MANUFACTURE OF DIAPHRAGM FOR SPEAKER

摘要

PURPOSE:To improve forming performance and to attain mass-production by welding thermally a foamed sheet and a polypropylene skin. CONSTITUTION:Graphite powder and mica powder are kneaded with a copolymer polypropylene to form a skin sheet with sheeting into 0.2mm. of thickness. The sheet is welded to both sides of foamed polypropylene with press-stick thermally into a prescribed thickness at 140-160 deg. of temperature to form the diaphragm. The speaker reproducing band of the diaphragm is widened to a high frequency, the peak of a high resonance frequency band is decreased and a flat sound pressure frequency characteristic is attained.