Improving Optical Quality of Poly methyl methacrylate Sheet by Forming with Rubber

Poly methyl methacrylate (PMMA) is one of the transparent polymers prevalently formed through thermoforming process. One of the important factors in this production is its optical quality. Using finite element simulation is very important to this aim. In this paper, PMMA thermoforming process is simulated using elastic-plastic model and accuracy of the results is verified by comparison with that of experimental data optained from tests. Then, thickness distribution and final shear strain are controlled by forming with rubber and a product with appropriate properties and quality is obtained. By choosing rubber with properties similar to the sheet, the rubber effects on sheet can be prevented..