Bleaching and dyeing; fluid treatment and chemical modification – Bleaching – Chemical
Reexamination Certificate
2000-04-04
2004-02-03
Gupta, Yogendra N. (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Bleaching
Chemical
C008S101000, C008S115510, C008S116100, C008S401000, C162S070000, C162S072000, C435S183000
Reexamination Certificate
active
06685748
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for enzymatic bleaching of natural non-cotton cellulose based fabrics. In particular, the present invention relates to a method for the bleaching of linen, flax, jute ramie and similar fabrics with an enzyme having xylanolytic activity.
2. State of the Art
Enzymatic treatment of cellulosic fabrics has achieved a great deal of success in the industry. In particular, the cotton textile, and particularly denim, industry has adopted cellulase enzymes as alternatives for chemical processes in such textile processing steps as stonewashing, biopolishing and depilling. In addition, amylase enzymes have been adopted for use as desizing agents. Oxido-reductase enzymes have been proposed for use in the textile industry for the purpose of bleaching and dye transfer reduction.
The cleaning industry has also adopted enzymes as useful agents in the laundering of soiled fabrics and clothing, with present technologies including the widespread use of protease, cellulase and amylase in detergent formulations. For example, describes protease compositions useful in the removal of protein based stains from fabrics. In addition, cellulase, amylase, cutinase, lipase, peroxidase, oxidase and xylanase (WO 98/39402) have been suggested for use in laundry detergents for the removal of stains or for providing other desirable attributes to the laundered fabric.
Xylans are complex heterpolymers mainly consisting of xylose and arabinose. Land plant xylans are composed of &bgr;-1,4-linked-D-xylopyranosyl main chain, which may be substituted with acetyl residues and residues of arabinose and methyl glucuronic acid. Xylans are, after cellulose, the second most abundant carbohydrate in biomass. A number of enzymes are needed for the complete hydrolysis of xylans, of which hemicellulases are the most widely appreciated.
For example, In the pulp and paper industry, hemicellulases have been used for the bleaching or pulps to decrease chemical dosages in subsequent bleaching or to increase the brightness of the pulp (Kantelinen et al., International Bleaching Conference, TAPPI Proceedings, 1-5 (1988); Viikari et al., Paper and Timber 7:384-389 (1991)). Such use has further been suggested to be free of cellulolytic activity which would harm the cellulose fibers. Such usage in the pulp and paper industry is further described in PCT Publication Nos. WO 89/08738, WO 91/02791 and WO 91/05908. Hemicellulases have also been suggested in the conversion of biomass to fuels (Viikari et al., “Hemicellulases for Industrial Applications”,
Bioconversion of Forest and Agricultural Wastes
, Saddler, J. ed., CAB International, USA (1993)) and as additives for feed.
As can be seen, extensive work has been done in the field of textiles and carbohydrate-xylan chemistry. However, the textile industry continues to look for improved methods of treating cellulosic fabrics with environmentally benign compositions which provide added value to these fabrics. In particular, the industry has had a long-felt need for the development of more efficient and clean methods of treating non-cotton natural cellulosic textile yarns and fabrics to produce improved products.
SUMMARY OF THE INVENTION
It is an object of the invention to provide for an enzymatic method of bleaching non-cotton cellulosic fibers, yarns and/or fabrics, and textiles made therewith.
It is yet another object of the invention to provide for an alternative method of bleaching non-cotton cellulosic fibers, yarns and/or fabrics, and textiles made therewith, which does not involve the use of environmentally dangerous and undesirable chemicals.
It is yet a further object of the invention to provide for a simple and efficient manner of whitening flax, linen, jute and or ramie which is compatible with industry standard wet processing practices.
According to the invention, a method is provided for bleaching a non-cotton cellulosic fiber, yarn or fabric by contacting the fiber, yarn or fabric with a hemicellulase enzyme for a time and under conditions suitable to produce a whitening of the fiber, yarn or fabric. Preferably, the hemicellulase enzyme is a xylanase or mannanase and most preferably a xylanase. In a particularly preferred method according to the invention, the fiber, yarn or fabric comprises flax, jute, ramie or linen.
In a process embodiment of the invention, the bleaching process of the invention occurs prior to the manufacture of a textile product. In another process embodiment of the invention, the bleaching process of the invention occurs on a clean, unsoiled textile product.
In a process embodiment of the invention the fiber, yarn or fabric bleached as provided herein is subsequently processed into a completed textile product. In another process embodiment of the invention, the fiber, yarn or fabric is treated with a hemicellulase in a continuous process or alternatively is treated with a hemicellulase in a batchwise process.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, a method is provided for bleaching a non-cotton cellulosic fiber, yarn or fabric by contacting the fiber, yarn or fabric with a hemicellulase enzyme for a time and under conditions suitable to produce a whitening of the fiber, yarn or fabric. Preferably, the hemicellulase enzyme is a xylanase or mannanase and most preferably a xylanase. In a particularly preferred method according to the invention, the fiber, yarn or fabric comprises flax, jute, ramie or linen.
In a process embodiment of the invention, the bleaching process of the invention occurs prior to the manufacture of a textile product. In another process embodiment of the invention, the bleaching process of the invention occurs on a clean, unsoiled textile product.
In a process embodiment of the invention the fiber, yarn or fabric bleached as provided herein is subsequently processed into a completed textile product. In another process embodiment of the invention, the fiber, yarn or fabric is treated with a hemicellulase in a continuous process or alternatively is treated with a hemicellulase in a batchwise process.
“Hemicellulase” as used herein means enzymes which catalyze the degradation and/or modification of hemicelluloses, including xylanase, mannanase, xylosidase, mannosidase, glucosidase, arabinosidase, glururonidase, and galactosidase. In a particularly preferred embodiment, the hemicellulase is a xylanase which is understood to mean any xylan degrading enzyme which is either naturally or recombinantly produced. Generally, xylan degrading enzymes are endo- and exo-xylanases hydrolyzing xylan in an endo- or an exo-fashion and include such enzymes as endo-1,3 ? xylosidase, endo-&bgr;1,4-xylanases (1,4-&bgr;-xylan xylanohydrolase; EC 3.2.1.8), 1,3-?-D-xylan xylohydrolase and &bgr;-1-4-xylosidases (1,4-&bgr;-xylan xylohydrolase; EC 3.2.1.37) (EC Nos. 3.2.1.32, 3.2.1.72, 3.2.1.8, 3.2.1.37). Preferred xylanases are those which are derived from a filamentous fungus or a bacterial source, including, for example the fungi of the genera Aspergillus, Disportrichum, Penicillium, Humicola, Neurospora, Fusarium, Trichoderma and Gliocladium or of the bacterium Bacillus, thermotoga, Streptomyces, Microtetraspora, Actinmadura, Thermomonospora, Actinomyctes and Cepholosporum.
The enzyme may be a xylanase enzyme which is engineered to have specific properties such as stability, activity or binding capabilities which are useful, or may be an enzyme which has little or no activity as a xylanase to begin with, but which is modified using principals of directed evolution or protein engineering to result in an enzyme having significant xylanase activity.
“Bleaching” as used herein means the process of treating a fiber, fabric and/or yarn to produce a lighter color in said fiber, fabric or yarn. For example, bleaching as used herein means the whitening of the fabric by removal, modification or masking of color causing compounds in the cellulosic fiber.
“Non-cotton cellulosic fiber, yarn or fabric” means fibers, yarns or fabrics which ar
Day Anthony G.
Power Scott D.
Victoria Doreen
Winetzky Deborah S.
Genencor International Inc.
Genencor International Inc.
Gupta Yogendra N.
Hamlin D G
LandOfFree
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