A solution for warpage in polymeric products by plug-assisted thermoforming

Thermoforming process is one of the most popular techniques in polymer processing due to its interesting capabilities. The fundamental defect inherent to the thermoforming technology is warpage of the products during their application which becomes particularly apparent under high temperatures. The warpage is understood as the process of non-uniform (heterogeneous) change of the geometrical dimensions of products in time resulting in a change (distortion) of their original form. The results of this work specify the causes of the warpage and the conditions for its development. Thereby, it is possible to work out in providing valid recommendations for partial and, in some cases, complete elimination of the defect. (c) 2006 Elsevier Ltd. All rights reserved.