US 2182321 A
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Patented Dec. 5, 1939 UNITED STATES PATENT'OFF/ICE Georges Rivat, Lyon, France, assignor to Henry Dreyfus, London, England No Drawing. Application January 22, 1938, Serial This invention relates to improvements in the production of effect fabrics and particularly to the production of fabrics showing pebble or cockle effects.
I have discovered that fabrics showing pebble or cockle effects may be obtained by treating fabrics containing in the warp and/or in the weft both yarns having a basis of an organic derivative of cellulose and other yarns, e. g.
3 natural or regenerated cellulose yarns or silk or wool yarns, with a solution of ammonium thiocyanate or other thiocyanate.
The process of the present invention is particularly applicable to the treatment of fabrics in 15 which the organic derivative of cellulose yarn is a cellulose acetate yarn, though it is also applicable to the treatment of fabrics containing yarns of other organic derivatives of cellulose, for example cellulose propionate, butyrate or nitro-acetate or 20 ethyl or butyl cellulose. Cellulosic yarn may be a natural cellulosic yarn, for example cotton or linen, or a regenerated cellulose 'yarn obtained, for example, by the viscose, cuprammoniumor nitrocellulose process. Examples of thiocyanates 25 which may be employed according to the process of the present invention are ammonium, sodium, potassium and calcium thiocyanates.
The concentration of thiocyanate in the treatment medium, the temperature of the medium,
30 the duration of treatment and the other operative conditions employed according to the process of the present invention are such as to effect shrinkage of the organic derivative of cellulose yarn without causing shrinkage of the cellulosic g5 yarn. The conditions employed are, therefore, interdependent, and, for example, arelatively high temperature. e. g. a temperature of 50 or 60 C. or more, maybe employed with a low concentration of thiocyanate and/ona short period of treatment, or a high concentration of a thiocyanate may be employed for a short treatment period and/or at a low temperature in order to obtain similar efiects.
In general, however, it is found preferable to 5 carry out the treatment approximately at ordinary temperature, for example 15, 20 or 25 C. for a period of l to 5 up to about 15 minutes, and to use an aqueous solution of ammonium thiocyanate in a concentration of about 20 to 60%,
50 ,e. g. 25, 30 or 45%. Similar molecular concentrations of other thlocyanates may be employed.
In carrying out the process of the present invention the mixed fabric after scouring and drying, if necessary, may be passed through a bath 55 containing a solution of a thiocyanate for a period In Great Britain February 9,
3 Claims. (01. 8-114) of about 2 to 5 minutes. On'emerging from the bath it may be passed through nip rolls to express adherent liquid, then washed thoroughly and dried in the absence oftension. Thus, for example, a mixed cellulose acetate viscose fabric 5 containing in the warp and/or in theweft yarns both of cellulose acetate and of viscose may be scoured and dried and then treated at a temperature of from 0 to 20 C. for l to 10 minutes in an aqueous solution of ammonium thiocyanate 10 of a concentration of about 20 to 60%. The exact conditions employed should be such that shrinkage of the cellulose acetate yarns is eifected without shrinkage of viscose yarns.
A treatment according to the process of the present invention may not only be applied to mixed fabrics uniformly over their whole surface, for example, by passing them through a bath, but it may also be applied locally, for example, by printing them with a suitable paste containing a thiocyanate, the paste being removed after shrinkage of the organic derivative of cellulose yarns has been effected.
The following examples illustrate the invention, but are not to be regarded as limiting it in any way:
Example 1 A fabric containing yarns of viscose silk and of cellulose acetate silk both in the warp and also so in the weft is immersed for two minutes in a solution of ammonium thiocyanate having a density of 12 B. and at a temperature of about 15 C.
It is then hydro-extracted, well washed with cold water and dried without tension at a moderate temperature.
Example 2 A similar fabric to that employed in the preceding example is immersed for about two minspectively is immersed for about three minutes in a solution of ammonium thiocyanate having a density of 9 B6. and at a temperature of about 15 0., and is then hydro-extracted, washed and dried as. described in Example 1. g
Example 4 A fabric having a weft made of cellulose acetate yarns and cotton yarns and a warp of cotton yarns only is immersed for 1% minutes in a solution of ammonium thiocyanate having a density of 8 B. and at a temperature of 45 to 50 C. It is then hydro-extracted, washed and dried as described in Example 1.
The product obtained according to each of the 10 preceding examples exhibits pebble or cockle efcentration molecularly quivalent to 20-60% of ammonium thiocyanate. l
2. Process for the production of fabrics showing pebble or cockle eflects, which comprises treating for about 1-5 minutes at l5-20 C. fabrics containing'in at least one of the yarn directions, yarns consisting of cellulose acetate alternating with yarns consisting of cellulose with a solution of a thiocyanate in concentration molecularly equivalent to 20-60% of ammonium thiocyanate.
3. Process for the production of fabrics showing local pebble or cockle effects, which comprises subjecting for about 1-5 minutes at 15-20 C.
fabrics containing in at least one of the yarn di-' rections, yarns consisting of cellulose acetate alternating with yarns consisting of cellulose to the localized action of a solution of a thiocyanate in concentration molecularly equivalent to 20-60% of ammonium thiocyanate.