US2411429A - Treatment of cellulosic textile materials - Google Patents

Description

Patented Non-19, 1946 TREATMENT OF CELLULO SIC TEXTILE MATERIALS Horace James Hogan, Coventry, and Edwin Holroyd Sharples, Kenilworth, England, as-

slgnors to Courtaulds Limited, London, land, a British company Eng- -No Drawing. Application November 6, 1944, Se-

it?! No. 562,264. In Great Britain January 12,

4 Claims. 1 This invention relates to treating cellulosic textile materials in order to obtain level dyeings when these materials are knitted into hosiery or woven into fabrics.

It is well known to subject cellulosic yarn or thread to a twisting operation and subsequently to set the twist by treatment with steam. When cellulosic yarns are subjected to steaming, there is a lowering of the affinity of the yarn for dyestuffs, which lowering is dependent upon the temperature and time of the steaming and the degree of wetness oi the yarn. When steaming the yarn on bobbins, there is a tendency for the outer layers of yarn to be more heavily steamed than the inner layers and also there is a possibility of drops of condensed water falling on the yarn so that there is a considerable tendency in the steaming process for variations in dyeing aflinity to be produced throughout the bobbin and on making this unevenly steamed yarn into hosiery and subsequently dyeing, the material exhibits marked differences in shade.

The object of the present invention is to obtain a yarn which will be stabilised towards the steam treatment so that any difierences occurring during the steaming process will not appreciably 2 artificial origin; for example, the process may be applied to cotton or to artificial yarns of cellulose regeneratedfrom viscose or cuprammonium cellulose solutions.

The following example illustrates the present invention, but the invention is not restricted to this example:

' Example Cakes of bleached, desulphurised 75 denier l8 filament viscose artificial silk are, without drying; placed in water in an autoclave and the temperature is raised to 120 centigrade. The treatment is continued for minutes, the cakes are removed irom the autoclave and dried. The yarn is wound from the cake on to bobbins and is then given a twist of 15 turns per inch. Thetwlsted yarn is then steamed to set the twist. 'The affect the dyeing affinity of the yarn, and therebilises the yarn so that any differences in the steaming operation do not deleteriously aflect the dyeing afiinity. The treated yarn is knitted or woven into fabric which on subsequent dyeing gives level'shades. I V

The conditions of time and temperature used in carrying out this invention are interdependout, a higher temperature giving a desired result m a shorter time. It is sometimes preferred to add a little soap or other alkaline softening agentto the water in which the yarn is heated.-

The process of the present invention is applicable to cellulosic textile materials of natural or 2. In the production of a dyed twisted cellulose yarn as claimed in claim 1 the addition of a 1 small proportion of soap to the water used. in the preliminary step.

3. In the production of a dyed twisted regen I .erated cellulose yarn the combination with the steps of drying, twisting, setting the twist by a steaming operation and dyeing, of a preliminary step of treatment in water under pressure at a temperature above 100 centigrade to stabilise the dyeing amnity of the yarn against the efl'ects of uneven steaming.

4.11: the production of a. dyed twisted regenerated cellulose yarnas claimed in claim 8 the addition 01' a small proportion of soap to the waterused in the preliminary step.

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