GB538865A - Improvements relating to knitted fabrics and manufactured knitted articles - Google Patents

Abstract

538,865. Treating knitted goods to reduce laddering. BREW, H. E. Nov. 18, 1939, Nos. 30312/39 and 7497/40. Drawings to Specification. [Class 15 (ii)] [Also in Groups IX and VIII] Knitted goods having anti-laddering properties a.re formed from a composite yarn which is comprised of at least one inert foundation filament and at least one potentially adhesive binding filament twisted together with a low degree of twist, the goods being subjected to treatment which will render the binding filament or filaments tacky or adhesive and will cause mutually-contacting adhesive parts to unite while, in general, not causing the adhesion of an adhesive part to the inert filament; the degree of twist in the composite varn is such that there are sufficient contacts of adhesive parts with each other to prevent laddering while allowing sufficient relative freedom between the component filaments of the yarn to maintain the desired elasticity. The binding filaments may be potentially adhesive throughout their whole length or at some parts only, and may be rendered potentially adhesive by a coating, e.g. of a natural or synthetic resin ; or a filament potentially adhesive throughout its length may have a resin applied at intervals. The union between the potentially adhesive parts of the binding filament may be effected by heat and pressure or by the application of a gelatinizing agent, the action of the agent being controlled by a diluent, which may be appreciably more volatile than the agent. The binding filament may be formed from cellulose esters, mixed esters or ethers, from polyamide' and vinyl resins or from natural or synthetic rubbers, or these potentially adhesive substances may be applied as a sheath, coating or impregnation to a filament of inert material, e.g. viscose. Examples of gelatinizing agents and diluents and of knitted goods and their treatment are given. Thus, a fabric made from a foundation filament of viscose and a binding filament of cellulose acetate, each having 2 turns per inch and twisted together in the opposite direction with 4 turns per inch, is immersed for 30 seconds in a bath of 4-6 parts by volume of dimethyl phthalate and 96-94 parts by'volume of benzene at a normal temperature and pressure ; the fabric is then dried by evaporating so that the air-dry fabric contains about 15 per cent. by weight of the dimethyl phthalate, is subjected to a hot pressing treatment for 0.25 minute or thereabouts at 135‹ C. and to an after-treatment of 10 minutes duration in a 0.5-1 per cent. soap solution at 70‹-80‹ C., and is finally dried. Specification 501,436 is referred to.