flow rinse boxes.

Drying: The yarns were passed over a series of rollers headed with super heated stream.

Thorough rinsing and drying over the headed rollers insured wash off and complete inactivation of the enzyme.

The control run consisted of identical process conditions minus the cellulase treatment. Fabric was woven from the cellulase treated (CTW-fabric) and no

cellulase treated warp (C-fabric). The two sets of fabrics were cut and sewn into garments, and were then subjected to the following wet processing steps: Desize On 50 lb. capacity UniMac at the following processing conditions: Liquor ratio: 20: 1 Amylase Desize 160 (available from Genencor Internatinal, Inc., Rochester N. Y.) @ 0.2 g/l, Wetting agent: Triton X 100 @ 0.1 g/I Temperature: 65 C Time: 10 min.

2 rinses with exaction Enzyme Washing IndiAge 2XL (available from Genencor International, Inc., Rochester N. Y) @ 1.0 g/l, 10: 1, pH 5.0,55 C, 60 min., load size 3.0 kg, no stones. Inactivation was performed by washing the fabric at 70 C in AATCC Standard detergent for 10 minutes followed by 2 rinses with extraction.

Bleaching: 4% of 11% active hypocloride chlorine bleach, 45 C, 10 min. Anticlor: hydrogen peroxide 30% @ 2 g/l, and 1 gui soda ash, 60 C, rinse 2 times with extraction.

The fabrics manufactured from these yarns were then evaluated for degree of abrasion, fabric hand, and fabric tensile strength loss.

After enzyme washing, CTW-denim fabric showed higher degree of denim abrasion compared to the C-denim fabric.

The C-Fabric was further enzyme washed so that the degree of abrasion of both the CTW-denim and the C-denim were identical by treating with tndiAge 2XL at 0.5 gui for 40 min., pH 4. 7, 55 C, 10: 1.

At equai denim abrasion levels, fabric strength loss was measured. The results are provided below in Table 1 and graphically in Figure 2.

Table 1

Fabric Type Fill Direction Strength Warp Direction Strength C-Denim 206 132 CTW-Denim 200 158 As can be seen in Table 1, at equal abrasion level, the CTW-Fabric gives roughly 15% higher fabric strength retention in fill direction.

Fabric Hand Evaluation: At each stage of wet processing, i. e., desizing, enzyme washing, and bleaching, the CTW-Fabric was determined by panel testing to be softer and smoother in feel.

Surface Appearance: At each stage of wet processing, i. e., desizing, enzyme washing, and bleaching, the CTW-Fabric was determined by panel testing to have less amount of surface fibers, giving a cleaner, crisper look to the fabric. Additionally, the twill lines are more distinct.