| 摘要 |
PURPOSE:To obtain a diaphragm having light and flexible edge with excellent molding property and strength by providing the edge obtained through the impregnation and working of an thermoplastic acrylic rubber to a paper-making sheet using Manila hemp as the major component to the diaphragm. CONSTITUTION:The diaphragm 11 is of free edge type and the edge 13 obtained by impregnating a thermoplastic acrylic resin with excellent flexibility to a fiber sheet using Manila hemp as the major component and applying heat mold working is mounted to the peripheral part of a cone part 12 formed by paper- making pulp fiber and molding it. The edge 13 formed by impregnating the flexible acrylic resin to the sheet made of fiber of the Manila hemp as the major component is fitted to the diaphragm at the same time the edge is molded by pressing and heating. Moreover, Japanese paper such as KOZO or MITSUMATA is used in place of Manila hemp. Similarly, a flexible rubbery resin such a urethane group, SBR or NBR is used in place of the acrylic resin.
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