Improvement of Soft Tooling Process Through Particle Reinforcement with Polyurethane Mould

Use of conventional flexible polymeric mould materials yields to longer solidification time of (wax/plastic) patterns in soft tooling process, thereby reducing the rapidity of the process to a great extent, which is not desirable in present competitive market. In this work, approach of particle-reinforcement with mould materials is introduced to reduce the cycle 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 filled polyurethane. It is observed that cooling time is significantly reduced particularly with higher loading condition of aluminium filler. This happens due to the increase of effective thermal conductivity of mould material. However, it is also found that the stiffness of mould becomes simultaneously high due to increase of effective modulus of elasticity of mould material. Realizing these facts, an extensive study is carried out to find the effect on equivalent thermal properties and modulus of elasticity of polyurethane composite mould materials with the reinforcement of aluminium and graphite particles independently through rigorous experimentation and correlation of experimental findings with the models cited in literatures.