GB426203A - Improvements in and relating to the manufacture of rubber material in lengths - Google Patents

Abstract

426,203. Rubber threads ; moulding rubber; yarns &c. LANDAU, L., 25, Highbury Place, Highbury, London. Sept. 25, 1933, No. 26404. [Classes 70 and 87 (ii)] [See also Group IX] A mould for making rubber lengths such as threads is comprised by a downwardly extending part of a single continuously-driven endless flexible member or band formed throughout its length with a passage of a cross section corresponding to that of the thread and slit throughout its length from one flat surface to the passage, means being provided for opening or spreading the slit locally to permit ingress and egress to and from the mould. As shown, a band 11 slit at 19 and having a reinforcement 20 passes over rollers 12-15 and the means for spreading consist of two pairs of inclined rollers 16, 17, latex being poured in at A and removed as a thread at B. The latex may be coagulated by wetting the walls of the passage 18 with a coagulant, or, when rubber tubes are produced by providing a hollow stationary metal former depending downwardly into the band to the zone where coagulation takes place, the coagulant may be introduced through the said hollow former. At first, provision is made for preventing the latex from running straight through the band-e.g. the band may not terminate at its lowest point but extend upwardly therefrom, a small quantity of latex being poured into the bottom part and coagulated there before production is commenced. Cores, as of metal and/or fabric or a thread produced according to the invention, may be covered with rubber by being fed through the band. In the case of a multi-layer thread having a wire core the layer next to the wire may be pure rubber-i.e. free from sulphur or other substances having a deleterious effect on the wire. Materials for layers other than the innermost may be chosen for their dielectric or low water - absorption properties. The internal configuration of the band may be such as to produce relief work such as lettering on the issuing thread, and the recesses of this relief work may be filled with differentlycoloured rubber by passing the thread through another band. Mottled effects can be produced by pouring simultaneously into the band latices of different colours. The latex may be natural or artificial, compounded, or processed-e.g. vulcanized or treated so as to produce spongy or porous products. Various shapes of moulds are described.