The Comparison Between Finite Element Analysis and Experimental Results of the Cooling of Injection Moulds with Hot Runner System

In an injection moulding process, the mould cooling s ystem is very important as an efficient and uniform cooling effect can improve b oth the productivity and part quality. Due to the complexity of the process, muc h research on the mould cooling analysis and cooling design optimization has bee n focused on the core and the cavity, excluding other systems of injection mould s. However, the runner system introduces a considerable amount of heat into the mould. In recent years, more and more hot runner systems are being applied in th e moulding industry to save material and decrease losses of injection pressure. This raises the need to include the hot runner system in the cooling analysis. I n this paper, a photo frame part was studied. The mould was built with a hot run ner system. Two thermal sensors were installed: one measures the temperature of lateral surface of hot runner nozzle; the other measures the plastic temperature from the core side. A pressure sensor was also installed to measure the pressur e of the core impression. Cooling analysis was performed using ABAQUS, ananalysi s software based on the Finite Element Method (FEM). The assembly including core , cavity and plastic part was modeled. Heat conduction from hot runner to cavity and from polymer melt to the mould and force convection on the cooling channel surfaces were studied. The natural convection between the ambient air and the ex terior mould surface was ignored. The simulations were adjusted with the experim ental results to find out the heat input from hot runner and its influence on mo uld cooling. Finally, the optimal cooling design and optimal injection condition were obtained.

Structural Scheme Optimization Design for the Stationary Platen of a Precision Plastic Injection Molding Machine

The current development of precision plastic injection molding machines mainly focuses on how to save material and improve precision, but the two aims contradict each other. For a clamp unit, clamping precision improving depends on the design quality of the stationary platen. Compared with the parametric design of stationary platen, structural scheme design could obtain the optimization model with double objectives and multi-constraints. In this paper, a SE-160 precision plastic injection molding machine with 1600 kN clamping force is selected as the subject in the case study. During the motion of mold closing and opening, the stationary platen of SE-160 is subjected to a cyclic loading, which would cause the fatigue rupture of the tie bars in periodically long term operations. In order to reduce the deflection of the stationary platen, the FEA method is introduced to optimize the structure of the stationary platen. Firstly, an optimal topology model is established by variable density method. Then, structural topology optimizations of the stationary platen are done with the removable material from 50%, 60% to 70%. Secondly, the other two recommended optimization schemes are given and compared with the original structure. The result of performances comparison shows that the scheme II of the platen is the best one. By choosing the best alternative, the volume and the local maximal stress of the platen could be decreased, corresponding to cost-saving material and better mechanical properties. This paper proposes a structural optimization design scheme, which can save the material as well as improve the clamping precision of the precision plastic injection molding machine.

Numerical Simulation of Injection Molding Cooling Process Based on 3D Surface Model

The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.

Seismic Response Analysis of Portal Water Injection Sheet Pile

To further the study on the newly developed portal water injection sheet pile under static loads, in this paper, by adopting the nonlinear calculation module of FEM software ANSYS, a model for the interaction between the soil and the sheet piles is set up, and the seismic response analysis for this type of space-retaining structure is performed. The effects of the embedded depth and the distance between the front pile and the back pile on the dynamic characteristics of the portal water injection sheet pile are studied.

Intravenous injection of AAV-PHP.eB across the blood-brain barrier in the adult mouse for central nervous system gene therapy

Objective To verify the neurotypicality of AAV-PHP.eB after tail vein injection in adult mice and its efficiency in crossing the blood-brain barrier(BBB).Methods The rAAV-SYN-GFP plasmid was constructed, and adult C57 BL mice were injected with AAV PHP.eB: SYN-GFP in the tail vein(300 nL, virus titer 3 × 10~9 vg) and in the prefrontal lobe(50 L, virus tite5 × 10^(11) vg). The green fluorescent protein(GFP) signal in the brain was observed at two weeks, while the GFP signal in the peripheral organs was observed at four weeks. Results Two weeks after tail vein injection, GFP expression was observed throughout the brain especially in the cortex, hippocampus, and geniculate nucleus. No GFP signal was observed or detected by western blotting in the peripheral organs after four weeks. GFP signal was observed mainly at the loca site after prefrontal lobe injection.Conclusion AAV-PHP.eB: SYN-GFP can effectively cross the BBB in adult mice. Using a neuron-specific promoter allows exogenous gene expression in neurons; therefore, AAV-PHP.eB can be used as an effective carrier for studying diseases in the central nervous system(CNS).

HSC-1.1:A USEFUL TOOL FOR INJECTION MOLDING

An integrated CAD/CAE/CAM system, HSC--1.1, is described in the paper. HSC--1.1 integrates surface modeling, mold design, technological simulations and NC machining into a full CAD/ CAE/CAM system with data exchange from one module to another. The practice shows that HSC-- 1.1 is a useful tool for injection molding and can assist engineers in reducing mold cost and improving mold quality.

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.

Numerical simulation of tungsten alloy in powder injection molding process

The flow behavior of feedstock for the tungsten alloy powder in the mold cavity was approximately described using Hele-Shaw flow model. The math model consisting of momentum equation, consecutive equation and thermo-conduction equation for describing the injection process was established. The equations are solved by the finite element/finite difference hybrid method that means dispersing the feedstock model with finite element method, resolving the model along the depth with finite difference method, and tracking the movable boundary with control volume method, then the pressure equation and energy equation can be resolved in turn. The numerical simulation of the injection process and the identification of the process parameters were realized by the Moldflow software. The results indicate that there is low temperature gradient in the cavity while the pressure and shear rate gradient are high at high flow rate. The selection of the flow rate is affected by the structure of the gate. The shear rate and the pressure near the gate can be decreased by properly widening the dimension of the gate. There is a good agreement between the process parameters obtained by the numerical simulation and the actual ones.

汽车中控壳注塑模及其五次六元复合斜滑块设计

汽车中控壳塑件注塑模具设计中,因塑件正面和背面都需要采用斜向脱模方式脱模,特别是背面的特征组成中,特征多且构成复杂,因此为该区域特征的脱模创新设计了一种五次六元复合斜滑块机构在局部区域实施抽芯脱模,并构建了该机构的力学运动模型。该复合斜滑块机构的结构设计为:利用油缸驱动1个主体斜滑块实施主抽芯,主体斜滑块的上端设置了一个先抽芯斜滑块即上斜滑块,上斜滑块先抽芯时驱动3个斜顶、4根弹簧顶针和1个C4侧型芯镶件;主体斜滑块的下端还设置了一个先抽芯斜滑块即斜型芯,该斜型芯也先于主体斜滑块抽芯;在上斜滑块完成先抽芯后,主体斜滑块的驱动油缸先驱动斜型芯抽芯,而后再驱动主体斜滑块及其上其余5种脱模元件一起完成抽芯。为实现塑件的自动化生产,在此复合斜滑块机构设计基础上,塑件的模具结构设计成热流道两板式两次开模模具,模具中还设计了1个正面油缸斜抽芯机构和4个斜导柱滑块机构,较好地实现了塑件的自动化生产。

非球面光学元件的快速制造技术

为满足光学行业的市场需求,非球面光学元件的快速制造技术是实现低成本、批量化、高精度生产的最佳解决方案之一。本文主要介绍了非球面光学元件的快速制造技术,包括精密光学玻璃模压成型技术和精密光学塑料注射成型技术,并对两种技术与其他非球面光学元件的制造技术进行了对比,阐述了模具材料种类、模具加工方法、成型材料、成型过程等内容。最后总结了近年来非球面光学元件的快速制造技术的发展现状,并对未来发展进行了展望。

中性束注入系统加速极电源高压部件设计

基于负离子的中性束注入是未来大型托卡马克装置不可或缺的辅助加热方式。中性束系统中的加速极电源需要输出-200 kV电压和5 MW的功率,还经常面临负载短路和断路的特殊工况。过去对加速极电源的研究中缺少高压部分的方案设计,而电源中高压部件的绝缘设计是电源研制过程中必不可少的关键环节。据电源指标和特殊工况的特点,计算了电源高压部分的隔离升压变压器、高压整流器和高压滤波器的电路参数,并对这些部件基于油浸式绝缘进行了工程设计,通过有限元仿真分析进行了绝缘验证。仿真结果表明,这些部件中的电场强度最高为16.22 kV/mm,小于变压器油击穿场强并具有2倍的绝缘裕度。设计的高压部件结构可以满足电源的绝缘要求。

注入井射孔段水泥环密封失效数值模拟研究

基于流固耦合有限元数值模拟方法,模拟了不同注入压力、水泥环弹性模量和泊松比下水泥环密封失效范围。结果表明:高注入压力的卸载会引发水泥环界面的脱粘,使得泥岩层力学性能降低,增大注入井周围的剪切滑移量,加剧了注入井发生套变的可能;水泥环弹性模量的减小,能够缩小水泥环界面失效的范围,同时增大注入压力宽裕度,提高了水泥环水力封隔能力;随着水泥环泊松比的增加,水压宽裕度逐渐增加,水泥环水力封隔能力逐渐增强,因此为防止发生窜槽,固井时应选取高泊松比的水泥环。

注射用盐酸头孢甲肟丁基橡胶塞质量控制研究

目的建立注射用盐酸头孢甲肟丁基橡胶塞的质量控制方法。方法以二氯甲烷-无水乙醇(1∶1,V/V)100℃水浴回流3.5 h处理胶塞,取续滤液。采用高效液相色谱法检测二硫化四甲基秋兰姆(简称秋兰姆)、2,6-二叔丁基-4-甲基苯酚(BHT)和单质硫,色谱柱为Shiseido CAPCELL PAK MGⅡC_(18)柱(250 mm×4.6 mm,5µm),流动相为1%三氟乙酸水溶液-乙腈(梯度洗脱),流速为1.0 mL/min,检测波长为280 nm,柱温为25℃,进样量为20µL。结果秋兰姆、BHT和单质硫的质量浓度分别在0.0002~0.0485µg/mL(r=0.9993)、0.46~230.67µg/mL(r=0.9999)和0.20~100.70µg/mL(r=0.9999)范围内与峰面积线性关系良好;精密度、稳定性试验结果的RSD均小于2.0%;平均加样回收率分别为58.22%,90.61%,104.46%,RSD分别为17.32%,5.58%,1.55%(n=9)。市场上抽取的16批空白丁基橡胶塞样品中BHT与单质硫的含量分别为0~169.88µg/g和0~102.79µg/g,均未检出秋兰姆。29批注射用盐酸头孢甲肟粉末样品中,BHT含量为0~36.61µg/g,且均未检测到单质硫和秋兰姆;包材胶塞中,BHT含量为0~125.64µg/g,单质硫的含量为0~79.93µg/g,均未检出秋兰姆,60℃下倒置5 d后与20℃及以下(阴凉库)放置比较,BHT含量无显著变化(P>0.05),单质硫含量显著减少(P<0.05)。结论所建立的方法操作简便、结果准确,可用于药用丁基橡胶塞中秋兰姆、BHT和单质硫的含量测定及注射用盐酸头孢甲肟的质量控制。

ICP-AES法测定左乙拉西坦注射液中微量元素含量

目的:建立电感耦合等离子体原子发射光谱法(ICP-AES)测定左乙拉西坦注射液中微量元素硅、硼、铝和钡含量的分析方法。方法:样品经酸化后直接用ICP-AES分析,以硅288.158 nm、硼249.772 nm、铝396.152 nm和钡493.408 nm为检测波长,建立标准方程,考察仪器精密度、样品重复性和回收率。结果:线性范围:硅0.5~5.0 mg/L,硼0.1~1.0 mg/L,铝1.0~10.0 mg/L,钡0.01~0.10 mg/L,线性相关系数均大于0.9995;检出限:硅0.044 mg/L、硼0.006 mg/L、铝0.017 mg/L和钡0.0005 mg/L;加标回收率:硅96.3%~103.1%,硼90.0%~95.0%,铝101.3%~106.0%,钡102.0%~105.0%。结论:该测定方法快速、准确、灵敏度高,适用于药品中包装材料迁移微量元素含量变化的研究。

电感耦合等离子体质谱法测定注射用芝麻油中10种无机元素含量

目的建立测定注射用芝麻油中10种无机元素含量的电感耦合等离子体质谱(ICP-MS)法。方法采用微波消解法前处理样品,采用ICP-MS内标标准曲线法检测各元素含量,射频功率为1500 W,雾化室温度为2℃,采用氦碰撞模式,载气(氩气)流速为0.8 L/min。结果铅、镉、砷、汞、钴、钒、镍、锂、锑、铜质量浓度分别在1.25~12.5 ng/mL、0.50~5.0 ng/mL、4.00~40.0 ng/mL、0.75~7.5 ng/mL、1.25~12.5 ng/mL、2.50~25.0 ng/mL、5.00~50.0 ng/mL、62.50~625.0 ng/mL、22.50~225.0 ng/mL、75.00~750.0 ng/mL范围内与各元素和内标仪器响应值比值线性关系良好(r>0.9900),检测限为0.0002~0.0420μg/g,定量限为0.075~7.5μg/g;精密度、重复性试验结果的RSD均小于10%;平均加样回收率为78.64%~110.39%,RSD为1.40%~6.41%(n=9)。结论所建立的方法灵敏,结果准确可靠,可用于注射用芝麻油中10种无机元素含量的测定。

电感耦合等离子体质谱法测定盐酸溴己新葡萄糖注射液中29种元素杂质含量

目的建立利用电感耦合等离子体质谱法(ICP−MS)同时测定盐酸溴己新葡萄糖注射液中29种元素杂质含量的分析方法。方法自2022年9—10月,采用ICP-MS法。样品直接稀释后分析,通过在线加入内标元素来校正测量结果。内标液添加异丙醇进行基质匹配以减少仪器信号漂移干扰和样品基体效应。射频功率1550 W;雾化气流量1.05 L/min;辅助气流量0.90 L/min;KED模式;碰撞气流量4.5 mL/min;全定量法采集。结果29个元素在各自的检测浓度范围内线性关系良好(r>0.9987)。检测限为0.0000573~0.285μg/L,平均回收率为91.0%~108.4%(n=3),重复性为1.3%~7.2%(n=6)。结论该方法快速、准确、操作简便,可用于盐酸溴己新葡萄糖注射液中元素杂质的质量控制。

一次和多次注射施肥对薄壳山核桃生长及品质的影响

【目的】探究同一施肥量下注射施肥次数对薄壳山核桃生长发育及品质的影响,为薄壳山核桃科学施肥提供技术依据。【方法】以13年生薄壳山核桃成年树‘马罕’为试材,在浙江金华进行田间试验。设置3个处理,分别为不注射对照、在树干基部距地面l5~25 cm处钻孔进行一次注射处理、多次(5次)注射处理,一次和多次注射处理的总施肥量相同。测定果实成熟期叶片和果实生物量及不同部位的养分含量,并调查果实外观和营养质量指标。用PLS-DA方法确定施肥处理对果实各指标差异的贡献。【结果】矿质元素在叶片中积累较多,其次是种仁,在木质部和韧皮部中积累较少。多次注射处理薄壳山核桃单果质量、单果径和核果高较对照分别显著增加了16.99%、7.52%和6.79%,较一次性注射处理分别提高了13.03%、4.50%和6.26%(P<0.05);种仁不饱和脂肪酸含量以及不饱和脂肪酸与饱和脂肪酸的比值均显著高于一次性注射处理(P<0.05);薄壳山核桃叶片Ca和Fe含量,种仁Mg、Mn、Cu和Zn含量,韧皮部Fe含量及木质部N和Ca含量均显著高于对照和一次注射处理(P<0.05);施肥处理对矿质元素在树体不同部位的分配没有显著影响。PLS-DA结果表明,一次和多次注射处理间存在显著差异,导致薄壳山核桃品质差异的主要物质为棕榈酸、棕榈油酸和种仁Cu含量。【结论】同一施肥量下,多次(5次)注射处理促进薄壳山核桃的生长,改善种仁品质,有助于树体各部位矿质营养元素的积累。

20号碳钢在模拟NaCl三元复合驱注入段溶液中的腐蚀行为

通过实验室模拟现场NaCl三元复合驱注入段溶液体系,采用电化学阻抗谱、动电位极化曲线的方法,结合扫描电镜表面分析技术和X射线粉末衍射技术,研究了20号碳钢在注入段溶液中的腐蚀行为。结果表明:注入段溶液中含有大量硫酸盐还原菌(SRB),少量的铁细菌(IB)和腐生菌(TGB);碱、聚合物和表面活性剂的协同作用使碳钢的整体腐蚀速率较小;由于Cl-作用,在浸泡初期碳钢的腐蚀速率达到最大,随着腐蚀产物以及生物膜的形成,碳钢的腐蚀速率减小,在浸泡后期,由于生物膜厚度不均匀以及FeS形成,碳钢腐蚀加速。