注射模具调温系统设计

模具温度(模温)指模具型腔和型芯的表面温度。不论是热塑性塑料还是热固性塑料成型,模具温度对塑料熔体的充模流动、固化定型、生产率及塑件的形状和尺寸精度都有重要的影响。主要介绍一防护罩制件注射模具调温系统设计方法,通过有效的对模具温度进行调节,对模具进行冷却或加热,必要时两者兼有,从而达到控制模温的目的。     

电热式变模温注塑模具热响应辅助分析程序开发

针对快速变模温注塑成型模具热响应分析复杂问题,对电热式变模温注塑模具热响应作了研究,采用随形加热系统设计方法,将复杂的电热式变模温注塑模具简化为单个加热细胞单元,以电热元件的规格和布局为设计变量,以加热时间和型腔表面温差为热响应指标,结合Matlab图形界面开发模块和ANSYS有限元分析软件,开发了基于加热细胞单元的电热式变模温注塑模具热响应辅助分析程序,并对其准确性做了验证分析。研究结果表明,该辅助分析程序可以较好地预测模具的加热效率和型腔表面温度均匀性,可为电热式变模温注塑模具的设计、分析一体化提供一条快捷和高效的途径。     

Moldflow软件在汽车零件注塑模具设计中的应用

汽车制造业的发展带动了汽车零件模具需求量的增长。传统的模具设计是依据设计人员的经验,难以设计出一套低成本、高效率、高质量的工艺方案。以汽车安全带上盖零件为例,利用Moldflow软件分析了汽车安全带上盖注塑模具的最佳浇口位置和冷却方式,同时对模具成型质量,如翘曲变形、困气现象、熔迹痕等进行模拟,预测设计中潜在的缺点,有效地减少试模次数,缩短了汽车注塑模设计周期。     

四通方盒的结构优化及其注射模具的CAD/CAE设计

介绍了模具计算机辅助设计(CAD)/计算机辅助工程(CAE)设计流程,对四通方盒的结构进行了优化设计,简化了模具结构,并利用Pro/E软件设计了注射模具成型零部件,进行了开模仿真,生成了相应的铸模,利用Moldflow软件对熔体充填时间、锁模力、流动前沿温度和熔接痕进行充填分析。实践证明,应用CAD与CAE软件相结合进行注射模具设计,可以缩短模具设计周期,降低研发成本,有效提高模具设计质量。     

基于CAE技术注塑模冷却系统优化设计

在塑料注塑成型过程中,冷却系统的方案设计对产品的成型质量、成型周期以及生产效率起到了关键性作用。基于注塑成型冷却理论,运用CAE技术对汽车轮轴盖注塑件进行数值模拟成型分析,以成型过程中模具温度、塑件顶出温度时间和塑件翘曲变形分布为性能指标,获取冷却系统设计的不足之处,进行方案改进优化。实践证明,冷却系统优化方法可靠有效,产品质量符合要求,对注塑模具结构设计有一定的参考价值。     

洗发水瓶盖注塑模具的模流分析及优化设计

以某知名品牌新型洗发水瓶盖注塑模具设计与制造为例,通过运用Moldflow2012模流分析软件,模拟热塑性塑料ABS注塑充填成型全过程。对其充填时间、充填区域、流动前沿温度、翘曲变形、气穴等参数进行了两种不同方案的成型比对分析研究,通过两种方案的实验比对分析,得出洗发水瓶盖注塑成型的优化设计方案。实验结果表明,方案二在成型过程中从充填时间上节省了1.162 s,区域充型更加均匀,料流前沿温差为7.7°,流动状态更稳定,翘曲变形总量为0.297 mm,符合尺寸公差要求,气穴缺陷分布不明显,总体分析来看方案二比方案一成型更加优化。根据Moldflow2012模流分析软件,模拟成型数据,优化了洗发水瓶盖的注塑模具设计,即采用平衡侧壁矩形浇口方式填充,配合型腔、型芯双侧循环冷却系统的优化成型设计方案。模流分析可在具体模具加工实施之前,发现成型缺陷,对于注塑模具设计与制造具有优化指导功能,在缩短制造成型周期、提高产品成型质量、扩大经济效益等方面均具有现实意义。     

正交试验设计的注塑成型工艺参数多目标优化设计

结合正交试验设计和注塑成型模拟软件Moldflow,对不同工艺条件下的注塑成型过程进行模拟分析,并运用模糊数学中的综合评判法,对塑件成型后的体积收缩率变化、表面缩痕指数和最大翘曲变形量三个目标值进行综合评判,得到综合评分.通过对综合评分的极差分析,确定模具温度、熔体温度、注塑时间、保压参数、冷却时间等工艺参数对综合评分的影响程度,并绘制因素水平影响趋势图,分析得出最优的注塑工艺参数组合方案,并对该工艺组合方案进行模拟验证.     

CAE技术在注塑成型浇注系统优化设计中的应用

注塑模浇注系统是塑料注塑成型模具设计中的关键技术之一,利用CAE软件Moldflow可对不同浇口位置进行流动模拟分析,预测可能存在的气泡和熔接痕的位置,为模具设计人员优化模具设计提供依据,提高一次试模的成功率。并经过实践证明,注塑成型中通过浇注系统位置的优化可以显著提高产品的质量。     

注塑工艺设计中模具CAE技术与正交试验的综合应用

模具CAE技术与正交实验、数据处理与分析技术的综合应用,可以有效地优化工艺参数方案,缩短模具设计周期、提高模具设计质量、降低模具制造成本。本文为注塑成型工艺方案的优化及模具设计提供了一种可行方案和技术路线。     

喷枪水道塑件成型质量控制与分析

通过对喷枪水道塑件的结构分析,确定了喷枪水道塑件注射成型模具的分型面位置;依据Autodesk Moldflow Insinght模拟分析熔融塑料充模时各部分的流动性,选择浇口位置;同时根据塑件结构特点以及运用牛顿流体力学原理与冷却定律分析设计塑件冷热交换冷却系统;经AMI成型模拟,产品成型质量良好,对此类产品的注塑模具设计具有一定的参考价值。     

Development of high gloss plastic for injection molding by utilizing wollastonite(CaSiO<Subscript>3</Subscript>) and talc fillers

The gloss of plastic products is an important factor with which customers rapidly and directly decide the value of product. In general, these high-gloss plastic molded parts are produced through the injection molding of glass fiber-added plastic resin using a high temperature mold with the fine surfaces like glass. However, making the mold temperature higher causes the cooling time of injection molding longer, and the prolongation of cooling time leads to the extension of whole cycle of injection molding process. In order to resolve this problem, we developed a resin which makes the high-gloss injection modeling possible at low mold temperature by replacing conventional glass fiber filler with wollastonite filler. The tensile strength, flexural strain, impact strength, flow rate, gloss level and so on of the developed resin were tested with respect to the content of wollastonite. The results show that most of the properties except for the flow rate and gloss level are reduced in the newly developed resin. However, the decline in these properties was not enough to limit the use of new resins. In the gloss level test, as for the equal gloss of injection molded parts, the mold temperature for the developed resin was 30 °C lower than the mold temperature for the conventional resin. The difference of gloss between two injection molded parts using two different resins has been confirmed from the surface inspection of injection molded parts by SEM (scanning electron microscope).     

Eliminating weldlines of an injection-molded part with the aid of high-frequency induction heating

High-frequency induction is an efficient way to heat mold surface by non-contact electromagnetic induction. It has been recently applied to injection molding because of its capability to heat and cool mold surface rapidly. This study applies high-frequency induction heating to eliminate weldlines in an injection-molded plastic part. To eliminate or reduce weldlines, the mold temperature at the corresponding weld locations should be maintained higher than the glass transition temperature of the resin material. Through 3 s of induction heating, the maximum temperature of 143 °C is obtained on the mold surface around the elliptic coil, while the temperature of the mold plate is lower than 60 °C. An injection molding experiment is then performed with the aid of induction heating, and the effect of induction heating conditions on the surface appearance of the weldline is investigated. The weldline on the heated region is almost eliminated, from which we can obtain the good surface appearance of the part.     

薄壁塑件注塑成形特性的试验研究

设计制造了一可成形薄壁塑件的模具,利用正交试验方法(田口方法)进行充模试验,研究各工艺参数(注射速度、注射压力、熔体温度、注射量和模具温度等)对薄壁塑件注塑成形充模过程的影响。研究结果表明:模具温度对薄壁塑件的填充起决定性作用,注射压力和注射量是影响薄壁塑件成形的重要工艺参数,注射速度与熔体温度之间的交互作用对薄壁塑件成形的影响显著。     

基于模拟的注塑工艺分析设计集成系统的开发

将模具设计、制造和注塑工艺作为模具设计开发过程中的三个重要因素 ,提出了在模具设计阶段并行地进行注塑工艺方案设计的思想。开发了一套基于 C- MOL D系统的注塑工艺方案设计系统 ,该系统是基于并行设计思想 ,集成了 CAD和注塑过程 CAE分析系统部分信息的新平台 ,为在模具设计阶段进行注射工艺方案的并行设计和在注射工艺方案设计阶段进行工艺方案评价提供了一个集成环境     

微细胞皿注塑模具变温系统设计

采用微细电火花技术铣削加工了细胞皿模具型腔,以聚丙烯(PP)为例进行了成形工艺数值模拟分析,结果表明,注射速率、模具温度、熔体温度对充模过程影响较大,模具温度需要达到120℃型腔才能充满。提出了油水电相结合的变模温技术,变模温实验结果表明,型腔温度从80℃变化到120℃大约需要6min。填充实验表明,油水电相结合的变模温技术对实现微注塑模具成形过程的变模温是可行的。     

CAE技术在注塑产品中的应用

应用CAE软件Moldflow对充电器底座进行流动模拟分析,发现产品成型存在欠注.在分析了欠注产生原因的基础上,通过优化充电器底座结构,以及调整模具温度、熔体温度、注射时间、保压压力和时间等注塑工艺参数,解决了欠注问题,同时改善了翘曲变形,保证了注塑产品的成型质量.     

Verification and evaluation of automatically designed cooling channels for block-laminated molds

This study discusses an automatic design method of injection mold cooling channels using a genetic algorithms (GA) and a finite element method (FEM), combined with an evaluation function based on unsteady-state heat transfer and linear static deformation. The uniformity of cooling and the deformation effect were observed in the injection mold with the automatically designed cooling channel through a verification experiment. The genetic algorithm was applied in the following steps: the generation of finite elements of individuals expressing different cooling channel shapes, the definition of the fitness function to evaluate individuals, the genetic operation for individuals, and the automatic generation of the cooling channel shape. Finally, based on a molding experiment, the cooling and deformation effects were investigated. Results of resin cooling uniformity, temperature distribution of molding parts, and deformation of mold were demonstrated.     

Injection molding of polymer micro- and sub-micron structures with high-aspect ratios

This work studies the injection molding characteristics of polymer micro- and sub-micron structures using demonstration mold inserts with micro- and sub-micron channels with high-aspect ratios. The effects of the injection molding parameters on the achievable aspect ratio of the micro- and sub-micron walls were investigated. Additionally, distinctive mold-filling behaviors and resulting defects were observed for various polymers, such as polymethyl methacrylate (PMMA), polypropylene (PP) and high-density polyethylene (HDPE). Experimental results reveal that the mold temperature determines the success of the injection molding of micro- and sub-micron walls. The satisfactory mold temperature for micro-injection molding significantly exceeds that for traditional injection molding. Moreover, the main injection pressure and the main injection time substantially affect the achievable aspect ratio of the micro- and sub-micron walls. Furthermore, unusual flow behaviors occur and poor molding results are obtained when PP and HDPE are used for micro-injection molding.     

多型腔注射模充填不平衡试验

多型腔注射模在实际生产中有着广泛应用,充填平衡是保证多型腔模塑制品质量均匀一致的关键。自然平衡流道中也会发生充填不平衡现象,其原因可能是熔体流动产生的剪切热所致,但一直没有试验结果予以证明。基于此,利用可视化注射模具和红外温度传感器,通过直接观测熔体在流道和型腔中的动态流动行为并测量型腔入口处熔体的温度变化,对不同注射速率下不同材料在自然平衡多型腔注射模的充填不平衡进行研究。结果表明,由于剪切热的作用,主流道中不均匀但对称的熔体温度分布在分流道中失去对称性是产生充填不平衡的根本原因;充填不平衡程度不但取决于主流道中熔体的温度分布,还取决于分流道中凝固层的分布及熔体粘度对温度变化的敏感性。解决自然平衡多型腔注射模充填不平衡问题的根本,在于改善或消除分流道中熔体温度分布在流动平面的不对称性。