精密注塑模具的注塑成型模拟

在精密注塑模具设计过程中应用计算机辅助分析的方法模拟注塑成型过程,对保证注塑成型产品的质量,提高生产率有极大的优越性。利用MoldflowPlasticInsight(MPI)软件对精密注塑模具的注塑成型过程进行了模拟,分别介绍了注塑参数、浇注系统和冷却系统的设计过程,比较了两套不同设计方案的注塑成型模拟结果。并对影响翘曲变形的各个因素进行了详细的分析。     

Optimization of conformal cooling channels with array of baffles for plastic injection mold

Cooling system has an important role in the injection molding process in terms of not only productivity and quality, but also mold-making cost. In this paper, a conformal cooling channel with an array of baffles is proposed for obtaining uniform cooling over the entire free-form surface of molded parts. A new algorithm for calculating temperature distribution through molding thickness, mold surface temperature and cooling time was presented. The relation among cooling channels’ configuration, process parameters, mold material, molding thickness and temperature distribution in the mold for a given polymer is expressed by a system of approximate equations. This relation was established by the design of experiment and response surface methodology based on an adequate physical-mathematical model, finite difference method and numerical simulation. By applying this approximate mathematical relation, the optimization process for obtaining target mold temperature, uniform temperature distribution and minimizing the cooling time becomes more effective. Two case studies were carried out to test and validate the proposed method. The results show that present approach improves the cooling performance and facilitates the mold design process in comparison to the trial-and-error simulation-based method.     

MoldflowXpress模块在SolidWorks零件结构及模具设计中的应用

MoldflowXpress可根据零件的几何形状、材料、浇注位置进行模拟注射而得出分析结果,演示零件在模具型腔内能否完全填充,智能化地提供塑料零件注射模具制造可行性的建议。这一功能可以使用户通过逼真的动态模拟分析直观了解塑料注入模腔时的流动情况,合理选择模具的注塑位置和塑件的壁厚,优化模具设计及注塑条件的参数设置,提高生产效率,降低零件生产成本。     

Study of injection molding process simulation and mold design of automotive back door panel

Numerical simulation of the injection molding process of the outer panel of the automotive plastic rear door and mold design is presented here. Computer aided three-dimensional interactive application (CATIA) is employed to design the original automotive steel structure, and the modal and thermodynamic properties of the plastic back door outer panel are changed by changing the different injection materials of the back door outer panel. In order to efficiently design the panels, finite element analysis is used to verify whether the designed parts meet the mechanical properties requirements such as light weight, low fuel consumption, short production cycle, strong modeling design, high corrosion resistance and good recovery, the above main parameters have been evaluated, and the above main parameters are carried out evaluate. To simulate the injection molding process, computer aided engineering (CAE) software such as ANSYS and HyperWorks are used to analyze the back door of the selected material. After the numerical analysis, suitable material is selected, so that the modal and thermodynamic properties of the product could be satisfied as well as improved. Unigraphics NX (UG) is employed to design the convex and concave mold for the injection molding of the automobile’s plastic back door panel. Combined with the characteristics of the parts and the design requirements of the injection mold, the multi-scheme design of the pouring and cooling system is carried out. By comparing the effects of different gating and cooling systems on injection molding, the best gating and cooling system is selected. The artificial fish swarm algorithm is used to optimize the process parameters of the injection molding process, and the best combination of the injection molding process parameters of the outer panel of the rear door of the automobile is obtained.

     

纳米压印复合软模具建模研究

基于复合软模具纳米压印是一种高效、低成本和批量化制造大面积微纳米结构的新方法,已经被看作是最具有工业化应用前景的微纳制造技术。大尺寸复合软模具的设计和制造是当前大面积纳米压印所面临的一项挑战性难题,也是影响和制约晶圆级微纳米压印广泛工业化应用的技术瓶颈。开展了大面积纳米压印复合软模具理论分析、数值模拟和试验验证的系统研究。基于薄板弯曲理论,建立复合软模具变形理论模型。利用ABAQUS模拟软件,揭示了模具几何特征、材料属性以及压印工艺要素对于复合软模具变形的影响及其规律。提出纳米压印复合软模具设计的基本准则。该研究为大面积纳米压印复合软模具设计、优化和制造奠定了重要理论基础,并为大面积纳米压印装备开发和工艺优化提供方向性指导。     

Optimization of injection molding process parameters using integrated artificial neural network model and expected improvement function method

In this study, an adaptive optimization method based on artificial neural network model is proposed to optimize the injection molding process. The optimization process aims at minimizing the warpage of the injection molding parts in which process parameters are design variables. Moldflow Plastic Insight software is used to analyze the warpage of the injection molding parts. The mold temperature, melt temperature, injection time, packing pressure, packing time, and cooling time are regarded as process parameters. A combination of artificial neural network and design of experiment (DOE) method is used to build an approximate function relationship between warpage and the process parameters, replacing the expensive simulation analysis in the optimization iterations. The adaptive process is implemented by expected improvement which is an infilling sampling criterion. Although the DOE size is small, this criterion can balance local and global search and tend to the global optimal solution. As examples, a cellular phone cover and a scanner are investigated. The results show that the proposed adaptive optimization method can effectively reduce the warpage of the injection molding parts.     

电弧喷涂模具材料性能研究

通过计算不同材料的电弧喷涂层与光敏树脂模型表面之间的剪切应力,选择低熔点、低收缩率的Ｚｎ、Ａｌ作为电弧喷涂制模材料。针对涂层硬度低、疏松等不足,增加了喷砂强化工序;尝试以合金强化机理提高模具材料强度、硬度,制备了Ｚｎ－Ａｌ伪合金涂层。计算与实验结果表明,Ｆｅ、Ｃｕ等高熔点材料用作电弧喷涂模具材料存在开裂、起皮等缺陷;喷砂强化可有效地提高Ａｌ涂层的强度、硬度;Ｚｎ－Ａｌ伪合金涂层制备简单,是一种有优     

基于Pro/E的扣板模具设计与制造

文章叙述了扣板塑件的注射成型工艺分析,扣板模具的Pro/E模具设计、模具的虚拟装配干涉检测,模具零件加工工艺分析,复杂模具零件的数控加工程序的自动生成、加工仿真等。     

气体辅助注射成型CAE分析前处理技术

介绍了三维实体流动模型的分析技术 ,指出了在进行 3D气体辅助注射成型 CAE中所采用的面网格分析及中面生成技术是目前薄壁注塑件流动模拟中适应性强 ,数值收敛性好 ,且能满足 CAE快速分析的关键技术。从此技术得到的 Shell和 Beam单元是进行气辅注射成型 CAE前处理 ,并进行准确预测分析的重要过程和方法。     

鼠标注射模的结构设计

针对全塑料鼠标的注塑模设计,对零件结构进行了工艺分析。确定了分型面、浇注系统等,选择了注射机,计算了成型零部件的尺寸。采用点浇口,利用直导柱导向及推杆顶料方式,对模具的材料进行了选择。如此设计出的结构可确保模具工作运用可靠。     

A CAD/CAE-integrated injection mold design system for plastic products

Mold design is a knowledge-intensive process. This paper describes a knowledge-based oriented, parametric, modular and feature-based integrated computer-aided design/computer-aided engineering (CAD/CAE) system for mold design. Development of CAx systems for numerical simulation of plastic injection molding and mold design has opened new possibilities of product analysis during the mold design. The proposed system integrates Pro/ENGINEER system with the specially developed module for the calculation of injection molding parameters, mold design, and selection of mold elements. The system interface uses parametric and CAD/CAE feature-based database to streamline the process of design, editing, and reviewing. Also presented are general structure and part of output results from the proposed CAD/CAE-integrated injection mold design system.     

超薄塑件注塑成形特性的试验研究与数值模拟

薄壁注塑成形技术具有节约材料、降低成本、减少制品重量和外形尺寸等优点,可促进移动电话等电子产品的迅速发展,特别是超薄塑件的注塑成形技术在微机电领域具有巨大的应用潜力。但随着制品厚度的减小也使注射成形难度加大,填充过程更为复杂,成形特性有待探索。设计制造出可成形超薄塑件的模具,利用正交试验方法(田口方法)进行充模试验和数值模拟技术研究各工艺参数(注射速度、注射压力、熔体温度、注射量和制品厚度等)对超薄塑件注塑成形充模过程的影响。研究结果表明,制品厚度对超薄塑件的填充起决定性作用;注射量及注射速度对超薄塑件注塑成形的填充起主导作用,提高注射速度能大幅度地提高填充率;熔体温度和注射压力相对于注射量和注射速度只起次要作用,但在填充过程中,高的熔体温度和注射压力也是必要的。     

Interference verification of injection molds on the web-based CAD viewer

As the interference between mold parts occurs in a small region, it is difficult to find the interference at the design stage. It is usually found at the assembly stage of injection molds, which delays both design and manufacturing leadtimes. Commercial CAD systems with interference inspection functions have been used so far. However, they are very expensive for the mold industry, and inadequate for performing collaborative work over the Internet. An interference examination system executable on a lower cost CAD viewer is required before releasing final drawings in the mold industry. In this paper, an interference examination algorithm for the Web-based interference verification system applicable to a single-level assembly is studied for injection mold design processes. To design a collaborative system executable on the Internet, a lightweight CAD file converted from a CAD data is used as a native file of the CAD viewer with interference verification capability. The validity of the developed system is confirmed through case studies.     

Optimal injection molding conditions considering the core shift for a plastic battery case with thin and deep walls

The objective of this paper is to examine the influence of injection molding parameters on the core shift to obtain the optimal injection molding conditions of a plastic battery case with thin and deep walls using numerical analyses and experiments. Unlike conventional injection molding analysis, the flexible parts of the mold were represented by 3-D tetrahedron meshes to consider the core shift in the numerical analysis. The design of experiments (DOE) was used to estimate the proper molding conditions that minimize the core shift and a dominant parameter. The results of the DOE showed that the dominant parameter is the injection pressure, and the core shift decreases when the injection pressure decreases. In addition, it was shown that the initial mold temperature and the injection time hardly affect the core shift. The results of the experiments showed that products without warpage are manufactured when the injection pressure is nearly 32 MPa. Comparing the results of the analyses with those of the experiments, optimal injection molding conditions were determined. In addition, it was shown that the core shift should be considered to simulate the injection molding process of a plastic battery case with thin and deep walls.     

玻璃精密模压成形的研究进展

玻璃精密模压成形是一种高效率、绿色环保的先进光学元件制造技术,近年来得到了飞速发展。本文首先介绍了光学元件的需求与种类,提出玻璃精密模压成形技术存在的问题。综述了国内外近年来精密模压成形光学透镜的重要研究进展,其中包括光学玻璃材料、模具材料与涂层、模具加工、模压过程仿真以及各种参数对透镜质量的影响。阐述了光学模压成形元件的坯料、镀膜技术和冷加工技术、成形元件的残余应力分布以及折射率、模具与玻璃间摩擦效应、模具的补偿技术、成形透镜质量的预测、模压技术的其他应用等。最后,对未来光学玻璃精密模压成形趋势进行了预测。     

Integrated numerical analysis to evaluate replication characteristics of micro channels in a locally heated mold by selective induction

High-frequency induction heating is an efficient way to heat mold surfaces by electromagnetic induction using a non-contact procedure. Due to its ability to rapidly heat and cool mold surfaces, this method has been applied recently to the injection molding of micro/nano structures. The present study investigates a localized heating method involving the selective use of mold materials to enhance the heating efficiency of high-frequency induction heating. A composite injection mold consisting of ferromagnetic material and paramagnetic material was used for localized induction heating. The feasibility of this localized heating method was investigated through numerical analyses in terms of its heating efficiency for localized mold surfaces and the resulting flow characteristics in micro channels. To take into account the effects of thermal boundary conditions of localized induction heating, a fully integrated numerical analysis effectively connecting electromagnetic field calculation, heat transfer analysis, and injection molding simulation was carried out. The proposed integrated simulation was applied to the injection molding of a rectangular strip containing micro channels, and the resulting mold heating capacity and replication characteristics of the micro channels were compared with experimental findings in order to verify the validity of the proposed simulation.     

基于Moldflow的薄壁件翘曲变形研究

翘曲变形是注塑件的主要缺陷,利用电器后盖对薄壁成型工艺进行研究。采用Moldflow软件对塑件成型过程进行数值模拟,研究了保压压力、塑件材料对注塑件翘曲变形的影响。对薄壁注塑件的数值仿真模拟结果进行统计分析,并且对影响注塑翘曲变形量的工艺参数进行综合分析,得到最优的工艺参数组合。研究结果表明:最佳的工艺参数组合可以使得塑件翘曲量变得最小。     

A virtual injection molding system based on numerical simulation

CAD and CAE have now become very popular in injection molding development. Integration with virtual reality is a new boost to these fields. This paper presents a research effort targeting the creation of a desktop-based, low-cost and independent virtual injection molding system, which is implemented based on the techniques such as virtual reality, finite element analysis, motion simulation and scientific visualization. With the stereoscopic display of the mold design and motion, the system provides engineers a cohesive view of mold structure and assembly. And by analyzing the numerical CAE results, the possible faults during molding process can also be highlighted. With this integration, the overall system would be a new powerful tool to mimic the real process of injection molding and evaluate various influences from product design to manufacturing, capable, therefore, of improving the moldability and the quality of molded products.     

热压罐成型框架式模具温度场分析

模具成型型面的温度均匀性对复合材料制件的成型精度具有重要影响。某大尺寸高平面度复合材料蜂窝夹层板构件利用热压罐工艺成型,模具为大型框架结构模具。文中采用有限元数值模拟方法,利用Simcenter12.0 软件对该大型框架结构模具热压罐成型工艺过程的温度场特性进行了模拟分析,模拟值与试验值误差小于10%,证明了模拟方法的准确性。模拟结果表明：成型固化工艺参数设置合理,模具型面温度均匀性较好,金属边框对模具的整体温度场影响较大;模具在热压罐内的位置在所设定的2.1 m 范围内沿长度方向移动对模具温度场的影响可以忽略。     

Experimental-based optimization of polymer injection molding process parameters using anfis-ga method

Compared with ordinary injection-molded parts, the slender, cantilevered, and thin-walled plastic parts are harsh on the injection molding process conditions. For complexity and particularity, it is difficult to form such parts. It is also more likely to cause excessive warpage deformation, affecting the molding quality and performance. The automobile audio shell is a typical slender, cantilevered, thin-walled plastic part. When the mold structure and material are determined, optimizing its injection molding process is the most economical and effective method to manufacture the products with the optimum properties. In order to minimize the warpage deformation, the adaptive network based fuzzy inference system (ANFIS) and genetic algorithm (GA) were adopted to optimize the injection molding process parameters. In particular, considering the high-dimensional nonlinear relationship between the process parameters and the warpage, the ANFIS is constructed as the prediction model of the warpage. Then, the GA is used to globally optimize the prediction model to determine the optimal process parameters. The results show that the optimization method based on ANFIS-GA has a good performance. The warpage is reduced to 0.0925 mm while reduced by 88.25 %. The optimal injection molding process parameters are used for simulation and manufacture, verifying the effectiveness and reliability of the optimization method.