Method for processing wool garments for inhibiting their subsequent felting and shrinkage, and a wool garment treated by the method

Abstract

A method for the treatment of wool garments with ozone gas to control and inhibit their felting and shrinkage during their subsequent industrial finishing process and/or domestic washing care, and a wool garment treated with said method. The method includes wetting the garments and treating the garments inside the interior of a rotative tumbler for a time period of between 15 and 60 minutes at ambient temperature with ozone gas, the ozone gas being at a concentration in air of between 20 g ozone/Nm.sup.3 and 150 g ozone/Nm.sup.3, where the rotative tumbler which contains the garments is rotated at a speed of between 10 rounds/min and 25 rounds/min. The method is improved by adding treating the garments with enzymes.

Claims

1. A method for the treatment of wool garments with ozone gas to control and inhibit their felting and shrinkage during their subsequent industrial finishing process and/or domestic washing care, which method comprises the steps of: wetting the garments; and treating the garments inside the interior of a rotative tumbler for a time period of between 15 and 60 minutes at ambient temperature with ozone gas, said ozone gas being at a concentration in air of between 20 g ozone/Nm.sup.3 and 150 g ozone/Nm.sup.3, wherein the rotative tumbler is rotated at a speed of between 10 rounds/min and 25 rounds/min; wherein the garments are wetted with water to a final water to garment concentration by weight of between 40% and 70%.

2. The method according to claim 1, wherein the ambient temperature is between 5 C. and 40 C.

3. The method according to claim 1, wherein the rotative tumbler interior volume to garments weight ratio is between 0.01 m.sup.3/kg and 1 m.sup.3/Kg.

4. The method according to claim 1, wherein the interior of the rotative tumbler inside which the garments are placed has a volume between 0.1 m.sup.3 and 10 m.sup.3.

5. The method according to claim 1, which further comprises rinsing the garments with water after treating them with ozone gas.

6. The method according to claim 1, which further comprises the following steps: wetting the garments with a mixture comprising water and at least one enzyme; waiting for a time period for said at least one enzyme to act on a surface of the garments; and stopping an action of the at least one enzyme.

7. The method according to claim 6, wherein the at least one enzyme to garments concentration by weight is between 0.01% and 20%.

8. The method according to claim 6, wherein the time period for said at least one enzyme to act on the surface of the garments is between 1 minute and 60 minutes.

9. The method according to claim 6, wherein the mixture comprising water and at least one enzyme has a temperature between 5 C. and 53 C.

10. The method according to claim 6 wherein the at least one enzyme is a protease.

11. The method according to claim 6, wherein stopping the action of the at least one enzyme is being done by rinsing the garments with water, and/or by heating the garments and/or the mixture comprising water and at least one enzyme to a temperature between 30 C. to 95 C.

12. The method according to claim 1, further comprising dyeing the garments.

13. The method according to claim 1, further comprising any of the following steps and combinations thereof: drying the garments; washing the garments; treating the garments with softeners and/or detergents and/or deodorizers.

14. A method according to claim 1, wherein wool garment is made of a fabric comprising comb wool, or coarse wool, or wool with cashmere, or mohair, or animal fiber yarn, or wool blended with other non-wool fibers.

Description

BRIEF DESCRIPTION OF FIGURES

(1) FIG. 1 is a photograph of two washed wool textile samples, wherein prior to washing one sample was treated according an embodiment of the method of the invention and the other sample was not. The shown scale bar at the bottom right of the photograph, corresponds to 5 cm length.

(2) FIG. 2 is two scanning electron microscope (SEM) images of the wool fibers of a textile sample, before and after treating the sample according to an embodiment of the method of the invention. The scale bar of each image of FIG. 2 corresponds to 10 micrometers.

(3) FIG. 3 is two photographs of wool textile samples dyed under different conditions, wherein one photograph shows samples which were treated according to an embodiment of the method of the invention, and the other photograph shows samples which were not treated according to the invention.

DETAILED DESCRIPTION

(4) In the first and preferred embodiment of the first aspect of the invention, the method for the treatment of wool garments with ozone gas to control and inhibit their felting and shrinkage during their subsequent industrial finishing process and/or domestic washing care, comprises the steps of: wetting the garments; and treating the garments inside the interior of a rotative tumbler for a time period of between 15 and 60 minutes at ambient temperature with ozone gas, said ozone gas being at a concentration in air of between 20 g ozone/Nm.sup.3 and 150 g ozone/Nm.sup.3, wherein the rotative tumbler which contains the garments is rotated at a speed of between 10 rounds/min and 25 rounds/min.

(5) In the aforementioned first embodiment, the speed of rotation of the rotative tumbler is a particularly important parameter which has to be within the indicated above range, otherwise the method will not work effectively. If the speed is higher than 25 round/min then the method does not work well and the garments shrink during their subsequent washing. This is shown in FIG. 1 which shows a wool sample B which was first treated according to the first embodiment of the method and for which the speed of tumbler was 10 rounds/min, and after the application of the method the sample was washed. FIG. 1 also shows a wool sample A (of same material and original dimensions as sample B) which was processed in the same manner as sample B but with the difference that the speed of the tumbler was 28 rounds/minute. Therefore, it is evident from FIG. 1 that sample A shrunk in length compared to sample B.

(6) All parameters indicated in the first embodiment of the method are important for achieving the good anti-felting and anti-shrinkage effect offered by the method. It was observed by the inventor that the application of the method and the achieved inhibition and control of the shrinkage and felting of the garments during their subsequent processing, are accompanied by a change of the micromorphology of the wool fibers of the textile of the garments. This change is shown in FIG. 2 which shows images taken using scanning electron microscopy (SEM). Image C of FIG. 2 shows the wool fibers of a sample before its processing according to the first embodiment of the method, and image D shows the wool fibers after the processing of the sample according to the first embodiment of the method. In image D the scales (cuticle) of the wool fiber appear more firmly attached to the body of the fiber, compared to the fiber shown in image C. In the aforementioned, being firmly attached may mean that each of said scales being firmly attached, is attached onto a surface of the body fitting and following the contour of the latter and has edges that are also attached to the surface of the body fitting the contour of the body and not standing out with respect the surface of the scale. In image C of FIG. 2 the body b1 of one of the two fibers shown therein is indicated by the drawn arrow. Moreover, in image C of FIG. 2 scale s1 with its edge e1, and scale s2 with it edge e2 are indicated. As can been seen in image C, both indicated edges e1 and e2 are not attached on the surface of the body b1, and in particular edge e1 visibly and obviously stands out from the surface of body b1 and from the rest of the surface of the scale s1. Likewise, edge e2 stands out from the body b1 and from the rest of the surface of the scale s2. Consequently, for the corresponding scales shown in image C of FIG. 2 it cannot be said that these scales are attached onto the surface of the body fitting and following the contour of the body and have edges that are also attached to the surface of the body fitting the contour of the body and not standing out with respect the surface of the scales. Nevertheless, in image D of FIG. 2 the therein indicated by another black arrow body b3 of one of the two wool fibers seen in the image, comprises the also therein indicated scale s3 which has an edge e3 which is attached on the surface of the body. The edge e3 clearly and obviously does not stand out with respect to the surface of the body and especially with respect to the rest of the surface of the corresponding scale s3. Moreover, it has been observed using SEM mages that another possible consequence of the optimum treatment of the wool garment with the present method is the partial or complete removal of the scales from the surface of the fiber and its body. The images of FIG. 2 were acquired with a Hitachi S4100 scanning electron microscope having a field emission gun capable of achieving a resolution of 1.5 nm at 60 kV, and equipped with a back scattered electron detector and system for capturing digital images. For capturing the image, the microscope was operated at 5 kV, and the working distance was 12 mm.

(7) As discussed before, the treatment-induced possible removal of the scales from the surface of the body, or the treatment-induced better and more uniform attachment of the scales and the scales' edges on the body of the wool fiber may originate from the physicochemical changes imparted on the wool fiber by the ozone gas under the specific conditions specified in the method. When the scales and/or edges are removed (partially or completely) or their attachment on the body is improved, then the interlinking (entanglement) and/or enlacement between the scales and/or of the scales' edges, especially between scales and edges of neighboring fibers, during the processing (e.g. laundering) of the wool garment can be mitigated or prevented or inhibited, and consequently the macroscopically observable shrinkage and/or felting associated with said interlinking (entanglement) and/or enlacement is inhibited or prevented i.e. the garment is rendered shrinkage-proof.

(8) The application of the first embodiment renders the garments sufficiently shrinkage-proof so they can be categorized as machine washable and/or total easy care garments, wherein the terms machine washable and total easy care refer to the respective categories of wool garments as defined by The Woolmark Company. The inventor performed several tests for evaluating the effectiveness and quality of the method and apparatus described herein, an example of such test is the TM31 defined by The Wool Mark company. This test measures shrinkage and fabric appearance after repeated home laundry.

(9) A second embodiment of the invention is the method according to the first embodiment, wherein the garments are wetted with water to a final water to garment concentration by weight of between 10% and 120%.

(10) A third embodiment of the invention is the method according to the first embodiment, wherein the garments are wetted with water to a final water to garment concentration by weight of between 40% and 70%.

(11) A fourth embodiment of the invention is the method according to the first embodiment, wherein the garments are wetted with water to a final water to garment concentration by weight of between 61% and 70%.

(12) Another embodiment of the invention is the method according to any of the previous embodiments, wherein wetting of the garments is achieved by wetting the garments with excess water and then extracting some of the excess water from the wetted garments.

(13) Another embodiment of the invention is the method according to any of the previous embodiments, and wherein the ambient temperature is between 5 C. and 40 C.

(14) Another embodiment of the invention is the method according to any of the previous embodiments, and wherein the rotative tumbler which contains the garments is sealed during the treatment of the garments with the ozone gas.

(15) Another embodiment of the invention is the method according to any of the previous embodiments, and wherein the rotative tumbler is connected to an ozone generator that produces from 50 to 2500 g (grams) of ozone gas per hour.

(16) Another embodiment of the method of the invention is the method according to any of the previous embodiments, and wherein the ratio of the rotative tumbler interior volume to garments weight is between 0.01 m.sup.3/kg and 1 m.sup.3/Kg, and preferably is between 0.05 m.sup.3/Kg and 0.5 m.sup.3/Kg.

(17) Another embodiment of the method of the invention is the method according to any of the previous embodiments, and wherein the volume of the interior of the rotative tumbler inside which the garments are placed, is between 0.1 m.sup.3 (cubic meter) and 10 m.sup.3.

(18) Another embodiment of the method of the invention is the method according to any of the previous embodiments, which further comprises the additional step of rinsing the garments with water after treating them with ozone gas. Another embodiment is the one according to the preceding one, and wherein the temperature of the water with which the garments are rinsed is between 5 C. and 20 C.

(19) Another embodiment of the invention is the method according to any of the previous embodiments, further comprising the following steps: wetting the garments with a mixture comprising water and at least one enzyme; waiting for a time period for said at least one enzyme to act on the surface of the garments; and stopping the action of the at least one enzyme.

(20) Another embodiment of the invention is the method according to the preceding embodiment, and wherein the time period for said at least one enzyme to act on the surface of the garments is between 1 minute and 60 minutes, and preferably is between 6 minutes and 60 minutes.

(21) Another embodiment of the invention is the method according to any of the previous embodiments that include the step of wetting the garments with a mixture comprising water and at least one enzyme, and wherein the temperature of the mixture is between 5 C. and 80 C., and more preferably the temperature of the mixture is between 5 C. and 53 C.

(22) Another embodiment of the invention is the method according to any of the previous embodiments that include the step of wetting the garments with a mixture comprising water and at least one enzyme, and wherein the at least one enzyme to garments concentration by weight is between 0.01% and 20%, and preferably is between 0.01% and 10%, and more preferably is between 0.1% and 3%.

(23) Another embodiment of the invention is the method according to any of the previous embodiments that include the step of wetting the garments with a mixture comprising water and at least one enzyme, and wherein the enzyme is a protease.

(24) Another embodiment of the invention is the method according to any of the previous embodiments that include the step of wetting the garments with a mixture comprising water and at least one enzyme, and wherein stopping the action of the at least one enzyme is being done by rinsing the garments with water, and/or by heating the garments and/or the mixture comprising water and at least one enzyme to a temperature between 30 C. to 95 C.

(25) Another embodiment of the invention is the method according to any of the previous embodiments, which further comprises dyeing the garments.

(26) Another embodiment is the method according to the any of the previous embodiments, further comprising any of the following steps and combinations thereof: drying the garments; washing the garments; treating the garments with softeners and/or detergents and/or deodorizers.

(27) Another embodiment is the method according to any of the previous embodiments, and wherein the fabric of the garment comprises comb wool or coarse wool or any other kind of wool including cashmere or mohair or any kind of animal fiber yarn or any wool blended with other non-wool fibers.

(28) In the first and preferred embodiment of the second aspect of the invention, a wool garment is treated with the method according to any of the embodiments of the method of the first aspect of the invention.

(29) A second embodiment of the second aspect of the invention is the wool garment according to the first embodiment, wherein the wool garment comprises wool fibers, each of said wool fibers having a body which, as a consequence of the treatment of the wool garment with the method, is either stripped of scales, or it comprises scales wherein each of said scales is attached onto a surface of the body fitting and following the contour of the latter and has edges that are also attached to the surface of the body fitting the contour of the body and not standing out with respect the surface of the scale.

(30) A third embodiment of the second aspect of the invention is the wool garment according to the second embodiment of the second aspect invention, wherein the scales being attached onto the surface of the body account for more than 50%, and preferably more than 80%, of all the scales of the body.

(31) Another embodiment of the second aspect of the invention is the wool garment according to any of the previous three embodiments of the second aspect invention, wherein the area of the surface of the garment changes by less than 10%, and preferably by less than 5%, when the garment is subsequently laundered.

(32) Another embodiment of the second aspect of the invention is the wool garment according to any of the previous embodiments of the second aspect invention, and wherein the wool garment meets the requirements for being categorized as machine washable according to test TM31 regarding dimensional stability of wool garments. Machine washable can be interpreted as being the garments for which a machine wash care claim can be made according to the TM31 test method (as for example described in page 6 of 8 of the SPECIFICATION SF-1: 2016 published electronically in the following URL: https://www.woolmark.com/globalassets/05-certification/product-specifications/sf-1_knitted_fabric_2016-1_2nov14_f.pdf).

(33) The TM31 test method is known in the prior at (published for example as: WOOLMARK TEST METHOD WASHING OF WOOL TEXTILE PRODUCTS, May 2000, pages 1-19.)

(34) In the following, some specific example of experiments carried out by the inventor for implementing the method of the invention, are described in detail:

Example 1

(35) 5 kg of wool garments were wetted with water to a final water to garment concentration by weight of about 62% and then placed in the interior of the rotative tumbler of an interior volume of approximately 3 m.sup.3 of a Jeanologia G2 E machine. This machine is designed as to not leak ozone gas to the environment during the processing of garments with ozone. The machine was operated in a specific mode so that the ozone is supplied into the tumbler in the form of gas and not in the form of gas-water solution. It was checked that when the tumbler is sealed, the ozone passed to the tumbler does not leak to the environment. The speed of the tumbler was set to 10 rounds/min and the ozone generator was set to producing 400 g of ozone per hour. The concentration in air of the ozone gas supplied to the chamber was monitored with an ozone gas measurement unit, and it was about 40 gr ozone/Nm.sup.3. This experiment was repeated several times by varying each time the time duration of the ozone treatment of the garments inside the tumbler, from 15 min (minutes) to 60 min. The shrinkage, meaning the percent (%) change of the length and width of garments treated as above, and of garments not treated by ozone, upon subsequent several washing of the garments according to the TM31 test, is shown in Table 1 from which it is evident that the ozone treatment inhibits the shrinkage of the garments.

(36) TABLE-US-00001 TABLE 1 Width Length Untreated 23.33% 23.33% Ozone, 15 min 11.67% 11.67% Ozone, 30 min 8.33% 8.33% Ozone, 45 min 8.33% 8.33% Ozone, 60 min 3.33% 3.33%

Example 2

(37) The same parameters as in example 1 were used, with the difference that the duration of the ozone treatment of the garments was fixed to 30 min, and that the ozone generator was controlled as to vary from 20 g/Nm.sup.3 to 120 g/Nm.sup.3 the concentration in air of the ozone gas supplied to the rotative tumbler. The shrinkage of the garments was tested similarly to example 1, and is shown in Table 2 from which it is evident that the method prevents the change of the width and length of the garments, especially when the ozone concentration is higher than 20 g/Nm3.

(38) TABLE-US-00002 TABLE 2 Width Length Untreated 26.09% 5.08% Ozone 20 g/Nm.sup.3 31.25% 3.39% Ozone 40 g/Nm.sup.3 11.11% 8.33% Ozone 80 g/Nm.sup.3 8.89% 5.00% Ozone 120 g/Nm.sup.3 4.44% 5.00%

Example 3

(39) This example demonstrates the synergistic anti-shrinkage and anti-felting effect produced by the combination of ozone treatment and enzyme treatment of wool garments, and the use of said synergistic effect for reducing the duration of the overall treatment required, without compromising the anti-shrinkage and anti-felting effect obtained by the treatment. In this example, originally identical wool garments were treated with four different treatment variations: (i) standard washing with no ozone or enzyme treatments, (ii) ozone treatment, (iii) enzyme treatment, (iv) ozone treatment followed by enzyme treatment. The standard washing was performed using a household washing machine. The ozone treatment performed as in example 1 with the following modifications: the ozone concentration in air was 80 g/Nm.sup.3 and for the variation (ii) the garments were treated with ozone for 60 min, while for the variation (iv) the garments were treated with ozone for 30 min. The enzyme treatment was performed by immersing for 15 min at ambient temperature the garments in an aqueous solution comprising the commercial product Savinase 16.0 L, the quantity of the latter was adjusted so that the enzyme to garments concentration by weight was 0.25% for variation (iv), and 0.75% for variation (iii). The volume of the aqueous solution used for the enzyme treatment, was approximately 20 liters for every 1 Kg of garments immersed in it.

(40) The shrinkage and felting of the garments after the application of repetitive home laundries, this is to say after repetitive domestic washing of the garments, which happened after each of the above treatment variations was inspected visually and also quantitatively. The visual inspection showed that the treatment variation (iv) was the best in preventing shrinkage and felting in comparison to the other variation (i), (ii) and (iii). The quantitative inspection was based on measuring the weight of pieces of the garments before and after the garments were subjected to said repetitive home laundries. The area of each piece was 5 cm.sup.2. By comparing the weight of said pieces of the garments before and after said repetitive laundries, it is possible to extract conclusions regarding whether the treatment applied before the repetitive laundries prevented shrinkage and felting of the garments during the repetitive laundries. An increase of the weight of the pieces after repetitively laundering the garments compared to the weight before repetitively laundering the garments, indicates the occurrence of felting and shrinkage, and the higher said increase is the more felting and shrinkage has been caused by the repetitive laundering, which means the least effective the treatment variation has been in inhibiting said felting and shrinkage. The increase in weight is expressed as a percent (%) positive number. The results of such measurements are shown in Table 3. From the data of Table 3, it is evident that although in (iv) a smaller concentration of enzyme was used compared to (iii), the anti-felting and anti-shrinkage effect achieved by (iv) was better, as evident by the smaller % increase in weight for (iv) compared to (iii). Similarly, the anti-shrinkage and anti-felting effect achieved by the treatment variation (iv) was almost identical compared to the same effects achieved by the variation (ii), despite the fact that the duration of the ozone treatment in (iv) was half compared to the duration of the ozone treatment in (ii).

(41) TABLE-US-00003 TABLE 3 Weight of 5 cm.sup.2 piece of fabric of garment Before repetitive After repetitive Increase in Treatment variation laundering (g) laundering (g) weight (i) Standard washing 0.49 0.82 40% (ii) Ozone treatment 0.59 0.62 5% (80 g/Nm.sup.3, 60 min) (iii) Enzyme treatment 0.43 0.5 14% (0.75% Savinase) (iv) Ozone treatment 0.57 0.61 7% (80 g/Nm.sup.3, 30 min) + Enzyme treatment (0.25% Savinase)

(42) Therefore, unambiguously a synergistic effect is produced by the combination of ozone treatment and enzyme treatment, and enzyme treatment is auxiliary to the ozone treatment and serves for reducing the required duration of the overall method and thus for improving the advantages and industrial applicability of the latter.

Example 4

(43) Similar parameters as in example 1 were used, with the ozone processing time fixed at 60 minutes and the ozone concentration fixed 40 g/Nm3, and the garments were additionally dyed with reactive dyestuff (Lanasol family from HUNTSMAN company) different dyeing temperatures and for 20 minutes and 45 minutes (45). The color of the dyed wool textile samples was visually inspected and compared. The dyed samples are shown in photograph F of FIG. 3. FIG. 3 also includes photograph E of samples which were dyed the same way as the samples of F but without treating the samples with ozone before dyeing them. It is evident from FIG. 3 that the ozone treated samples of F absorbed more dye and for this reason they became darker compared to the samples of E.