BigPatents India

The invention relates to a method for production of a brush from thermoplastic polymers. During the injection moulding, the polymer melt is injected under pressure into a brush-forming channel with given lengths and given cross-sectional change over said length and the channel ventilated during the injection process. According to the invention, injection-moulded brushes with excellent flexibility may be produced, whereby the injection pressure is set depending on the cross-section change in the brush-forming channel such that a shear flow with a high core speed in the centre of the polymer melt with a high shear effect as a result of the wall friction of the polymer melt with marked longitudinal orientation of the polymer molecules, at least in the region of the polymer melt near the wall, is generated and maintained along the length of the channel. The channel is simultaneously ventilated along the length thereof such that the shear flow is maintained. A device for carrying out said method is also disclosed. (FIG. 10)