DESC:TECHNICAL FIELD OF INVENTION
The present invention relates to a fabric finishing method and a system.

BACKGROUND OF THE INVENTION
Denim is warp faced twill fabric where mostly warp is indigo dyed, and weft is undyed. The denim garment is well known from many generations, worn by people of all classes and ages. Now-a-days, denim trend is changed from non-stretch to high stretch fabric/garment or body fitting garments. Stretch denim is made by using elastane filaments during fabric manufacturing process. Generally, the denim fabric after manufacturing goes through final finishing process. In fabric finishing process of the denim fabric, the fabric is treated chemically and thermally to improve physical, functional and aesthetic properties. Generally, the finishing process includes singeing step, de-sizing step, and final finishing step. In case of stretch denim fabric, the finishing step includes heat setting step after the desizing step which is followed by final finishing step.
Singeing is a process to remove protruding fibers from textile/fabric surface and get clean surface of textile/fabric. De-sizing is a process, to remove sizing agent present on textile/fabric surface, which was applied during the said sizing process to improve weavability. The desizing process is carried out by padding the singed fabric in the water bath or desizing bath. This de-sizing of the said textile/fabric improves fabric hand, appearance and absorbency for further processes. The de-sizing also helps to reduce the widthwise shrinkage of textile/fabric which is followed by the heat setting step. The heat setting is a process to control stretch and make textile/fabric dimensionally stable. Finally, textile/fabric is treated with various finishing chemicals in wet finishing as per requirements of end use application. This can include binders, softeners etc. as per the requirement of the final product. It is observed that the de-sizing and wet finishing process consume approx. 8 – 10 liters of water per meter. Further, the waste water from desizing bath and wet finishing step needs to be processed before it discharged back to nature and increases effluent load, and also cost of process.
Hence, there is a need to reduce the water consumption in the finishing process of denim industries as well as to reduce energy consumption without affecting physical, aesthetic and functional properties of denim fabric.

SUMMARY OF THE INVENTION
The present invention provides, in one aspect, a finishing method for a fabric. In the method, steam is passed over a singed fabric having yarns sized with water soluble size to make the fabric moist. Simultaneously, said fabric is agitated under pressure to relax. The agitation includes striking the fabric on a plate for relaxation. The fabric is agitated mechanically by high air pressure. The fabric is agitated with a hot air, having temperature ranges between 100°C –190°C. The air is supplied at a pressure ranging from 4.5 bar to 5.5 bar. The temperature of steam ranges between 95°C –150°C. The fabric is treated with chemical in the form of foam in final finishing process.
In another aspect, the present invention provides a system for a finishing the fabric that includes a guide roller for guiding a singed fabric, having yarns sized with water soluble size, in a path through the system. A plurality of steam sprayers and a plurality of air nozzles are arranged above and below in the path of the said fabric to moist and agitate the fabric. At least one plate is positioned at the end of the relaxation chamber wherein the fabric relaxes after striking on the plate. A surface applicator is used for applying a chemical in the form of foam on a surface of said fabric in final finishing process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of a method of finishing denim fabric;
FIG. 2 shows a schematic diagram of a system of the present invention; and
FIG. 3 shows a schematic diagram of a setup of final finishing of the system of FIG. 2.

DESCRIPTION OF THE INVENTION

The various embodiments of the present invention provide a process to reduce the water consumption in denim/textile/clothing industries as well as to reduce energy consumption without affecting physical, aesthetic and functional properties of denim fabric.

In the following description, for purpose of explanation, specific details are set forth as an indicative configuration in order to provide an understanding of the invention. It will be apparent, however, to one skilled in the art that the invention may be practiced without these details. One skilled in the art will recognize that embodiments of the present invention, some of which are described below, may be incorporated into a number of configurations (flexibility). Structures and devices shown in the figures are illustrative of exemplary embodiments of the invention and are meant to avoid obscuring the invention.

Furthermore, connections between components within the figures are not intended to be limited to direct connections. Rather, these components may be modified, re-formatted or otherwise changed by intermediary components as per storage requirements.

References in the specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

According to the present invention, denim fabric finishing process is sustainable and eco-friendly in nature. This sustainable process includes singeing, system, foam finishing with minimum use of water. Further, to achieve minimum water usage, changes may require in upstream processes which helps to facilitate finishing process of denim fabric.

Referring to Fig. 1, a schematic diagram (300) of a method for finishing denim fabric is shown in accordance with an embodiment of the present invention. The finishing process comprises in first step, providing a fabric having yarns sized with water-soluble size. The water-soluble size includes but not limited to potato starch, carboxymethyl cellulose, modified starch, acrylates, and polyvinyl alcohol etc. It is understood here that the size is applied onto the yarn to withstand vigorous load of weaving process.

After weaving process fabric undergoes singeing, relaxation chamber and final finishing process. The singeing process provides removal of short fibre, thus reduces hairiness on the surface of the fabric. The temperature of singeing process ranges between 900°C to 1400°C. In the next step, the fabric is passed through the system of the present invention. The system is used for for relaxation of the fabric. This system also helps to reduce widthwise shrinkage and softens the fabric. Further, final finishing process is used to make fabric dimensionally stable.

Referring to FIG. 2, a schematic diagram of passing of fabric through the system (202) in accordance with an embodiment is shown. The fabric (100) is subjected to steam and agitation under predefined pressure and temperature. In an embodiment, the agitation is a mechanical agitation with hot air. In accordance with the present invention, the fabric is supplied from a fabric supply chamber (10) to the relaxation chamber (20). The speed of the relaxation chamber (20) is maintained at 5-30 mt/min and the dwell time is 2-5 seconds.

In accordance with an embodiment, a first plate (40A) is placed between the fabric supply chamber (10) and the relaxation chamber (20) to provide mechanical agitation to the fabric. In the relaxation chamber (20), the fabric (100) is subjected to hot air and steam. The fabric (100) is drawn from the relaxation chamber (20) due to built up pressure and collected into the fabric collection chamber (30). The fabric (100) hits on a second plate (40B) placed between the relaxation chamber (20) and the fabric (100) collection chamber (30). A plurality of steam sprayers (Not shown) and a plurality of hot air nozzles (not shown) are arranged above and below in the path of the said fabric (100) to moist and agitate the fabric. The hot air pressure ranges from 4.5 - 5.5 bar. Further, the fabric maybe passed to the relaxation chamber (20) either from the fabric supply chamber (10) or from the fabric collection chamber (30). The plates (40A, 40B) positioned at both the end of the system chamber are used for relaxation of the fabric. The fabric (100) pushed out off the system chamber (20) strikes over the at least one plate (40A, 40B).

Referring Fig. 3, a schematic diagram of a final finishing process (203) in accordance with an embodiment of the present invention is shown. In this process, the fabric (100) is passed through a guide roller (101), a j-scray unit (102). The guide roller (101) is used for guiding the fabric and the j-scray unit (102) is used for collecting the fabric. In the next step, the fabric is passed through a surface applicator (103), in this unit the chemical is applied on the surface of the fabric which helps to improve rubbing fastness of the fabric. The chemical is applied in foam form. The final finishing process (203) includes application of chemical on surface of the fabric through surface applicator to improve rubbing fastness. The chemicals include anti-foaming agent or the chemical which improve rubbing fastness of fabric.

The fabric is further passed through foam finishing process unit (104). The foam finishing process unit (104) includes a skew unit (105), a sanforising unit (106) and a moisture control unit (107). The skew unit (105) is used for denim fabric on which fabric twill line is set. The sanforising unit (106) is used for making the fabric dimensionally stable. The moisture control unit (107) is used for drying the fabric. The residual moisture in the fabric passed through the moisture control unit (107) is approximately 1%. The finished fabric is wound on to a roller (108).

By using the described method, the water consumption is reduced by at least 50%.
For Example:
A fabric is manufactured by the process as disclosed in the description. The fabric details as below:
Warp – 8s Ne Ring
Weft – 12 CSY + 70D elastane
EPI X PPI – 64 X 44

Product A Weight (Oz/Sq. yd.) ASTM D3776 Widthwise Shrinkage AATCC 135 % Stretch ASTM D3107 Rubbing Fastness AATCC 8
Existing finishing process 11.75 - 14.00 28 3
Finishing process according to the present invention 12.00 - 12.00 26 3

The above table shows the test results of product a finish with two process routes, existing finishing process and the finishing process (300) of the present invention. As per the results, the test results of finishing process (300) of the present invention is comparable with existing finishing process.

Hence, the present invention provides a process to reduce the water consumption in denim industries as well as to reduce energy consumption without affecting physical, aesthetic and functional properties of denim fabric.

The denim fabric finishing process described herein is sustainable and eco-friendly in nature. This sustainable process includes singeing, system, finishing with minimum use of water. The invented process reduces at least 50% usage of water during finishing of denim fabric.
,CLAIMS:

1. A fabric finishing method comprising the steps of:
passing steam over a singed fabric having yarns sized with water soluble size to make the fabric moist and simultaneously agitating said fabric under pressure to relax the said fabric.

2. The method as claimed in claim 1, wherein the step agitating includes striking the fabric over a plate for relaxing the fabric.

3. The method as claimed in claim 1 or 2, wherein the fabric is agitated mechanically by high air pressure.

4. The method as claimed in any one of the preceding claims 1-3, wherein the fabric is agitated with a hot air ranges between 100°C - 190°C.

5. The method as claimed in claim 4, wherein the air is supplied at a pressure ranging from 4.5 bar to 5.5 bar.

6. The method as claimed in any one of the preceding claims 1-4, wherein the temperature of steam ranges between 95°C - 150°C.

7. The method as claimed in one of the preceding claims 1 to 5, wherein the fabric is treated with chemical in the form of foam.

8. The method as claimed in one of the preceding claims 1 to 4, wherein sped of the fabric is maintained at 5 – 30 mt/min.

9. A fabric finishing system for a fabric comprising:
a guide roller for guiding a singed fabric, having yarns sized with water soluble size, in a path through the system;
a plurality of steam sprayers and a plurality of air nozzles arranged above and below in the path of the said fabric to moist and agitate the fabric; and
at least one plate positioned at at least one end of the system chamber.

10. The system as claimed in claim 9, wherein speed of the system chamber is maintained at 5 -30 mt/min.

11. The system as claimed in claim 9 further comprises a surface applicator for applying a chemical in the form of foam on a surface of said fabric.