METHOD FOR CHANGING THE COLOUR OF A TEXTILE, FABRIC AND GARMENT

Abstract

The invention refers to a fabric finishing method suitable for changing the colour of a coloured fabric thereby providing a vintage look to the fabric. The invention refers also to the fabric obtainable by the above method and to a garment comprising such fabric.

Claims

1. A method for changing the colour of at least a part of a coloured fabric comprising the following steps: a) providing said coloured fabric with one or more of an oxidizing agent, preferably selected from: perborate, persulfate, peroxide, permanganate, perchlorate, dichromate, chlorate, chlorite, bromate, nitrite ions, nitrate ions and/or salts containing the above ions; b) heating the fabric obtained according to step a); and c) subjecting at least a part of the fabric obtained according to step b) to a laser treatment; wherein step b) comprises heating said fabric at a temperature comprised in the range of 110 C. to 250 C.

2. The method according to claim 1, wherein the heating temperature is comprised in the range of 110 C. to 220 C.

3. The method according to claim 1, wherein the heating temperature is comprised in the range of 160 C. to 200 C.

4. The method according to claim 1, wherein heating step b) is carried out for a time of at least 20 seconds.

5. The method according to claim 1, wherein said oxidizing agent is selected from nitrate ions and/or nitrate salts.

6. The method according to claim 1, wherein said oxidizing agent is selected from hydrated nitrates.

7. The method according to claim 1, wherein said fabric with one or more of an oxidizing agent is obtained by applying a composition comprising said one or more oxidizing agents to said fabric.

8. The method according to claim 7, wherein said composition is an aqueous composition comprising an amount of said oxidizing agent in the range of 40 g/L to 200 g/L and/or an amount of wetting agent comprised in the range of 0.5 g/L to 20 g/L.

9. The method according to claim 1, further comprising a drying step a), said step a) being carried out after step a) and before step b) and at a temperature comprised in the range of 80 C. to 220 C., the temperature of step a) being lower than the temperature of step b).

10. The method according to claim 1, wherein said laser treatment of step c) is carried out using one or more of the following laser parameters: a dpi value comprised in the range of 20 to 50; a focal length comprised in the range of 80 to 148 cm; a laser beam frequency of 5 kHz; an energy per pulse comprised in the range of 450 to 650 W; a jump speed is about 5150 m/s; and a jump delay comprised in the range of 50 to 300 s.

11. The method according to claim 1, wherein said coloured fabric is coloured with indigo and/or at least an indigoid dye.

12. The method according to claim 1, wherein said coloured fabric includes cellulose-based fibres.

13. The method according to claim 1, wherein a stone washing step d) is carried out after step c).

14. The method according to claim 1, wherein said coloured fabric is part of a garment or apparel.

15. A fabric as obtainable according to steps a) and b) as defined in claim 1, said fabric comprising an oxidizing agent.

16. A fabric as obtainable according to the method of claim 1, comprising elastic yarns.

17. A garment comprising the fabric according to claim 15.

18. A method for increasing the colour fading of a laser treatment on coloured fabrics, characterized in that steps a) and b) as defined in in claim 1 are carried out before said laser treatment in the absence of acid catalysts.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0055] FIG. 1 represents a garment, in particular a pair of pants, showing vintage look in determined areas.

[0056] FIG. 2a is a picture of a comparative fabric which is subjected to laser treatment only. FIG. 2b is a picture of a fabric of the invention.

[0057] FIG. 3a is a macro picture of a comparative fabric which is subjected to laser treatment only. FIG. 3b is a macro picture of a fabric of the invention.

EXPERIMENTAL SECTION AND DETAILED DESCRIPTION OF THE FIGURES

[0058] The invention is further illustrated by means of FIGS. 2a, 2b, 3a and 3b of examples that are provided for illustrative purposes only and do not aim to limit the scope of the invention.

Example 1

[0059] A composition comprising 120 g/L of magnesium nitrate hexahydrate and 3 g/L of a nonionic wetting agent (Cottoclarin TR (BRP Kimya)) is prepared. An indigo coloured cotton fabric is padded with the so-prepared composition (step a)), thereby providing 22 g of magnesium nitrate hexahydrate per square meter of indigo coloured cotton fabric. Then, the fabric is dried in a stenter machine at 150 C. until it reaches 6% of relative humidity (step a)). Afterward, the fabric is heated in the same stenter at 180 C. for 45 seconds (step b)). Finally, a laser treatment step with a CO.sub.2 laser (VAV r-Series 650 W) is carried out on a predetermined area of the fabric (step c)). Laser parameters are 37 dpi, focal length: 148 cm, frequency: 5 kHz, energy per pulse: 450 W, jump speed: 5149.7 m/s and jump delay: 50 s. The colour has faded in the area where laser treatment has been carried out, thereby a vintage look is obtained.

[0060] To further improve the vintage look of the fabric, the fabric has been subjected to stone washing for 30 minutes (step d)). The colour has faded on the whole fabric; the area where laser treatment has been carried out presents a higher colour fading with respect to the other areas.

Example 2

[0061] Comparative Example of Change in Colour

[0062] A fabric of the invention is prepared according to steps a), a), b) and c) as disclosed in Example 1.

[0063] A comparative fabric is prepared by carrying out laser treatment using the same parameters disclosed in Example 1 starting from an identical fabric as the one of Example 1. The comparative fabric has not been subjected to steps a), a) and b) of the method of the invention.

[0064] The change in colour of the fabrics is evaluated by Datacolor 6000 spectrophotometer using the strength adjustment method, which is a conventional method for comparing the strength of colours. Max absorption peak is set at 660 nm. Fix adjustment strength is set to 100%. The comparative fabric shows a result of 100% strength. The fabric of the invention shows a result of 52% strength. According to the above results, the fabric of the invention has less colour strength compared to the comparative fabric, therefore a higher colour fading is obtained with the method of the invention compared to the laser treatment only. The results of this example are also showed in FIGS. 2a and 2b, which show respectively the comparative fabric and the fabric of the invention, and FIGS. 3a and 3b, which show respectively macro pictures of the comparative fabric and of the fabric of the invention. As it can be observed by FIGS. 2 and 3, the change in colour is more apparent in the fabric of the invention (FIGS. 2b and 3b) with respect to the change in colour in the comparative fabric (FIGS. 2a and 3a).

[0065] Therefore, it has been demonstrated that carrying out steps a) and b) of the method of the invention before laser treatment improves the colour fading effects of the laser treatment itself.

Example 3

[0066] Energy and Time Saving of the Method of the Invention

[0067] A comparative fabric and a fabric of the invention have been prepared starting from identical untreated fabrics. The comparative fabric has been prepared carrying out only laser treatment on the untreated fabric.

[0068] It has been observed by the present Example that the laser treatment to manufacture the fabric of the invention provided an energy saving of about 12% to 20% and a time saving of about 12% to 15% per garment, in particular per pair of pants, and an energy saving of about 120 to 130 W and of about 86 seconds per m.sup.2 of treated fabric, with respect to the laser treatment to manufacture the comparative fabric, to provide a comparable vintage look.

[0069] The present Example proves that the laser treatment (step c)) of the method of the invention, compared to laser treatment only, (i) provides cost-savings in terms of energy-savings and time-savings, and (ii) can be carried out with reduced values of the operational parameters that may cause damages to the fabric, such as laser energy and laser treatment time.

Example 4

[0070] The method of the invention is carried out on a fabric. 5 g of such fabric are kept in 200 mL of deionized water for 30 minutes at a temperature of 50 C. Then, complexometric titration is carried out on the water above using EDTA. It resulted that such water contained 5.8 mg/L of magnesium ion corresponding to about 62 mg/L of magnesium nitrate hexahydrate.