PLASTICIZING DEVICE FOR MOLDING SPECTACLE LENS, SCREW FOR PLASTICIZING DEVICE, METHOD FOR MANUFACTURING SPECTACLE LENS AND MOLDING APPARATUS FOR SPECTACLE LENS

摘要

PROBLEM TO BE SOLVED: To provide a plasticizing device for forming a spectacle lens being free from trouble cause of a compatibility shortage of a resin by a polymer blend and also being able to prevent resin burning. SOLUTION: A Dulmage zone 33 is formed at a measuring zone MZ of a screw 24. A compression ratio being a ratio of a depth of a spiral groove h1 at the measuring zone MZ to a depth of a spiral groove h2 at a material feeding zone is less than 2.5. The compatibility of the resin is improved as a result that a resin on the surface layer of the cylinder and a resin running on the surface part of the screw are gathered to a fin groove 35 of the Dulmage zone 33 and remelted. Therefore, a trouble by the compatibility shortage by the polymer blend (a problem by a striae defective of a resin) does not occur and the resin can also prevent resin burning. COPYRIGHT: (C)2005,JPO&NCIPI