Patent GB-1112646-A (GB)
Title: Method of manufacturing fabrics consisting of elastic fibres
IPC: D06Q1/02
Filed: 1965-08-24
Abstract: Fabrics consisting of or containing elastic fibres are made by wet-dry or semi-melt spinning a solution of a polyurethane and a polyvinyl alcohol in an organic solvent, drawing the filaments thereby produced to an extent such that their elasticity is reduced to that of conventional non-elastic filaments, making up the drawn filaments (or staple fibres produced therefrom) either alone or in admixture with other fibres into fabrics consisting of or containing the drawn filaments or fibres, and at least partially dissolving the polyvinyl alcohol component out of the drawn filaments or fibres of the fabric in order to restore their elasticity at least partially. The organic solvent may be dimethyl sulphoxide, dimethyl-formamide or dimethyl acetamide. The spinning solution may be extruded into a coagulating bath containing an aliphatic alcohol, a ketone, an aromatic hydrocarbon, or an aqueous solution of an inorganic salt. The bath may contain a proportion of the same organic solvent as is used in the spinning solution.  The spun filaments prior to drawing may still contain some of the spinning solution solvent.  The elasticity of the drawn fibre may be between 3 and 100%.  In two of the examples the spun filaments are drawn to 400 to 500% of their original length at room temperature and in the third example to 550% at 150 DEG  C.  The polyvinyl alcohol may be dissolved out of the drawn fibres in the fabric with water at 100 DEG  C. in 30 to 60 minutes.  Up to 10% by weight of polyvinyl alcohol may be allowed to remain in the drawn fibres in the fabric.  The drawn fibres in the fabric may be caused to adhere to one another by subjecting the fabric to heat or to a swelling agent for the polyurethane component of the drawn fibres.  The polyvinyl alcohol component of the drawn fibres may be a wholly or predominantly saponified polyvinyl ester either as such or partially acetalized or urethanized. It may have a molecular weight of 500 to 3,000.ALSO:Fabrics consisting of or containing elastic fibres are made by wet, dry, or semi-melt spinning a solution of a polyurethane and a polyvinyl alcohol in an organic solvent, drawing the filaments thereby produced to an extent such that their elasticity is reduced to that characteristic of conventional non-elastic filaments, making up the drawn filaments (or staple fibres produced therefrom) either alone or in admixture with other filaments or fibres which are non-elastic into fabrics consisting of or containing the drawn filaments or staple fibres, and at least partially dissolving the polyvinyl alcohol component out of the drawn filaments or fibres of the fabric in order to restore their elasticity.  The organic solvent may be dimethyl sulphoxide, dimethyl-formamide or dimethyl acetamide.  The spinning solution may be extruded into a coagulating bath containing an aliphatic alcohol, a ketone, an aromatic hydrocarbon, or an aqueous solution of an inorganic salt.  The bath may contain a proportion of the same organic solvent as is used in the spinning solution.  The spun filaments prior to drawing may still contain some of the spinning solution solvent.  The elongation of the drawn fibre may be between 3 and 100%.  In two of the examples the spun filaments are drawn to 400 to 500% of their original length at room temperature and in the third example to 550% at 150 DEG C.  The polyvinyl alcohol may be dissolved out of the drawn fibres in the fabric with water at 100 DEG C. in 30 to 60 minutes.  Up to 10% by weight of polyvinyl alcohol may be allowed to remain in the drawn fibres in the fabric.  The drawn fibres in the fabric may be caused to adhere to one another by subjecting the fabric to heat or to a swelling agent for the polyurethane component of the drawn fibres.  The polyvinyl alcohol component of the drawn fibres may be a wholly or predominantly saponified polyvinyl ester either as such or partially acetalized or urethanized.  It may have a molecular weight of 500 to 3,000.