PURPOSE: To obtain the titled lens having a large aperture and thickness deviation, by compression molding a cut plastic lens material, which has been obtained by the casting method, in compression molds when only part of the material adjacent to the surface is melted to be flowable.
CONSTITUTION: A monomer, a half polymer or a mixture of the monomer and the half polymer is cast in casting molds, and is bulk-polymerized to obtain the plastic material 2. The plastic material 2 is cut to have the surface roughness of 10W30μm by a lathe and preferably an NC lathe, and is set between cores 6, 7 associated with mold plates 1, 3, with the heated molds open. Then the molds are closed, and after they are left to stand until only part of the material adjacent to the surface is melted to be flowable, the material is compression molded. In this case, the circulation of the temperature controlling medium is stopped, and a cooling medium is passed through mold cooling medium flowing bores 12 thereby the molds are cooled.
| JPS5217572 | METHOD OF PRODUCING SILICON RUBBER MOLD |
MATSUDA SHIYUNSUKE
TAMURA TOORU
MURAKAMI YOSHINOBU
MITANI KATSUAKI
| JPS5325445A | 1978-03-09 | |||
| JPS5196855A | 1976-08-25 |