Patent GB-538665-A (GB)
Title: Process for the production of fabrics resistant to stretching and shrinking
IPC: D06M15/17
Filed: 1940-03-06
Abstract: 538,665. Treating textiles with liquids &c. ROHM & HAAS CO. March 6, 1940, No. 4224. Convention date, May 1, 1939. [Class 15 (ii)] A fabric is rendered resistant to subsequent shrinking or stretching by depositing within the yarns or fibres thereof from 1 to 6 per cent by weight of a thermosetting resin, heat pressing the fabric in a dampened condition on to the distended side of a heavy blanket passing over. a roll, passing the blanket and adherent fabric around a heated drum revolving in an opposite direction to the roll, and separating the fabric from the blanket. As shown, the fabric is treated with a solution of thermosetting resin in a pad box 1, and then passed between the rolls 2 of a hydraulic mangle so as to squeeze out excess of resin solution. The fabric passes through a drying tenter 3, through a spray chamber 4 for dampening the fabric, then through an expander 7 and then through a mechanical shrinking apparatus where the fabric is mechanically shrunk and the resin rapidly fused and set. A solution of resin of 2-10 per cent may be used. The preferred resin is a water-soluble ureaformaldehyde condensate. The pressure on squeeze rolls 2 is preferably such that all the solution not absorbed by the threads themselves is squeezed out of the fabric. The spray chamber 4 has water sprinklers 5 and steam inlets 6. The shrinking device comprises a.  main drum 8, feed-in roll 9, heated shoes 10, and endless blanket of felt 11. The fabric is brought in contact with the outside surface of the blanket as it passes over feed-roll 9. The heated shoe 10 presses it against the expanded surface of the blanket. As the direction of curvature is reversed the fabric is compressed and thereby mechanically shrunk. The main drum 8 is maintained at 250-315‹F. so as to harden and set the resin. The process is applicable to the treatment of cotton, silk, wool, linen, or cellulose derivative fabrics or to fabrics made of fibres of synthetic substances. The thermosetting resin may be urea-formaldehyde, phenol-formaldehyde, or a resin obtained by condensing formaldehyde with guanidine, dicyandiamide, or an amino-triazine such as ammeline, thio-ammeline, or melamine. The treated fabrics may be subjected to calendering treatment without losing their resistance to shrinking. In an example, cotton fabric is passed through a dilute aqueous solution of dimethylol urea containing a wetting agent such as sodium octyl phenoxy ethyl sulphate and an acidic catalyst such as mono ammonium phosphate. The fabric is squeezed and then passed round steam-heated copper drying rolls and through a heated tenter frame. The fabric is damped with water, pulled to normal width by a clip expander, expander rolls, or pin tenter frame, and then passed through the mechanical shrinking device which is heated to melt and then harden and set the resin. The blanket of the shrinking device may be made of wool and rubber. In another example, a fabric containing viscose and cellulose acetate fibres is treated with a solution of dimethylol urea containing dimethyl benzyl cetyl ammonium chloride and mono-ammonium phosphate and then mechanically shrunk. Specification 480,171 is referred to.