This invention relates to a method of treating fabrics and garments. Such fabrics may be made at least partly of cotton, cotton mixes, denim, twill, CVC (chief value cotton), linen, linen-mixes, ramie, polyester mixes, hemp, and bamboo, and the garments are made of these fabrics.

For over 150 years, denim jeans have been worn as sturdy workwear. It is also common knowledge that two major characteristics can be seen in all pairs of jeans:

the fabric gets softer and more comfortable after continuous use and washing; and - due to the inherent use of indigo as the dye stuff of choice, the blue colour fades out during wash, because the indigo dye has a bleed out effect.

During the 1950s, the younger generation started to use denim garments as casual wear rather than workwear, but it was not until the 1970s that "prewashed jeans" were sold at retail and that the jeans were adopted as the general and commonplace casual wear throughout the world. It was from this point on that consumers and producers took an active interest in applying various treatments during the wash or wet processing to achieve the used and worn look (sometimes referred to in the fashion industry as "vintage look") that previously could only be achieved after wearing the garments for long periods of time and subjecting them to multiple wash cycles.

As the demands of the fashion industry have increased so has the innovation within the wash industry to achieve the ultimate vintage look. Previous wash processes have always included large quantities of water as the core and then multiple abrasion techniques as well as application of various chemicals to speed up the commercial wash process whilst achieving the desired look. As the wash process evolved, the use of pumice, bio enzymes, potassium permanganate, silicone and sand blasting have dominated the production cycles.

Washing is one of the most important finishing treatments applied on apparel in the garment industry, e.g. on such cotton-based fabrics as denim, and garments made of such fabrics, and which together with chemical and/or abrasion techniques create a look that replicates the effect of the atmosphere, light and wear and tear on such fabrics and garments. Such a vintage look is intended to mimic the look of the garments after long-term wearing and use. The desired objective is to recreate the real effects and signs of wear and tear that naturally occur during the day-to-day wearing of the garaients, achieving a lived-in look whilst guaranteeing consistent results for commercial applications. Such signs of wear and tear include (but are not limited to) wrinkles, folds, puckering, whiskers, both flat and three-dimensional, and scratches/abrasions in specific areas of the garment that are caused by the resultant movement/friction of the wearer and external factors against the fabric composition.

In existing methods used for treating denim and denim jeans, for the purpose of creating such a vintage look on the fabrics and garments, many chemicals and a large amount of water are required. In one such conventional method involving both dry processing and wet processing, for treating a batch of denim jeans of a total weight of 60kg:

a. the dry processing stage requires:

i. 3kg to 4kg of aluminium oxide for sand blasting;

ii. 20g to 30g of potassium permanganate (KMn0 ₄ ) for spraying the jeans;

b. the wet processing stage requires:

i. 3,500 litres of water;

ii. 400g of amylase enzyme;

iii. 500g of cellulase enzyme;

iv. 1kg of detergent;

v. 30kg of stone;

vi. 10 litres of bleach;

vii. 500g of caustic soda;

viii. 1kg of sodium metabisulfite; and

ix. 1kg to 2 kg of softener.

Some other chemicals which may be used in the existing methods include sodium hypochlorite, peroxide, and ethylenediamine-tetra-acid (as a chelating agent). The above figures may vary up or down according to the desired visual results or machinery/water used.

In the existing methods:

a. many chemicals (some now being or shortly to be forbidden for use by some countries or territories) and a large volume of water are used, which is thus environmentally unfriendly;

b. a large amount of electricity is used; and

c. the structure and strength of fabrics and garments are physically weakened or even damaged.

The present invention provides a method of treating fabrics and garments in which the aforesaid shortcomings are mitigated, and thereby provides a useful alternative to the trade, whilst maintaining the purpose of producing vintage-look fabrics and garments. References below to "topical abrasion" refer to the application to the fabrics or garments of a combination of one or more electrical, electronic (including laser), mechanical and manual processes, whether to selected areas or random areas of the fabrics or garments, to create a vintage look to the fabrics or garments as a whole. The intended effect is to cause immediate distress to and deterioration of selected parts of the fabrics or garments.

According to the present invention, there is provided a method of treating fabrics and garments, said method including carrying out the following steps in the following order: (a) forming at least one pattern on said fabrics or garments by topical abrasion; (b) rinsing said fabrics or garments with water; (c) subjecting said fabrics or garments to ozone treatment; and (d) rinsing said fabrics or garments with water; wherein the aforesaid steps are taken in the absence of any chemical, not including ozone and water.

A method for treating denim jeans according to an embodiment of the present invention will now be discussed by way of an example only. It should be understood that although the present invention is here described with reference to an exemplary method of treating denim jeans, the present invention can be practiced on various fabrics, including fabrics made at least partly of cotton, cotton mixes, denim, twill, CVC (chief value cotton), linen, linen-mixes, ramie, polyester mixes (i.e. a combination of polyester and natural fibre), hemp, and bamboo, and garments made of such fabrics.

Patterns are first formed by topical abrasion on the denim jeans. Such patterns may, for example, be whiskers (i.e. alternate stripes of darker and lighter colours) on a front side of the jeans or patches of worn out colours on the knee portions. This step may be carried out by a laser machine for a time duration within a range whose median is 3 minutes, e.g. 3 minutes, and at an operating power of about 170 watts.

The time durations given are those conducted under controlled conditions to produce the vintage effect of the control Sample A listed below. Variations in time duration and power will still achieve a vintage look, though with a different visual effect.

Specific areas (e.g. those areas with patterns formed by the laser machine) of the jeans may then be hand-sanded, so as to emphasize the desired worn look on such areas. "Hand-sanding" means polishing, rubbing or scraping the surfaces of the jeans by sand paper by hand, or by use of an automatic or manual brushing machine. Subsequently, the jeans may be subjected to general hand-sanding, in which the whole jeans, including the front and back panels, are hand-sanded. It should be understood that as such hand-sanding processes are carried out manually, the pressure or intensity may be varied to create the desired aesthetic effect. Further destruction can be achieved using grinding.

The jeans are then rinsed for a first time. Specifically, the jeans are rinsed for a time duration within a range whose median is 10 minutes, e.g. 10 minutes, at a water temperature within a range whose median is 60°C, e.g. 60°C. The amount of water used is on a water-to-fabrics/garment ratio within a range whose median is 3:1, e.g. 3:1, i.e. 3 kilograms (i.e. 3 litres) of water for each kilogram of fabrics or garments which, in the present example, is denim jeans. Thus, for rinsing 60kg of denim jeans, about 180kg (i.e. 180 litres) of water is used. Again, such values, i.e. temperature and volume of water, although variable up or down, will still achieve a vintage look but with a different visual effect. This rinsing is, firstly, to remove as much of the sizing as possible and, secondly, to introduce and retain the necessary amount of moisture which is essential to the subsequent ozone treatment, according to the desired effect.

The jeans are then put in an extraction machine for about 1 to 5 minutes for extraction of some of the water until a preferred moisture level (to be discussed below) in the fabrics or garments is reached.

The jeans are subsequently subjected to ozone treatment in an ozone machine for 1 to 90 minutes or a time duration within a range whose median is 30 minutes, and preferably for about 30 minutes. The temperature in the ozone machine is the same as the ambient room temperature. The jeans in the ozone machine are of a preferred moisture level of a range whose median range is 40% to 70%, e.g. about 40% to 70%. If it is intended to achieve a light vintage effect, the moisture level should be close to 70%; and if it is intended to achieve a more intense vintage effect, the moisture level should be close to 40%. It should be clarified that the moisture level is calculated as — eight of water— _χ 100%. During weight of denim jeans

operation of the ozone machine, the concentration of ozone in the machine is about 80g per cubic metre. Two critical factors, namely (a) the moisture level of the jeans when placed in the ozone machine and (b) the actual time duration for which the ozone treatment is applied, must be controlled so as to take account of atmospheric and other factors which will affect the treatment. The control is necessary for the commercial viability of the process because of customer requirement for consistency of appearance when producing a large quantity of jeans whereby each style requires conformity. Such treatment will therefore be varied by adjusting the aforementioned critical factors according to the customer requirements as to the appearance of the final products.

Comparative tests have been carried out on eight pairs of sample indigo denim jeans (Sample I to Sample VIII), all being made of 99% of cotton and 1% of spandex and from the same roll of fabric, to investigate the general effects which each of the above two factors has on the appearance of denim jeans treated according to the present invention. In a first test, Samples I, II, III and IV were also subjected to ozone treatment for a time duration of 20 minutes, but with different moisture level. In particular, the respective moisture level of these four samples are shown in Table 1 below:

Table 1

Visual inspection of Samples I to IV revealed that Sample IV is generally paler than Sample III, which is in turn generally paler than Sample II, which is in turn generally paler than Sample I. This shows that, when keeping all other factors constant, the lower the moisture level is when a pair of jeans are when being subjected to ozone treatment, the paler (and thus more significant worn and vintage look) the pair of jeans will appear to be.

In a second test, Samples V, VI, VII and VIII, all with a same moisture level of 70%, were subjected to ozone treatment for different time durations. In particular, the respective time duration for which these four samples were subjected to ozone treatment are shown in Table 2 below:

Table 2

Visual inspection of Samples V to VIII revealed that Sample VIII is generally paler than Sample VII, which is in turn generally paler than Sample VI, which is in turn generally paler than Sample V. This shows that, when keeping all other factors constant, the longer the time duration a pair of denim jeans are subjected to ozone treatment, the paler (and thus more significant worn and vintage look) the pair of jeans will appear to be.

After ozone treatment, the jeans are rinsed again with water for a time duration within a range whose median is 5 minutes, e.g. about 5 minutes, at a water temperature within a range whose median is 40°C, e.g. about 40°C, and on a water-to-fabrics/garment ratio within a range whose median is 3:1, e.g. about 3:1, i.e. 180 kg (equivalent to 180 litres) of water for 60 kg of denim jeans. Finally, the jeans are dried by a commercial tumble drier.

It can be seen that significantly less water and no chemicals (not including ozone and water) are used in the wet processing treatment method according to the present invention. In particular, only a total of 360kg (i.e. 360 litres) of water is used in the two rinsing steps for treating 60kg of denim jeans according to the present invention, which is significantly less than the 3,500 litres of water used in the conventional method discussed above.

Denim jeans treated by a method according to the present invention are more durable than those treated according to the conventional methods. In particular, because of the destructive nature of the conventional methods, fabrics or garments treated by the conventional methods will lose more weight as well as fibre thickness and become less durable (meaning that the fibres are thinner and therefore less strong). On the other hand, because of the non-destructive nature of the methods according to the present invention, fabrics or garments treated by such methods will retain more weight and are more durable. The above only discusses an exemplary method of treating fabrics and garments according to the present invention. The various parameters (e.g. time duration, temperature, moisture level of the fabrics/garments when being subjected to ozone treatment, and water-to-fabrics/garment ratio) of carrying out the method may be varied to produce vintage looks of different visual effects.

Comparative tests have also been carried out on three pairs of sample indigo denim jeans, all being made of 99% of cotton and 1% of spandex and from the same roll of fabric. Sample A was treated by the method according to the present invention as described above; Sample B underwent a conventional chemical-wash process in which resin was added to give a three-dimensional effect; and Sample C underwent a conventional chemical -wash process only, with no resin added. The chemical wash to Samples B and C were carried out to create a look as close as possible to that of Sample A.

The samples were also subjected to "sandblasting" in the case of Samples B and C and topical abrasion without chemicals or sandblasting in the case of Sample A to obtain the corresponding test results. In particular, Sample A was treated by a laser machine to fade out some areas of the jeans. As to Samples B and C, they were processed with chemicals and abrasion/sand-blasting to achieve the same look. The following tables show results of the tests carried out on these three pairs of sample denim jeans:

Table 3: Test Results on Tensile Strength without Topical Abrasion

Table 4: Test Results on Tensile Strength with Topical Abrasion Sample A Sample B Sample C

Warp (pounds) 161.0 65.1 140.3

Weft (pounds) 66.2 42.6 42.2

Table 5: Test Results on Tearing Strength without Topical Abrasion

Table 6: Test Results on Tearing Strength with Topical Abrasion

The Tensile Strength Tests were conducted in accordance with ASTM D5034 - 09 Standard Test Method for Breaking Strength and Elongation of Textile Fabrics (Grab Test); and the Tearing Strength Tests were conducted in accordance with ASTM D1424 - 09 Standard Test Method for Tearing Strength of Fabrics by Falling-Pendulum Type (Elmendorf) Apparatus.

Full scale range of pendulum for both warp and weft yarn testing is 14 pounds for all three samples; and full scale range of pendulum for weft yarn testing is 14 pounds for Sample A and Sample B and 7.2 pounds for Sample C.

The tensile strength test results show that:

a. when not subjected to topical abrasion:

i. the tensile strength of Sample A on the warp is 112 pounds stronger than that of Sample B and 48 pounds stronger than that of Sample C;

ii. the tensile strength of Sample A on the weft is 31 pounds stronger than that of Sample B and 26 pounds stronger than that of Sample C;

b. when subjected to topical abrasion:

i. the tensile strength of Sample A on the warp is 95 pounds stronger than that of Sample B and 20 pounds stronger than that of Sample C;

ii. the tensile strength of Sample A on the weft is 23 pounds stronger than that of

Sample B and 24 pounds stronger than that of Sample C.

Similar results show from the tearing strength tests. The present invention is a combination of abrasion techniques performed in a specific sequence with an ozone treatment and rinsing process, and is able to replicate all existing processes of achieving the vintage outlook, but significantly reducing:

the ecological footprint caused by the use of chemicals and large amounts of water in the existing commercial wash applications,

- the large amounts of electricity used in the existing commercial washing processes,

the damage to the garments by existing applications of chemical and sandblasting as measured by the significant increase in tensile strength by use of the disclosed methods, all hazardous substances used in the existing washing processes that are now being forbidden by European legislation, and

- the costs of manufacturing process, by the elimination of manpower and damage to machinery caused by the existing methods of wash (including, but not limited to, damage by abrasive elements to machinery).

By varying the intensity of either the abrasion techniques or the ozone treatment comprised in the present invention, a variable outlook on the garments can be achieved which results in an outlook that truly reflects the variable age processing during natural wear.

It should be understood that the above only illustrates an example whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention. It should also be understood that various features of the invention which are here, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.