Study on the Accuracy of Injection Molded Plastic Gear with the Assistance of Supercritical Fluid and a Pressurized Mold

Plastic gears are lighter and less noisy compared to steel gears, and they can be easily shaped into diverse forms by the injection molding process. For this reason, plastic gears are widely used in industry. An extensive amount of research has been conducted on gear materials and methods of shaping plastic gears for durability and for broader applications. In this article, the focus is on producing a plastic gear shaping method incorporating the injection molding process.

The most important factor influencing the durability of a plastic gear is its accuracy. Unlike steel gears, the dimensions of plastic gears are subject to considerable change during formation, and this is due to certain conditions during the injection molding process and to the mold structure. The main causes of size variability here are the high viscosity of plastic and the shrinkage ratio of the resin. In our study, a supercritical fluid was used to reduce the viscosity of the plastic, and a pressurized mold was used to control the shrinkage ratio of the resin. Thus, production of an improved, more highly accurate plastic gear was achieved.     

Improving the design and technology of molds for ceramic articles

Ways of improving the design and the manufacturing technology of porous and poreless molds for shaping ceramic articles by the methods of slip casting and plastic molding are considered. New techniques for the production of porous molds are suggested, which make it possible to decrease the cost of the molds and optimize the processes of slip casting and plastic molding of ceramic articles.     

塑料模具异型水路制作与应用

传统的塑料模具模冷却水路加工往往依赖于钻加工,加工中必须避免干涉到模具机构,钻加工方式是直线型的,不能均衡地降低模温,无法解决塑料制品中许多缺陷。分析了模具中异型冷却水路的原理,并阐述了加工制造过程。对复合加工技术在模具中应用、结合浇口套实例做了介绍,采用异型冷却水路复合加工技术可达到模具均衡冷却,用以提高塑料制品质量。     

Wood‐Plastic‐Composites: Rheologische Charakterisierung und Füllverhalten im Spritzgießprozess

Wood‐plastic composites (WPC) show a complex and completely different material and flow behavior in comparison to pure polymers. Especially the flow behavior is very important for the processing of these composites. In the following article results of rheological characterization and investigations of the filling behavior during the injection molding process are presented. Furthermore, appearing challenges and possible methods of resolution are discussed.     

模糊PID法在塑料成型条件优化中的应用

针对比例–积分–微分(PID)方法在塑料成型加工仿真模拟中存在一定的超调和震荡现象的问题,利用模糊控制对工艺参数改变的反应不太敏感的特点,将两种方法进行联用,可在一定程度上弥补PID方法的超调和震荡现象,从而实现塑料加工过程快速高效的控制。为此,综述了模糊PID控制方法在塑料注射成型、挤出成型、吹塑成型、压延成型等成型方法中的应用,并着重阐述了其在注塑机料筒温度控制和电液系统控制方面的应用。     

Chinaplas~2011塑料成型加工设备绿色技术浅析

介绍了Chinaplas2011塑料成型加工设备绿色技术。结果认为绿色化成为塑料成型加工设备新时期研发的方向;节能、环保、洁净、节材、智能控制等是塑料成型加工设备重点研发的绿色技术;应该围绕绿色技术开展塑料成型加工设备的创新创造工作;绿色技术是不断发展进步的技术。     

Liquid crystal polymer-based blends: “Universal grade” polymers?

Polymeric materials can be easily processed with different processing operations thanks to suitable rheological properties. Melt flow index, or grade, which is a measure of the fluidity of the polymers, is the most commonly parameter used to characterize the polymers from the point of view of their melt viscosity. Injection molding requires high grade materials, whereas low grade values are best suited for extrusion. Of course, it would be no doubt of interest if single “universal grade” materials could be used for all processing operations. In this paper it is demonstrated that the blends of low grade polymers with small amounts of liquid crystal polymers can be conveniently used for all processing operations. Mechanical and thermal properties of the polymer matrix are in general retained or, in some cases, improved.     

Development of a pressure–volume–temperature measurement method for thermoplastic materials based on compression injection molding

The pressure–volume–temperature (pvT) relationship of polymers is vitally important information in designing and manufacturing polymers. Because of the special behavior of polymers, however, it is extremely difficult to accurately measure the data in a way that matches the thermal conditions of injection molding, which is one of the most widely used processing methods. As neither widely used, commercially available measuring devices, nor special equipment mentioned in the literature can fully satisfy this need, it was decided to build a new device able to determine the pvT relationship during injection molding of the polymer. The new device consists of a special mold that can be used on an injection molding machine and a data collection system connected to it. With the help of this device, pvT data can be measured during processing according to the thermal conditions of injection molding, and also considerably faster, and even in an industrial setting. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41140.     

注塑成型模拟技术在注塑工艺中的应用

注塑成型工艺已经发展成为塑料工业最重要的加工手段,注射模塑过程中需要选择和控制的压力包括塑化压力、注射压力和保压压力,它们直接影响塑料的塑化和塑件质量。通过对注塑过程中所涉及的工艺条件如何影响塑料制品的质量作了探讨,借助注塑工程分析软件对塑料制品的成型过程进行模拟,合理确定这些工艺参数,并分析了一个应用CAE技术优化工艺参数的实例,提出了比较切合实际并容易提高产品质量的注塑工艺方案。     

Effect of the physicochemical properties of the components of temporary technological binders on the deformation behavior of corundum plastic mixtures

The physicochemical parameters of water-soluble polymers of different nature and the deformation properties of plastic corundum mixtures plasticized by their solutions with the concentration of the dispersion media close to the optimum molding concentrations were determined. It is recommended to design compositions of temporary technological binders and control the properties of plastic molding mixtures with allowance for the components of the temporary technological binder.Translated from Steklo i Keramika, No. 7, pp. 17–20, July, 1996.     

聚合物PVT关系在线测试技术

提出一种新的聚合物PVT(压力-体积-温度)关系在线测试技术,利用这种技术设计制造的聚合物PVT关系在线测试设备对低密度聚乙烯(LDPE)进行了PVT关系测试,测试条件符合工业加工条件。因此,利用此技术可以建立典型商业材料的PVT数据库,作为优化相应材料的工业加工参数的基础数据。     

注塑包装设备科学发展的分析研究(1)

注塑包装设备的品种朝着功能化专用化方向发展,成型能力朝着高速化方向发展,控制系统朝着智能化方向发展,加工性能朝着节能化环保化方向发展。高速成型是注塑包装设备的首位加工性能,也是决定是否具有市场发展前途的标志。根据塑料包装容器的应用领域和功能特点,运用现代先进技术开发塑料包装设备,满足内需,推动塑料包装行业的发展。高速成型的研发重点是塑化注射机构、复合平行回路。节能技术的研发重点是伺服动力驱动节能系统、塑化加热节能系统、节能执行机构。能量的回收利用成为节能技术研发的又一个重要课题。创新实例说明注塑包装设备实现高速节能成型的关键是创新高速运行机构和高速成型回路。举例说明我国注塑包装设备科学发展已取得的初步成就。     

注塑工艺参数对制品残余应力和收缩的影响

注塑成型工艺参数对制品的最终残余应力和收缩有着直接的影响。基于线性黏弹性模型模拟计算了注塑成型过程中由温度和压力引起的残余应力和收缩。以无定型材料PS和ABS为例,系统地研究了不同成型工艺条件下平板制件的最终残余应力和收缩,并和实验结果进行对比验证。结果表明：在流动方向上无定型材料的收缩基本保持不变,残余应力沿壁厚分布的形状也基本相同,但流动末端处的应力值稍大于流动入口处;保压压力是影响制品收缩的关键因素,提高保压压力和注射温度可以降低制品的最终收缩,而模具温度对收缩的影响较小。     

滚塑发泡成型技术及其发展方向

介绍了一种新型的发泡成型技术———滚塑发泡成型技术。该技术既继承了传统滚塑成型的众多优点,同时又具有其独有的特点,即:具有发泡的芯层的同时又有光滑的表面,能大大提高产品的力学性能,弥补传统滚塑成型技术的缺点。主要从滚塑发泡成型技术的发展历程、工艺流程、加工原理、影响因素以及技术特点等几个方面,详细地介绍了如何利用滚塑发泡成型技术加工具有非发泡外壳和发泡内芯的塑料制品,并且着重介绍了一步法滚塑发泡成型工艺原理及影响因素,展望了滚塑发泡成型未来的发展方向。     

多方案填充内燃捣固镐外壳的流场分析

利用CAE技术建立ND-5型内燃捣固镐塑料外壳的注塑成型过程的物理和数学模型,分析注射成型过程中的流场,模拟分析了塑料件的多个注射成型填充过程,并分析各方案的充模特征,通过对比填充过程和缺陷,选取了最适合塑料件的注射成型方案。     

Optimalization of processing conditions for thermosetting polymers by determination of the degree of curing with a differential scanning calorimeter

The curing reaction of thermosetting polymers is accompanied by exothermal heat which has been measured with a differential scanning calorimeter. The Perkin-Elmer DSC-1 B was used for recording the curing behavior of a diallyl phthalate molding compound and two unsaturated polyester molding compounds. The residual heat of reaction has also been determined by a dynamic DSC scan of partly cured products made at various mold temperatures and curing times. It was thus possible to calculate the degree of curing and to dictate the optimum processing conditions for the indicated molding compounds. The interpretation of results leads to the conclusions that the DSC can be used to set specifications and to perform quality control for the molding compounds and that the most significant processing parameter is mold temperature.     

功能化注塑机的科学发展研究及自主创新(上)

功能化注塑机是特种具有注塑功能的复合型成型加工设备,驱动注塑技术的科学发展。提出了功能化注塑机的内涵,分析了功能化注塑机科学发展十个方面存在的理念问题,简述了功能化注塑机的科学发展的八个特点,研究了十类功能化注塑机的技术发展现状及科学发展要点,介绍了功能化塑料件引领创新创造功能化注塑机的实例及一种自主创新的功能化的工具箱包注吹机。     

功能化注塑机的科学发展研究及自主创新(下)

功能化注塑机是特种具有注塑功能的复合型成型加工设备,驱动注塑技术的科学发展。提出了功能化注塑机的内涵,分析了功能化注塑机科学发展十个方面存在的理念问题,简述了功能化注塑机的科学发展的八个特点,研究了十类功能化注塑机的技术发展现状及科学发展要点,介绍了功能化塑料件引领创新创造功能化注塑机的实例及一种自主创新的功能化的工具箱包注吹机。     

聚醚酰亚胺典型注塑制品成型技术

通过对聚醚酰亚胺塑料性能的研究,确定了典型制品过滤器壳体的注射成型工艺,证明了聚醚酰亚胺可用于制造特殊的过滤器壳体。结合工艺实践及最新的CAE成型理论提出了聚醚酰亚胺制品设计、模具设计、成型工艺的操作要点,为开发特种工程塑料制品积累了数据。     

塑料配电柜的研制和应用

研制了一种塑料配电柜，该塑料配电柜由改性树脂经注塑成型或者热压成型加工制作而成。另外，根据塑料配电柜的不同要求有的塑料配电柜中还使用了尼龙网或钢丝网或者钣金件骨架，这样既保证了塑料配电柜的绝缘性能，又增加了塑料配电柜的刚性，同时还增加了塑料配电柜对电磁辐射的屏蔽性能，试验结果表明，该塑料配电柜耐老化、免油漆、耐雨水冲刷、耐腐蚀、绝缘性能好、电磁波屏蔽性能佳、加工工艺简啦、生产制作成本低廉，综合性能优于会属材料制作而成的配电柜。