V-ribbed belts and process for their manufacture

摘要

A V-ribbed belt (B) comprising: a V-ribbed belt body (10) made of rubber and provided with a plurality of V-shaped ribs (15) which extend in a belt length direction and are arranged parallel to each other in a belt width direction; and a cord (14) embedded in the V-ribbed belt body (10) so that the cord (14) forms a spiral pattern with a pitch (P) in the belt width direction, the cord (14) being made of a twisted yarn having a total fiber count in the range of 2200 dtex to 5500 dtex, wherein the twisted yarn is made by a plurality of yarns having a first twist, each of the yarns having a first twist is obtained by rotating a bundle of polyester-based fibers in one direction, and then rotating the plurality of yarns with a first rotation in a direction opposite to the first rotation direction is formed, a fiber fineness of the cord (14) per belt width corresponding to the individual V-shaped rib ranges from 10,000 dtex to 19,000 dtex, characterized in that a dry heat shrinkage force of the belt per belt width corresponding to the single V-shaped rib 44 is N to 55 N, the dry heat shrinkage force of the Belt is a load increase with respect to a belt length of 300 mm 30 minutes after applying, in an atmosphere of 150 ° C, a load of 6N in the belt longitudinal direction and holding the belt.