Abstract: A toothed belt has therein a core wire (3) including a core thread (1) made of aramid fiber and a filament thread (2) made of nylon fiber, and has belt tooth portions (4) and belt groove portions (5) alternately formed therealong. The core wire (3), the belt tooth portions (4), and the belt groove portions (5) are integrated with one another by a rubber material (7). It should be noted herein that the core thread (1) and the filament thread (2) are integrally twined around each other so that the filament thread (2) is formed in the shape of a plurality of loops around the core thread (1). The filament thread (2) in the shape of the loops enters tooth root portions (9) of the belt tooth portions (4) to be arranged therein. As a result, the tooth root portions (9) are strengthened.

Abstract: A toothed belt has therein a core wire (3) including a core thread (1) made of aramid fiber and a filament thread (2) made of nylon fiber, and has belt tooth portions (4) and belt groove portions (5) alternately formed therealong. The core wire (3), the belt tooth portions (4), and the belt groove portions (5) are integrated with one another by a rubber material (7). It should be noted herein that the core thread (1) and the filament thread (2) are integrally twined around each other so that the filament thread (2) is formed in the shape of a plurality of loops around the core thread (1). The filament thread (2) in the shape of the loops enters tooth root portions (9) of the belt tooth portions (4) to be arranged therein. As a result, the tooth root portions (9) are strengthened.

Abstract: The present invention provides a PFA resin helical blade for use in a compressor, which is superior in dimensional precision and surface smoothness with a superior anti-fatigue property, and a manufacturing method thereof. In a manufacturing method of a compressor-use helical blade of the present invention, a PFA composite resin, which is formed by mixing an inorganic filler with a tetrafluoroethylene/perfluoroalkylvinyl ether copolymer (PFA resin) having a —CH2OH terminal group, which has not been subjected to a stabilizing process, and has fluidity of not ness than 15 g/10 min, is used, and after the resin has been molded into a helical blade through an injection-molding process, the resulting matter is subjected to a heating process at a temperature from 280 to 300° C. for a period from not less than 10 hours to not more than 300 hours.