双料注射外角撑制件的浇口位置选择

利用Moldflow软件对外角撑制件双料注射成型不同浇口位置方案中的制件界面结合与翘曲变形进行研究,以确定成型质量最佳的浇口位置组合.综合分析实验数据发现,材料A从制件主体直短边进浇和材料B从密封边中部进浇的方案最优;界面主体结构侧温度分布的不均匀可能导致不均匀的界面结合强度.     

基于RBF神经网络断路器注塑成型工艺优化

塑壳断路器一般通过注塑成型工艺制得。在注塑成型过程中，模具温度、熔体温度、保压压力以及保压时间均对制件的翘曲变形产生一定的影响。以模具温度、熔体温度、保压压力以及冷却时间作为研究参数，以翘曲变形量作为研究目标，采用最优拉丁超立方抽样法抽取合适的样本，建立RBF神经网络模型，结合遗传算法对制件的翘曲变形量进行优化，得到最佳的成型工艺参数组合。结果表明：四个因素的影响程度大小为模具温度>冷却时间>保压压力>熔体温度。当模具温度为50℃、熔体温度为250℃、保压压力为60 MPa以及冷却时间为10 s时，制件的翘曲变形量最小为2.307 7 mm，相较未优化前降低1.294 2 mm，制件成型质量得到明显改善。     

基于响应面传动器成型缺陷研究

传动器通过注塑成型工艺制得,其成型质量直接影响传动器的性能。在注塑成型工艺过程中,模具温度、熔体温度、保压压力以及冷却时间等工艺参数对制件的影响较显著,不合理的工艺参数导致制件出现较大的翘曲变形。通过建立响应面模型,以模具温度、熔体温度、保压压力以及冷却时间为响应参数,以制件的翘曲变形量为响应目标,优化一组最佳的成型工艺参数组合。结果表明：四个变量的影响程度分别为：模具温度>保压压力>冷却时间>熔体温度。当模具温度80℃、熔体温度180℃、保压压力90 MPa、冷却时间20 s,制件的翘曲变形量最小为1.955 mm,较未优化的翘曲变形量降低0.427 7 mm,有效地改善了制件的成型质量。     

专利文摘

一种自动检测与控制冷却时间的塑料注射装置 本发明的塑料注射装置包括超声检测装置和注射机，超声波在异质界面发生反射与透射，通过反射声波强度的变化推测塑料温度的变化，从而计算冷却时间；超声检测装置包括安装在模具表面的一个或多个超声探头，通过对超声反射信号的采集、处理和计算得到制件的最佳冷却时间；超声检测装置与注射机控制器相连，将计算获得的最佳冷却时间发送给注射机控制器，注射机控制器在生产过程中根据冷却时间进行冷却过程的控制。通过自动检测与控制冷却时间，提高注射机的生产效率（申请专利号：CN201310688281．X）。     

蒸汽加热变模温注射成型数值模拟与结果分析

采用Moldflow软件对变模温注射成型过程进行数值模拟。利用蒸汽加热和冷却水冷却的变模温注塑工艺,研究不同蒸汽加热时间下注塑位置处压力以及制件冷凝层的变化规律,同时分析了制件表面和模具型腔表面的热响应规律。结果表明,相比于传统注射成型工艺过程,变模温注射成型通过提高注塑充填过程中模具温度,使得制件冷凝层出现在充填阶段之后;随着模具加热时间从10、15、25 s增加到40 s,注塑位置处最大注射压力从87.0608、84.6064、79.6863 MPa减小到74.4342 MPa,大大提高了熔体注塑充填过程中的充填能力;通过不同的蒸汽加热时间,制件表面和模具型腔表面可以获得不同的温度值,同时通过模拟获得了传热系数对制件表面温度的影响。     

基于Moldflow电机外壳注塑成型质量分析

电机外壳一般通过注塑成型制得，对电机起保护作用。文章通过Moldflow软件对制件成型过程进行模流分析，以模具温度、熔体温度、保压压力以及冷却时间为响应变量，以制件的翘曲变形量为响应目标建立响应面模型，通过回归方程以及方差分析对制件的成型工艺参数进行优化。结果表明：当模具温度为70℃、熔体温度为220℃、保压压力为120 MPa、冷却时间为15 s时，制件的翘曲变形量最小为2.386 0 mm，较未优化前降低了1.732 3 mm。各因素对制件翘曲变形量的影响依次为：冷却时间>保压压力>熔体温度>模具温度。通过响应面法能够有效降低制件的翘曲变形量，为类似翘曲变形工艺参数优化提供参考。     

基于计算机数值模拟技术的汽车内饰面板注塑成型工艺优化

针对汽车内饰面板注塑成型翘曲变形问题,采用模流分析软件Moldflow对其进行成型过程分析,以模具温度、熔体温度、保压压力以及冷却时间为工艺变量,以制件的翘曲变形量为目标建立响应面模型,得出最佳的成型工艺参数组合。结果表明：当制件的模具温度为56℃、熔体温度为250℃、保压压力为120 MPa、冷却时间为21 s时,制件的最大翘曲变形量为2.305 mm,与未优化前相比降低1.105 mm。因素影响大小依次为：冷却时间>保压压力>模具温度>熔体温度。在最优工艺参数条件下,制件质量基本达到工业要求,制件整体成型质量较好。     

曲面薄板注塑成型翘曲数值模拟及优化

利用Moldflow的MPI/Warp分析模块对曲面薄板塑件注射成型冷却过程进行数值模拟,预测其成型后的翘曲变形.通过正交试验法对影响塑件翘曲变形的工艺参数进行优化,确定影响该塑件翘曲变形的主要因素为材料收缩性能,其次为模具温度、注射保压冷却时间和熔体温度,并给出工艺优化方案.所获得结果可以用于指导和优化实际生产工艺.     

基于Moldflow汽车内饰锁本体注射成型研究

通过Moldflow模流分析软件对汽车内饰锁本体注射成型过程进行模拟,获得了最佳浇口位置,分析了制件充填、流动、翘曲和冷却过程。根据制件内气穴分布情况和模具结构,合理确定了浇注系统。结果表明,在保压时间一定的情况下,随着恒压时间的延长,制件的总变形量具有最小值;制件的结构决定了制件的翘曲变形,大面积薄壁区冷却速度起主导作用,该处具有较大的翘曲变形;局部厚壁区体积收缩率较大,翘曲变形严重。     

影响注射成型冷却时间的因素分析

介绍了一种估算注射成型过程中冷却时间的数学公式，并用它和CAE软件一起，以一平面薄板为例，全面讨论了冷却管道和制品距离、不同塑料材料和不同制品厚度、开模温度、模具热传导率、冷却介质（水）初始温度对冷却时间的影响程度，得出最大的影响因素是制件的厚度，开模温度及冷却水温度。     

双料注射外角撑装饰板的浇口位置确定

以双料注射成型某轿车外角撑装饰板为例,综合考虑不同浇口位置组合对制件翘曲变形和界面结合力的影响,在Moldflow软件平台上,分析确定浇口位置的最佳组合.在评价界面结合强度时,采用界面区基体局部熔化层最大深度和熔化持续时间作为判断结合力的依据,这对于双料注射成型其它类似塑料件的界面结合强度判断具有一定借鉴意义.     

Adhesion control for injection overmolding of polypropylene with elastomeric ethylene copolymers

Two types of random semicrystalline copolymers (ethylene–octene and ethylene–butene) were overmolded on a core polypropylene. Maximum solid–liquid interface temperature achieved for the overmolding injection process is used as the key parameter for adhesion control. The main bonding process is shown to be a Rouse‐type fingering mechanism that develops in short time scales. Normalized peel tests were conducted on overmolded samples to measure the resulting polypropylene copolymers' bonding strength. All the ethylene random copolymers used for this study give good adhesion to polypropylene in overmolding processes, provided the right range of interface temperature is reached. Adhesion strength can be easily controlled for efficient debonding and recycling of used overmolded parts. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Sequential injection overmolding of an elastomeric ethylene‐octene copolymer on a polypropylene homopolymer core

A systematic approach was used to study and compare the bonding of an ethylene‐octene random copolymer and a low‐density polymer, injection molded over polypropylene homopolymer. Wide ranges of overmolding and cooling interface temperatures and packing pressures were explored. Standard peeling tests were conducted at room temperature on overmolded samples, to measure the bonding strength. Large differences were found for bonding strength for both ethylene‐based polymers, which are explained on a molecular basis. The analysis of the experimental results gives strong indications about the bonding mechanism and the temperatures and time scaleinvolved in the process. Simple, reliable rules to design the overmolding process parameters for these polymers pairs are developed. Polym. Eng. Sci. 44:2110–2116, 2004. © 2004 Society of Plastics Engineers.     

Bonding strength at solid-melt interface for polystyrene in a sequential two-staged injection molding process

The effects of processing parameters, such as melt temperature, mold temperature and cooling time, on the bonding strength of the interface in a sequential two-staged injection molding process were investigated both theoretically and experimentally. A theoretical bonding strength model, which accounts for the cooling profile through the thickness of the part and the interpenetration depth of polymer chains across the interface, was proposed. Under various mold and melt temperatures, experiments of sequential two-staged injection molding processes for polystyrene (PS) were also conducted to verify the validity of the model. Finally, an interrelationship between the average extent of reaching an effective interpenetration depth and the degree of bonding has been constructed. The model proposed in this research would be useful in the CAE analysis for a two-staged injection molding process in which distortions or even fractures might occur at the interface.     

厚透光灯片多次包胶注塑工艺与模具设计

探讨了大厚度注塑件的堆积注塑成型和多次包胶注塑成型工艺,结合聚甲基丙烯酸甲酯(PMMA)材料性能,拟定车灯透光片采用一次注塑、二次包胶的注塑成型工艺;并完成了带二套独立热流道系统、含3个热流道喷嘴、由具有旋转分度功能的顶出旋转机构组成、具有六工位的注塑模具设计。使用效果表明:采用多次包胶注塑成型工艺,可有效实现对外观质量要求较高、厚度大、成型时间长,用普通模具成型工艺难以完成的注塑产品的成型。     

A review of liquid silicone rubber injection molding: Process variables and process modeling

Liquid silicone rubber (LSR) is an elastomer molded into critical performance components for applications in medical, power, consumer, automotive, and aerospace applications. This article reviews process behavior, material modeling, and simulation of the (LSR) injection molding process. Each phase of the LSR injection molding process is discussed, including resin handling, plastication, injection, pack and hold, and curing; and factors affecting the molding process are reviewed. Processing behavior of LSR is marked by transient interactions between curing, shear rate, temperature, pressure, and tooling. Therefore, current LSR models for curing, viscosity, pressure, and temperature are discussed. Process dynamics and material modeling are combined in LSR injection molding simulations with applications in mold design, troubleshooting process-induced defects, and management of shear stress and non-uniform temperatures between LSR and substrates during overmolding. Finally, case studies using commercial simulation software are presented, which have shown cavity pressure and flow front advancement within 3% of experimental values. Optimization of LSR materials, data collection, model fitting, venting, and bonding remain areas of continued interest.     

Effect of process parameters on the adhesion strength in two‐component injection molding of thermoset rubbers and thermoplastics

Recently, a novel two‐component injection molding process has been developed for combining thermoplastics with thermoset rubbers. This process is of interest for example when thermoplastic parts include seals which are usually produced out of thermoset rubber. The present study evaluates the influence of different process parameters on the bond strength by means of a half factorial experimental design. The considered process parameters are the mold temperature at the interface, the injection temperature, the injection speed, the holding pressure, and the initial roughness of the thermoplastic part at the later interface. The study indicates a large influence of the mold temperature at the interface. Furthermore, the holding pressure only affects the adhesion strength when it is set too low or when the holding time is too short. The other process parameters have no significant effect on the adhesion strength. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46495.     

含字符按键的双色塑件的注塑模设计

根据双色按键塑件材质的结构特点及生产要求，设计了一套双色注塑模具。通过一次注射为塑件主体聚碳酸酯（PC）材质，针对塑件结构上设置的多处薄壁状骨位填充困难及注射压力过大的问题，模具采用细水口多点进胶的方式解决；二次注射为塑件外观面热塑性弹性体（TPE）软胶材质，优化设计的3点细水口通过滑块抽芯机构转后模垂直翻转搭底进胶的方式配合排气槽、排气针和排气镶件结构，解决外观表面无法进胶和TPE材质易困气产生流痕、气纹和结合线的问题；特殊的后模浮板结构解决了产品上字母R/e/o/a及中间环形圈封闭的孤岛进胶问题。经过实际生产验证，一次注射时完整的填充注射压力减少了16%，二次注射时未出现流痕、气纹和结合线不良，产品成型质量良好，模具设计达到实际生产的要求。     

计算机模拟的工艺参数及模具结构对双组分注塑PP/TPE结合强度的影响

针对于双组分注塑质量稳定性差的问题,以Ford C346发动机舱侧饰条制备为例,采用注塑级改性聚丙烯(PP)为硬料,热塑性弹性体(TPE)为软料,通过计算机辅助工程进行模流分析,设计生产工艺参数及模具的结构,通过拉伸强度测试验证了双组分注塑工艺参数和模具处理对软硬料结合强度的影响。结果表明,模具温度60℃,熔体温度210℃,注射速度20cm3/s和保压压力7 M Pa是双组分PP/TPE注射的最佳工艺条件;模具结构采用增加硬料和软料接触面的粗糙度、对硬料加固处理和圆弧过渡方式可明显改善PP/TPE结合强度。计算机分流模拟的结果与实践结果基本是相同的。