Thermal Analysis of Selected Polymer Materials for Precision Casting Models

This paper shows preliminary thermal analysis of 6 polymer materials which are commonly used or can be used as models for precision casting. Thermal analysis was carried out with use of derivatograph and allowed to determine two fundamental properties of examined materials - their phase transition during heating to the temperature of 800⁰C and mass of dry residue after burning which can be used to evaluate polymer residues remaining in the casting mould cavity. The subject of this paper is related to increasing participation of rapid prototyping methods in casting with use of printed models. Determination of changes in materials, in particular their linear and cubical expansion and analysis of dry residue after burning in casting mould cavity is extremely important for the construction of form crust and surface quality of casting. A problem is to design a polymer-based casting model which allows non-residue burning and simultaneously causes no cracking of ceramic form during heating.