植物秸秆电磁感应辅助加热挤压膨化技术研究

利用电磁感应辅助加热挤压膨化机对植物秸秆进行了膨化加工试验。研究结果表明:电磁感应辅助加热挤压膨化机利用高频转换器产生的高频电流,从而达到控制挤压膨化温度的作用。一级电磁感应加热,预热植物纤维,控制温度在80～110℃,二级电磁感应加热,为秸秆挤压膨化加工提供稳定的高温高压条件,控制温度在250～300℃。膨化量可达到200～400 kg/h,膨化产品粗纤维含量下降30%～50%,无氮浸出物含量在20%以上,代谢能提高近10倍。电磁感应辅助加热挤压膨化技术研究为形成工业化规模的秸秆膨化加工利用奠定了良好的基础。     

电磁感应加热在轮胎硫化机上的应用研究

针对轮胎硫化生产中蒸汽用量大、耗能严重等问题,引入具有热效率高、节能效果显著等特点的电磁感应加热替代传统蒸汽加热,并设计了一种单元式电磁感应加热方案,对电磁感应加热工艺下热板的温升情况、温度周向均匀性、径向温度分布以及节能效果进行了研究。结果显示,电磁感应加热方法具有温度分布均匀、温模速度快、降低能耗等优势,可提升生产效率并降低生产成本,进而能提高轮胎在价格方面的竞争力。     

实心轮胎电磁感应加热硫化工艺

以某规格实心轮胎为例,采用电磁感应加热方法对实心轮胎进行硫化,通过调整感应线圈的排布方式及电磁加热参数对电磁感应加热方案进行优化.结果表明,采用优化后的电磁感应加热方案对轮胎进行硫化,整个硫化过程中轮胎周向和纵向温升一致,轮胎纵向硫化不均问题得到很大改善,纵向温差大幅减小,可控制在5℃范围内.     

基于磁-热耦合有限元法的挤出机电磁感应加热温度场模拟研究

通过Ansoft Maxwell和Ansys Mechanical软件对挤出机电磁感应加热的三维有限元模型进行磁-热耦合仿真研究,计算了挤出机机筒与螺杆在电磁感应加热条件下的电流密度分布以及涡流和涡流损耗;并将涡流损耗结果导入Ansys Mechanical热分析模型中,计算得到机筒与螺杆三维模型在电磁感应加热条件下的稳态温度场分布。通过模拟及节电效果估算表明:电磁感应加热方式是一种节能高效的挤出机加热方式。     

吹膜挤出机的电磁感应加热系统建模与有限元模拟研究

为实现吹膜挤出机在电磁感应加热条件下能效的定量分析,对吹膜挤出机电磁感应加热的三维有限元模型进行了研究,导出了对应于指定机筒和螺杆材料的电流透入深度与电磁感应加热器的各设计参数之间的关系;分析了挤出机的机筒与螺杆等关键部件在电磁感应三段式分区加热条件下的磁场分布、电流密度场分布及焦耳热能分布的相对趋势。结果表明,感应磁场主要分布在机筒内表面,而相应的感应电流主要分布在机筒外层,且当机筒上缠绕的3组匝数相同的电磁感应加热线圈中加载有大小相等、方向相同的交变电流时,电流密度和产生的焦耳热能集中在机筒和螺杆的中部,而适当增加进料段与计量段加热区所对应的两组线圈匝数可获得较为均匀的电磁感应加热效果。相对于电阻式加热,电磁感应加热的能量损耗较小,是一种环保节能的吹膜挤出机加热方式。     

基于ANSYS的注射机料筒感应加热温度场数值模拟

应用感应加热理论,利用麦克斯韦方程组和导热微分方程,并引入复矢量磁位,建立了电磁场与温度场耦合的有限元数学模型,利用大型通用有限元分析软件ANSYS对注射机料筒的感应加热过程进行了模拟分析.讨论了感应加热有限元分析中温度场与电磁场耦合、料筒材料物理参数对温度依赖性等关键技术问题的处理方法.分析了料筒的感应透热过程,得到了料筒内的温度分布状况以及温度随时间的变化规律.模拟分析了频率、线圈电流强度系数等参数对料筒温度控制的影响.通过得到的结果,了解感应加热温升过程和特点,从而为注射机料筒温度控制提供一定的依据以及为感应加热器的参数选取提供一定指导作用.     

微机在注射机控制中的应用研究

利用微机技术实现对注射机动作的程序控制和工艺参数的控制,可提高注射机的自动化水平和可靠性,大大改善工艺参数的控制精度和灵活性。本文介绍了利用单板机实现对注射机模具温度、熔体温度、料筒温度和注射时间、保压时间、冷却时间的控制和显示;对注射机注射速度、注射压力、保压压力的控制,以及对注射机动作的程序控制。     

电磁感应加热在三氯氢硅反应炉上的应用

针对三氯氢硅反应炉电阻加热方式存在的问题,提出采用工频电磁感应的加热方式,并通过试验及实际应用,证实了将工频电磁感应加热方式运用到三氯氢硅反应炉的加热上是完全可行的,而且经济实用.     

注射成型模具电磁感应加热技术

阐述注射成型模具电磁感应加热技术的原理及模外感应加热和模内感应加热的实现方式,着重介绍当前常用的机械手辅助感应加热、模芯通电感应加热、感应加热管加热、模具内置线圈感应加热和模芯内嵌线圈感应加热的方法,并分析了各种方法的优缺点,展望了电磁感应加热在注射成型模具上的发展趋势。     

废塑料裂解方式及其设备设计

针对目前塑料连续热裂解装置存在的一些问题,提出了一种电磁感应加热式三段废旧塑料热裂解装置,这种结构的热裂解装置具有生产率高、塑料受热均匀、对零件材料高温下的强度要求降低等优点,而且与传统热裂解相比,三段式电磁感应加热裂解装置可以准确调节裂解温度,有效控制裂解产物的成分,提高裂解产物的质量。电磁感应加热裂解设备具有广阔的应用前景。为高效的连续热裂解装置的设计提供参考。     

电磁感应加热技术在注塑机螺杆上的设计

注塑机螺杆的加热工艺不断提高,传统的电阻丝螺杆加热已成为注塑机向节能环保型机械装备发展的瓶颈,新型电磁感应加热具有节能环保、加热均匀等优点,得到重点研究和快速应用.结合注塑机快速加热的工艺特点,设计一套相应的电磁感应加热控制器,有效监控电磁感应加热的过程并不断改善加热效果.     

基于PLC的注塑机多段温度控制系统设计

为保证注塑机注塑质量和加工精度,应对注塑机料筒温度进行精确控制,因此设计了基于可编程控制器(PLC)为核心控制器的注塑机温度控制系统。首先介绍了注塑机结构和注塑工艺流程,以PLC、触摸屏为控制器核心设计了注塑机硬件系统。采用热电偶传感器采集各段温度并传送到PLC中,通过比例积分微分(PID)智能控制算法完成温度的闭环精确控制。结果表明:基于PLC的注塑机PID多段温度控制系统能够实现温度的精确控制,温度误差能控制在±0.3℃以内;该控制系统完全满足注塑工艺要求,能够显著提高注塑机的自动化程度。     

Fully-Coupled Numerical Analysis of High-Frequency Induction Heating for Thin-Wall Injection Molding

In recent years, rapid mold heating has served to enable the injection molding of thin-walled parts or micro/nano structures. Induction heating is an efficient way to heat metal parts by means of an electric current that flows through a conductive material by electromagnetic induction. The present study covers a numerical investigation of high-frequency induction heating of an injection mold in order to rapidly raise the mold temperature. To take into account the effects of thermal boundary conditions of induction heating, a fully coupled numerical analysis effectively connecting electromagnetic field calculation, heat transfer analysis, and injection molding simulation was carried out. The proposed integrated simulation was applied to the injection molding of a thin-wall part, and its results were compared with experimental findings in order to verify the validity of the proposed simulation.     

诱导式全电动注塑机电控系统设计

使用特制的诱导电机和有效的过程控制技术,开发出了性能价格比高的诱导式全电动注塑机。介绍了诱导式全电动注塑机电控系统的工作原理和主要组成部分。诱导式全电动注塑机相对于油压式注塑机而言,在环保、节能和性能方面有着独特的优势,且比永磁全电动注塑机价格低。     

Research on a New Variotherm Injection Molding Technology and its Application on the Molding of a Large LCD Panel

The polymer injection products produced by using the current injection molding method usually have many defects, such as short shot, jetting, sink mark, flow mark, weld mark, and floating fibers. These defects have to be eliminated by using post-processing processes such as spraying and coating, which will cause environment pollution and waste in time, materials, energy and labor. These problems can be solved effectively by using a new injection method, named as variotherm injection molding or rapid heat cycle molding (RHCM). In this paper, a new type of dynamic mold temperature control system using steam as heating medium and cooling water as coolant was developed for variotherm injection molding. The injection mold is heated to a temperature higher than the glass transition temperature of the resin, and keeps this temperature in the polymer melt filling stage. To evaluate the efficiency of steam heating and coolant cooling, the mold surface temperature response during the heating stage and the polymer melt temperature response during the cooling stage were investigated by numerical thermal analysis. During heating, the mold surface temperature can be raised up rapidly with an average heating speed of 5.4°C/s and finally reaches an equilibrium temperature after an effective heating time of 40 s. It takes about 34.5 s to cool down the shaped polymer melt to the ejection temperature for demolding. The effect of main parameters such as mold structure, material of mold insert on heating/cooling efficiency and surface temperature uniformity were also discussed based on simulation results. Finally, a variotherm injection production line for 46-inch LCD panel was constructed. The test production results demonstrate that the mold temperature control system developed in this study can dynamically and efficiently control mold surface temperature without increasing molding cycle time. With this new variotherm injection molding technology, the defects on LCD panel surface occurring in conventional injection molding process, such as short shot, jetting, sink mark, flow mark, weld mark, and floating fibers were eliminated effectively. The surface gloss of the panel was improved and the secondary operations, such as sanding and coating, are not needed anymore.     

橡胶注射成型机的应用及新进展

简要介绍了日本KRV-60型橡胶注射成型机的主要结构和控制部件,主要技术参数和工艺参数及对胶料的要求和新进展。橡胶注压工艺具有高温快速硫化、节能及自动化程度高等优点,以橡胶注射成型机代替平板硫化机是橡胶加工业的发展方向。     

Effect of rapid mold surface inducting heating on the replication ability of microinjection molding light‐guided plates with V‐grooved microfeatures

This study applies a magnetic induction heating method for rapid and uniform heating of a mold surface for injection molding of 2‐inch light‐guided plates (LGPs). Mold temperature is an important process parameter that affects microinjection molding quality. This research investigates the effects of high‐mold surface temperature generated by induction heating in enhancing the replication rate of microfeatures of LGPs. This study has three stages. First, an appropriate power rate setting is determined for induction heating and injection molding process window. Second, all key parameters affecting microfeature quality are identified to determine the optimum LGP micromolding parameters using the Taguchi and ANOVA methods. Third, the quality of microfeature heights and angles are experimentally verified. Polymethyl methacrylate was molded under various injection molding conditions to replicate an electroformed nickel stamper with V‐grooves 10 μm in width and 5 μm in depth. In this investigation, injection speed was set in the conventional range. Experimental findings indicate that instead of high‐mold temperature, the combination of low mold temperature and high surface temperature obtained using induction heating improve replication quality and reduce cycle time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

注塑制品件重重复精度的影响因素研究

对影响注塑制品件重重复精度的塑化位移、背压、螺杆转速、加热温度、螺杆性能、注塑压力、注射速率、注射效率、模具温控性能等主要因素,从理论和实践上作了比较具体的分析,提出了提高注塑制品件重重复精度的具体措施。     

微注射成型中变模温控制技术

阐述了变模温控制在微注射成型中的重要性，介绍、比较了当前出现的电热水冷、感应加热、薄膜电阻式加热、复合模壁绝热-加热、复合模壁绝热-压缩热空气加热几种变模温控制实现方法，展望了未来微注射成型中变模温控制的发展趋势。     

前端控制式新型超高速精密注射成型原理的研究

对前端控制式超高速精密注射成型的工作原理以及技术优势进行了介绍。提出了一种通过控制前端喷嘴阀门开关使蓄积压力势能的高聚物熔体实现超高速注射成型的新方法。研究利用超磁致伸缩材料伸缩响应速度快、承载能力强等特点制造电磁控制注射喷嘴,为解决超高速精密注射成型中高应答性和高控制精度的问题提供了一种新方案。