AN ASSESSMENT ON OPTICAL QUALITY OF MOLDED BACKLITE COMPARED TO THERMOFORMED BACKLITE

摘要

Injection molding and thermoforming are common processes in both plastics and automotive industry. A preliminary study was made comparing the quality of large, complex, transparent, and optical rear window parts (automotive backlite prototypes) produced from an injection-compression molding process and a vacuuming thermoforming process. Optical quality on the parts was evaluated in terms of optical clarity (only the haze is discussed in this paper), optical distortion, birefringence and stress, shape and dimension. It was demonstrated that overall the molded backlites had much better optical quality than the vacuum thermoformed backlites based on the same shape and dimensions. Process recommendation, quality control and improvement for large complex optical application of plastic products, such as automotive polycarbonate (PC) glazing, are given during the discussion.