| 摘要 |
PURPOSE:To eliminate the drawback that a diaphragm using paper has poor productivity and undesired permeability by heating and molding a composite material which is prepared by laminating a refractory high molecular thin film upon a unwoven fabric through a thermoset adhesive layer. CONSTITUTION:An unwoven fabric 1 of a synthetic resin such as an unwoven fabric of polyester span band having a surface density of 800 g/m<2> is heated and laminated under pressure upon a refractory high molecular thin film 3 such as a polyethylene terephthalate film having a thickness of 4 microns, to one side of which a thermoset adhesive 2 of an epoxy resin is applied, thus preparing a composite material. This composite material is molded into a conical shape by a heat press. Thus, the resultant diaphragm has an excellent molded shape and has its permieability prevented and its elastic modulus slightly improved. Moreover, the diaphragm has an excellent regidity, is free from distorsion and can be prepared to have an excellent quality by one shot of the hot press. |
