液压注塑机加热系统的分析与改进
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摘要
注塑成型是目前应用较为广泛的塑料加工方法,注塑机是注塑成型的主要加工设备。注塑机料筒温度是注塑工艺的重要参数,过低或过高的温度都会影响产品的最终质量,对料筒温度进行有效地控制是保证塑料制品成型质量和生产效率的重要环节。
热流道系统是塑胶模具和生产设备中的重要组成部分,其工作原理是在注射模内装上分流板及热嘴,利用加热和温度控制的原理,使模具的流道部分保持熔融状态,制品的浇口如同直接接触到注塑机的射嘴一样,那么成品在脱模时就不会拖着一条或多条胶口。
无论是注塑机料筒的加热系统还是热流道系统的加热环节,如果能解决好加热和温度控制的问题,对注塑机塑料制品的质量和生产效率都有质的提高。现在,注塑机采用的加热方法大多是在外部紧固几段加热圈,只是不同的机型加热圈的段数可能不同。目前,对于注塑机加热系统的改造,主要集中在控制策略和控制算法方面。但是,现如今注塑机的加热方式不论采用哪种方式,其根本都是通过热传导、热辐射来实现的,普遍存在加热慢、加热不均匀的问题。要从根本上解决这一问题,仅仅依靠控制策略和控制算法的优化是远远不够的。
微波加热拥有内外同热,加热迅速、均匀,热能利用率高,无污染,劳动条件好的优点。本文引入微波加热技术,对注塑机料加热系统的改造进行了理论分析。
由于注塑机料筒加热系统特别是加热环节比较简单,本文不作讨论。
本文主要研究内容如下:
首先,介绍了热流道系统,讨论了与热流道相关的技术以及热流道系统的能量损失,最后提出了热流道系统的优势和不足;
然后,介绍了微波加热技术的基本原理和基本关系式,给出了微波加热设备的基本构成和选择标准,并讨论了材料性能对微波加热的影响;
最后,给出了注塑机微波加热系统的结构框图,并对适用的微波加热方式进行了理论分析。最后,设计了一个微波加热器的温度控制系统,进一步完善了对注塑机加热系统的改造。
Injection molding is the method of plastic processing which is applied more extensive presently, injection molding machine is the primary equipment in the injection molding process. The barrel temperature of injection molding machine is the important parameter of injection molding technology, the higher or lower temperature will affect the product quality finally, and effective control of the barrel temperature is the important part to ensure the product quality and the production efficiency.
Hot runner system plays an important role in the plastic molds and the production equipments. Its working principle is that fitting the shunting plate and the heat spout on the injection mold, by means of the principle of heating and temperature control, keeps the segment of the mold's runner fusing, as if the gate of plastic is directly in contact with the heat spout of an injection molding machine, which will not lead to dragging one or several plastic sprue when final products demold.
Whether the barrel heating system of injection molding machine or the heating segment of hot runner system, if the problem of heating and temperature control can be solved, it will improve the quality and production efficiency of the plastic product. The major heating method of injection molding machine is that fixing some heating circles on the outside surface of the barrel, different models have different number of heating circle. Nowadays, the modification of the barrel heating system of injection molding machine basically focuses on control strategy and control algorithm. However, no matter what heating ways are used, the fundamental theory are thermal conduction and thermal radiation, the existing problems are slower and inhomogeneous heating. In order to solve this problem essentially, it is inadequate that only depending on the optimization of control strategy and control algorithm.
Microwave heating has a great deal of merit, such as simultaneous heating, rapid heating, homogeneous temperature distribution, higher utilization ratio of thermal energy, pollution-free and better labor condition. This article introduces microwave heating, puts up a theory analyses on the feasibility of the modification of injection molding machine heating system.
Because the barrel heating system of injection molding machine is more uncomplicated, it will not be discussed.
The main contents of the article as follows:
Firstly, introducing the hot runner system, discussing relevant technology and energy loss, lastly, putting forward the advantage and shortage of the hot runner system.
Secondly, introducing the principle and relational expression of the microwave heating technology, showing the fundamental structure and selection criterion of the microwave heating equipment, and discussing the material's nature effects on microwave heating.
Finally, giving the structure block diagram of microwave heating system of injection molding machine, analyzing the suitable microwave heating pattern. At last, designing a temperature control system of microwave heater, making further modification on heating system injection molding machine.
热流道系统是塑胶模具和生产设备中的重要组成部分,其工作原理是在注射模内装上分流板及热嘴,利用加热和温度控制的原理,使模具的流道部分保持熔融状态,制品的浇口如同直接接触到注塑机的射嘴一样,那么成品在脱模时就不会拖着一条或多条胶口。
无论是注塑机料筒的加热系统还是热流道系统的加热环节,如果能解决好加热和温度控制的问题,对注塑机塑料制品的质量和生产效率都有质的提高。现在,注塑机采用的加热方法大多是在外部紧固几段加热圈,只是不同的机型加热圈的段数可能不同。目前,对于注塑机加热系统的改造,主要集中在控制策略和控制算法方面。但是,现如今注塑机的加热方式不论采用哪种方式,其根本都是通过热传导、热辐射来实现的,普遍存在加热慢、加热不均匀的问题。要从根本上解决这一问题,仅仅依靠控制策略和控制算法的优化是远远不够的。
微波加热拥有内外同热,加热迅速、均匀,热能利用率高,无污染,劳动条件好的优点。本文引入微波加热技术,对注塑机料加热系统的改造进行了理论分析。
由于注塑机料筒加热系统特别是加热环节比较简单,本文不作讨论。
本文主要研究内容如下:
首先,介绍了热流道系统,讨论了与热流道相关的技术以及热流道系统的能量损失,最后提出了热流道系统的优势和不足;
然后,介绍了微波加热技术的基本原理和基本关系式,给出了微波加热设备的基本构成和选择标准,并讨论了材料性能对微波加热的影响;
最后,给出了注塑机微波加热系统的结构框图,并对适用的微波加热方式进行了理论分析。最后,设计了一个微波加热器的温度控制系统,进一步完善了对注塑机加热系统的改造。
Injection molding is the method of plastic processing which is applied more extensive presently, injection molding machine is the primary equipment in the injection molding process. The barrel temperature of injection molding machine is the important parameter of injection molding technology, the higher or lower temperature will affect the product quality finally, and effective control of the barrel temperature is the important part to ensure the product quality and the production efficiency.
Hot runner system plays an important role in the plastic molds and the production equipments. Its working principle is that fitting the shunting plate and the heat spout on the injection mold, by means of the principle of heating and temperature control, keeps the segment of the mold's runner fusing, as if the gate of plastic is directly in contact with the heat spout of an injection molding machine, which will not lead to dragging one or several plastic sprue when final products demold.
Whether the barrel heating system of injection molding machine or the heating segment of hot runner system, if the problem of heating and temperature control can be solved, it will improve the quality and production efficiency of the plastic product. The major heating method of injection molding machine is that fixing some heating circles on the outside surface of the barrel, different models have different number of heating circle. Nowadays, the modification of the barrel heating system of injection molding machine basically focuses on control strategy and control algorithm. However, no matter what heating ways are used, the fundamental theory are thermal conduction and thermal radiation, the existing problems are slower and inhomogeneous heating. In order to solve this problem essentially, it is inadequate that only depending on the optimization of control strategy and control algorithm.
Microwave heating has a great deal of merit, such as simultaneous heating, rapid heating, homogeneous temperature distribution, higher utilization ratio of thermal energy, pollution-free and better labor condition. This article introduces microwave heating, puts up a theory analyses on the feasibility of the modification of injection molding machine heating system.
Because the barrel heating system of injection molding machine is more uncomplicated, it will not be discussed.
The main contents of the article as follows:
Firstly, introducing the hot runner system, discussing relevant technology and energy loss, lastly, putting forward the advantage and shortage of the hot runner system.
Secondly, introducing the principle and relational expression of the microwave heating technology, showing the fundamental structure and selection criterion of the microwave heating equipment, and discussing the material's nature effects on microwave heating.
Finally, giving the structure block diagram of microwave heating system of injection molding machine, analyzing the suitable microwave heating pattern. At last, designing a temperature control system of microwave heater, making further modification on heating system injection molding machine.
引文
[1]王志新,张华,葛宜远.现代注塑机控制:微机及电液控制技术与工程应用[M].北京:中国轻工业出版社,2001,20-22
[2]A.R.A grawal,I.O.Pandeildis,M.Pecht.Injection-molding process control-A review[J].Polymer Engineering&Science,2004,27(18):1345-1357
[3]胡志鹏.我国塑料机械市场发展现状与趋势[J].工程塑料应用,2004,32(4):56-59
[4]王志新,张华,葛宜远.现代注塑机控制:微机及电液控制技术与工程应用[M].北京:中国轻工业出版社,2001,27-33
[5]钱泓.注塑机液压控制系统的发展-电液比例控制技术在注塑机中的应用[J].轻工机械,1999(1):56-59
[6]张友根.我国注塑机的特点及发展方向[J].上海塑料,2004(1):4-8
[7]Zhangbao Chen,Lih-sheng Turng.A review of current developments in process and quality control for injection molding[J].Advances in Polymer Technology,2005,24(3):165-182
[8]张克惠.塑料材料学[M].西安:西北工业大学出版社,2005
[9]许健南.塑料材料[M].北京:中国轻工业出版社,1999
[10]关越悟.塑料成型工艺学[M].轻工业出版社,1992
[11]饶利滨.浅析我国塑料机械行业的概况及发展方向[J].中国塑料,1995(4):10-16
[12]班旗,周煌煌.塑料件的高速自动化成型[J].工程塑料应用,1999(4):12-13
[13]王兴天.注塑技术与注塑机[M].化学工业出版社,2005
[14]张思农.上海塑料工业现状与展望[J].上海塑料,1999(1):2-4
[15]熊国中.国内外注塑机液压系统现状及其发展趋势-兼论二通插装比例控制技术在注塑机中的应用[J].塑料科技,1996(1):33-39
[16]钟汉如.注塑机控制系统[M].北京:化学工业出版社,2004
[17]邓惠芳.热流道技术在塑料容器注塑加工中的应用[J].食品与机械,2006(4):126-127
[18]王建华,徐佩弦.热流道系统的设计和喷嘴的选择[J].塑料制造,2006(5):31-36
[19][瑞典]丹尼尔·弗伦克勒,[波兰]亨里克·扎维斯托夫斯基著.[英国]罗伯特·沃克登英译.注射模具的热流道[M].徐佩弦译.北京:化学工业出版社,2005
[20]LongST.热流道新品.国外塑料,2005(1):56
[21]D.Frenkler,H.Zawistowski.Hot Runner in injection moulds[J].Rapra Technology Ltd.UK,2001
[22]Cang-Chin Yang,Sheng-Jye Hwang,Huei-Huang Lee,et al.Control of Hot Runner Type Micro Injection Molding Module[C].The 33rd Annual conference of the IEEE Industrial Electronics Society(IECON),2007,2928-2933
[23]金振江,刘廷华,王涛.热流道系统温度场的数值模拟[J].模具工业,2003(6):51-54
[24]陈剑玲,黄锐,刘廷华.浅析热流道模具中外加热式喷嘴的径向热传导问题[J].模具工业,2004(3):48-51
[25]徐佩弦,王建华.注射模热流道的传热损失和加热计算[J].模具工业,2005(2):41-42
[26]赵红玉.热流道的性价比优势[J].国外塑料,2006(4):55-56
[27]黎昱,周雄辉,胡炜,邱有华.热流道系统的应用[J].模具技术,2004(2):40-42+54
[28]钱鸿森.微波加热技术及应用[M].哈尔滨:黑龙江科学技术出版社,1985
[29]李绪益.电磁场与微波技术[M].广州:华南理工大学出版社,2002
[30]刘钟栋.微波技术在食品工业中的应用[M].北京:中国轻工业出版社,1998
[31]张永林.微波加热系统的组件功能与结构[J].武汉工业学院学报,1999(2):42-46
[32]Robert.V.Decareau.Microwave in the Food Processing Industry[J].New York.Academic press.Inc.1985
[33]Ratanadecho P,Aoki K,Akahori M.A Numerical and Experimental Investigation of the Modeling of Microwave Heating for Liquid Layers Using a Rectangular Wave Guide(Effects of Natural Convection and Dielectric Properties)[J].Applied Mathematical Modeling,2002,26(3):449-472
[34]Arne W.Fliflet,Member,IEEE,Ralph W.et al.Application of Microwave Heating to Ceramic Processing:Design and Initial Operation of a 2.45-GHz Single-Mode Furnace[J].Plasma Science,1996(3):1041-1049
[35]钟志雄.塑料注射成型技术[M].第2版.广东科技出版社,2005
[36]温耀贤.塑料注射成型技术[M].机械工业出版社,2007
[37]Lizhuang Ma,Dominique-Lynda Paul,Nick Pothecary,et al.Experimental Validation of a Combined Electromagnetic and Thermal FDTD Model of a Microwave Heating Process[J].IEEE Transactions on Microwave Theory and Techniques,1995(43):2565-2572
[38]WangYing,Jing Youhuang,Wei Aijun,et al.Numerical Model of Microwave Heating to Organic Reation[C].Computational Electromagnetics and its Applications,1999.Proceedings.(ICCEA 99)1999 International Conference on,1999:505-508
[39]R.Diehm,U.Pape,M.Nowottnick,et al.Low Temperature Processing of Highly Integrated Assemblies by Selective Microwave Heating[C].Eleetronies Systeminteqration Technology Conference,2006(1):608-611
[40]宋扶轮.热处理炉温度测量与控制[M].国防工业出版社,1984
[41]姜忠良,陈秀云.温度的测量与控制[M].北京:清华大学出版社,2005
[42]陶永华.新型PID控制及其应用[M].第2版.北京:机械工业出版社,2002
[2]A.R.A grawal,I.O.Pandeildis,M.Pecht.Injection-molding process control-A review[J].Polymer Engineering&Science,2004,27(18):1345-1357
[3]胡志鹏.我国塑料机械市场发展现状与趋势[J].工程塑料应用,2004,32(4):56-59
[4]王志新,张华,葛宜远.现代注塑机控制:微机及电液控制技术与工程应用[M].北京:中国轻工业出版社,2001,27-33
[5]钱泓.注塑机液压控制系统的发展-电液比例控制技术在注塑机中的应用[J].轻工机械,1999(1):56-59
[6]张友根.我国注塑机的特点及发展方向[J].上海塑料,2004(1):4-8
[7]Zhangbao Chen,Lih-sheng Turng.A review of current developments in process and quality control for injection molding[J].Advances in Polymer Technology,2005,24(3):165-182
[8]张克惠.塑料材料学[M].西安:西北工业大学出版社,2005
[9]许健南.塑料材料[M].北京:中国轻工业出版社,1999
[10]关越悟.塑料成型工艺学[M].轻工业出版社,1992
[11]饶利滨.浅析我国塑料机械行业的概况及发展方向[J].中国塑料,1995(4):10-16
[12]班旗,周煌煌.塑料件的高速自动化成型[J].工程塑料应用,1999(4):12-13
[13]王兴天.注塑技术与注塑机[M].化学工业出版社,2005
[14]张思农.上海塑料工业现状与展望[J].上海塑料,1999(1):2-4
[15]熊国中.国内外注塑机液压系统现状及其发展趋势-兼论二通插装比例控制技术在注塑机中的应用[J].塑料科技,1996(1):33-39
[16]钟汉如.注塑机控制系统[M].北京:化学工业出版社,2004
[17]邓惠芳.热流道技术在塑料容器注塑加工中的应用[J].食品与机械,2006(4):126-127
[18]王建华,徐佩弦.热流道系统的设计和喷嘴的选择[J].塑料制造,2006(5):31-36
[19][瑞典]丹尼尔·弗伦克勒,[波兰]亨里克·扎维斯托夫斯基著.[英国]罗伯特·沃克登英译.注射模具的热流道[M].徐佩弦译.北京:化学工业出版社,2005
[20]LongST.热流道新品.国外塑料,2005(1):56
[21]D.Frenkler,H.Zawistowski.Hot Runner in injection moulds[J].Rapra Technology Ltd.UK,2001
[22]Cang-Chin Yang,Sheng-Jye Hwang,Huei-Huang Lee,et al.Control of Hot Runner Type Micro Injection Molding Module[C].The 33rd Annual conference of the IEEE Industrial Electronics Society(IECON),2007,2928-2933
[23]金振江,刘廷华,王涛.热流道系统温度场的数值模拟[J].模具工业,2003(6):51-54
[24]陈剑玲,黄锐,刘廷华.浅析热流道模具中外加热式喷嘴的径向热传导问题[J].模具工业,2004(3):48-51
[25]徐佩弦,王建华.注射模热流道的传热损失和加热计算[J].模具工业,2005(2):41-42
[26]赵红玉.热流道的性价比优势[J].国外塑料,2006(4):55-56
[27]黎昱,周雄辉,胡炜,邱有华.热流道系统的应用[J].模具技术,2004(2):40-42+54
[28]钱鸿森.微波加热技术及应用[M].哈尔滨:黑龙江科学技术出版社,1985
[29]李绪益.电磁场与微波技术[M].广州:华南理工大学出版社,2002
[30]刘钟栋.微波技术在食品工业中的应用[M].北京:中国轻工业出版社,1998
[31]张永林.微波加热系统的组件功能与结构[J].武汉工业学院学报,1999(2):42-46
[32]Robert.V.Decareau.Microwave in the Food Processing Industry[J].New York.Academic press.Inc.1985
[33]Ratanadecho P,Aoki K,Akahori M.A Numerical and Experimental Investigation of the Modeling of Microwave Heating for Liquid Layers Using a Rectangular Wave Guide(Effects of Natural Convection and Dielectric Properties)[J].Applied Mathematical Modeling,2002,26(3):449-472
[34]Arne W.Fliflet,Member,IEEE,Ralph W.et al.Application of Microwave Heating to Ceramic Processing:Design and Initial Operation of a 2.45-GHz Single-Mode Furnace[J].Plasma Science,1996(3):1041-1049
[35]钟志雄.塑料注射成型技术[M].第2版.广东科技出版社,2005
[36]温耀贤.塑料注射成型技术[M].机械工业出版社,2007
[37]Lizhuang Ma,Dominique-Lynda Paul,Nick Pothecary,et al.Experimental Validation of a Combined Electromagnetic and Thermal FDTD Model of a Microwave Heating Process[J].IEEE Transactions on Microwave Theory and Techniques,1995(43):2565-2572
[38]WangYing,Jing Youhuang,Wei Aijun,et al.Numerical Model of Microwave Heating to Organic Reation[C].Computational Electromagnetics and its Applications,1999.Proceedings.(ICCEA 99)1999 International Conference on,1999:505-508
[39]R.Diehm,U.Pape,M.Nowottnick,et al.Low Temperature Processing of Highly Integrated Assemblies by Selective Microwave Heating[C].Eleetronies Systeminteqration Technology Conference,2006(1):608-611
[40]宋扶轮.热处理炉温度测量与控制[M].国防工业出版社,1984
[41]姜忠良,陈秀云.温度的测量与控制[M].北京:清华大学出版社,2005
[42]陶永华.新型PID控制及其应用[M].第2版.北京:机械工业出版社,2002