POLYTETRAFLUOROETHYLENE BELLOWS, PROCESS FOR MANUFACTURING THE SAME, APPARATUS THEREFOR AND FLUID PUMPING EQUIPMENT UTILIZING THE BELLOWS

摘要

PROBLEM TO BE SOLVED: To solve a problem of an adverse effect on various branches of technical fields utilizing a conventional PTFE bellows formed by cutting work that generates chips not separated from the molded article and left there in the cutting.;SOLUTION: A bellows is obtained by melting-pressure molding into a bellows form, and is made of PTFE. The bellows is obtained by inserting a core in the inside of a PTFE bellows constituted by preliminarily shaping the PTFE in a cylindrical shape or cutting and machining or blow molding the same, carrying out fusion pressure bonding with the use of, for example, a special metal mold; and drawing out the core, optionally followed by welding. The special metal mold consists of a plurality of movable outer slave molds and the same number of back-push outer slave molds. The movable outer slave molds and back-push outer slave molds are alternately disposed, and while sliding, narrow the circle made thereby to accomplish fusion pressure bonding of molding. Thereafter, the movable outer slave molds and back-push outer slave molds are detached to expand the molding. Simultaneously, mechanical force is applied to expand a flange portion. The core is taken out, optionally followed by welding. Thus, a bellows can be obtained.;COPYRIGHT: (C)2009,JPO&INPIT