Patent GB-764307-A (GB)
Title: Improvements in or relating to the manufacture of brassieres
IPC: A41C5/00
Filed: 1953-08-07
Abstract: 764,307. Making brassieres; rubber compositions. INTERNATIONAL LATEX CORPORATION. Aug. 7, 1953 [Aug. 9, 1952], No. 27484/55. Divided out of 764,306 [Group VII]. Classes 70 and 87(2). Brassieres formed of a continuous film of deposited latex of which the lower portion of the front is thicker than the remainder are moulded by dipping all the brassiere-generating surface of the dipping former into a bath of liquid latex and re-dipping it with the deposited film into another bath of liquid latex at such an angle and to such a depth that additional latex will be deposited up to the required level. Figs. 1 and 2 are views of two opposite sides of a suitable dipping former for producing articles which are continuous round the girth of the wearer without a joint, the length round the girth being governed by the extent of the opposite faces 2, 3 and the width being defined by the spacing between a lip 8 and an inward shoulder or undercut portion 9. The end 7 may be made so that the surface does not continue round it, to make a brassiere which is discontinuous girthwise and has fastened at its ends. To thicken the lower part of the brassiere, whereby it gives additional support in use, the former is first dipped into latex below the level AB, Fig. 5, and then, at an inclination conse. quent upon the difference in length between struts 10 and 11, into latex to the level CD, so depositing latex, in the second dip, in a limited zone comprising only lower portions of the cup generating surfaces 4, 5. The cup generating surfaces protrude from opposite sides of the former, as shown in Fig. 3 (not shown), the latex compound used in the first dip may have a composition resistant to the biochemical effects of contact with the human body, such a composition being arrived at by adding an emulsion polymer of chlorobutadiene to the latex, or a butadiene-acrylonitrile copolymer. The proportions by weight of one suitable composition specified are : natural rubber latex 75, emulsion polymer of chlorobutadiene 25, sulphated methyl oleate 3, sulphated monoester of a mixture of higher fatty alcohols 1À5, zinc oxide 3, titanium dioxide 10, zinc . dimethyldithiocarbamate 0À5, di-benzothiazyl-dimethyl-thiol urea 1, sulphur 2. The latex compound used in the second dip is of a character to deposit a less elastic film than the first, one suitable composition having the proportions by weight : centrifuged natural latex 100, latex polymerised from 85 per cent styrene and 15 per cent butadine 25, potassium hydroxide 0À5, sulphur 1, zinc oxide 1, tetramethyl thiuram disulphide 1. Reinforcing inserts such as tapes and threads are first coated with latex and then positioned on the former before dipping or on the deposited latex after the first dip. A reinforcing effect may also be attained by applying a coagulant to the former which results in a thicker latex deposit in the desired regions, or by grooving the former to cause the deposited latex to accumulate in the groove and have the required extra thickness. Instead of the cup-generating surfaces protruding from opposite sides they may be provided by an exterior convex surface 51, Fig. 12, and an interior concave surface 4<SP>1</SP>, one cup being turned inside out when the article is stripped from the former. The difference in size is minimised by making the wall of the former thin. A more conventional dipping former is shown in Figs. 15 and 16, in which two cup generating surfaces 104, 105 protrude from the front and the front of the brassiere is formed on the front of the former and the girth extensions are formed on the back of the former, the forming surface being defined by a lip and shoulder on the front, as in Fig. 1, and, on the rear, by a shoulder 108 and undercut 109, are shown in cross-section, Fig. 19. This frame may be modified by the back face following the contour of the front face, whereby the material is thinner, Fig. 25. The girth forming surfaces are on extensions as shown in Fig. 24 and it is thus possible to deposit latex films simultaneously on the inside and outside of the former so that two brassieres are made in one dipping operation. To form an air cushion between the latex and the body of the wearer the brassiere may be lined with very short cotton or rayon fibres which are blown through nozzles against the wet surface of the liquid latex and become embedded therein. Excess moisture is removed by hot air circulation and the brassieres, still carried on the formers, are placed in a bath of water just below boiling temperature and kept there till the latex is cured. Finally the brassieres are stripped from the formers and turned inside out. Suitable materials for the formers are metal, plastic or ceramic.