MODELING THE INFRARED SHEET HEATING IN ROLL-FED THERMOFORMING

摘要

The heating stage is of primary importance in the thermoforming process. Computational methods using the finite element technique for modelling the radiation heating stage of thin gauge, roll-fed plastic sheet is presented and discussed. The theoretical approach as well as the experimental validation is also presented. The proposed approach takes into account the dynamic effects of sag and the displacement of the sheet inside the oven. The volumetric power absorption representing a heat generation term, which is critical in the case of semi-transparent materials, is also integrated by using Beer's absorption law.