GB603116A - Improvements in brushes - Google Patents

Abstract

603,116. Brushes. STIFF, F. R., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. Nov. 8, 1946, No. 26374/45. [Class 19] Brushes are bristled with bristles of a synthetic filament forming material each having a cross-section which is greater in one diameter than in another at right angles, the said bristles being positioned so that more than 50 per cent of the bristles have their aforesaid large dimensions substantially parallel to each other and lying in the same direction. The bristles are thereby rendered more resistant to bending in one direction than in any other and may be so positioned in tooth brushes, hair brushes, clothes brushes and other hand brushes, longhandled brushes and mechanically-operated brushes that the aforesaid direction is in that direction in which the brush most frequently moves in use. The bristles may be the shape of an ellipse, rectangle, rhombus or isoscles triangle in cross-section. Bristles of the required shape may be obtained by extrusion through a suitably shaped orifice and they may be tapered, for example, by the method described in Specifications 535,263 and 578,324, [both in Group IV]. The bristles may be glued into holes in a brush backing or inserted into a layer of heat-softened resin attached to a brush backing. Preferably, the brush is made by threading continuous filaments or bunches of filaments of correct cross-section through holes in a backing plate so as to form a series of loops on the bristle side of the plate, attaching the filaments to the plate and then cutting the loops, especially as described in Specification 588,576. The filaments are preferably made of a synthetic polyester obtained as described in Specification 578,079, [Group IV], such as polyethylene terephthalate or nylon.