基于ANSYS Workbench及Moldflow的精密注射模镶块变形分析

通过Moldflow模拟注射成型过程,并将分析结果导入有限元分析软件中,定量分析微流控芯片注射模镶块变形量,并结合注射成型试验进行验证。结果表明,芯片厚度不一致是由镶块微变形造成的,在微流控芯片注射成型过程中,模具镶块产生的微变形与最终制品厚度差均在30μm左右,两者变化趋势基本一致。     

聚合物微成型模具设计与制造技术

介绍了近年来大连理工大学模塑制品教育部工程研究中心在聚合物微成型模具设计与制造技术方面的研究工作,重点探讨了微注射、微热压和微挤出3种成型方法中微成型模具的设计与制造技术。在此基础上,论述了微细胞皿和微流控芯片注射模、仿生鲨鱼皮微结构滚压模具以及五腔微管挤出模的设计方法和制造技术。     

注射工艺参数对微流控芯片成型影响实验研究

利用正交试验方法研究了各工艺参数（模具温度、冷却时间、保压时间及注射压力）对较大尺寸下的微流控芯片成型过程的影响。研究结果表明模具温度对芯片沟道成型起主要作用,冷却时间、保压时间及注射压力次之。该结论为深入开展微流控芯片成型研究提供了有益的借鉴。     

模内自动冲切浇口凝料机构的微流控芯片注射模设计

以具有微纳米结构的碟形微流控芯片为研究对象,设计了具有模内自动冲切浇口的注射成型模具。通过对碟形微流控芯片注射时熔体流动均匀性和散热翘曲分析,注射成型模具采用1模1腔的形式,注射浇口选择盘形浇口,冷却水道采用环形水道。为了提高生产效率,降低后续消除浇口对芯片造成的二次破坏,注射模中增加了模内自动切浇口凝料机构,以实现开模前完成浇口凝料切除,并用工具显微镜观察切口成型质量。     

基于3D扫描技术的模具镶块修复与重制

冲压模具在生产过程中因为使用不当或者磨损,造成模具损坏或者不能满足精度要求,需要重新制造镶块。介绍了利用3D扫描技术在镶块修复和重制中的应用,提出了基于Geomagic Design X进行镶块逆向建模和曲面精度分析的方法,最后还原出镶块的3D数模,最大精度偏差为0.03mm,镶块经过加工推光后,可直接更换原损坏的镶块,经过简单调试后即可用于生产,不仅缩短了镶块制造周期,且节约制造成本和生产停滞时间。     

化学微蚀刻法和微细电镀法制备微流控芯片金属模具工艺对比研究

针对化学微蚀刻法和微细电镀法制备微流控芯片金属模具进行了工艺对比研究。采用激光共聚焦显微镜分别检测表征由这两种加工工艺制备所得的模具微结构特征,对其侧壁陡度、尺寸均匀性、粗糙度进行对比分析。结果表明,化学微蚀刻法制备的模具微结构的侧壁呈不规则弧形、尺寸均匀性差,表面粗糙度较大 (R_a=3.58 μm)。而微细电镀法制备的模具微结构的侧壁则呈规则的梯形、尺寸均匀性好,表面粗糙度较小(R_a=0.65 μm)。微细电镀法制备的微流控芯片金属模具综合效果比化学微蚀刻好。     

基于微细电铸法制备微流控芯片模具工艺

提出了一种制备微流控芯片模具的方法。首先,在分析微细电铸流场特性的基础上研究了流速对微流道传质的影响;然后,讨论了脉冲频率、电流密度、安培时、温度四个参数对微流控芯片模具质量的影响;最后,分析了基底毛化与模具结合力的关系。该方法实现了表面粗糙度值小、侧壁垂直度高的微流控芯片模具的制备。     

SUV汽车侧围拉伸模制造工艺

根据SUV汽车整体侧围拉伸模制造工艺方案,结合模具特点,介绍了拉伸模制造中的上、下模座的加工,下模本体加工,修边凹模镶块的加工,型面扣料加工,模具型面、修边凹模镶块刃口、翻边凸、凹模的研配,从中提出了加工技巧,对同类模具的制造有一定借鉴作用。     

粘接工艺在电火花成型加工中的应用及电加工专用粘合剂

本文仅就电火花成型加工技术在各类花纹模具加工中的电极柄安装采用粘接工艺;各类型腔模具的电极制造采用镶拼组合技术与粘接工艺的结合;并与旧工艺的对照介绍于众,以便交流。一、各种类型的花纹模具用量激增。为制造立体感强的浮雕型模具或一般平面型模     

注射模镶件结构设计

通过对九线基座、接线柱定位夹具注射模镶件的工艺分析,确定了成型镶件分半镶拼式结构。其结构的使用解决了小孔加工困难的问题,并直接降低了模具的制造成本,缩短了模具的制造周期,对同类产品的模具设计具有一定的借鉴作用。     

FRP筒形件车铣钻加工系统的设计与分析

介绍了缠绕成型技术和纤维增强复合材料加工技术的特点。针对现有的加工方法存在的问题,设计了纤维增强复合材料筒形件的车铣钻复合加工系统。根据实际生产加工需要在三维建模软件SolidWorks中对纤维复合材料筒形件的车铣钻加工装置进行总体设计与装配。采用ADAMS进行运动仿真,验证了筒形件夹紧装置在加工过程中能够起到夹紧的作用。为保证加工精度,将关键零部件导入ANSYS Workbench 中进行静力学分析,验证了设计的合理性。     

注射模CAE中粘度模型的参数拟合

在高分子材料加工的数值模拟过程中 ,常采用粘度模型来描述高聚物的粘性行为 ,粘度模型能够在加工温度、压力条件下 ,剪切速率从101s-1 到105s-1的变化范围内 ,相当精确地描述高聚物的粘性 ,为注射模具设计和成型模拟提供理论依据     

Adaptive spline modelling of observation data (ASMOD): a solution to the problems in conducting polymer-based sensors

The development of conducting polymer sensors is a multi-dimensional task. It requires the design of intelligent data processing that controls the dynamic behaviour of the polymer. It also needs a smart computerized system by which a dynamic model can be created to predict, correctly, the dynamic character of ‘unstable’ conducting polymer sensors. Using an adaptive neuro-fuzzy modelling method, it is possible to design such a computerized processing system by which a pattern and a model can be predicted.     

Plasma Sprayed PMMA Coatings on Steel

PMMA coatings have been applied to steel by plasma spraying. The work shows that the polymer decomposition temperature is a function of the particle residence time in the plasma and is much higher than in conventional polymer processing. The analysis indicates that realistic prediction of the temperature profiles of in-flight polymer particles can only be obtained by using this dynamic decomposition temperature. The process model predicts that only the surface layers of the polymer feedstock particles undergo significant decomposition under optimized spraying conditions.     

塑料成型加工中的振动技术

介绍了在塑料加工中应用振动技术的动态加工方法,阐述了振动力场在挤塑和注塑过程中的作用。运用高分子链及其链段运动理论,分析说明振动场的存在可使塑料熔体的粘弹性减小,表现为实际加工过程中压力降低、流率增加、能耗减小和制品质量提高。     

NQ—A型聚合物水溶性淬火介质的应用

综合论述了ＮＱ—Ａ聚合物淬火介质的冷却性能和工艺性能，通过典型钢件淬火硬度、变形和开裂倾向的研究，证明以一定浓度的ＮＱ—Ａ聚合物水溶性介质取代水和淬火油，可使钢件获得满意的淬火效果。     

A comparative study of viscous polymer processed ceramics based on aqueous and non-aqueous binder systems

Lead zirconate titanate (PZT) is an important piezoelectric material which has wide range of applications as sensors, actuators and transducers. Various forms are required for different devices applications. In this work, extrusion and press forming of PZT ceramic rods and thick films produced via a viscous polymer processing (VPP) route have been investigated. The relationships between the rheology, microstructure and formability of both an aqueous and a non-aqueous polymer binder system have been compared. The non-aqueous PVB system exhibits substantially higher bulk yield stress during plug die flow and higher biaxial extensional stress during squeeze film flow compared to the aqueous PVA system. Discussion of the results is based on differences in the adsorption of the polymer onto the PZT particles and the migration behaviour of the polymer/solvent phase in the two systems.     

Hydroxyapatite-reinforced polymer biocomposites for synthetic bone substitutes

Hydroxyapatite (HA)-reinforced polymer biocomposites offer a robust system to engineer synthetic bone substitutes with tailored mechanical, biological, and surgical functions. The basic design rationale has been to reinforce a tough, biocompatible polymer matrix with a bioactive HA filler. A large number of studies have investigated modifications to the biocomposite structure and composition, aimed at improving the mechanical properties, often through modified or novel processing methods. In this article, the effects of the polymer composition and molecular orientation; the HA/polymer interface; and the HA-reinforcement content, morphology, preferred orientation, and size are reviewed with respect to mechanical properties, drawing frequent comparisons between various HA-reinforced polymer composites and bone tissue.     

PEDOT/PSS bending actuators for autofocus micro lens applications

This paper reports on the development of micro autofocus lens actuators using conducting polymer actuators. We propose a hydrophilic treatment for polyvinylidene difluoride (PVDF) membranes and a polyethylenedioxythiophene/poly(styrene sulfonic acid) (PEDOT/PSS) casting method for easily producing bending conducting polymer actuators with high mechanical strength.We first designed micro autofocus lens actuators using bending conducting polymer actuators, and then determined experimentally that the electrical conductivity and breaking strain of the PEDOT/PSS films could be improved by the addition of polyethylene oxide (PEO). Furthermore, we made hydrophobic PVDF membrane surfaces hydrophilic using polyethylene glycol methacrylate (PEGMA) and coated a solution of a mixture of PEDOT/PSS and PEO on the membrane surfaces to form a laminated film. We produced bending conducting polymer actuators by processing this film. Tests simulating the actuator's use in micro autofocus lenses showed the actuators to operate stably for more than a million cycles.     

Towards all-polymer field-effect transistors with solution processable materials

We have fabricated polymer field-effect transistors (FET) from solution processable polymers. Starting with an inorganic structure using only an organic semiconductor (regio-regular poly(3-hexylthiophene)), the transistor performance was studied as the inorganic materials were replaced with polymeric alternatives one at a time. We see a gradual increase in subthreshold swing and off-currents and an increased threshold voltage when substituting the inorganic materials with polymer materials. The small reduction in transistor performance when going from inorganic substrate and insulator to polymeric materials indicates that it is possible to make flexible polymer devices from solution processed materials suitable for roll-to-roll processing. The all-polymer FET was realized using two different conducting polymers, polyaniline for the source and drain electrodes and poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), PEDOT:PSS, for the gate electrode.