带金属嵌件的手机外壳注塑成型翘曲变形分析

在Moldflow模拟分析的基础上,通过正交试验研究了熔体温度、模具温度、注射时间、保压压力、保压时闻和冷却时间等工艺参数对带金属嵌件的手机外壳注塑成型翘曲变形的影响,并优化了成型工艺.结果表明,保压时间和保压压力对翘曲变形的影响最大,最佳工艺组合为:熔体温度310℃,模具温度120℃,注射时间0.3 s,保压压力14...     

基于稳健设计的注塑成型工艺参数多目标优化

以某医用仪器盒下盖的翘曲变形和体积收缩为研究对象,结合稳健设计、均值分析,分别获得翘曲变形及体积收缩最小的最优工艺参数组合及影响趋势,运用综合加权评分法确定兼顾两目标最优的工艺参数组合为:熔体温度260℃,模具温度90℃,注射时间1 s,保压时间15 s,保压压力为注射压力的98%。结果使得优化后的翘曲变形减小了28.4%,体积收缩率降低了27.9%,对实际生产起到指导作用。     

基于AMI与正交试验的餐盘翘曲变形优化

针对塑料餐盘在注射成型过程中由于翘曲变形造成的中间凸起引起使用性能的缺陷,结合AMI注射成型分析软件和正交试验设计对餐盘的注射成型过程进行数值模拟,通过对试验结果数据的定量分析,系统分析了模具温度、熔体温度、注射速率、保压压力、保压时间、冷却时间等工艺参数对餐盘翘曲变形的影响规律和影响贡献率,从而得到最优的工艺参数组合,并模拟分析出最优工艺参数组合下的翘曲变形量。用数值模拟结果指导餐盘注射成型模具设计,并通过实际注射成型验证其明显改善了塑料餐盘的翘曲变形缺陷。     

汽车轮眉注塑成型工艺分析及优化设计

对汽车轮眉的注塑成型过程进行了模拟分析。首先通过有限元软件ANSYS对轮眉进行载荷分析,得到轮眉的应力分布图和形变分布图。然后利用Moldfl ow软件模拟轮眉的注塑成型过程,设计了两种注塑成型方案,分别进行流变、冷却和翘曲模拟,分析轮眉的填充、保压、收缩和变形等情况,选择最优的注塑成型方案。再采用正交试验法分析影响轮眉翘曲变形的因素,寻找可使轮眉翘曲变形量最小的最优参数组合。结果表明:轮眉应力集中的位置在外表面拐角处;最优的注塑成型方案为单浇口浇注;各因素对翘曲变形的影响程度为保压时间保压压力熔体温度模具温度注射时间;最优工艺参数组合为熔体温度250℃、模具温度40℃、注射时间2.5 s、保压时间10 s、保压压力90 MPa。最优工艺条件下,轮眉的最大翘曲量可降至0.774 mm。     

空调转接头的注塑工艺参数优化

以空调转接头塑料制品为例,结合正交实验,以翘曲量为评价指标,研究模具温度、熔体温度、保压压力、保压时间等注塑工艺参数对制品翘曲变形的影响,运用极差法对正交实验结果进行分析,得到各工艺参数对翘曲变形影响的主次程度,最终获得最优工艺参数组合,即模具温度60℃,熔体温度240℃,保压压力35 MPa,保压时间15 s,在此工艺组合下的翘曲量为0.092 1 mm。     

基于正交试验的PP车门内饰板注塑工艺参数优化

采用正交试验方法,利用Moldflow分析软件对汽车车门内饰板进行注塑成型模拟,分析了熔体温度、模具温度、注射时间、保压压力和保压时间等对注塑件翘曲变形的影响,找出了可以降低车门内饰板翘曲变形量的最佳工艺参数,并通过实际生产验证了所选工艺参数的正确性。当模具温度为35℃、保压时间为18 s、保压压力为60MPa、熔体温度为220℃、注射时间为7 s时,车门内饰板的翘曲变形量最小,Moldflow软件模拟出的最小值为8.33 mm;而采用优选工艺参数进行实际注塑得到的车门内饰板翘曲变形量为8.85 mm,与模拟结果基本吻合。     

基于Moldflow和正交试验法的塑料杯注塑工艺参数优化

以某一塑料杯为研究对象,采用正交试验法设计试验方案,使用Moldflow对其进行翘曲模拟分析。以熔体温度、模具温度、注射时间、保压时间、保压压力为试验因素,分析其对翘曲变形量的影响规律,旨在获取最小翘曲变形量,找到最优的工艺参数组合,再次模拟验证得到翘曲变形量为0.066 0 mm。通过分析,有效减小翘曲变形,并且发现5因素对翘曲变形影响程度为:保压时间熔体温度模具温度注射时间保压压力,进而提高了制品的尺寸精度和使用性能,为实际注塑工艺参数的设置提供了正确理论指导。     

基于Mold?ow和BP神经网络的汽车后视镜外壳注塑工艺优化

为解决汽车后视镜外壳的注塑翘曲缺陷问题,利用Moldflow对正交试验16组参数水平组合的成型过程进行模拟,得到各因素对翘曲变形量的影响程度,然后采用BP神经网络预测的方法得到最佳工艺参数组合为:模具温度70℃、熔体温度210℃、注射时间1.4 s、保压时间16 s及保压压力100 MPa。     

变模温注塑模瞬态温度场数值模拟与工艺优化

应用Autodesk三维有限元瞬态传热分析方法对变模温模具传热过程和模具与熔体之间的耦合传热进行了瞬态求解和数值模拟,获得了模具温度场的变化过程及分布规律。应用三维瞬态注塑模拟,结合正交试验设计,对变模温成型工艺参数进行了优化。数值模拟后获得的最优结果:热水温度150℃,熔体温度250℃,冷却时间4s,注射时间0.3s,保压时间2s,保压压力为注射压力的110%。最后对最佳工艺参数进行了数值模拟验证,获得的结果是最大翘曲变形量为0.180 mm。     

基于正交试验汽车前灯注塑工艺参数优化

以某厂汽车前灯为研究对象,采用正交试验法设计试验方案,使用Moldflow对其进行翘曲模拟分析,以保压压力、保压时间、注射时间、V/P(速度/压力)转换为试验因素,分析其对翘曲变形量的影响规律,旨在获取最小翘曲变形量,找到最优的工艺参数组合,再次模拟验证得到翘曲变形量为1.828 mm,通过分析,优化后的工艺参数组合有效减小了翘曲变形量,并且发现4因素对翘曲变形影响程度为:保压压力保压时间注射时间V/P(速度/压力)转换,进而提高了制品的使用性能,为实际注塑工艺参数的设置提供了正确理论指导。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997