Patent GB-615741-A (GB)
Title: Improvements in or relating to a process for refining textiles
IPC: D06Q1/08
Filed: 1945-12-31
Abstract: Textile fibres, yarns or fabrics of regenerated cellulose are subjected to treatment with an alkaline swelling agent in the absence of carbon disulphide and then, after removing excess of swelling agent by centrifuging, squeezing or suction they are subjected to treatment with dry, moist or superheated steam alone or containing other treating agents in vapour form.  After the steaming treatment, the materials are treated with agents neutralizing the swelling agent, and are thoroughly washed.  The swelling agent may be caustic soda, caustic potash, an alkaline sulphide, an organic base, or ammoniacal copper oxide.  The materials may be in tensioned or untensioned condition during the swelling and steaming treatments. The treatment with swelling agent may be combined with other treatments.  At the end of the steaming treatment, volatile reagents which neutralize the swelling agent may be added to the steam.  The treatment may be followed by dyeing, printing, shrink-proofing, water-proofing, crease-proofing, or other finishing treatment.  Any discolouration caused by the steaming treatment may be removed by bleaching with chlorine or active oxygen.  This discolouration may be avoided by adding reducing agents such as hydrosulphites, thiosulphites, bisulphites, formaldehyde or formaldehyde-bisulphite, to the alkaline swelling agents.  The cellulosic fibres may be mixed with other fibres, e.g. animal fibres, synthetic fibres, albumen or casein artificial fibres.  The swelling agent may be applied locally so as to obtain pattern effects.  Crepe or crinkle effects may be obtained by allowing shrinkage to take place.  The pattern effects may be enhanced by incorporating dyes or pigments in the reserve printing compositions or in the thickened solutions of the swelling agents, or by dyeing after the steaming operation.  In an example, viscose staple fibre muslin is treated with caustic soda lye containing aldehyde-bisulphite and sodium sulphate, and after squeezing, is steamed without tension at 130-160 DEG  C.  It is then immersed in dilute acetic acid.  The fabric is resilient, lustrous and transparent.  Pattern effects may be obtained by pretreatment of the fabric with cellulosic or synthetic resin reserves, or by the local action of aldehydes, synthetic resin initial condensates, or ester or ether forming reagents.  The alkaline swelling agent may be neutralized by adding acetic acid vapour to the steam during the final stage of the steaming operation.  The Specification as open to inspection under Sect. 91 comprises also the use of other swelling agents, e.g. zinc chloride, calcium thiocyanate and carbon disulphide.  This subject-matter does not appear in the Specification as accepted.ALSO:Textile fibres, yarns or fabrics of natural or regenerated cellulose are subjected to treatment with an alkaline swelling agent in the absence of carbon disulphide and then, after removing excess of swelling agent by centrifuging, squeezing, or suction, they are subjected to treatment with dry, moist, or superheated steam alone or containing other treating agents in vapour form. After the steaming treatment, the materials are treated with agents neutralizing the swelling agent, and are thoroughly washed. The swelling agent may be caustic soda, caustic potash, an alkaline sulphide, an organic base, or ammoniacal copper oxide. The materials may be in tensioned or untensioned condition during the swelling and steaming treatments.  The treatment with swelling agent may be combined with other treatments.  At the end of the steaming treatment, volatile reagents which neutralize the swelling agent may be added to the steam.  The treatment may be followed by dyeing, printing, shrink-proofing, water-proofing, crease-proofing, or other finishing treatment.  Any discolouration caused by the steaming treatment may be removed by bleaching with chlorine or active oxygen. This discolouration may be avoided by adding reducing agents such as hydrosulphites, thiosulphates, bisulphites, formaldehyde, or formaldehyde-bisulphite, to the alkaline swelling agents.  The cellulosic fibres may be mixed with other fibres, e.g. animal fibres, synthetic fibres, albumin or casein artificial fibres.  The swelling agent may be applied locally so as to obtain pattern effects.  Crape or crinkle effects may be obtained by allowing shrinkage to take place.  The pattern effects may be enhanced by incorporating dyes or pigments in the reserve printing compositions or in the thickened solutions of the swelling agents, or by dyeing after the steaming operation.  In an example, bleached cotton fabric is treated with 30 DEG  Baume soda lye at 5 DEG  C. and after squeezing it is stretched and steamed for 12 minutes at 130 DEG  C.  It is rinsed with hot and cold water, and then neutralized and washed again.  The material is soft and smooth and has a silky lustre.  If the process is repeated, the fabric becomes transparent.  Cotton jersey material is impregnated with soda lye, squeezed, and treated with steam under pressure, free shrinking being allowed.  After neutralizing and rinsing, the fabric has the appearance of suede.  Mercerized cotton muslin is rendered transparent by means of strong sulphuric acid.  It is then treated with a caustic soda lye containing a reducing agent, squeezed, and then steamed.  Pattern effects may be obtained by pre-treatment of the fabric with cellulosic or synthetic resin reserves, or by the local action of aldehydes, synthetic resin initial condensates, or ester or ether forming reagents.  The alkaline swelling agent may be neutralized by adding acetic acid vapour to the steam during the final stage of the steaming operation. The Specification as open to inspection under Sect. 91 comprises also the use of other swelling agents, e.g. zinc chloride, calcium thiocyanate and carbon disulphide.  This subject-matter does not appear in the Specification as accepted.