Diffused Reflection of Microcellular Foamed Polycarbonate

Abstract

Microcellular foamed plastics have significantly contributed to the plastics industry by achieving product's weight reduction and material cost savings. Limitations in petroleum resource reserves have propelled recent active research into the area of the foaming process. In particular, the extremely small cell size at less than 10 µm and higher density for microcellular foaming process compared to the existing chemical foaming keep its mechanical property decline small. In short, microcellular foamed plastics keeps mechanical property decline to minimum and products light. The research into microcellular foaming process thus far focused on elevating foaming expansion ratio or keeping off mechanical property decline such as intensity. This paper describes the research outcome on the optical properties of microcellular foamed plastics, especially light's diffused reflection via microcellular foamed cells. Varying size and density of the cells were used in the research process to identify changes in light reflectivity. Batch process using high pressure vessels was employed for the test and PC (Polycarbonate), known for its most outstanding optical property, was used as test material. Another test method worthy of notice is desorption time concept applied to control cells' distribution and control.