| 摘要 |
PURPOSE:To obtain a diaphragm with a high quality by melting the fiber with a lower melting point or a finer diameter by heating to form knots in a non-woven cloth in which the same kind of short fiber varied in the melting point and the diameter is dispersed evenly regardless of the directionality thereof and molding thereof under heat and pressure in the form of a prepreg sheet after the cloth is pregnated with a foaming resin. CONSTITUTION:The same kind of fiber including aromatic polyamide fiber and acrylic fiber each varied in the melting point and the diameter is cut to the length of 10mm or less and is dispersed evenly with respect to the directionality and the local weight distribution of the fiber. Then, it is heated at such a temperature as to melt the fiber with the lower melting point and finer diameter to form a non- woven cloth having a strong knot between the fibers. The non-woven cloth thus obtained is impregnated with a paint obtained by dissolving or suspending a foaming resin such as acrylic resin group and urethane resin group in a solvent to form a prepreg sheet, which is molded under heat and pressure to obtain a diaphragm as originally designed. |
