V-Ribbed Belt Molding Reduces Canvas Stretching

The canvas is pre-stretched in a controlled manner before the molding process. The pre-stretching device applies uniform tension to the canvas in advance, so that when the ribs are formed during molding, the canvas is less likely to be excessively stretched and roughened. This preliminary preparation action prevents the harmful effect of excessive stretching during the molding process.

The invention changes the physical parameters of the canvas by pre-stretching it to a specific tension and degree before molding. This parameter change (pre-applied tension) allows the use of ordinary canvas instead of expensive special canvas, while still preventing excessive stretching and roughening during the molding process. The pre-stretching creates optimal initial conditions that eliminate the need for costly material modifications.

The invention replaces the expensive polyurethane elastic yarn (which has poor heat resistance) with ordinary canvas that is pre-stretched. The pre-stretching provides the necessary tension control without relying on heat-sensitive elastic materials. This substitution eliminates the reliability problem of polyurethane degradation while maintaining the benefit of controlled canvas stretching.

The canvas is pre-stretched uniformly before molding, creating a stable base that resists excessive local stretching during rib formation. This preliminary preparation prevents the canvas surface from becoming roughened, thereby preventing rubber from seeping into the texture and reducing friction and noise generation.