双色高光注塑成型技术及发展

介绍双色高光注塑技术的特点,通过比较双色高光注射成型与单色高光注塑成型、普通注射成型,深入分析了双色高光注塑成型塑件结构与黏合设计及模具结构设计要点。阐述了国内外双色高光注塑技术的应用现状及发展。讨论并指出了将双色高光注塑成型技术进一步推广有待解决的关键技术问题。     

基于MoldfloW/MPI的双色注塑成型分析

首先在Pro/E三维软件中建模,然后导入到Moldflow/MPI对其进行双色注塑成型模拟分析,包括熔体的充模时间、体积温度和塑件翘曲,为双色注塑模具的设计及工艺提供了重要依据.     

鼠标面盖双色注塑模具设计

根据鼠标面盖塑件的结构特点,对该制品的双色注塑模具进行了详细的结构设计。重点介绍了模具的设计过程、工作过程、设计经验和技巧。通过对浇注系统、侧向抽芯机构、冷却系统和脱模系统的分析研究,确定了合理的双色注塑模具结构。通过采用双模架、双浇注系统、双脱模系统和辅助型芯等复杂模具结构,达到了双色注射成型的特殊要求。     

双色内螺纹旋钮的热流道注塑模设计

以内螺纹旋钮的双色注射模为例.阐述双色注射模热流道的结构特点、设计要点以及工作过程.通过对塑件结构特点的分析,确定注塑模具的整体设计方案,并对模具设计过程中的要点和难点进行分析.并介绍一种内螺纹自动脱模机构.该模具的设计方法对双色注射模具设计具有一定的指导意义.     

基于Moldflow的汽车尾灯双色注塑模分析

以前双色注塑制品的出现是基于功能的需要，现在双色注塑制品已经成为一种时尚，利用Moldflow的热塑性重叠注塑分析模块可以分析两种不同的材料在模腔李的流动和预测塑件可能出现的情况，对缩短模具生产周期和节省模具成本具有重要的指导意义。     

高光注塑成型模具热响应研究

高光无痕注射成型技术是一种新兴的注射技术,能够消除塑件表面熔接痕等缺陷,表面可以达到镜面效果,免去二次喷涂。本文通过建立模具的二维几何模型,利用ANSYS模拟了加热、冷却过程,获得了模具表面及熔体中心层的热响应和温度分布情况。同时对比分析了常规注塑与高光注塑成型两种成型工艺,通过加热、冷却时间及温度分布等结果的对比,验证了高光注塑的优越性。     

高光无痕注塑成型模具热响应的研究

高光无痕注射成型技术是一种新开发的注射技术,能够消除塑件表面熔接痕等缺陷,表面可以达到镜面效果,免去二次喷涂。通过建立模具的二维几何模型,应用ANSYS模拟了加热、冷却过程,获得了模具表面及熔体中心层的热响应和温度分布情况;对比分析了常规注塑与高光无痕注塑两种成型工艺;通过加热、冷却时间及温度分布等对比,验证了高光无痕注塑的优越性。     

操控旋钮双色注射成型热流道模具设计

设计了一种旋转式双色注射成型热流道模具用于旋钮盖双色塑件的生产,模具选用四板式3次开模双色模模架。双色模具由均为1模2腔的塑件内衬基体注塑模具和包胶层注塑模具组成。模具采用热流道+冷流道相结合的方式进行浇注,解决了圆柱壁模腔充填困难问题,保证了流道废料的自动切除。模具共设计了36个结构相似、占用设计空间小的锁紧块T型槽驱动滑块机构来实施侧抽芯脱模,减少了模具整体结构尺寸。最后,通过一种插杆式机构来对模板的顺序开闭进行控制,机构动作可靠。     

基于BP神经网络的双色塑件翘曲变形量预测

以某遥控器前壳双色塑件注塑成型为例,以该塑件在注塑成型过程中的翘曲变形量为研究目标,提出了一种结合AMI数值模拟、正交试验和BP神经网络的双色塑件翘曲变形量快速、准确的预测方法。首先建立了基于AMI数值模拟的CAE模流分析模型,并对注塑成型工艺参数及翘曲变形量进行数值模拟分析;之后结合正交试验设计法使AMI软件数值模拟结果在指定的工艺参数范围内实现了离散分布;最后以正交试验数据为基础建立BP神经网络预测模型,通过Matlab训练网络使其满足误差精度要求,从而达到准确预测新工艺参数下翘曲变形量的目的。结果表明:训练出的BP神经网络模型具有很高的预测精度,能够满足对该双色塑件翘曲变形量准确、快速的预测要求。     

人机工程学鼠标底壳双色注塑模具设计

通过具有人机工程学复杂曲面造型的双色鼠标底壳零件,介绍了双色注塑零件可注塑性工艺分析方法,利用UG6.0对双色注塑的鼠标底壳模具进行了结构设计,比较详细地论述了在复杂曲面和双色成型双重特点下模具设计的考虑因素,着重介绍了双色模具内外抽芯机构设计过程和热塑性弹性体TPE外层包覆粘合的双色模具设计特点和成型方法。试模结果表明,该模具设计合理,制造方便,实现全自动双色注塑成型操作,成型过程能力指数Cpk大于1.33, 成型周期仅43 s,完全满足了鼠标底壳高品质和高效率的注射成型要求。     

高光成型制品体积收缩率的数值模拟优化与结果预测

以高光液晶前壳为研究对象,以高光注射成型制品体积收缩率为成型性能指标,基于CAE仿真试验和正交试验设计获得相关数据并研究了工艺参数对高光制品体积收缩率的影响趋势及影响程度,得出保压压力为最显著性影响因素,并获得了使制品体积收缩率最小的最优工艺参数组合.在数值模拟和正交试验获得的样本数据基础上,采用径向基(RBF)神经网络建立了工艺参数与制品体积收缩率之间的非线性映射关系,实现了在工艺参数变化情况下能够快速、准确地预测出高光成型制品的体积收缩率,对实践生产具有一定的指导意义.     

Optical and surface properties of whey protein isolate coatings on plastic films as influenced by substrate,protein concentration,and plasticizer type

Composite film structures of common plastic polymers including polypropylene (PP) or poly(vinyl chloride) (PVC) with whey protein isolate (WPI) coatings may be obtained by a casting method. Optical and surface properties of the resulting WPI‐coated plastic films, as affected by protein concentration and plasticizer type, were investigated to examine the biopolymer coating effects on surface modification with polymeric substrates of opposite polarity. The measured properties involved specular gloss, color, contact angle, and critical surface energy. Regardless of the substrates, WPI‐coated films possessed excellent gloss and no color, as well as good adhesion between the coating and the substrate when an appropriate plasticizer was added to the coating formulations. The protein concentration did not significantly affect gloss of WPI‐coated plastic films. Among five plasticizers applied, sucrose conferred the most highly reflective and homogeneous surfaces to the coated films. The WPI coatings were very transparent and the coated films with various protein concentrations and plasticizers showed no noticeable changes in color. Experimental results suggest that WPI coatings formulated with a proper plasticizer can improve the visual characteristics of the polymeric substrate and enhance water wettability of the coated plastic films. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 335–343, 2004     

电话听筒注塑模具设计

分析了电话听筒外壳塑件的结构与成型工艺,针对听筒前壳与后盖塑件配对生产、壁薄、加强筋多、存在侧凹、表面质量要求高等特点,设计了一次注射成型配对塑件的模具,并在其上采用了动、定模镶块组合,斜导柱和摆杆式复合内外侧凹脱模、顺序开模和多种形式的顶出结构,介绍了主要成型零件、模具浇注系统、侧向分型抽芯和顶出与复位机构的设计。实践表明：模具结构紧凑、运动平稳可靠,设计方案合理。     

蒸汽加热模具及模具变温辅助控制装置的研制

对高光无痕注射成型工艺的成型装置和辅助控制系统进行了研究和开发,介绍了蒸汽加热注射成型工艺原理。通过辅助系统来控制蒸汽加热模具的型腔温度,特殊的水道设计使模具型腔的温度能够迅速升至熔体的热变形温度以上,进而获得高光表面制品。同时指出了蒸汽加热模具在模具材料的选择、测温点的分布等方面的设计思想,阐述了辅助控制装置的组成部分及控制原理。结果表明,蒸汽加热模具可加工高表面光洁度、无熔接痕、无流痕的塑料制品,可免除后续喷涂工艺,降低了生产成本,成型周期由120 s 缩短到43 s。     

成型温度对PP和ABS试样表面颜色和光泽度的影响

以K31皮纹为例,研究了成型温度对聚丙烯(PP)和丙烯腈-丁二烯-苯乙烯塑料(ABS)试样表面颜色和光泽度的影响。结果表明,随着模具温度和熔体温度的升高,无论是PP还是ABS,其试样颜色的L值均呈增加趋势而光泽度均呈降低趋势,且ABS试样的光泽度降低程度比PP试样高。注塑温度和模具温度升高,材料的流动性提高,冷却时间延长,试样复制模具皮纹的能力提高,使得PP和ABS试样表面皮纹深度均有所增加,从而使试样的光泽度降低、同时L值升高。与PP结晶型材料不同,ABS作为非结晶型材料,其流动性受温度影响更为显著,随着成型温度的升高,使得ABS试样的光泽度降低的程度更大。     

Effects of injection‐molding conditions on the gloss and color of pigmented polypropylene

The effects of processing conditions on appearance characteristics of injection‐molded mineral‐filled polypropylene (compounded with pigments giving differing intensities of a beige color) have been studied; characteristics studied included gloss, color, and texture. A mold cavity embossed with smooth, fine, and coarse surface patterns was used. In‐mold rheology and gate‐seal analysis were used to select the filling and postfilling processing parameters. Interest was focused on the effects of filling rate, holding pressure, and mold temperature on the appearance characteristics, and a significant influence of these processing conditions on the gloss and color was found. For all the surface patterns examined, a better replication of the mold texture was obtained with a low melt viscosity at a high shear rate (high injection speed or short injection time) and a high mold temperature. This gave a higher gloss in the smooth surface regions and a lower gloss in the textured regions. An increase in the holding pressure had an effect similar to but smaller than increasing the filling rate or mold temperature. The gloss (or surface topography) had a significant effect on the color; an increase in gloss was associated with an increase in the color coordinate b* and a decrease in the lightness L*. POLYM. ENG. SCI. 45:1557–1567, 2005. © 2005 Society of Plastics Engineers     

On the relations between color,gloss, and surface texture in injection‐molded plastics

The relation between color and gloss of injection‐molded plastic specimens was evaluated by means of a 45°/0° geometry spectrophotometer and a glossmeter. The specimens were plaques having one smooth, glossy field and one rougher, textured region made of two different polymeric materials (acrylonitrile‐butadiene‐styrene and polypropylene) in a range of colors. A significant influence of the lightness L* of the specimens on the measured gloss of the textured field, with a low gloss appearance, was found. This can probably be attributed to a contribution from bulk scattering, which is linked to the reflectance from within the specimen. The influence of texture on the measured color of the plaques was assessed by evaluating the color difference between the smooth field and the more textured area on the specimens. When the surface was textured, the color changed; in general it became lighter and less saturated. The magnitude of the change depended on the color of the material. The darker the material was, the larger was the increase in lightness L* as the surface became rougher. The shift in chroma C* was determined not only by the saturation but also by the lightness of the specimens. Darker specimens exhibited a larger decrease in chroma when the surface was textured. The change in the measured color caused by increasing the surface roughness could be predicted in a satisfactory manner using a model developed for xerographic printing paper. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 291–298, 2009     

Effects of two staining methods on color stability of wood flour/polypropylene composites during accelerated UV weathering

Two staining methods of wood flour/polypropylene composites in an attempt to improve the color stability of wood‐plastic composites (WPCs) were investigated. The first was to dye wood flour (WF) before compounding with polypropylene (PP) to make stained composites. The second method involved mixing pigments directly with WF and PP. Nine groups of composites were weathered in a QUV accelerated weathering tester for 960 h. Their surface color, surface gloss, washing resistance, and flexural properties were tested during weathering. Additionally, the weathered surface was characterized by SEM and ATR‐FTIR. The results revealed that (1) the washing resistance of composites were improved after staining treatments; (2) composites made of dyed WF showed higher surface gloss values and less cracks on weathered surface at the early stage of weathering; while composites containing pigments displayed brighter color, less color change, and less loss of flexural properties during weathering; and (3) weathering resulted in the protrusion of WF and photodegraded lignin on exposed surface. Adding pigments was proven to be more effective staining method for improving composite color stability during weathering. POLYM. COMPOS., 38:1194–1205, 2017. © 2015 Society of Plastics Engineers     

FHB5.20壳体注塑模具及其工艺设计

以一种塑料壳体为例,对其侧抽芯及成型工艺设计要点进行分析。针对具有凸起、阶梯、凹槽的薄壁塑件壳体,进行结构及成型工艺分析,设计了阶梯形分型面、多方向抽芯机构、浇注系统等,完成了一模两腔的模具设计;并结合Moldflow软件对塑件进行工艺分析,再进一步优化,进而获得较佳的注塑工艺参数。     

The effect of gloss on color

A model was developed for the effect of gloss on reflected color, taking the measurement geometry of the color measuring device into account. It considers the total front surface reflectance of a given sample to be independent of gloss and determined only by its refractive index and the angle of the incident beam. Although the total front surface reflectance is fixed, its specular component increases (and the diffuse component decreases) with increasing sample gloss. Therefore, the diffuse reflectance factor measured by a spectrophotometer decreases with sample gloss. In this article, a defined curve was fitted to the measured reflectance factor of black xerographic print samples having a range of gloss values for the 0/45 and diffuse spectrophotometer geometries, and this curve was used to predict the CIELAB color values for samples of the other colors at various gloss levels. The predicted color was compared to the measured color for cyan, magenta, yellow, red, green, and blue images that spanned a wide range of gloss. The RMS color error between the predicted and measured color of all of these images was found to be about 3 CIELAB ΔE* units. © 1999 John Wiley & Sons, Inc. Col Res Appl, 24, 369–376, 1999