METHOD OF DYEING WOOLLEN FABRICS AND ITEMS OF CLOTHING TO PRODUCE A SHOT EFFECT

Abstract: Woollen material is laid into a dyeing tank with de­ purated water and glue, with addition of pigment diluted with a dispersing product. The bath is cooled, the dyed material is rinsed and put again into clean water with elastomere which acts as a dyeing binder, and some catalyst is added for fixing; the material is rinsed and centrifugated. At last the material is dried or rinsed with addition of a softener. The said treatment causes the sedimentation of the pigment small powder on the bottom of the piece mantle, thus carrying out an opaque ground colouring. This one imparts a particular surface brilliancy to the emerging part of the mantle from which the fine dust has been removed.

Description: The invention concerns a method of dyeing shot woollen fabrics and items of clothing, hereinafter called "the products" for short. The aim of the present invention is to dye the products in such a way as to produce a shot effect which causes the colour of the products themselves to change when viewed from different angles, in accordance with she varying angle of incidence of the light rays. The method as claimed below achieves this shot effect by dyeing or colouring the fibres of the product fabric, and not the surface filaments of the fibres themselves. At the end of the dyeing process, the sad filaments retain a natural white sheen and form a downy "nap" which hides the true colour of the woven fibres from view and creates different colour effects depending on the angle from which the products are viewed. Basically, the method consists in dyeing the products in two stages, first in water in a rotary dyeing vat, without fixing the dye to the fabric, followed by rinsing, and then placing the products in a second bath, again with the dyeing vat in motion, in order to fix the dye with an elastomer activated by a catalyst. The two basic stages of the method are described in more detail below. First of all, the products are dry cleaned before undergoing the dyeing treatment, and are placed in a rotary dyeing vat in a bath of purified water in the ratio of 40 litres of water to every 1 kg of product. Size, is added to the bath in the proportion of 10% of the weight of the products to be dyed. The dyeing vat is made to rotate and heated to a temperature of 50°C, allowing it to continue rotating for 30 minutes. Colorant is then added to the bath in variable proportions, depending on the desired colour intensity to be achieved, diluted with a dispersing agent. The dyeing vat is further heated to a temperature of 95°C and allowed to continue rotating for 60 minutes. At the end of the first stage envisaged by the present method, the dyebath is cooled to 50°C, the vat drained of the dyeing solution and the products rinsed. The second stage consists in fixing the dye to the products treated in the previous stage. To do this, the products are placed in a bath of clean water, again with the dyeing vat in motion, to which an elastomer is added. The proportion of elastomer for the fixing bath is 10% of the amount of water used. During rinsing and during the bath with the elastomeric bonding agent, the colorant that had settled on the surface filaments of the product fibres comes off the said filaments and settles on the body of the said fibres. Subsequently, a catalyst is added to the bath in order to activate the binding action of the elastomer and, consequently, to fix the dye to the product fibres. During experiments on the method, the ideal proportion of catalyst to obtain this pH was found to be 1% of the amount of water for the fixing bath. The products are allowed to remain in this bath, with the dyeing vat in motion, for 30 minutes. At the end of the second stage, the dyeing vat is drained, the products rinsed (if there are any impurities to be removed), together with a softening agent, if necessary, and finally dried, at 140°C and transferred to subsequent processes.

Claims: A method of dyeing shot woolen fabrics and items of clothing which may be implemented using a rotary dyeing tank, colorants and bonding agents to fix the colorants to the fibres of the products to be dyed, the said method being characterized by the following stages: a) dyeing the products which have been first drycleaned in a bath of water in a ratio of 40 litres of water to every 1 kg of product, adding to the bath in successive steps firstly a size in a ratio of 10% of the weight of the products, heating the vat to a temperature of 50°C and making it rotate for 30 minutes, and adding secondly a colorant diluted in a dispersing agent and then heating the vat to 95°C and making it rotate for a further 60 minutes; b) cooling the vat to 50°C, with the vat rotating, and rinsing the treated products; placing the products, treated according to step a), in a bath of clean water, adding to the bath an elastomer in the proportion of 10% of the amount of water used, subsequently activating the elastomer by adding a catalyst to the bath in the proportion of 1% of the amount of water used, and allowing the dyeing vat to rotate for a further 30 minutes; rinsing the products, which are then centrifuged and thoroughly dried at 140° C.

Inventors: SILLI, ALESSANDRO
Applicants: SILLI, ALESSANDRO
Application year: 1987
Main classification: D06P3
IPC codes: D06P1, D06P3