The big difficulty "Blower Fan" that the PP injection molding of a desired thickness is less than 1mm, in order to ensure tightness. This is in addition to the molding conditions, but also need to sum up the resin injected into the mold of technical experience. Technology development associated with the Group's industrial SHIMIZU (Headquarters: Kariya City, Aichi) cooperation. Through the efforts of both sides, the front and rear portions of the length of the damper from the past 110mm shortened to 40mm.