The treatment of synthetic fibres

摘要

A process for setting deformations such as crimps, twist, pleats in polyacrylonitrile fibres, which may be in the form of continuous filaments or staple fibres or yarns, threads or fabrics containing a major proportion thereof, comprises the application, e.g. by immersion or spraying, of a swelling agent for the polyacrylonitrile to the fibres before or after the deformations are imparted. Fibres obtained by a wet-spinning p process may be treated in the aquagel or dried state, e.g. undried "as spun" filaments or fibres (before or after crimping) are immersed, sprayed or padded with the agent, dried (before or after crimping) and may then be steamed to stabilize the deformations. The swelling agent may be a mixture of water and a cyanoalkyl amide, e.g. bis-cyanoethyl formamide, ethylene carbonate, dimethyl sulphoxide, butyrolactone, succino-dinitrile, tetramethylene sulphone, resorcinol, phenol, metacresol, urea or thiourea, or an aqueous solution of sodium thiocyanate, chromic sulphate or zinc sulphate.ALSO:A process for setting deformations such as crimps, twist, pleats in polyacrylonitrile fibres, which may be in the form of continuous filaments or staple fibres or yarns, threads or fabrics containing a major proportion thereof, comprises the application, e.g. by immersion or spraying, of a swelling agent for the polyacrylonitrile to the fibres before or after the deformations are imparted. Fibres obtained by a wet-spinning process may be treated in the aquagel or dried state, e.g. undried "as spun" filaments or fibres (before or after crimping) are immersed, sprayed or padded with the agent, dried (before or after crimping) and may then be steamed to stabilize the deformations. A fabric may be pleated by applying the swelling agent and folding the fabric into pleats while wet with the agent: the fabric is dried while so folded. The swelling agent may be a mixture of water and a cyanoalkyl amide, e.g. biscyanoethyl formamide, ethylene carbonate, dimethyl sulphoxide, butyrolactone, succinodinitrile, tetramethylene sulphone, resorcinol, phenol, meta-cresol, urea or thiourea, or an aqueous solution of sodium thiocyanate, chromic sulphate or zinc sulphate. The Provisional Specification describes the application of swelling agents in paste form to selected areas of a polyacrylonitrile fabric to produce embossed, e.g. seersucker, effects.