GB756573A - Concentration of natural rubber latex by electrodecantation - Google Patents

Abstract

756,573. Concentrating rubber latex by electrodecantation. DUNLOP RUBBER CO., Ltd. Oct. 25, 1954 [Nov. 4, 1953], No. 30415/53. Class 41. [Also in Group V] Natural rubber latex to be concentrated by electrodecantation in an apparatus having a plurality of substantially vertical semi-permeable membranes, is continuously supplied to the apparatus at a point above the membranes but below the level of the latex therein, whereby deposition of rubber on the membranes is reduced. The apparatus illustrated comprises a container 1 in which spaced vertical semipermeable membranes 2 are disposed parallel to and between electrodes 3 and 4 (not shown) each enclosed in a box provided with vents 5, 6 for conducting away gases formed by electrolysis. Latex is supplied through two tubes 7, 8 which extend downwardly through the top of the apparatus to a level just above the membranes 2. The latex serum is withdrawn through an outlet 10 (not shown) at the bottom of the container 1, whilst the rubber enriched latex is withdrawn through a horizontal tube 11 and a tube 12 having vertical and horizontal portions. The horizontal part of the tube 12 is rotatable to vary the height of the tube 11, a pointer 13 being provided to indicate said height. The tube 11 is preferably positioned at a distance above the membranes 2 which is approximately two thirds of their height. The deposition of rubber on the membranes 2 is further reduced by reversing periodically the electric potential difference applied to the latex.