Study of Temperature Profile and its Effect on Surface Roughness of Expanded Polystyrene Foam during Hot Wire Slicing

Expanded Polystyrene (EPS) or Plastic foam, commonly known as thermocol is used mainly for packaging and insulation purposes. Another important usage is pattern making for lost foam casting. Our focus in this paper will be restricted to the latter purpose. Hot tool is used for making various intricate shape easily and in lesser time. Moreover, the hot tool cutting process involves minimum cutting force compared to mechanical cutting. In this process nichrome wire is used as cutting tool which is heated by passing electricity through it. Nichrome wire diameter, feed rate and supply voltage are taken as input variable in the experiment whereas surface roughness as output variable. This paper explores into the plastic foam cutting process with a number of experimental cutting trials (more than 100), at different values of input variable and finding the effect of input variables on surface roughness. The objectives of the paper are to establish a mathematical model for steady state hot wire temperature and verify the same with experiment and to find out optimum input variables at which surface roughness is minimum. Surface roughness was measured using contact type profilometer.