Strategy of molding shrinkage control for Bi-layered RHCM based on Kriging and GA

doi:10.11949/j.issn.0438-1157.20160637

Abstract

Abstract:

Due to high temperature and high pressure conditions of Bi-layered rapid heating cycle molding(Bi-layered RHCM), the molding shrinkage of its products is extremely sensitive to the change of process parameters, therefore, the key to improve quality of products is the strategy of molding shrinkage control.In order to explore and develop the strategy of molding shrinkage control, a remote control's front cover of air conditioner was an example for molding in this paper.Determined a multi-objective evaluation system and process parameters for measuring molding shrinkage.Latin Hypercube Sampling was used to design experiments, moreover, a numerical simulation software named Moldflow was used to simulate mold filling, pressure maintaining and cooling process to obtain test data.The mathematical relationship between parameters and evaluation index was estabilished by Kriging model.In order to find out the optimal evaluation index of molding shrinkage and corresponding process parameters, the mathematical relationship was iterative calculation by means of genetic algorithm(GA).Both simulation and production test were applied to verify the strategy of molding shrinkage control based on Kriging model combined with GA, and provide the reference of molding shrinkage control of Bi-layered RHCM.

Key words: Bi-layered RHCM, shrinkage control, Kriging model, genetic algorithm, numerical simulation

摘要：

高温、高压的成型条件，使双层变模温制品的成型收缩对工艺参数的变化极为敏感，双层变模温制品的成型收缩控制策略成为提高制品质量的关键。以某空调遥控器前盖双层变模温成型工艺开发为例，探讨并制定了其成型收缩的控制策略。确定了考量成型收缩的多目标评价体系及参数变量，以拉丁超立方取样设计试验，并利用数值模拟软件进行充模、保压及冷却等过程模拟获取试验数据，建立了基于Kriging代理模型的变量与评价指标间的数学关系；利用遗传算法对数学关系进行迭代，寻找最优成型收缩的评价指标及变量组合；最后，将模拟及生产试验对研究策略的科学有效性进行验证。

关键词: 双层变模温成型, 收缩控制, Kriging模型, 遗传算法, 数值模拟

CLC Number:

TQ320.66

WANG Menghan, LIU Xiao, WEI Kang, LI Yanzhao. Strategy of molding shrinkage control for Bi-layered RHCM based on Kriging and GA[J]. CIESC Journal, 2017, 68(1): 391-397.

王梦寒, 刘晓, 危康, 李雁召. 基于Kriging与GA的双层变模温注射成型收缩控制策略[J]. 化工学报, 2017, 68(1): 391-397.

References 23

[1]	DONDERO M, PASTOR J M, CARELLA J M, et al. Adhesion control for injection over molding of polypropylene with elastomeric ethylene copolymers[J]. Polymer Engineering & Science, 2009, 49(10):1886-1893.
[2]	ARZONDO L M, PINO N, CARELLA J M, et al. Sequential injection over molding of an elastomeric ethylene-octene copolymer on a polypropylene homopolymer core[J]. Polymer Engineering & Science, 2004, 44(11):2110-2116.
[3]	WANG G L, ZHAO G Q, LI H P, et al. Analysis of thermal cycling efficiency and optimal design of heating/cooling systems for rapid heat cycle injection molding process[J]. Materials & Design, 2010, 31(1):3426-3441.
[4]	NIAN S C, TSAI S W, HUANG M S, et al. Key parameters and optimal design of a single-layered induction coil for external rapid mold surface heating[J]. Int. Commun. Heat Mass, 2014, 57:109-117.
[5]	JIANG G J, ZHANG F S, WU H, et al. Comparative studies on enhanced interfacial adhesion between PE and PA6 through two routes in a sequential injection molding process[J]. Polymer-Plastics Technology & Engineering, 2014, 53(1):9-18.
[6]	NGUYEN S, PEREZ C J, DESIMONE M, et al. Adhesion control for injection over molding of elastomeric propylene copolymers on polypropylene. Effects of block and random microstructures[J]. International Journal of Adhesion & Adhesives, 2013, 46:44-55.
[7]	YAN B W, WU H, JIANG G J, et al. Interfacial crystalline structures in injection over-molded polypropylene and bond strength[J]. ACS Applied Materials & Interfaces, 2010, 2(11):3023-3036.
[8]	陈茂顺. 基于多浇口时序控制的双色高光注塑技术研究[D]. 南昌:南昌大学, 2012. CHEN M S. Research on high-gloss double-injection molding technology based on multi-gates sequence control[D]. Nanchang:Nanchang University, 2012.
[9]	WANG G L, ZHAO G Q, LI H P, et al. Research of thermal response simulation and mold structure optimization for rapid heat cycle molding processes, respectively, with steam heating and electric heating[J]. Materials & Design, 2010, 31(7):382-395.
[10]	WANG G L, ZHAO G Q, WANG X X. Development and evaluation of a new rapid mold heating and cooling method for rapid heat cycle molding[J]. International Journal of Heat and Mass Transfer, 2014, 78:99-111.
[11]	XIAO C L, HUANG H X. Optimal design of heating system for rapid thermal cycling mold using particle swarm optimization and finite element method[J]. Applied Thermal Engineering, 2014, 64:462-470.
[12]	刘东雷, 申长雨, 刘春太, 等. 模具温度对高光注射成型制品表面沉降的影响[J]. 高分子材料科学与工程, 2012, 28(1):168-171. LIU D L, SHEN C Y, LIU C T, et al. Influence of mold temperature on the sink mark of rapid heat cycle molding plastic part[J]. Polymer Materials Science and Engineering, 2012, 28(1):168-171.
[13]	刘东雷, 申长雨, 刘春太, 等. 基于响应曲面法与改进遗传算法的RHCM成型工艺优化[J]. 机械工程学报, 2011, 47(14):54-61. LIU D L, SHEN C Y, LIU C T, et al. Efficient process parameters optimization of rapid heat cycling molding technology based on response surface methodology and improved genetic algorithm[J]. Journal of Mechanical Engineering, 2011, 47(14):54-61.
[14]	LUCCHETTA G, FIOROTTO M, BARIANI P. Influence of rapid mold temperature variation on surface topography replication and appearance of injection-molded parts[J]. CIRP Annals-Manufacturing Technology, 2012, 61(1):539-542.
[15]	高月华, 王希诚. 基于Kriging代理模型的稳健优化设计[J]. 化工学报, 2010, 61(3):676-681. GAO Y H, WANG X C. Robust optimization based on Kriging surrogate model[J]. CIESC Journal, 2010, 61(3):676-681.
[16]	葛学伟, 韩先洪, 陈巍, 等. 基于Kriging代理模型的气辅注射成型工艺优化[J]. 化工学报, 2010, 61(4):909-915. GE X W, HAN X H, CHEN W, et al. Processing parameters optimization based on Kriging meta-model for gas-assisted injection molding[J]. CIESC Journal, 2010, 61(4):909-915.
[17]	KUSUM D, MANOJ T. A new crossover operator for real coded genetic algorithms[J]. Applied Mathematics and Computation, 2007, 188(1):895-911.
[18]	马永杰, 云文霞. 遗传算法研究进展[J]. 计算机应用研究, 2012, 29(4):1201-1206. MA Y J, YUN W X. Research progress of genetic algorithm[J]. Application Research of Computers, 2012, 29(4):1201-1206.
[19]	张小聪. BP神经网络与GA算法相结合的双色成型保压曲线优化[J]. 中国塑料, 2015, 29(1):80-84. ZHANG X C. Optimization of pressure in bi-color molding through a hybrid of back propagation neural network and genetic algorithm[J]. China Plastics, 2015, 29(1):80-84.
[20]	杨海. 基于空调遥控器的双色高光蒸汽注塑技术研究[D].重庆:重庆大学, 2014. YANG H. Research on bi-color high-gloss injection molding technology based on air-condition remote control[D]. Chongqing:Chongqing University, 2014.
[21]	KABANEMI K K, VALLANCOURT H, WANG H, et al. Residual stresses, shrinkage, and warpage of complex injection molded products:numerical simulation and experimental validation[J]. Polymer Engineering & Science, 1998, 38(1):21-37.
[22]	MCKAY M D, BECKMAN R J, CONOVER W J. A comparison of three methods for selecting values of input variables in the analysis of output from a computer code[J]. Technometrics, 2000, 42(1):55-61.
[23]	SOREN N L, HANS B N, JACOB S. DACE a Matlab Kriging toolbox[DB/OL]. 2002[2005-02-19]. http://www.imm.dtu.dk/~hbn/dace/.> [22] MCKAY M D, BECKMAN R J, CONOVER W J. A comparison of three methods for selecting values of input variables in the analysis of output from a computer code[J]. Technometrics, 2000, 42(1):55-61.
	SOREN N L, HANS B N, JACOB S. DACE a Matlab Kriging toolbox[DB/OL], 2002[2005-02-19]. http://www.imm.dtu.dk/~hbn/dace/