基于AcfiveX和MPI优化注射成型保压压力

运用ActiveX技术实现VB对MPI软件的有效控制,开发出优化注射成型保压压力的程序,自动为用户提供2种保压方式：先恒压后线性递减保压和先恒压后阶梯降压保压供用户选择。先恒压后线性递减保压方式较有利于提高塑件的表面质量。当注塑机不能很好实现保压压力线性递减或塑件壁厚变化较大时。则应采用先恒压后阶梯降压保压方式。确定保压方式后优化程序将根据MPI分析结果确定保压时间和保压压力,让用户能快速确定保压参数。     

Moldflow在汽车置物箱翘曲变形分析中的应用

利用Moldflow的MPI/Warp分析模块对汽车置物箱进行模拟,预测其成型后的翘曲变形,通过正交试验法对塑件成型工艺参数进行优化。结果表明:当材料为Teijin TN_3813BL PC+ABS,保压压力为注射压力的95%,模具温度65℃,熔体温度270℃时,塑件翘曲变形最小,影响塑件翘曲变形的主要因素为材料的性能,其次为熔体温度、保压压力和模具温度。     

保压工艺条件对塑件翘曲变形影响的研究

保压过程是注射成型一个非常重要的阶段,保压控制是否合理直接影响到塑件的成型质量。文章以手机电池壳为例,采用CAE数值方法实现了对保压过程的数值模拟仿真,研究了保压压力、保压时间及保压方式对塑件翘曲变形的影响,为优化塑件的成型质量提供理论根据,也充分表明了CAE数值模拟的方法在注射成型应用中的可靠性和实用性。     

U盘上盖的翘曲变形分析与工艺参数优化

以U盘上盖的注塑成型为实例,运用Taguchi试验设计法,结合信噪比(S/N)和变量分析方法(ANOVA),以减少塑件的翘曲量为目的,研究熔体温度、模具温度、保压压力和保压时间等工艺参数对塑件翘曲的影响,分析各工艺参数的影响程度,并优化成型工艺。结果表明:保压压力、熔体温度对塑件翘曲变形影响最大,优化后的塑件翘曲量降低了约16%。     

开关塑件注塑成型模拟与分析

为提高电钻开关塑件质量,运用CAE软件对塑件进行了填充、流动、冷却及翘曲等数值模拟。分析了注射压力、翘曲变形、熔接纹分布和气穴等情况,优化了保压压力、保压时间,以减小注射缺陷和塑件变形,为模具设计及注射过程工艺参数的设定提供了指导。     

降低塑料直尺残留应力的优化分析

针对塑料直尺注射成型容易产生翘曲变形的问题,对其注射成型过程进行了优化分析,以降低注射成型中塑件的模内残留应力,提高塑件质量。采用正交优化方法和Minitab统计分析软件,将塑件的模内残留应力作为优化目标、对成型过程中影响塑件模内残留应力的模具温度、熔体温度、注射速率、保压压力与注射压力比和保压时间等5个工艺参数进行了优化分析。在此基础上,选取熔体温度、注射速率和保压时间这3个对优化目标有显著影响的工艺参数进行了二次优化,得到最优组合。最后进行试验,验证了数值模拟的合理性和优化分析的有效性。     

科学成型方法在注射模成型中的应用

通过对科学成型的介绍,阐述了注射成型时如何确定注射速度、注射压力和保压压力;同时对注射浇口封闭及注射过程中的压力损失进行了阐述;在注塑机中设置模拟最佳工艺参数组合,生产出塑件符合质量要求,说明了科学成型法在优化注射工艺和提升塑件的综合质量提供了实用的经验。     

基于CAE技术的薄壁塑件注射成型分析与工艺优化

以某薄壁塑件面板注射成型为例,介绍应用Moldflow软件进行CAE分析的步骤,通过填充、流动、冷却和翘曲等数值模拟,分析注射压力、翘曲变形、熔接线分布和气穴等情况,优化保压压力、保压时间,以减小注射缺陷和塑件变形,结合分析结果指导模具设计及注射过程工艺参数的设定。     

大型LED前壳高光无痕模具设计及塑件变形控制研究

针对快速热循环高光注塑成型新技术,进行了大型LED电视机前壳高光模具结构设计和塑件变形规律研究,获得了优化的高光模具结构和减少变形的保压压力控制方法.经生产实践证明,采用优化的模具结构和注塑保压工艺参数,能够获得满足整机装配要求的高光塑件,可用于指导高光模具设计和注塑生产.     

薄壁塑件注射工艺参数的Taguchi方法优化

利用Moldflow软件,结合Taguchi法选择三因素(模具温度、熔体温度、保压方式)三水平对手机电池后盖的翘曲变形进行了研究。通过比较9种组合工艺的塑件翘曲变形量,得出了优化的工艺参数。优化后塑件的最小翘曲变形量为0.306 4 mm,比优化前降低了11.6%。从显著性检验看,熔体温度对零件的翘曲变形有显著影响,模具温度和保压方式对零件翘曲变形影响不显著。     

Relative influence of injection molding processing conditions on HDPE acetabular cups dimensional stability

The effects of processing conditions on the characteristics of injection-molded high density polyethylene (HDPE) acetabular cups for the total hip replacement implants have been studied. The study has been focused on the effects of filling rate (injection speed), packing pressure, packing time and hot nozzle temperature of the mold on the dimensional stability, weight variation and visual appearance of the acetabular cups. A considerable influence of these processing conditions on the weight and dimension variation was found. Information regarding cycle time duration was obtained through numerical simulation of the entire molding process using a commercial dedicated code Moldflow Plastics Insight 6.1 (Moldflow Corporation, 2007). Within the influencing process parameters studied, the packing pressure was found to be the most significant one affecting the part dimensions and weight. An increase in the injection speed (decrease in the injection time) had a negative effect on the weight and on the most of the part’s analyzed dimensions. The influence of the hot nozzle temperature and packing time was considered irrelevant, for the range of process parameters under analysis. For all the set-point variation tests, two singularities on the linear dimension variations were identified: anisotropic shrinkage in flow and normal to flow direction and a slight plastic expansion at the location around the hall furthest away from the injection point.     

A study of the effects of process parameters for injection molding on surface quality of optical lenses

The purpose of this study is to determine the effects of process parameters on optical quality of lenses during injection molding. The quality characteristics chosen are light transmission, surface waviness and surface finish. The Taguchi method is used to perform screening experiments to identify the important significant process parameters affecting quality of lenses. Through empirical and theoretical analysis, the most significant process parameters affecting surface waviness is the melt temperature, followed by mold temperature, injection pressure and packing pressure. On the other hand, injection molding process parameters are found to have little effect on light transmission and surface finish of lenses. Regression approach is then implemented based on surface waviness data from full factorial experiments to formulate the regression models. Three different regression methods are used, namely, linear, exponential and nonlinear regression. Verification experiments are executed to examine the accuracy of the regression model for predicting quality characteristics of lenses. The result showed the highest accuracy prediction of surface waviness was from a nonlinear regression model. An error of only 4.24% suggested the existence of a correlation among injection molding process parameters.     

Warpage of injection-molded thermoplastics parts: Numerical simulation and experimental validation

A mathematical model and the integrated simulation program for predicting part warpage, which arises during injection molding of thermoplastic polymers, were developed. To build the model, the finite element method (FEM) was used and the theory of shells, represented as an assembly of flat elements formed by combining the constant strain triangular element and the discrete Kirchhoff triangular element, was applied. This shell theory is well suited for thin injection molded products of complex shape. Furthermore, in this work, experimental research on flat plates was performed to study the effect of the plastic material, the mold structure, and certain key processing parameters on warpage. The investigated processing parameters include injection pressure, packing pressure, injection time, packing time, cooling time, and melting temperature. Different examples were presented to examine the developed simulation software, and results predicted from the simulation program were verified in the above experiments and showed reasonable accuracy compared with experiment data.     

用超细粉末注射成型金属微细结构的方法

研究了采用μPIM(超细粉末注射成型)成型316L型不锈钢微细结构的方法。采用2种不同的模具型腔在普通注塑机上注射成型,根据不同的型腔尺寸和原料特性确定合适的成型参数,这些参数包括:相关的模具温度、注射压力和保压压力等。结果显示,316L型不锈钢在成型100μm×200μm微细结构时可以成型,但是在成型60μm×191μm微细结构时会出现充模不足和脱模困难等问题。成型的制品完全可以成功脱模并烧结。     

注射工艺参数对微流控芯片成型影响实验研究

利用正交试验方法研究了各工艺参数（模具温度、冷却时间、保压时间及注射压力）对较大尺寸下的微流控芯片成型过程的影响。研究结果表明模具温度对芯片沟道成型起主要作用,冷却时间、保压时间及注射压力次之。该结论为深入开展微流控芯片成型研究提供了有益的借鉴。     

基于正交试验的气辅成型工艺优化

以加强筋为研究对象,对气辅成型中的熔体温度、熔体预注射量、气体注射压力、气体注射延迟时间、气体注射时间等影响气辅成型质量的主要参数进行数值模拟,并对影响塑件成型质量的相关工艺参数进行正交试验。先通过初步的五因素四水平L16(45)正交试验获得工艺参数的大致范围,然后在该基础上再进行改进的四因素三水平L9(34)正交试验,最终获得较好的工艺条件。     

注射模变形的数值计算与试验研究

在注射成型中,模具型芯、型腔的变形会影响塑件的尺寸精度,但现有的注射成型CAE软件都没有考虑模具的变形,在简化注射模结构的基础上,建立了受力模型,并实现了注射成型CAE软件与结构分析软件的集成。即将注射成型CAE充模分析所得的熔体压力场导入ANSYS,作为模具型芯、型腔的载荷,计算模具的变形量,试验验证了该方法的可行性和正确性。     

对高光无痕注射成型塑件翘曲变形的研究

针对快速热循环高光无痕注射成型技术的特点,分析了高光无痕注射工艺参数对液晶平板电视机前壳翘曲变形的影响规律,提出了减少塑件变形的保压压力控制方法。通过CAE分析和试验验证,获得了高光无痕注射工艺参数的优化组合。实践证明,采用优化后的高光无痕注射工艺参数,可以显著减少塑件的翘曲变形,满足整机的装配要求。