METHOD AND APPARATUS FOR TREATING A TEXTILE FABRIC

Abstract

A method and an apparatus for desizing and/or shrinking a textile fabric, the textile fabric having a length and a width, the method including moving, lengthwise, the fabric, and wetting the fabric within a first pool of liquid, the first pool of liquid including water; passing the fabric through a chamber, and in the chamber contacting the fabric with at least one heatable roller heated at a treatment temperature; soaking the fabric with a main pool of liquid, the main pool of liquid including water; and treating the fabric with ozone. The apparatus includes a first module for wetting the fabric, a second module with a heatable roller for heating the fabric, a third module for soaking the fabric, and fourth module for treating the fabric with ozone. The second module may optionally be integrated with the first module.

Claims

1. A method for desizing and/or shrinking a textile fabric, the textile fabric having a length and a width, the method comprising: moving, lengthwise, the fabric, wetting the fabric within a first pool of liquid, the first pool of liquid comprising water; passing the fabric through a chamber, and, in said chamber, contacting the fabric with at least one heatable roller heated at a treatment temperature of between 80° C. and 160° C.; soaking the fabric with a main pool of liquid, the main pool of liquid comprising water; and treating the fabric with ozone.

2. The method according to claim 1, wherein the first pool of liquid has a pH of between 4 and 12.

3. The method according to claim 1, wherein the first pool of liquid has a temperature of between 10° C. and 100° C.

4. The method according to claim 1, wherein wetting the fabric with the first pool of liquid comprises inducing a wet pickup value of more than 50%.

5. The method according to claim 1, wherein wetting the fabric with the first pool of liquid comprises contacting the fabric with a rotatable washing drum positioned in a tank containing said first pool, the rotatable washing drum being configured so that when it rotates it agitates said first pool of liquid and contacts and guides the fabric so that the latter enters and exits said first pool of liquid as the fabric moves lengthwise, and with said rotatable washing drum guiding the fabric so that the latter enters and exits the first pool of liquid.

6. The method according to claim 1, wherein passing the fabric through a chamber comprises moving the fabric lengthwise at a production speed of between 1 m/min and 200 m/min.

7. The method according to claim 1, wherein passing the fabric through the chamber comprises having the fabric in said chamber for a total duration of between 0.1 minutes and 10 minutes.

8. The method according to claim 1, wherein soaking the fabric with the main pool of liquid comprises: guiding the fabric so that the latter moves from an entrance part to an exit part while successively entering and exiting multiple times the main pool of liquid, the latter extending from said entrance part to said exit part, and inducing a flow of the liquid from said exit part towards said entrance part.

9. The method according to claim 1, wherein treating the fabric with ozone is treating the fabric with ozone in gas, and comprises: passing the fabric through a pre-treatment tank containing water; squeezing out water from the fabric to a final wet pickup value of between 20% and 90%; moving the fabric lengthwise through an ozone treatment hollow chamber at a linear speed that is between 5 m/min and 140 m/min, the ozone treatment hollow chamber comprising rollers for directing the movement of the fabric and containing ozone at a concentration in gas that is between 2 g/Nm.sup.3 and 150 g/Nm.sup.3, the ozone treatment hollow chamber being configured so that the fabric moves within the chamber along a linear path that has a length of between 5 m and 120 m; and passing the fabric through a post-treatment tank containing water.

10. An apparatus for desizing and/or shrinking a textile fabric, the textile fabric having a length and a width, the apparatus comprising: a first module that is configured for containing a first pool of liquid comprising water for wetting the fabric when the apparatus is operated, a second module that comprises a chamber wherein there is at least one heatable roller, and the second module is configured for heating said at least one heatable roller at a treatment temperature of between 80° C. and 160° C. and for heating the fabric via contacting the latter with said at least one heatable roller when the apparatus is operated, a third module that is configured for containing a main pool of liquid comprising water for soaking the fabric thereat when the apparatus is operated, and a fourth module that is configured for treating the fabric with ozone when the apparatus is operated, the apparatus being configured for moving lengthwise the fabric successively passing it through the first module, the second module, the third module, and the fourth module when the apparatus is operated.

11. The apparatus according to claim 10, wherein the first module comprises a first tank that is configured to contain the first pool of liquid when the apparatus is operated, and the first module also comprises a rotatable washing drum positioned in said first tank and is configured to agitate said first pool of liquid when the apparatus is operated, and is also configured to contact and guide the fabric so that the latter enters and exits said first pool of liquid when the apparatus is operated.

12. The apparatus according to claim 10, wherein the chamber of the second module has a second module entrance with an entrance tank thereat that is configured to contain an entrance pool of liquid when the apparatus is operated, and the second module further comprises: a second module exit with an exit tank thereat that is configured to contain an exit pool of liquid when the apparatus is operated, a heatable ceiling, and a plurality of heatable rollers within said chamber, wherein each of said heatable rollers is configured to be heated at the treatment temperature, the heatable rollers are rotatable and are configured to guide the fabric so that the latter successively contacts each of said heatable rollers and moves from the second module entrance towards the second module exit when the apparatus is operated, the second module entrance is configured to allow the fabric to enter into the chamber via passing through said second module entrance and through the entrance pool of liquid thereat when the apparatus is operated, the second module exit is configured to allow the fabric to exit from the chamber via passing through said second module exit and through the exit pool of liquid when the apparatus is operated, the second module entrance is configured to prevent air from passing through the second module entrance and from inside the chamber to outside of it without said air passing through the entrance pool of liquid when the apparatus is operated, and the second module exit is configured to prevent air from passing through the second module exit and from inside the chamber to outside of it without said air passing through the exit pool of liquid when the apparatus is operated.

13. The apparatus according to claim 12, wherein the first module is integrated with the second module entrance and the first pool of liquid is the entrance pool of liquid.

14. The apparatus according to claim 10, wherein the third module comprises liquid flow means, a plurality of guiding rollers, an entrance part, an exit part, the main pool of liquid extending from said entrance part to said exit part, wherein the plurality of guiding rollers are configured to guide the fabric so that the latter moves from the entrance part to the exit part while successively entering and exiting multiple times the main pool of liquid when the apparatus is operated, and the liquid flow means are configured to induce a flow of the liquid within the main pool of liquid from the exit part towards the entrance part when the apparatus is operated.

15. The apparatus according to claim 10, wherein the fourth module is configured for treating the fabric with ozone gas, and comprises: a pre-treatment tank that is configured to contain water and is configured for the fabric to pass through and be wetted at said pre-treatment tank when the apparatus is operated; a Foulard type roller configured for receiving the fabric from the pre-treatment tank and for squeezing out water from the fabric when the apparatus is operated; an ozone treatment hollow chamber adjacent to the pre-treatment tank, wherein the ozone treatment hollow chamber comprises rollers and the apparatus when operated is configured for lengthwise moving through the ozone treatment hollow chamber the fabric when the latter exits the pre-treatment tank and the Foulard type roller, the rollers being configured for directing the movement of the fabric through the hollow chamber when the apparatus is operated, and the apparatus comprises an ozone generator configured to generate and provide to the ozone treatment hollow chamber ozone at a concentration in gas that is between 2 g/Nm.sup.3 and 150 g/Nm.sup.3 when the apparatus is operated, the apparatus being further configured when operated to move the fabric through the ozone treatment hollow chamber along a linear path of a length that is of between 5 m and 120 m when said apparatus is operated; and a post-ozone treatment tank that is configured to contain water for wetting the fabric when the apparatus is operated, and is configured for receiving the fabric from the ozone treatment hollow chamber when the apparatus is operated.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0083] The previous and other advantages and features will be more fully understood from the following detailed description of embodiments, with reference to the attached figures, which must be considered in an illustrative and non-limiting manner, in which:

[0084] FIG. 1 is a schematic diagram of a preferred embodiment of an apparatus according to the second aspect of the invention.

[0085] FIG. 2 is a schematic diagram of a part of another preferred embodiment of an apparatus according to the second aspect of the invention.

[0086] FIG. 3 is a schematic diagram of a top view of a part of an embodiment of an apparatus that is according to the second aspect of the invention.

[0087] FIG. 4 is a flow diagram of an embodiment of a method according to the first aspect of the invention.

[0088] FIG. 5 is a flow diagram of a part of an embodiment of a method according to the first aspect of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0089] FIG. 1 shows a schematic diagram, that is a cross section, of a preferred embodiment of an apparatus for desizing and/or shrinking a textile fabric, the textile fabric having a length and a width, the apparatus comprising a first module 1 that is configured for containing a first pool of liquid comprising water for wetting the fabric when the apparatus is operated, a second module 2 that that comprises a plurality of heatable rollers 21 and is configured for heating said plurality of heatable rollers 21 at a treatment temperature and for heating the fabric via contacting the latter with said at least one heatable rollers 21 when the apparatus is operated, a third module 3 that is configured for containing a main pool of liquid (not shown) comprising water for soaking the fabric thereat when the apparatus is operated, and a fourth module 4 that is configured for treating the fabric with ozone gas when the apparatus is operated, the apparatus being configured for moving lengthwise the fabric successively passing it through the first module 1, the second module 2, the third module 3, and the fourth module 4 when the apparatus is operated. In FIG. 1 there is also indicated the textile fabric that is lengthwise spread across the apparatus as is represented by the gray line grey line extending across the length of the apparatus going through the latter's various modules.

[0090] As is shown in FIG. 1 the first module 1 comprises a first tank 11 that is configured to contain the first pool of liquid when the apparatus is operated, and the first module 1 also comprises a rotatable washing drum 12 positioned in said first tank 11 and is configured to agitate said first pool of liquid when the apparatus is operated, and is also configured to contact and guide the fabric so the latter enters and exits said first pool of liquid when the apparatus is operated.

[0091] As is also shown in FIG. 1 the second module 2 comprises a chamber 22 that has a second module entrance 23 with an entrance tank 24 thereat that is configured to contain an entrance pool of liquid when the apparatus is operated,

[0092] a second module exit 25 with an exit tank 26 thereat that is configured to contain an exit pool of liquid when the apparatus is operated,

[0093] a heatable ceiling 27, and

[0094] the plurality of heatable rollers 21 within said chamber 22,

[0095] wherein

[0096] each of said heatable rollers 21 is configured to be heated at the treatment temperature,

[0097] the heatable rollers 21 are rotatable and are configured to guide the fabric so that the latter successively contacts each of said heatable rollers and moves from the second module entrance 23 towards the second module exit 25 when the apparatus is operated,

[0098] the second module entrance 23 is configured to allow the fabric to enter into the chamber 22 via passing through said second module entrance 23 and through the entrance pool of liquid thereat when the apparatus is operated,

[0099] the second module exit 25 is configured to allow the fabric to exit from the chamber 22 via passing through said second module exit 25 and through the exit pool of liquid when the apparatus is operated,

[0100] the second module entrance 23 is configured to prevent air from passing through the second module entrance and from inside the chamber to outside of it without said air passing through the entrance pool of liquid when the apparatus is operated,

[0101] the second module exit 25 is configured to prevent air from passing through the second module exit and from inside the chamber to outside of it without said air passing through the exit pool of liquid when the apparatus is operated.

[0102] More specifically FIG. 1 shows that in the specific embodiment the first module comprises eight heatable rollers 21.

[0103] In the embodiment shown in FIG. 1 the third module 3 comprises liquid flow means (not shown), a plurality of guiding rollers 31, an entrance part 32, an exit part 33, the main pool of liquid extending from said entrance part 32 to said exit part 33, wherein the plurality of guiding rollers are configured to guide the fabric to move from the entrance part 32 to the exit part 33 while successively entering and exiting multiple times the main pool of liquid when the apparatus is operated, and the liquid flow means are configured to induce a flow of the liquid within the main pool of liquid from the exit part 33 towards the entrance part 32 when the apparatus is operated.

[0104] Likewise, in the embodiment shown in FIG. 1 the fourth module 4 comprises: [0105] a pre-treatment tank 41 that is configured to contain water and is configured for the fabric to pass through and be wetted at said pre-treatment tank when the apparatus is operated; [0106] a Foulard type roller 42 configured for receiving the fabric from the pre-treatment tank 41 and for squeezing out water from the fabric when the apparatus is operated; [0107] an ozone treatment hollow chamber 43 adjacent to the pre-treatment tank 41, wherein the ozone treatment hollow chamber 43 comprises rollers 44 and the apparatus when operated is configured for lengthwise moving through the ozone treatment hollow chamber the fabric when the latter exits the pre-treatment tank 41 and the Foulard type roller 42, the rollers 44 being configured for directing the movement of the fabric through the hollow chamber 43 when the apparatus is operated, and the apparatus comprises an ozone generator (not shown) configured to generate and provide to the ozone treatment hollow chamber 43 ozone at a concentration in gas, the apparatus being further configured when operated to move the fabric through the ozone treatment hollow chamber 43 along a linear path; [0108] a post-ozone treatment tank 45 that is configured to contain water for wetting the fabric when the apparatus is operated, and is configured for receiving the fabric from the ozone treatment hollow chamber 43 when the apparatus is operated.

[0109] As indicated in FIG. 1 the specific embodiment, and specifically the fourth module, comprises at least one tension compensator 52 that is in contact with the fabric and configured to control (adjust, probe) the lengthwise tension of the fabric, and to preferably maintain said fabric tensed (lengthwise) when the apparatus is operated.

[0110] Also in FIG. 1 there is shown in the specific embodiment there are two J-boxes 5a, 5b on either sides of the shown apparatus; the J-boxes are optional components of the apparatus. The apparatus shown in FIG. 1 also comprises traction rollers 51.

[0111] FIG. 2 shows the first, second and third module of another embodiment of an apparatus according to the second aspect of the invention, wherein the first module 1 is integrated with the second module entrance 23 and the first pool of liquid is the entrance pool of liquid. Therefore, in effect in the embodiment shown in FIG. 2 the second module's second tank is also the first module's first tank that was mentioned further above in relation to FIG. 1. As is also indicated in FIG. 2 the third module comprises drive motors 35 that are configured for rotating corresponding guiding rollers 31 of the apparatus; this does not signify that all guiding rollers 31 are necessarily connected to drive motors. FIG. 2 essentially also shows a preferred embodiment of an apparatus according to the third aspect of the invention. In the embodiment shown in FIG. 2, a rotatable washing drum 12 is in the entrance tank 24.

[0112] FIG. 3 shows a top view of a the main pool of liquid in the third module of the apparatus of any of the embodiments shown in FIG. 1 and FIG. 2. Said main pool of liquid is contained in a main tank 34 of said third module, and said main pool of liquid extends from the entrance part 32 to the exit part 33. The main tank 34 is shaped (configured to) form a zig-zag shaped channel, wherein the main pool of liquid extends along said zig-zag shaped channel. The fabric progressively moves across the main pool of liquid along the direction indicated by the straight arrowed line, and as the fabric moves across the third module successively enters and exits said main pool of liquid. The third module comprises flow means (not shown) that cause the liquid/water within the main tank to flow along the direction indicated by the curved arrows in FIG. 3.

[0113] FIG. 4 is a flow diagram of a preferred embodiment of a method that is according to the first aspect of the invention. As indicated in FIG. 4 the method comprises successively performing the steps of wetting the fabric 1001, heating the fabric 1002, soaking the fabric 1003, treating the fabric by means of ozone 1004. Wetting and soaking are done utilizing water. Said treating with ozone is most preferably performed by exposing the fabric to a gaseous atmosphere that comprises ozone.

[0114] FIG. 5 shows a flow diagram of some important steps of a preferred way of treating the fabric with ozone. As indicated in FIG. 5 said preferred way comprises executing successively the step of: [0115] pre-treatment wetting (of) the fabric 2001, e.g. wet/rinse/soak the fabric with water (before exposing the fabric to ozone); [0116] adjusting the wet pickup value 2002 of the fabric, e.g. controllably squeezing out water or the fabric and/or controllably drying the fabric; [0117] exposing the fabric to ozone 2003, e.g. passing the fabric through a chamber that contains a gaseous atmosphere that comprises ozone gas; [0118] post-treatment washing the fabric 2004, e.g. rinse/soak the fabric with water (after exposing the fabric to ozone).

[0119] The inventors have observed a beneficial effect on achieving good desizing by adding certain chemicals in the liquid used in the first step of the method i.e. in the liquid(s) used for wetting the fabric before heating it in the second step, said liquid(s) being or comprising water. Likewise, the inventors have noticed a beneficial effect on achieving good desizing by increasing the temperature of said liquid (increasing temperature relative to the temperature of the ambient environment) i.e. by heating the liquid. Accordingly, the following table 1 indicates some chemicals and/or temperatures that should preferably be used in/with the water used in the first step of the method for efficiently removing from the fabric the corresponding size material shown in the table's left column:

TABLE-US-00001 TABLE 1 Favorable conditions in liquid wetting the fabric Size material before heating the latter Starch and It is removed using amylase enzyme at 60° C. derivatives Polyvinyl It is removed using detergent at 90-95° C., pH 7-9 alcohol PVA to avoid coagulation. Soluble in water. Polyvinyl It is removed using detergent at 98° C. and pH 10. acetate PVAC Soluble in wáter. Polyacrylate PAC pH 9.5-10.5. Washing temperature 80-98° C. Polyacrylate It can be removed using using detergent and carbonate (ammonium salt) at 95-100° C. Polyester PES High pH with carbonate or soda can cause it to precipitate (and set). Wash at 80-98° C. carboxymethyl It can be removed in alkaline medium and at 70-80° cellulose CMC C. It is soluble in water

[0120] The method and the apparatus are preferably used for treating denim, and more preferably for treating elastic denim.

[0121] When the water used in the method and apparatus is recycled/reused, e.g. when the apparatus comprises a water recirculation system, then this allows to have a water consumption of as low as 1 L/m of treated fabric.

[0122] The method of the first aspect of the invention works exceptionally well for (pre)shrinking fabrics. A preferred embodiment of the method of the first aspect of the invention implemented via a preferred embodiment of the apparatus of the second aspect of the invention allowed for processing a textile fabric with a water consumption of just 2 L/kg. According to experiments conducted by the inventors, shrinking has been achieved for several different textiles, some of which are the following with their composition respectively indicated: [0123] Marvel: 75% CO/22% PES/3% EA; [0124] Vogue: 97% CO/3% EA; [0125] Stop: 98% CO/2% EA; [0126] Nevada: 98% CO/2% EA; [0127] Ranger: 100% CO,

[0128] wherein CO means cotton, PES means polyester, and EA means elastane. For all of said materials treated using the present invention a significant dimension stability (shrinkage control) was achieved after washing at 60° C. This is evident from the following table 2 which shows the achieved shrinking for the case of the Marvel fabric (for all the aforementioned fabrics similar experimental results have been achieved) that is according to quality standards of the fabric; the shrinking was studied following the test method AATCC 135. For the Marvel fabric studied, the specifications regarding quality dimensional stability are that a warp-wise shrinking of −2%±1.5%, and a weft-wise shrinking of −8%±2% should be achieved so that any subsequent further significant shrinking of the fabric is avoided. Indeed, as shown in table 2 with the present invention the achieved shrinking values are within said specification values regarding the fabric's quality dimensional stability.

TABLE-US-00002 TABLE 2 Original (cm) After wash (cm) After wash (%) Process Width Warp Weft Warp Weft Warp Weft Present 150.4 35.0 35.0 33.8 31.7 −3.43 −9.43 invention

[0129] The processed fabric complies with the quality requirements regarding elasticity. Experiments have shown that the fabric which was shrinked as described in relation to table 2, did not lose its elasticity. More specifically, in relation to the weft of the fabric, stretch tests have been performed and have shown that the processed fabric exhibits a stretch of 51.82%. Therefore, the present invention works exceptionally well with elastic fabrics, particularly elastic denim.

[0130] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.