Experimental investigation on equivalent properties of particle reinforced silicone rubber: Improvement of soft tooling process

Abstract

The main disadvantage in soft tooling process using conventional flexible reactive polymeric mould materials, namely silicone rubber, is the longer solidification time of (wax/plastic) patterns that yields to reduce the rapidity of the process to a great extent, which is not desirable in the present competitive market. The approach of particle reinforcement with mould materials is introduced here to reduce the cooling time of soft tooling process and the resulting cooling time is experimentally investigated in considering a case of manufacturing of a typical wax pattern with aluminium particle–reinforced silicone rubber mould material. It is observed that cooling time is significantly condensed, particularly with higher loading condition of aluminium filler. This is due to the increase of equivalent thermal conductivity of mould material. However, it is also noticed that at the same time, the stiffness of mould becomes high due to the increase of equivalent modulus of elasticity of mould material. Therefore, in order to effectively utilize the particle-reinforced silicone rubber for preparing mould, it is important to have a perceptive on the equivalent thermal conductivity and modulus of elasticity of composite mould materials with different filler loadings. Based on this realization, an extensive study is carried out to find the effect on equivalent thermal properties and modulus of elasticity of silicone rubber composite mould materials with the reinforcement of various metallic and non-metallic filler particles independently through rigorous experimentation and correlation of experimental findings with the models cited in literatures.