基于CAE和DOE的注塑成型工艺多目标优化研究

结合注塑模拟分析软件Moldflow和正交试验法,对不同工艺条件下的塑件成型过程进行模拟分析,确定塑件制品品质评价指标为制品体积收缩率、表面缩痕指数和最大翘曲量,运用模糊数学中的综合评判法,建立主要成型工艺影响因素的多指标综合评价数学模型;通过对综合目标值的极差分析,确定熔体温度、模具温度、注射时间、保压压力、保压时间等工艺参数对综合目标值的影响程度的大小,绘制因素水平影响趋势图,分析得出最优的工艺参数组合方案,并对该工艺组合方案进行模拟验证。     

薄壁塑件注塑压缩成型多指标工艺参数的优化

基于Minitab软件建立6因素5水平的田口试验并与模糊数学中的综合评判法相结合,以电脑显示器外壳为研究对象,对不同工艺条件下的注塑压缩成型过程进行模拟分析,对塑件成型后的最大翘曲变形量、平均熔接线和平均体积收缩率等3个目标值进行综合评判。通过对综合评分进行极差分析,确定了模具温度、熔体温度、压缩力、压缩速度、压缩距离和压缩时间等对注塑压缩成型的影响程度,得出了最优注塑压缩成型工艺参数组合方案,并对该工艺参数组合方案进行了模拟验证。最终得出最优工艺参数:模具温度为75℃,熔体温度为260℃,压缩力为60 t,压缩速度为14 mm/s,压缩距离为1.5 mm,压缩时间为7 s。     

基于BP神经网络遗传算法的汽车塑件CAE优化分析

以汽车内饰中立柱本体注射成型为例,基于Moldflow中CAE分析基础上,对塑件注塑所需的成型工艺参数进行了仿真,并分析了塑件翘曲成因,给出了翘曲改善优化目标。结合注塑工艺规律,借助于Tugachi正交试验法、BP神经网络遗传算法、Matlab数值分析对塑件注射成型工艺参数协同进行优化,并对优化结果进行了CAE比对验证。结果表明:神经网络预测推荐的工艺参数能有效将翘曲结果控制在质量误差范围内,提出的优化设计方法能有效降低模具试模成本,改善塑件成型质量。     

基于BP神经网络的显示仪框注塑CAE优化分析

以汽车显示仪框的注塑成型为例,构建了该汽车塑件两种浇注方案的CAE分析模型,得到了最佳浇注方案,运用Moldflow软件对塑件的注塑成型工艺参数进行了仿真,并对塑件注塑过程中的翘曲、熔接痕、气穴等缺陷成因进行了分析,给出了质量改善优化目标,最后提出了一种新的结合Tugachi试验法、BP神经网络预测的注塑成型工艺寻优方法,并对寻优结果进行了CAE模流分析验证。结果表明:神经网络预测结果与CAE模流分析结果相近,运用Tugachi正交试验分析、BP神经网络、CAE模流分析相结合的方法,能获得较佳的注塑成型工艺参数,使汽车塑件的注塑质量得到明显改善。     

基于神经网络与正交试验的塑件翘曲变形优化

针对塑件在注塑成型过程中出现的翘曲变形过大的问题,采用了人工神经网络、正交试验和数值模拟三者结合的方法改进了注塑成型的工艺参数,优化塑件的翘曲变形。首先以正交试验得到的数据作为神经网络的训练样本,建立了输入、输出分别为成型工艺参数与塑件翘曲变形量的神经网络模型,并用样本验证模型的准确度,从而提高了成型工艺参数的选择效率。其次,采用验证过的神经网络模型代替CAE模拟仿真来获得塑件的翘曲变形量,结合正交试验法,改进了注塑成型工艺参数,得到了塑件的最佳成型工艺参数组合,使塑件的最大翘曲变形量降低了61%。最后,通过对塑件的实际制造证实了优化方案的正确性。     

基于正交试验法的吸尘器电机罩板注塑工艺优化设计

以吸尘器电机罩板为例,结合正交试验法和模流分析软件Moldflow,对不同注塑工艺条件下的罩板零件成型过程进行分析,确定塑件的翘曲量为塑件表面质量的评价指标。选定熔体温度、模具温度等工艺参数作为分析因子并合理取值,进行了CAE分析。对评价指标的分析结果进行极差分析,绘制各水平对评价指标的影响趋势图,最终得出优化的注塑工艺参数配置,并对该工艺参数配置下的成型过程进行了模拟对比分析。对塑件成型过程中出现的气穴、熔接痕等缺陷进行了分析,给出了缓解缺陷影响的措施。     

轿车手套箱箱体注塑成型CAE优化分析

分析了某轿车内饰手套箱箱体的结构特征,根据该塑件的结构特征进行了模塑成型工艺分析,为获得塑件最优成型方案,降低生产成本,通过Moldflow软件进行了塑件注塑成型CAE优化分析,对塑件的浇口位置、浇注系统、充填、保压、冷却时间及翘曲变形进行了优化,获得了塑件最佳注塑成型工艺参数,该CAE优化分析结果得到了实际验证,塑件成型质量良好,为同类汽车塑件成型的CAE优化分析提供有益参考。     

基于MPI和正交试验的翘曲变形研究

结合田口玄一博士提出的正交试验法,运用CAE模流分析软件对注塑成型过程进行模拟试验,得出各注射工艺参数与塑件翘曲变形之间的关系,获得比较理想的成型工艺参数。     

基于CAE的扶手后盖翘曲变形注塑参数优化设计

借助CAE技术,对塑件的注塑成型进行了流动分析,潜在的成型缺陷在于塑件注塑成型翘曲变形大,通过调整注塑成型工艺参数,先对料温和模温进行优化,获得了较好的翘曲优化效果,再通过保压工艺的参数优化,将翘曲变形控制在2.052 mm以下,有效地保证了塑件的成型效果。优化获得的最终注塑成型工艺为:模温60℃,料温240℃,保压控制为40 MPa-15 s,25 MPa-5 s,冷却时间28 s。实践表明:经CAE分析后,该塑件的外观质量、尺寸、装配性能等均满足生产要求,具有较好的参考价值。     

双色注塑成型工艺参数多目标优化

以某双色塑料扣为例,针对总翘曲变形量、第一射和第二射的平均体积收缩率等多个质量指标要求,运用正交试验法和综合评分法,通过Moldflow软件进行双色注塑模拟仿真,优化双色注塑成型工艺参数。建立5因素4水平的正交试验矩阵获得原始质量指标数据,并对其进行标准化处理和线性组合计算,得到综合得分值。经均值和极差分析,得到影响质量指标的显著因素和最优工艺参数组合。试验结果表明符合工艺参数的优化目标,为双色塑件成型提供了依据。     

聚乳酸荧光防伪纤维的耐酸碱性分析

选用L16(54)正交试验表,探讨了p H值、温度及处理时间三因素对聚乳酸荧光防伪纤维性能的影响。利用荧光光谱仪、荧光显微镜、纤维强度仪等测试仪器,分析了经酸碱处理的聚乳酸荧光防伪纤维的荧光性能和力学性能。方差分析结果表明:p H值、温度及处理时间对聚乳酸荧光防伪纤维的荧光强度的影响均不显著,纤维在荧光性能方面表现出良好的耐酸碱性和耐热性;聚乳酸荧光防伪纤维的力学性能受温度的影响显著,但p H值和处理时间对其影响不显著,随着温度的升高,聚乳酸荧光防伪纤维的断裂强度呈下降趋势。     

注射成型工艺参数对注塑制品翘曲变形的影响研究

采用Taguchi实验设计技术设计了L9(34)实验矩阵进行实验,运用标准变量分析技术分析了模具温度、熔体温度、注射速率、保压压力等工艺参数对注塑制品翘曲变形的影响,预测最小翘曲变形并优化工艺参数。研究表明,所选择的工艺参数对X、Y、Z方向上的翘曲变形有不同程度的影响。通过优化工艺参数,可使所需方向上的翘曲变形最小,进而提高注塑制品的质量。     

Optimization of mechanical strength of reinforced composites. 1. Study on the effect of reactive bismaleimide on the mechanical performance of CaCo3-filled polypropylene

The effect of 3-phenylene bismaleimide on the mechanical performance of an inorganic filler-based polypropylene composite was studied. The selection of processing temperature played a significant role in the preparation of such composites. A positive effect of the bismaleimide compound was obtained for a processing temperature above the decomposition temperature of bismaleimide. The chemical composition of the modified composite was correlated to its mechanical strength by experimentation involving a rotatable design. An interaction between polymer and CaCO₃ has been proposed based on ESCA analysis.     

Processing–structure–property relationships in poly(ethylene terephthalate) blown film

An investigation was undertaken to establish processing–structure–property relationships in poly(ethylene terephthalate) (PET) blown film. For the study, a commercial grade of PET was used to fabricate the film specimens by means of a tubular film blowing process. In this process, the stretch temperature was accurately controlled by an oven. The annealing treatment of the oriented specimens involved clamping the sample in an aluminum frame and then putting the clamped sample in an oven, controlled at a temperature between the glass transition temperature (70°C) and the melting point (255°C) of PET, for a specified annealing period. The structure of the blown film samples was characterized by density, bulk birefringence, flat plate wide-angle X-ray scattering, and pole figure analysis. The processing variables, namely, takeup ratio, blowup ratio, and stretch temperature were found to significantly affect the bulk birefringence and density of the oriented PET blown film samples. It was found that both the bulk birefringence and density of the specimens increased upon annealing at an elevated temperature. Both the crystalline and amorphous orientation functions were calculated from the data of bulk birefringence, density, and the pole figure analysis. Compared to the amorphous orientation functions, the crystalline orientation functions were found to be relatively insensitive to the processing variables. It was concluded that equibiaxially oriented PET films can be produced via a tubular film blowing process by judiciously controlling the processing and annealing conditions. It has also been observed that the tensile stress-at-break of equibiaxially oriented PET film increases with decreasing stretch temperature and increasing annealing temperature.     

注射成型工艺对制品收缩与翘曲的不同影响

以PP盒形制品为例,设计了一种测量方案使得收缩与翘曲可以独立度量,分别考察了这两者在不同工艺水平下的变化。使用单因素方差分析表确定熔体温度、保压压力等注射成型工艺参数对收缩与翘曲的影响程度,并以置信区间图示出各参数对收缩与翘曲的影响规律。通过对实验数据的总结发现,保压压力对收缩影响最为显著,而模具温度对翘曲影响最显著。制品收缩与翘曲随工艺参数变化呈3种不同特征：收缩与翘曲呈相反的变化趋势,提高注射速率或熔体温度,制品收缩率减小而翘曲增大;随保压压力升高收缩率单调减少而翘曲呈“U”形曲线变化;调整其他工艺参数,收缩与翘曲有相同的变化趋势。这些影响规律的总结为减小注射成型中塑料制品的收缩与翘曲提供依据。     

Effect of processing conditions on morphology and mechanical properties of injection-molded poly(l-lactic acid)

This work investigates the relationship among the processing, morphology, and the mechanical properties of injection-molded poly(L -lactic acid) (PLLA). Melt processing temperature, mold temperature, injection flow rate, and holding pressure were systematically changed following a design of experiments array. The thermomechanical environment imposed during processing was estimated by computer simulations for the mold-filling phase, which allows the calculation of shear stress, shear rate, and the thickness of frozen skin layer. The morphology was characterized by differential scanning calorimetry and hot recoverable strain measurements. The analysis of variance results of influence of processing factors on the morphology are in good agreement with the analysis of thermomechanical parameters on the morphology. The primary factor for inducing the crystallinity in PLLA product was the stress-induced crystallization, whereas the thermal induced crystallization had a little effect. The morphology–mechanical property relationships were established. The crystallinity developed during processing has little effect on elastic modulus, increases the yield strength, and severely decreases the elongation at break. The level of molecular orientation developed during processing has little effect on elastic modulus, but increases both the yield strength and the elongation at break. POLYM. ENG. SCI., 47:1141–1147, 2007. © 2007 Society of Plastics Engineers     

Untersuchung zur Vorhersage der Bindenahtfestigkeit in spritzgegossenen Formteilen

Weld lines in injection molded parts are often weak spots and should therefore be taken into account as early as possible when developing new parts. The influence of material, nozzle and mold temperature respectively injection speed on weld line strength was investigated. By obtaining the actual temperature in the weld line, the interrelated processing influences can be expressed by a common relation. Physical analysis shows that this is the molecular mobility, which in turn is dependent on temperature. It opens a route backed by experimental results to assess the weld line strength of different materials in dependence of the processing parameters.     

加工温度与助剂对聚碳酸亚丙酯热降解性影响

通过特性黏度法研究加工温度与助剂对聚碳酸亚丙酯(PPC)热降解性的影响,并采用凝胶渗透色谱法评价特性黏度法结果的可靠性。结果表明:PPC对温度敏感,温度升高,特性黏度变低,相对分子质量变低。当加工温度从120℃升高到160℃,PPC的特性黏度从2.16 dL/g下降到1.31 dL/g,继续升高到200℃时,特性黏度从1.31dL/g下降到1.18 dL/g,说明温度越高,PPC特性黏度越低,热降解加剧,在120—160℃下降解速率较在160—200℃下快。在加工温度为140℃时,PPC的特性黏度为1.62 dL/g,PPC/MAH和PPC/AO1010的特性黏度比PPC的特性黏度分别提高了0.65 dL/g和0.25 dL/g,说明封端剂MAH、热稳定剂AO1010的加入能抑制PPC的热降解,提高PPC的热稳定性。采用特性黏度法研究PPC热降解的方法是可行的,且经济、方便、快捷,是研究PPC热降解性、可实现在线分析的一种良好方法。     

橡胶冷喂料挤出机螺杆造型及工艺参数与挤出温度的数学模型

研究了螺杆造型（长径比，螺旋升角，螺槽深度，螺杆几何压缩比），挤出工艺（螺杆转速，机头口型）和胶料种类对橡胶冷喂料挤出机挤出温度的影响，并对各实验因素及实验结果做了统计分析，得出了他们之间的定量数学模型。     

Measurement of the adhesion of diamond films on tungsten and correlations with processing parameters

Adhesion between diamond films and tungsten substrates is reported as a function of the deposition processing parameters. Diamond films were grown by a hot filament method as a function of seven different processing parameters: substrate scratching prior to diamond deposition, substrate temperature, methane content of the input gas mixture, filament temperature, filament-substrate distance, system pressure, and total gas flow rate. Adhesion was measured by using a Sebastian Five A tensile pull tester. Testing was complicated by the non-uniformity of the film thickness, diamond quality, film cohesion, and surface preparation across the full substrate surface area. Various types of film failure mode were observed, which did not correlate with the film processing parameters. The measured adhesion values showed larger variations from point to point across the sample surface and from identically prepared samples than variations as a function of the film processing parameters. Weak correlations of adhesion with the processing parameters were found using statistical analysis of the results from multiple pulls on a large number of samples. The statistical results suggest that substrate preparation, gas flow rate, and gas pressure are the most important processing parameters affecting the film adhesion, while the temperature of the hot filament has little or no effect on the adhesion of the film. However, improvements in film processing and adhesion testing need to be made before true quantitative adhesion testing of high-quality diamond films can be accomplished.