DESC:TECHNICAL FIELD OF THE INVENTION
The present invention relates to the field of finishing processes for fabrics.
BACKGROUND OF THE INVENTION
Denim is a popular apparel for many generations. Over a period of time, denim fabric has undergone various changes from non-stretch to stretch, comfort stretch, high stretch, skinny denim, performance denim, ripped denim etc. The denim garment includes jeans, jacket, shirt, dresses etc. Now-a-days, the focus of the denim industry in on improving aesthetics, visual appearance and hand feel of the denim fabric. During manufacturing, a denim fabric undergoes different washing processes. The washing processes are categorised in two main categories, i.e., dry washing processes and wet washing processes. The dry processes include micro sanding, brushing, fraying, and making whiskers and chevrons on denim garments. The wet processes include different washes like rinse, enzyme, stone and bleach. It is well known in denim industry that removal of dye from predefined area can achieve desired aesthetic look of the garment. For example, dye is removed from predefined area to create whiskers or chevrons on a denim fabric. Typically, some of the aforementioned processes are carried out manually using water and suitable chemicals. Thus, the aforementioned processes consume water, chemicals and energy, and may require manual intervention. Further, being a manual process, reproducibility of the same pattern on each denim garment may not be possible, which hampers uniformity of the design on the denim garments.
To reduce water and chemical consumption during the wet processes, laser treatment is used to remove dye from predefined area on the fabric. It has been observed that desired removal of the dye from the fabric surface can be obtained in short time span using the laser treatment. Additionally, the laser treatment facilitates increased reproducibility of the dye removal pattern irrespective of geography of the fabric. The laser treatment is a highly controlled process, wherein laser intensity and pixel density along with laser exposure time are controlled. The intensity of laser rays is mainly based on fiber contents of the fabric to be treated and also on desire aesthetic look.
Conventionally, there are two known methods to make a fabric laser friendly. One method involves addition of a chemical during the fabric processing which boosts laser sensibility of fabric. However, this method does not work effectively, and involves a huge cost as well. Another method of making fabric laser sensible involves changing parameters of the dyeing process. The dyeing parameters are altered to get a ring dyeing effect on yarn, so that the core of the yarn remains un-dyed. This helps to easily remove dye particles from predefined area on the laser fabric when exposed to the laser rays as the dye particles are not penetrated deeply into yarns of the fabric. However, in this method, a fabric can be made laser friendly during the dyeing process. If the parameters are not altered to get a ring dyeing effect on the yarns, such fabric cannot be made laser friendly after post dyeing.
The fabric is further washed with different chemicals to get rinse, enzyme and bleach shade. It involves use of water and harmful chemicals during washing and ultimately consumes time as well as increases effluent load.
As per the available methods of making fabric laser friendly, the fabric needs to be manufactured with defined parameters.
Therefore, there is felt a need of a process which can overcome at least one of the disadvantages of existing processes and provide a laser friendly fabric as well as reduce water consumption.
SUMMARY OF THE INVENTION
The present invention discloses a process for making a laser friendly fabric. The fabric is a dyed fabric. The process comprises the step of abrading a dyed fabric in an emerizing unit having an abrasive surface to obtain a dyed fabric having soft surface. The process comprises the step of washing the fabric with a cleaning agent in a hydro-thermomechanical treatment unit to remove loose dye from the soft fabric to obtain a laser friendly fabric.
In an embodiment, the fabric is passed through a singeing unit prior to abrading with the abrasive surface, and treated in the singeing machine at temperature ranging from 800 degree Celsius to 1200 degree Celsius for removal of protruding fibres from a surface of the fabric.
DETAILED DESCRIPTION OF THE INVENTION
Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.
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.
The present invention provides a process of making a laser friendly fabric. The fabric is treated with the process of the present invention after dyeing.
In accordance with the present invention, a dyed fabric is subjected to finishing processes as per the following route.
Singe – Desize – Emerizing– Hydro-thermomechanical treatment - Final finishing
The dyed fabric is passed through a singeing machine for removal of protruding fibres from the surface of the fabric. The fabric is treated in the singeing machine at temperature ranging from 800 °C to 1200 °C. The singed fabric is exposed to desizing process in which the impurity and applied sized chemicals are removed.
The process of the present invention includes the step of abrading a dyed fabric with an abrasive surface to obtain a soft fabric. In this step, the dyed fabric is subjected to abrasion with the help of an abrasive surface. In an embodiment, the fabric is subjected to abrasion post the singeing and desizing process. However, it is to be noted that the dyed fabric can be directly subjected to abrasion process without singeing and desizing process.
In an embodiment, the dyed fabric is abraded in an emerizing unit. The emerizing unit has various abrasive surfaces for facilitating abrasion of the dyed fabric. In an embodiment, the abrasive surface is selected from the group consisting of a diamond abrasive surface, a carbon abrasive surface, a silica abrasive surface, brussel abrasive surface, and any combination thereof. In another embodiment, a diamond abrasive surface is used. More specifically, a diamond emerizing is used in the emerizing unit.
The fabric can be passed through the emerizing unit at various speed depending upon the texture of the fabric and required abrasion. In an embodiment, the dyed fabric is passed through the emerizing unit at a speed ranging from 20 meter/minute to 40 meter/min. In an embodiment, the dyed fabric is passed though the emerizing unit at a speed of 25 meter/min to achieve desired effects.
The abrasion of the fabric surface loosens a portion of dye particles from the surface of the fabric and makes the fabric soft. Due to loosening of dye particles, laser rays can effectively remove dye from selected portions of the fabric. Additionally, post abrasion, the fabric has softer hand feel compared to that of presently available finished fabric.
The fabric is then washed with a cleaning agent to remove loose dye from the soft fabric to obtain a laser friendly fabric. In an embodiment, the cleaning agent is water. In another embodiment, the cleaning agent includes water, caustic and softner.
In an embodiment, the fabric is washed in a hydro-thermomechanical treatment unit by passing it through said hydro-thermomechanical treatment unit at a speed ranging from 5 meter/minute to 50 meter/minute. In the hydro-thermomechanical treatment unit, the fabric is washed with the minimum amount of water. To optimize the water usage, water is sprayed onto the fabric. The soft fabric is passed through the treatment unit at a speed ranging from 5 meter/minute to 50 meter/minute. In an embodiment, the fabric is passed through the treatment unit at a speed of 15 meter/min. Chemicals may be added at a time of processing, which can help to achieve washed look of denim in fabric form itself along with enhanced laser sensitivity. This helps to reduce water, chemicals and energy consumption in garmenting stage, as the treated fabric is more laser sensitive. Thus, the effect, such as whisker, chevron etc., can be achieved much more efficiently by exposing the fabric/garment to the laser rays.
In the final finishing process, the fabric is treated with foam or water and dimensional stability of the fabric is achieved.
It is to be noted that any type of fabric can be treated with the process disclosed in the present invention to make it laser friendly. The fabric can be a woven fabric, denim fabric, a knitted fabric, or any other type of fabric. In an embodiment, the fabric is denim woven fabric.
In an embodiment, the fabric includes interlacement of warp yarns and weft yarns, wherein warp yarns are dyed with desirable dyes and the weft yarns are kept undyed. In an embodiment, the warp yarns are dyed with indigo dye, sulphur dye or combination of dyes. The warp or weft yarn can be manufactured using natural fibres, regenerated fibres, synthetic fibres, elastomeric fibres, recycled fibres or any combination thereof. The warp or weft yarn count can range from 4s Ne to 30s Ne. More particularly, the yarn count can range from 8s Ne to 20s Ne. The elastomeric filament count can range from 40 denier to 140 denier. More particularly, the elastomeric yarn count ranges from 70 denier to 105 denier. In an embodiment, the fabric is woven in denim weaves including, but not limited to, twill, sateen/satin, dobby etc. The fabric can have a weight ranging from 6 to 16 Oz./Sq. yard. More particularly, the fabric can have a weight ranging from 8 to 12 Oz./Sq. yard. The fabric, after subjecting to the aforementioned method steps, has light sensitive fabric (LSF) rating ranging from 10 to 15.
Following is an example of a laser friendly fabric manufactured in accordance with aforementioned processes of the present invention.
Example 1:
Warp: 7s Ne- Cotton
Weft: 10 CSY + 70D Cotton spandex
Weave: 3/1 Twill
Weight: 12 Oz./Sq. yard
LSF rating: 12
The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

,CLAIMS:
1. A process for making a laser friendly fabric, said process comprising the steps of:
abrading a dyed fabric in an emerizing unit having an abrasive surface to obtain a dyed fabric having soft surface; and
washing said fabric with a cleaning agent in a hydro-thermomechanical treatment unit to remove loose dye from said fabric to obtain a laser friendly fabric.
2. The process as claimed in claim 1, wherein the abrasive surface is selected from the group consisting of a diamond abrasive surface, a carbon abrasive surface, a silica abrasive surface, brussel abrasive surface or a combination thereof.
3. The process as claimed in claim 2, wherein said dyed fabric is passed through said emerizing unit at a speed ranging from 20 meter/minute to 40 meter/minute.
4. The process as claimed in claim 1, wherein said cleaning agent includes water, caustic and softner.
5. The process as claimed in claim 1, wherein said fabric is passed through a singeing unit prior to abrading with said abrasive surface and treated in said singeing machine at a temperature ranging from 800 degree Celsius to 1200 degree Celsius.
6. The process as claimed in claim 1, wherein said soft fabric is washed in said hydro-thermomechanical treatment unit at a speed ranging from 5 meter/minute to 50 meter/minute.
7. The process as claimed in claim 1, wherein fabric or warp yarn is dyed with an indigo dye, a sulphur dye, or a combination of said dyes.
8. A fabric comprising warp and weft yarns having count ranging from 4s Ne to 30s Ne and elastomeric filaments having count ranging from 40 denier to 140 denier, and said fabric having light sensitive fabric (LSF) rating ranging from 10 to 15.
9. The fabric as claimed in claim 8, wherein weight of said fabric ranges from 6 to 16 Oz./Sq. yard.
10. The fabric as claimed in claim 8, wherein said fabric is woven in denim weaving pattern including twill, satin/sateen, dobby.
11. The fabric as claimed in claim 8, wherein said fabric is dyed with an indigo dye, a sulphur dye, or a combination of said dyes.
12. The fabric as claimed in claim 8, wherein said fabric having a warp and weft yarn is manufactured using natural fibres, regenerated fibres, synthetic fibres, elastomeric fibres, recycled fibres or any combination thereof.
13. The fabric as claimed in claim 8, wherein said fabric is laser friendly.
14. The fabric as claimed in claim 8, wherein the said fabric is a knitted fabric.