| 摘要 |
PURPOSE:To reduce pressure in the cavity from before the beginning of vacuum casting of molding material until the completion of casting by a method wherein the filter through which gas is allowed to pass but viscous liquid is not allowed to pass is provided in the vacuum port of the mold through which the molding material such as synthetic resin, etc. is poured in vacuum. CONSTITUTION:In the pouring hole 3 for molding material, a vacuum exhaust tube has a dual structure, porous paper or plastic sheet 3a with pore diameters 1-50mu is arranged on the side of the cavity of the exhaust port and then glass nonwoven fabric or glass filter 3b with pore diameters 1-500mu are distributed. Further, sintered metal 3c with pore diameters 1-500mu is disposed. Regarding the combination of filters, in order to resist pressure due to vacuum and that due to hardening, paper or plastic sheet 3a or nonwoven fabric, with sintered metal 3c as the base or glass filter 3b alone can be used. |
