Multi-scale analysis of void evolution in large-section plastic mold steel during multi-directional forging

The void evolution of large-section plastic mold steel during multi-directional forging(MDF)was investigated using multiscale analysis.To simulate the forging process of the plastic mold steel(SDP1 steel)and realize micro-void reconstruction in a representative volume element(RVE),MDF experiment and void-characteristic evaluation of the SDP1 steel were carried out.Traditional upsetting and stretching forging(TUSF)and MDF were simulated to comparatively analyze the evolution of temperature,effective stress,and effective strain.By embedding RVE with a micro-void and using boundary condition by point tracking into the forging process,the single-void evolution in TUSF and MDF was studied.The effect of void orientation on single-void evolution was also investigated.The multi-scale analysis revealed the following results.(1)Compared with TUSF,MDF achieved a higher efficiency in void closure.(2)The closing efficiency of the void increased with the increase in angle h(the angle between the Z and long axes of the void).(3)The closing efficiency increased with the increase in the orientation angle during the forging process.On the basis of the important role of the main stress in each forging step on the void closure,an integral formula of the main stress was proposed.When main compressive-stress integration reached-0.4,the closed state of the void could be accurately determined.

IMPROVE THE KINETIC PERFORMANCE OF THE PUMP CONTROLLED CLAMPING UNIT IN PLASTIC INJECTION MOLDING MACHINE WITH ADAPTIVE CONTROL STRATEGY

The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment, The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.

Development of a plastic injection molding training system using Petri nets and virtual reality

In this study, Virtual Reality (VR)-based plastic injection molding training system (VPIMTS), which can be modeled as an integrated system with a task planning module, an intelligent instruction module, a simulation module, and virtual envi-ronment (VE) module, was developed. Presented in this paper are an architecture of VPIMTS, a practical knowledge modelling approach for modelling the training scenarios of the system by using Petri nets formalism and key techniques (FEM, injection molding procedure modelling) which have been developed independently. The utilization of the Petri net model realized the environment where the trainee can behave freely, and also made it possible to equip the system with the function of showing the next action of the trainee whenever he wants. The overall system is a powerful approach for highly improving the trainee’s comprehension and injection molding study-efficiency by building digital, intelligent, knowledgeable, and visual aids.

Computer Aided Alloy Design of High Performance Prehardened Mold Steel for Plastic

prehardened mold steel for plastic, Thermo-Calc ＆ DICTRA software package, machinability, heat treatment technology, free cutting phase.

Novel Plastic Encapsulation Holding Method for Automobile Glass Using Injection Molding Process

Glass positioning and holding is difficult in the process of injection molding encapsulation of automobile glass. A suction cup or soft resin is always introduced in this process. However,these materials cannot hold glass tightly,thus resulting in the unsteady quality of toughened glass and encapsulated plastic. To solve this problem,a novel holding method called magnetic high-pressure holding with twin bags is proposed to address the features of toughened glass and the encapsulation injection process. Firstly,a pair of permanent magnets is introduced as energy source,followed by the magnetization of a couple of magnetic particle bags. Contact between the single bag and the glass surface will enable the couple of magnetic particle bags to hold glass tightly and to self-adapt the freeform of the glass. Secondly, an experimental system with mechanical and control systems is designed. This system is controlled by the opening and closing force of the mold,which turns the magnetic field on or off to hold or loosen the glass. The magnetic field distributions are measured at important positions of the permanent magnets and in the magnetized particles in the experiments to determine the holding performance. Finally, the process of determining the parameters of the magnet and its attenuation is analyzed, including the minimum friction force between the glass and the particle bag during injection molding,the magnetic energy product and the magnetized filed distributions,and the re-checking method for these parameters. The theoretical analysis and the experimental result show that this flexible holding system may produce sufficient holding force,which not only protects glass but self-adapts the glass freeform as well. The production practice meets the technical requirements of injection molding with a defect-free surface,with no scratches and cracks on the glass and no slight glass movements in the mold cavity.

Computer aided design of free-machinability prehardened mold steel for plastic

In order to improve the machinability but not to impair other properties of the prehardened mold steel for plastic, the composition was designed by application of Thermo-Calc software package to regulate the type of non-metallic inclusion formed in the steel. The regulated non-metallic inclusion type was also observed by SEM and EDX. Then the machinability assessment of the steel with designed composition under different conditions was studied by the measurement of tool wear amount and cutting force. The results show that the composition of free cutting elements adding to mold steel for plastic can be optimized to obtain proper type of non-metallic inclusion in the aid of Thermo-Calc, compared with the large volume fraction of soft inclusion which is needed for promoting ductile fracture at low cutting speeds, the proper type of inclusion at high cutting speeds is glassy oxide inclusion. All those can be obtained in the present work.

基于Moldflow软件的塑料内饰件注射成型模拟

针对注塑件在实际生产中所产生的短射、气穴、翘曲、滞留、飞边及色差等问题,利用有限元理论,运用Moldflow软件对轿车塑料内饰件中央饰罩的3种浇注系统进行充型、熔接痕、翘曲分析的数值模拟,直观体现塑料在型腔内的变化过程.比较分析结果表明,选择充型均匀、平稳,熔接痕深度较浅,翘曲较小的浇注系统设计方案.

基于Moldflow的后盖CAE流动方案优化分析

以后盖为研究对象,阐述了产品的网格划分与MPI方案热流道的创建过程,介绍了MPI方案选材与基本成型条件,采用两种方案对产品的填充过程进行了模拟和分析,通过Moldflow软件对产品的变形和熔接痕进行了对比分析,最终选取方案2对产品成型进行优化分析,得到了一套切实可行的产品成型方案。研究表明,采用计算机辅助技术(CAE分析)对产品的成型优化具有较大的实用价值。

Moldflow软件在无绳电话机面板模具设计中的应用

在无绳电话机面板模具设计中,应用Moldflow软件分析了不同的浇口数量、位置及相应的保压压力、保压时间对制品的充模压力、熔接痕分布、翘曲变形量和缩痕缺陷等的影响。通过优化浇口数量、位置并辅助适宜的保压压力和保压时间,减少了注塑缺陷和制品变形,这对模具设计及注塑过程工艺参数的设定均有一定的实际意义。实践表明,Moldflow的分析结果与实际生产中通过试模所得到的方案非常相近,说明了Moldflow分析结果在塑料模具优化设计中具有很好的可靠性。

Moldflow软件在无绳电话机底盖模具设计中的应用

运用Moldflow软件,对无绳电话机底盖注塑成型过程的填充、保压、冷却进行模拟,详细分析了Moldflow软件在注塑模具优化设计中的应用。结果表明,Moldflow分析与实际生产中的成型工艺非常相近,其分析结果对塑料模具优化设计具有良好的指导作用。

基于Moldflow的薄壁注塑件成形工艺优化设计

基于Moldflow软件分析薄壁塑件的成形工艺,给出了通过调整模具温度、熔料温度、注射时间和注射压力等注塑工艺参数来实现成形工艺优化设计的方法,并得出了最佳成形工艺参数。

基于Moldflow的注塑件翘曲优化及影响因素分析

结合Taguch i试验设计方法和注塑模拟Moldflow分析软件,对不同工艺条件下的塑件成型过程进行模拟分析,以减小翘曲量为质量目标对工艺参数进行优化。采用方差分析方法(ANOVA),分析了模具温度、熔体温度、注射时间、保压压力,保压时间等工艺参数对塑件翘曲变形的影响,并通过绘制因素水平影响趋势图,分析得出最优的注塑参数组合方案,并对该工艺组合方案进行模拟验证。

基于UG和Moldflow的塑料外壳注塑模具设计与数控加工

以某塑料外壳为例,采用Moldflow软件进行注塑成型分析,得到了优化的浇注系统和冷却系统,并对塑件翘曲变形进行比较分析,获得了最优工艺参数。应用UG Moldwizard模块进行注塑模设计,并利用UG CAM模块对模具型腔进行数控加工工艺分析、生成刀路轨迹仿真并进行联机加工。该方法实现了模具CAD/CAE/CAM的一体化设计,缩短了开发周期,改善了塑件质量,对指导企业生产有一定的实用价值。

基于Moldflow的摩托车边盖浇口优化设计

浇口的设计对注塑成型的影响至关重要,CAE技术可以快速、准确的模拟出塑料熔体的整个充填过程,从而避免可能出现的设计缺陷,为模具的优化设计及生产提供可靠的参考。本文借助MoldF low软件分析了摩托车边盖注塑成型过程,并对浇口进行了优化设计。实验结果表明,合理的选择浇口的位置、数量以及尺寸等参数不仅能有效抑制欠注、气泡、翘曲、熔接痕等缺陷,还可以改善充填时间、型腔压力等,使实际生产更经济、高效。

基于Moldflow和DOE技术的翘曲变形工艺优化

文章采用CAE模拟软件Moldflow结合DOE试验技术对开关上盖进行填充、保压、冷却以及翘曲的模拟分析,研究模具温度、熔体温度、保压压力和保压时间等不同成型工艺参数对翘曲指标的影响,通过对试验结果运用极差和方差进行分析,在试验范围内获得最佳成型工艺参数组合。

基于Moldflow的双色成型数值分析及正交法优化

以双色塑料扣板为例,采用Moldflow软件成型窗口分析确定了第1色和第2色的最佳注射时间分别为0.733,0.537 s;使用型腔质量分析确定了第1色、第2色的最佳保压时间分别为7,8 s;采用田口正交试验确定了熔体温度、模具温度、保压压力等参数,最终得到了最佳的工艺参数组合为:成型的第1色、第2色熔体温度分别为295,230℃,模具温度分别为60,74℃,保压压力分别为最大注射压力的90%,80%。在此条件下成型的注塑料制品的翘曲变形量为1.975 mm,变形量较优化前(2.853 mm)降低31%,满足成型质量要求。

基于Moldflow的塑件注射成形模拟及其应用

介绍了基于Moldflow软件的CAE解决方案。通过实例详述了采用Moldflow软件对塑件的最佳浇口、填充、冷却、翘曲等注塑过程进行模拟分析。分析的结果能验证模具工艺的合理性,为模具的设计提供依据,同时大大缩短了产品的开发周期、降低了费用,具有显著的经济效益。

Moldflow在放大镜注塑件中的应用

提出了用Moldflow软件通过模拟来评估、改进、优化产品设计和制造参数。针对放大镜零件的成型工艺及产品性能应用Moldflow的MPI模块进行了分析。结果表明,通过塑料CAE模拟计算,可最大限度消除产品设计、模具设计及产品制造成型过程中可能出现的不足,取代传统的反复试模、修模等过程,从而降低产品制造成本,缩短产品开发周期。

基于Moldflow的模内装饰注射成型分析

介绍了模内装饰技术,以某一电子塑件为例,阐述了Moldflow软件模内装饰注射成型分析过程。通过与无薄膜塑件的分析比较,得出了模内装饰注射成型在充填、温度分布、翘曲等方面的特点,对模具设计和工艺有一定参考。

基于Plastic Advisor 7.0的注塑模具模流分析的研究与应用

分析了传统注塑模具设计方法中存在的不足,介绍了利用Pro/E Wildfire 4.0内建的Plastic Advisor 7.0软件进行模流分析的方法和技巧,并对风机盖塑件实例进行了详细的模流分析,指出了借助计算机辅助工程分析软件可大幅度提高注塑模具的设计效率、产品的合格率,缩短了产品的开发周期。