형체압축성형을 이용한 도광판의 복굴절 저감효과에 관한 실험적 연구
An Experimental Study on the Reduction of a Birefringence Distribution in LGP by Injection-Press Molding
The residual birefringence in molded plastic parts can be divided into two kinds of residual birefringence, i.e., the flow induced residual birefringence produced in flowing stages and the thermally induced residual birefringence produced in cooling stage. In this paper, the effect of new injection-press molding process with normal injection mold, i.e. I) injection-compression mode, ii) injection-press mode, on the distribution of birefringence was studied. It was found that the values of the birefringence was reduced at i) low clamping force and ii) longer mold opening length by injection-press molding.