GB594436A - Method of finishing plastic filaments in brushes - Google Patents

Abstract

594,436. Brushes. LEVER BROS. & UNILEVER, Ltd. (Pepsodent Co.). June 14, 1945, No. 15154. [Class 19] A method of finishing and shaping the ends of thermoplastic bristles in brushes, especially tooth-brushes, comprises applying heat to the free ends of the bristles to melt the same, allowing the melted ends to solidify and pulling away the melted portions when solidified. Suitably, the bristle ends are brought into contact with a heated plate whereby molten globules, which may coalesce, form on the bristle ends, Fig. 3, and may be pulled off when 'solidified by combining, picking or brushing. The bristle ends may be given any desired contour by use of a suitably-shaped plate as shown, for example, in Figs. 1 and 12 ; the surface of the plate may be stippled or minutely irregular, thereby resulting in bristle tips containing depressions facilitating retention of tooth paste, as shown in Fig. 9. The desired contour may be produced by contacting the bristle end with a heated plate in a single operation, by step-wise contact with two or more contoured plates, by moving the bristles over the heated plate while in contact therewith or by successive application of a suitably small heated plate to different portions of the brush at varying angles. The method is preferably employed in finishing brushes containing nylon filaments and, if desired, the bristles may be trimmed to approximately the desired length and contour prior to the application of heat. Specification 550,229 is referred to.