High thermal conductivity mould insert materials for cooling time reduction in thermoplastic injection moulds

Abstract

Decreasing the time of cooling phase in injection Moulding is of paramount importance in shortening the cycle time. Cooling phase takes more time when compared to other phases and is only stage which has scope of reducing cycle time and increasing production rate further. The given amount of heat energy that should be removed from melt is almost same in every cycle. The time taken to remove that heat energy is purely dependent on properties of materials across which the heat is being transferred from melt to coolant. This heat transfer generally occurs in convection-conduction-convection mode. In this paper Mould inserts across which heat is being dissipated, made of different materials are implemented and investigated in an injection Mould for a cosmetic product cap manufacture. Quality parameters like volumetric shrinkage and warpage are also observed along with time taken to reach ejection temperature. MoldFlow analysis tool is used to carry out the simulations with different Mould insert materials,The simulated results are found to be in good agreement with experimental values.The experimental work has been carried out at vasantha tool crafts pvt limited. However manufacturing of Mould inserts with desired materials may be expensive, implementing this for mass (large quantity) production orders in multi cavity Moulds turn out to be economical or profitable as the production rate increases without compromising in quality.