Title: Effect on cooling time in soft tooling process using particle reinforcement with polyurethane mould material

Authors: Arup Kumar Nandi; S. Datta

Addresses: Central Mechanical Engineering Research Institute (CSIR-CMERI), MG Avenue, Durgapur 713209, West Bengal, India ' School of Materials Science and Engineering, Bengal Engineering and Science University, Shibpur, Howrah 711103, West Bengal, India

Abstract: Use of conventional flexible polymeric mould materials yields to longer solidification time of (wax/plastic) patterns in soft tooling (ST) 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 increase the productivity of ST process and the resulting cooling time is experimentally investigated in considering a case of manufacturing of a typical wax pattern with aluminium filled polyurethane (PU). It is observed that cooling time is significantly reduced particularly with higher loading condition of aluminium filler due to the increase of equivalent thermal conductivity (ETC) of mould material. But simultaneously, it is also found that the stiffness of mould becomes high due to increase of equivalent modulus of elasticity of mould material. Realising these facts, an extensive experimental study is carried out to find the effect on equivalent thermal properties and modulus of elasticity of PU composites by reinforcing aluminium and graphite particles independently with different loading conditions. The existing models of ETC and modulus of elasticity of composites are also tried to validate based on the experimental findings.

Keywords: soft tooling; flexible mould materials; polymeric mould materials; particle reinforcement; cooling time; equivalent thermal conductivity; equivalent modulus of elasticity; wax pattern; aluminium filled polyurethane.

DOI: 10.1504/IJRAPIDM.2011.043459

International Journal of Rapid Manufacturing, 2011 Vol.2 No.3, pp.192 - 213

Published online: 18 Feb 2015 *

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