| 摘要 |
PROBLEM TO BE SOLVED: To produce a lens low in molding residual stress without requiring annealing treatment. SOLUTION: In the production of a lens for a light of a vehicle by injection compression molding, a mold of which the product thick-walled part is compressible is used and the cavity thereof is filled with a polycarbonate resin melted by a heating cylinder in an amt. of 20-80% by vol. of a final molded product and, in this stage, a compression speed is set to 10-30mm/sec to compress the cavity and gradually changed from 3mm/sec to 8m/sec to apply compression force. By this method, molding residual stress is lowered and annealing treatment can be dispensed with. |
