剥层法测量注塑制品残余应力的实验研究
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摘要
注塑制品因其优异的性价比得到越来越广泛的应用。但在注塑成型过程中,复杂的热力过程导致了残余应力的形成。对于注塑制品,残余应力的存在可能会导致制品出现细微裂纹、银纹等,使其光学性能下降,抗冲击强度降低等影响其使用性能。残余应力一般分为流动不均衡导致的流动残余应力和冷却不均匀导致的热残余应力两种。由于热残余应力比流动残余应力大一个数量级,所以注塑制品的残余应力主要是指制品冷却不均匀产生的热残余应力。
本文以无定型聚合物聚碳酸酯(PC)为研究对象,进行实验分析。主要工作如下：
1.选用无定形聚合物聚碳酸酯为实验材料进行注塑实验。先将注塑制品制备为样条,然后对不同工艺条件下的试样进行剥层,测量剥层后的变形情况。根据采集到的数据进行相关的力学分析,将变形量转化为曲率,代入推导出的残余应力计算公式,计算出PC制品厚度方向各层平均残余应力,并分析不同注射压力、保压压力和模具温度条件下对残余应力的影响。
2.利用Moldflow对不同工艺条件下的残余应力进行分析,并根据模拟结果中厚度方向的残余应力计算各层平均残余应力,将模拟结果与计算结果进行对比分析。
3.退火处理会使聚合物一些链段重新排列组合,使原有的部分应力得以松弛。在本文中对部分试样进行退火处理,分析相同工艺条件下残余应力的变化。
Injection products are applied more and more widely for their high cost performance. But the complex heat history lead to the formation of residual stress in the injection molding process. The existence of residual stress will result in the craze, making the optical performance and impact strength of products decrease and affecting their application. The residual stress are generally caused by uneven flow and colling, called flow residual stress and thermal residual stress. Due to the thermal residual stress is one order of magnitude bigger than the flow residual stress, the thermal residual stress was studied in this paper.
Based on the amorphous polycarbonate (PC) as the research object, main work is as follows:
1. The PC splines were prepared by injection molding with different processing parameters, firstly. Then Layer removal method was carried out and the deformation was measured for all samples.With the mechanics analysis, the collected data of deformation were converted to curvature, then the values of residual stress along the thickness direction of PC samples were estimated using the derived residual stress formula. The effects of injection pressure, holding pressure and mold temperature on the residual stress were discussed respectively.
2. The residual stresses under different processing parameters were calculated using Moldflow technology. The mean value of residual stress of each layer were estimated. Then the experimental results and simulation results were compared in the paper.
3. The chain segment will rearrange during annealing and releasing part of residual stress. Annealing treatment was carried out on part of PC samples, and the effects of annealing on the residual stress were studied.
本文以无定型聚合物聚碳酸酯(PC)为研究对象,进行实验分析。主要工作如下：
1.选用无定形聚合物聚碳酸酯为实验材料进行注塑实验。先将注塑制品制备为样条,然后对不同工艺条件下的试样进行剥层,测量剥层后的变形情况。根据采集到的数据进行相关的力学分析,将变形量转化为曲率,代入推导出的残余应力计算公式,计算出PC制品厚度方向各层平均残余应力,并分析不同注射压力、保压压力和模具温度条件下对残余应力的影响。
2.利用Moldflow对不同工艺条件下的残余应力进行分析,并根据模拟结果中厚度方向的残余应力计算各层平均残余应力,将模拟结果与计算结果进行对比分析。
3.退火处理会使聚合物一些链段重新排列组合,使原有的部分应力得以松弛。在本文中对部分试样进行退火处理,分析相同工艺条件下残余应力的变化。
Injection products are applied more and more widely for their high cost performance. But the complex heat history lead to the formation of residual stress in the injection molding process. The existence of residual stress will result in the craze, making the optical performance and impact strength of products decrease and affecting their application. The residual stress are generally caused by uneven flow and colling, called flow residual stress and thermal residual stress. Due to the thermal residual stress is one order of magnitude bigger than the flow residual stress, the thermal residual stress was studied in this paper.
Based on the amorphous polycarbonate (PC) as the research object, main work is as follows:
1. The PC splines were prepared by injection molding with different processing parameters, firstly. Then Layer removal method was carried out and the deformation was measured for all samples.With the mechanics analysis, the collected data of deformation were converted to curvature, then the values of residual stress along the thickness direction of PC samples were estimated using the derived residual stress formula. The effects of injection pressure, holding pressure and mold temperature on the residual stress were discussed respectively.
2. The residual stresses under different processing parameters were calculated using Moldflow technology. The mean value of residual stress of each layer were estimated. Then the experimental results and simulation results were compared in the paper.
3. The chain segment will rearrange during annealing and releasing part of residual stress. Annealing treatment was carried out on part of PC samples, and the effects of annealing on the residual stress were studied.
引文
[1]黄锐.塑料成型工艺学.第二版[M].北京：中国轻工业出版社,1997：145-146
[2]刘方辉,钱心远,张杰.注塑成型新技术的发展概况[J].塑料科技,2009,37(3)：83-88
[3]李明哲,方明磊,刘红.注塑工艺参数对塑料长尺残余应力的影响[J].浙江科技学院学报,2009,21(3)：213-216
[4]周大路.基于Moldflow Insight2010的残余应力优化分析[J].现代制造工程,2012,1：96-99
[5]郝如江.聚合物熔体粘弹参数拟合及注塑件残余应力研究[D].[硕士学位论文].郑州：郑州大学,2002
[6]G.Kamanayo, F.Trochu, and B.Sanschagrin. Prediction of shrinkage by dual kriging for injection molded polypropylene plaques[J]. Adv. Polym. Tech.,1994,13(4):305～314
[7]A.J.Pontes, M.J.Olivera, A.S.Pouzada. The effect of holding pressure on the shrinkage and birefringence of injection moulded polypropylene plates[J]. Mater. Sci. Forum,2004,23: 455～456
[8]V.leo and C.Cuvelliez. The effect of the packing parameters, gate geometry, and mold elasticity on the final dimensions of a molded part[J]. Polym. Eng. Sci.,1996,36(15): 1961～1971
[9]Marucci. Testing of a constitutive equation for entangled networks by elongational and shear data of polymer melts[J]. Rheol Acta,1973,12(2):269～275
[10]中华人民共和国国家质量监督检验检疫总局,中国国家标准化管理委员会.GB/T26140-2010.无损测量测量残余应力的中子衍射法[S].北京：中国质检出版社,2011
[11]郭志英,阮雪榆,李德群.注塑制品翘曲变形数值分析模型[J].中国机械工程,2002,13(17)：1515-1518
[12]奚国栋,周华民,李德群.注塑制品残余应力数值模拟的研究[J].中国机械工程,2007,18(17)：112-116
[13]刘芬,周华民,李德群.注射成形残余应力与翘曲变形的数值模拟[J].上海交通大学学报,2008,42(1)：61-66
[14]陈静波,中长雨,刘春太等.聚合物注射成型流动残余应力的数值分析[J].力学学报,2005,37(3)：272-278
[15]吴海宏,陈政,赵振峰等.纤维增强聚合物注塑残余应力的分析计算[J].郑州轻工业学院学报,2005,20(4)：9-11
[16]赵振峰,陈政,吴海宏等.ABS注塑制品的模内蠕变试验研究[J].实验力学,2006,21(8)：497-501
[17]中长雨,吴海宏,赵振峰.注塑制品内应力计算的非线性黏弹性本构方程[J].化工学报,2007,58(2)：490-494
[18]吴海宏,赵振峰,黄明等.聚合物注塑内应力和翘曲变形的数值模拟[J].高分子材料科学与工程,2007,23(6)：16-19
[19]吴海宏,赵振峰,中长雨.聚合物注塑成型内应力数值计算的非线性模型[J].材料科学与工艺,2008,16(1)：82-85
[20]吴海宏,赵振峰,申长雨.聚合物注塑内应力计算的蠕变模型[J].机械工程学报,2008,44(12)：221-225
[21]赵振峰,吴海宏,中长雨等.聚合物注塑内应力数值计算的黏弹性模型[J].中国机械工程,2008,19(10)：1250-1253
[22]吴海宏,冯兰芳,畅同晨等.精密注塑制品残余应力的试验研究及其计算[J].机械工程学报,2012,48(2)：115-120
[23]李阳,赵鹏,李德群.三维塑料注射成形热残余应力及收缩模拟[J].高分子材料科学与工程,2010,26(10)：159-162
[24]吴建军,马泽恩,甘忠等.注塑件残余应力计算及弯曲变形分析[J].机械科学与术,1996,15(13)：468-472
[25]徐千军,余寿文.高分子材料注塑固化阶段的残余应力分析[J].力学学报,1998,30(2)：157-160
[26]陈静波,中长雨等.聚合物注塑成型流动残余应力的数值分析[J].力学学报,2005,37(3),273-278
[27]奚国栋,周华民等.注塑工艺参数对制品残余应力和收缩的影响[J].化工学报,2007,1：248-254
[28]丁海.注塑过程后充填过程残余应力的数值模拟[D].[硕士学位论文].郑州：郑州大学,2007
[29]J.Greener, R.Kesel and B.Contestable. The birefringence problem in optical disk substrates: A modeling approach[J]. Adv. Inorg. Chem.,1989,35(3):449～458
[30]Marucci. Testing of a constitutive equation for entangled networks by elongational and shear data of polymer melts[J]. Rheol Acta,1973,12(2):269～275
[31]A.I.Isayev and C.A.Hieber. Toward a viscoelastic modeling of the injection molding of polymers[J]. Rheol Acta,1980,19:168～182
[32]F.P.T.Baaijens. Calculation of residual stresses in injection molded products[J]. Rheol Acta, 1991,30:284～299
[33]M.Flaman. Buildup and relaxation of molecular oriention in injection molding.Part 1:Formulation[J]. Polym. Eng. Sci.,1993,33(4):193-201
[34]H.Kim, S.J.Park, S.T.Chung etc. Numerical modeling of injection/compression molding for center-gated disk. Part 2:Effect of compression stage[J]. Polym. Eng. Sci.,1999,39(10): 1943-1952
[35]Boitout F, Agassant J F, Vincent hi. Elastic calculation of residual stresses in injection mold[J]. Inte. Polym. Proce.,1995,10(3):237～242
[36]M.R.Kamal, R.A.Lai-Fook and J.R.Hernandez-Aguilar. Residual thermal stresses in injection moldings of thermoplastics:a theoretical and experimental study[J]. Polym. Eng. Sci.,2002,42(5):1098～1114
[37]Kabanemi K K, Vaillancourt H, Salloum G. Residual stresses, shrinkage, and warpage of complex injection moulded products:numerical simulation and experimental validation [J]. Polym.Eng. Sci.,1998,38(1):21～28
[38]Shih-jung Liu. Modeling and simulation of thermally induced stress and warpage in injection molded thermoplastics[J]. Polym. Engi. Sci.,1996,36(6):807～818
[39]Kim H, Park SJ, Chung ST. Numerical modeling of injection/compression molding for center-gated disk. Part1:Injection molding with viscoelastic compressible fluidmodel [J]. Polym.Eng. Sci.,1999,39(10):1930～1942
[40]Sang Kyun kin, Seok Won Lee, Jae Ryoun. Measurement of residual stresses in injection molded short fiber composites considering anisotropy and modulus variation[J]. Rheol. J., 2002,14(3):107～114
[41]W.F.Zoetelief, L.F.A. Douven and A.J.I.Housz. Residual thermal stresses in injection molded products[J]. Polym. Eng. Sci.,1996,36(14):1886-1896
[42]B. Ekmekci, N.Ekmekci, A.E.Tekkaya etc. Residual stress measurement with layer removal method[J]. Proceedings Of the First Cappadocia International Mechanical Engineering Symposium,2004,14:123～131
[43]W.T.Read. Formulas for the determination of residual stress in wires by the layer removal method[J]. J.App.Phy.,1951,22(4):415-419
[44]Chea Hwan kim, Jea Ryoun Youn. Determination of residual stresses in injection-moulded flat plate:Simulation and experiments [J]. Polym.Test.,2007,26:862～1868
[45]M.P.I.M.Eijpe, P.C.Powell. Residual stress evaluation in composites using a modified layer removal method[J]. Compos. Struct.,1997,37:335～342
[46]吕恩年,李洪利,司丹丹.聚碳酸酯的生产、应用及前景展望[J].河南化工,2011,(28)：29-32
[47]袁发荣,伍尚礼.残余应力的测试与计算[M].湖南大学出版社,1987,295-298
[48]Isayev A I, Crouthamel D L. Residual stress development in the injection molding of polymers[J], Polym. Plast. Techonol. Eng.,1984,22(2):177～232
[49]奚国栋,周华民,李德群.注塑工艺参数对制品残余应力和收缩的影响[J].化工学报,2007,58(1)：248-254
[50]Jay Shoemaker著,傅建,姜勇道,赵国平泽Moldflow设计指南[M].成都：四川大学出版社,2010,44-45
[51]Isayev A.I ed. Injection and compression molding fundamentals [J]. Mater. Manufa. Processes,1994,9(5):1005～1006
[52]张于贤,王红.工艺参数对PC光学制品残余应力的影响[J].光学技术,2007,33：123-124
[53]ChanM F C F, Kee D D. Relation between stress growth and stress relaxation functions[J], Rheol. Acta.,1992,31(5):490～495
[54]王庆明,孙渊.残余应力测试技术的进展与动向[J].机电工程,2011,28(1)：11-16
[55]Giesekus H. A simple constitutive equation for polymer fluids based on the concept of deformation-dependent tensorial mobility[J]. J. Non-newtonian Fluid Mech.,1982,11 (2): 69～109
[56]Kwok C S, Tong L, White J R. Generation of large residual stresses in injection moldings[J]. Polym.Eng.Sci.,1996,36(5):651～656
[57]Liou M J, Suh N P.Reducing residual stresses in molded parts[J]. Polym.Eng.Sci.,1989, 29(7):441-447
[58]Wang T H, Young W B. Study on residual stresses of thin-walled injection molding[J]. Eur. Polym.J.,2005,41:2511～2517
[2]刘方辉,钱心远,张杰.注塑成型新技术的发展概况[J].塑料科技,2009,37(3)：83-88
[3]李明哲,方明磊,刘红.注塑工艺参数对塑料长尺残余应力的影响[J].浙江科技学院学报,2009,21(3)：213-216
[4]周大路.基于Moldflow Insight2010的残余应力优化分析[J].现代制造工程,2012,1：96-99
[5]郝如江.聚合物熔体粘弹参数拟合及注塑件残余应力研究[D].[硕士学位论文].郑州：郑州大学,2002
[6]G.Kamanayo, F.Trochu, and B.Sanschagrin. Prediction of shrinkage by dual kriging for injection molded polypropylene plaques[J]. Adv. Polym. Tech.,1994,13(4):305～314
[7]A.J.Pontes, M.J.Olivera, A.S.Pouzada. The effect of holding pressure on the shrinkage and birefringence of injection moulded polypropylene plates[J]. Mater. Sci. Forum,2004,23: 455～456
[8]V.leo and C.Cuvelliez. The effect of the packing parameters, gate geometry, and mold elasticity on the final dimensions of a molded part[J]. Polym. Eng. Sci.,1996,36(15): 1961～1971
[9]Marucci. Testing of a constitutive equation for entangled networks by elongational and shear data of polymer melts[J]. Rheol Acta,1973,12(2):269～275
[10]中华人民共和国国家质量监督检验检疫总局,中国国家标准化管理委员会.GB/T26140-2010.无损测量测量残余应力的中子衍射法[S].北京：中国质检出版社,2011
[11]郭志英,阮雪榆,李德群.注塑制品翘曲变形数值分析模型[J].中国机械工程,2002,13(17)：1515-1518
[12]奚国栋,周华民,李德群.注塑制品残余应力数值模拟的研究[J].中国机械工程,2007,18(17)：112-116
[13]刘芬,周华民,李德群.注射成形残余应力与翘曲变形的数值模拟[J].上海交通大学学报,2008,42(1)：61-66
[14]陈静波,中长雨,刘春太等.聚合物注射成型流动残余应力的数值分析[J].力学学报,2005,37(3)：272-278
[15]吴海宏,陈政,赵振峰等.纤维增强聚合物注塑残余应力的分析计算[J].郑州轻工业学院学报,2005,20(4)：9-11
[16]赵振峰,陈政,吴海宏等.ABS注塑制品的模内蠕变试验研究[J].实验力学,2006,21(8)：497-501
[17]中长雨,吴海宏,赵振峰.注塑制品内应力计算的非线性黏弹性本构方程[J].化工学报,2007,58(2)：490-494
[18]吴海宏,赵振峰,黄明等.聚合物注塑内应力和翘曲变形的数值模拟[J].高分子材料科学与工程,2007,23(6)：16-19
[19]吴海宏,赵振峰,中长雨.聚合物注塑成型内应力数值计算的非线性模型[J].材料科学与工艺,2008,16(1)：82-85
[20]吴海宏,赵振峰,申长雨.聚合物注塑内应力计算的蠕变模型[J].机械工程学报,2008,44(12)：221-225
[21]赵振峰,吴海宏,中长雨等.聚合物注塑内应力数值计算的黏弹性模型[J].中国机械工程,2008,19(10)：1250-1253
[22]吴海宏,冯兰芳,畅同晨等.精密注塑制品残余应力的试验研究及其计算[J].机械工程学报,2012,48(2)：115-120
[23]李阳,赵鹏,李德群.三维塑料注射成形热残余应力及收缩模拟[J].高分子材料科学与工程,2010,26(10)：159-162
[24]吴建军,马泽恩,甘忠等.注塑件残余应力计算及弯曲变形分析[J].机械科学与术,1996,15(13)：468-472
[25]徐千军,余寿文.高分子材料注塑固化阶段的残余应力分析[J].力学学报,1998,30(2)：157-160
[26]陈静波,中长雨等.聚合物注塑成型流动残余应力的数值分析[J].力学学报,2005,37(3),273-278
[27]奚国栋,周华民等.注塑工艺参数对制品残余应力和收缩的影响[J].化工学报,2007,1：248-254
[28]丁海.注塑过程后充填过程残余应力的数值模拟[D].[硕士学位论文].郑州：郑州大学,2007
[29]J.Greener, R.Kesel and B.Contestable. The birefringence problem in optical disk substrates: A modeling approach[J]. Adv. Inorg. Chem.,1989,35(3):449～458
[30]Marucci. Testing of a constitutive equation for entangled networks by elongational and shear data of polymer melts[J]. Rheol Acta,1973,12(2):269～275
[31]A.I.Isayev and C.A.Hieber. Toward a viscoelastic modeling of the injection molding of polymers[J]. Rheol Acta,1980,19:168～182
[32]F.P.T.Baaijens. Calculation of residual stresses in injection molded products[J]. Rheol Acta, 1991,30:284～299
[33]M.Flaman. Buildup and relaxation of molecular oriention in injection molding.Part 1:Formulation[J]. Polym. Eng. Sci.,1993,33(4):193-201
[34]H.Kim, S.J.Park, S.T.Chung etc. Numerical modeling of injection/compression molding for center-gated disk. Part 2:Effect of compression stage[J]. Polym. Eng. Sci.,1999,39(10): 1943-1952
[35]Boitout F, Agassant J F, Vincent hi. Elastic calculation of residual stresses in injection mold[J]. Inte. Polym. Proce.,1995,10(3):237～242
[36]M.R.Kamal, R.A.Lai-Fook and J.R.Hernandez-Aguilar. Residual thermal stresses in injection moldings of thermoplastics:a theoretical and experimental study[J]. Polym. Eng. Sci.,2002,42(5):1098～1114
[37]Kabanemi K K, Vaillancourt H, Salloum G. Residual stresses, shrinkage, and warpage of complex injection moulded products:numerical simulation and experimental validation [J]. Polym.Eng. Sci.,1998,38(1):21～28
[38]Shih-jung Liu. Modeling and simulation of thermally induced stress and warpage in injection molded thermoplastics[J]. Polym. Engi. Sci.,1996,36(6):807～818
[39]Kim H, Park SJ, Chung ST. Numerical modeling of injection/compression molding for center-gated disk. Part1:Injection molding with viscoelastic compressible fluidmodel [J]. Polym.Eng. Sci.,1999,39(10):1930～1942
[40]Sang Kyun kin, Seok Won Lee, Jae Ryoun. Measurement of residual stresses in injection molded short fiber composites considering anisotropy and modulus variation[J]. Rheol. J., 2002,14(3):107～114
[41]W.F.Zoetelief, L.F.A. Douven and A.J.I.Housz. Residual thermal stresses in injection molded products[J]. Polym. Eng. Sci.,1996,36(14):1886-1896
[42]B. Ekmekci, N.Ekmekci, A.E.Tekkaya etc. Residual stress measurement with layer removal method[J]. Proceedings Of the First Cappadocia International Mechanical Engineering Symposium,2004,14:123～131
[43]W.T.Read. Formulas for the determination of residual stress in wires by the layer removal method[J]. J.App.Phy.,1951,22(4):415-419
[44]Chea Hwan kim, Jea Ryoun Youn. Determination of residual stresses in injection-moulded flat plate:Simulation and experiments [J]. Polym.Test.,2007,26:862～1868
[45]M.P.I.M.Eijpe, P.C.Powell. Residual stress evaluation in composites using a modified layer removal method[J]. Compos. Struct.,1997,37:335～342
[46]吕恩年,李洪利,司丹丹.聚碳酸酯的生产、应用及前景展望[J].河南化工,2011,(28)：29-32
[47]袁发荣,伍尚礼.残余应力的测试与计算[M].湖南大学出版社,1987,295-298
[48]Isayev A I, Crouthamel D L. Residual stress development in the injection molding of polymers[J], Polym. Plast. Techonol. Eng.,1984,22(2):177～232
[49]奚国栋,周华民,李德群.注塑工艺参数对制品残余应力和收缩的影响[J].化工学报,2007,58(1)：248-254
[50]Jay Shoemaker著,傅建,姜勇道,赵国平泽Moldflow设计指南[M].成都：四川大学出版社,2010,44-45
[51]Isayev A.I ed. Injection and compression molding fundamentals [J]. Mater. Manufa. Processes,1994,9(5):1005～1006
[52]张于贤,王红.工艺参数对PC光学制品残余应力的影响[J].光学技术,2007,33：123-124
[53]ChanM F C F, Kee D D. Relation between stress growth and stress relaxation functions[J], Rheol. Acta.,1992,31(5):490～495
[54]王庆明,孙渊.残余应力测试技术的进展与动向[J].机电工程,2011,28(1)：11-16
[55]Giesekus H. A simple constitutive equation for polymer fluids based on the concept of deformation-dependent tensorial mobility[J]. J. Non-newtonian Fluid Mech.,1982,11 (2): 69～109
[56]Kwok C S, Tong L, White J R. Generation of large residual stresses in injection moldings[J]. Polym.Eng.Sci.,1996,36(5):651～656
[57]Liou M J, Suh N P.Reducing residual stresses in molded parts[J]. Polym.Eng.Sci.,1989, 29(7):441-447
[58]Wang T H, Young W B. Study on residual stresses of thin-walled injection molding[J]. Eur. Polym.J.,2005,41:2511～2517