Patent GB-552225-A (GB)
Title: Improvements in or relating to cord and like structures
IPC: D07B9/00
Filed: 1941-08-13
Abstract: 552,225. Cords. CHASE, E., and PATCHETT, R. V. Aug. 13, 1941, No. 10286. [Class 109] [Also in Groups IV and VII] Cords, made of smooth and slippery materials such as silk or artificial silk are'secured against disintegration by incorporating with yarns of non-thermo-plastic fibres at least one yarn of a thermo-plastic material and subjecting the structure to the action of a softening agent for such thermo-plastic yarns to cause them to conform to the shape of neighbouring yarns and to adhere thereto. The method may be applied to the repair of defective cords, to the whipping of the ends of cords, to the formation of enlarged or narrower ends on cords, and to the tying of knots. The softening treatment may be a heat treatment, with or without pressure, but preferably a solvent treatment is employed with a cord containing fibres of a cellulose ester such as cellulose acetate, cellulose formate, propionate, or butyrate, mixed esters such as acetatepropionate or acetate-butyrate, or cellulose ethers such as ethyl and benzyl cellulose, or polyvinyl esters such as polyvinyl acetate or a co-polymer or vinyl acetate and vinyl chloride. The added fibres may contain a plasticising agent to avoid imparting brittleness to the cord. Fig. 1 shows a braided cord having a number of core yarns 1 with a braided cover 2. The core yarns and all the braided yarns except one may consist of filaments of cellulose acetate that have been stretched in the presence of a softening agent and then saponified while the remaining yarn 3 consists of one end 4 of similar filament to the above and two ends 5 of unsaponified cellulose acetate yarn. The cord is run at a rate of 2 to 3 feet per second through 50 to 80 per cent. acetone and dried. The resulting braided cord is compacted by the tension under which it is dried and held together in this compact state by the softening and setting of the cellulose acetate filaments. Figs. 3 and 4 show a cord composed of core yarns 9 and cover yarns 10 held together by a binder thread 11 which has broken or run out at 12. To repair such a cord, a double helical lapping of yarn 13 consisting of mixed, stretched and saponified cellulose acetate filaments and unsaponified cellulose, acetate filaments is bound on, and the section of cord dipped into acetone and held taut, for say 15 seconds, to allow the softened yarn to set. Fig. 5 shows a braided cord whipped at one end with cellulose acetate yarn 14 to form an enlarged end and then dipped in acetone. The major part of the cellulose acetate yarn 14 may be cut and stripped away leaving the end of the cord of slightly less diameter as shown in Fig. 6, but with the fibres bound together by the cellulose acetate derived from the whipping. Such cords are capable of threading through eyes, and the method may be applied to the production of shoe laces without separate tags. Fig. 8 shows a knot of slippery cord tied with a few strands 19 of cellulose acetate yarn trapped in' the knot, which is then dipped in acetone as before to secure adhesion and prevent the knot from slipping. Specifications 438,567, 438,656 and 443,707, [all in Group IV], are referred to.