Design For Heating System Of Electrical Rapid Heat Cycle Molding Mold Based On Heating Cell Unit

The Rapid Heat Cycle Molding(RHCM)technique is a new injection molding technology developed recently,which can effectively eliminate surface quality defects of plastic part,such as welding line,floating fiber,rough surface,poor glossiness,and so on.In this research,an Electrical Rapid Heat Cycle Molding(ERHCM)mold was applied for studying thermal response analysis.In order to heat mold cavity surface rapidly and uniformly,the thermal response of mold cavity surface and how to design the heating system were studied.The main research work and conclusions are as follows:1.The thermal balance analysis and key structure design.Based on the heat transfer theory,the heat transfer for ERHCM mold was analyzed and the thermal balance equations during heating stage was established.Then,some efficient ways to improve the mold heating efficiency was obtained.According to the traditional injection mold design theory and RHCM process principle,the design guidelines for heating system of ERHCM mold were proposed.2.Thermal response analysis of ERHCM mold.ERHCM mold heating process was simulated by using ANSYS software,and the characteristics of mold thermal response were investigated.Then,the heating cell unit was proposed,and the meaning of the two evaluation index for thermal response efficiency of ERHCM mold was intuitively elaborated.Based on heating cell unit,the effect of mold materials,mold structure,and heating element on heating efficiency and temperature uniformity of the mold cavity surface was investigated and some efficient ways to improve the mold heating efficiency and heating uniformity was discussed.3.An efficient design method for heating system of ERHCM mold was proposed.First,the heating system of ERHCM mold was simplified as multiple heating cell units for thermal response analysis based on conformal design theory.Then,a strategy consisting of thermal response analysis,neural network,multi-objective optimization and multiple-attribute decision-making technique was applied to obtain the optimized heating cell unit.Finally,the modified heating cell unit was then mapped into the entire mold to finish the heating system design of ERHCH mold.During this design process,the central composite design(CCD)method was employed in factorial experiments.In order to obtain experimental data,a thermal response aided analysis program of ERHCM mold was developed.Subsequently,a response surface using back propagation neural network(BPNN)was formed on the ground of initial finite element experiments.Then,combing Non-dominated sorting genetic algorithm II(NSGA-II)and the technique for order preferenceby similarity to ideal solution(TOPSIS)based on entropy-based weight,in which the required heating time and mold cavity surface temperature difference are the objective functions,the optimized heating cell unit for ERHCM mold was obtained.4.This developed thermal response aided analysis program can provide a fast and efficient way for heating system design of ERHCM mold and hence shorten the mold development cycle time.The related research results perfect the theoretical system of RHCM process and provide important references for heating system design of ERHCM mold,which has strong engineering and practical significance.