精密注射成型技术的进步英文翻译毕业论文.doc

精密注射成型技术的进步文摘：聚合物精密注塑成型技术的影响因素，包括精密模具，注塑机的控制精度，精密注塑过程控制和其他的计算机控制技术的精密注塑。这些因素进行了讨论，并给予相应的解决方案，最后介绍了一些先进的成型技术。关键词：精密注塑，注射成型机精密注塑技术，精密注塑模具 近年来，随着电子、通讯、医疗、汽车等行业迅速发展。高精度塑料制品和高性能的要求日益增长的精密成型技术继续进步，新技术不断涌现。精密注射产品尺寸精度要求高，但也应该有优良的光学性能。注塑成型时最重要的塑料成型方法，包括塑料包装、塑料、注射剂、冷却和一些基本的过程，从而影响精密注射成型的诸多因素。1、 精密模具。 为了生产的先进产品，精密模具是必要的。一般模具，会受到温度控制精度，模具及精密模具设计制造，使用的塑料收缩率的影响。1、1精密模具的温度控制 在一般的精密注塑成型部分，控制模具温度可以提高生产力。然而精密模具的温度控制具有着很大影响，它影响到部分的收缩，形状，结晶，如压力，冷热电路设计，模具温度分布要求合理，精确的控制精度，模具的最佳温度冷水机控制。模具温度控制和冷却时间对产品及其性能影响方面的原因：(1) 融化塑料注塑模具和双循环的时间会产生的模具温度差异的波动，因此被降低到最低点波动性高峰。(2) 通过具体的加热的传热过程，模具会发生改变，因此对媒体的控制是关键，一般进出口的冷却水温差异小于1C的应用理论计算的平均温度，从而可以保证稳定的热传递。媒体的流动与传热是相通的，模具的表面温度可以用来控制媒体流量的传感器，以补偿环境温度变化引起的模具温度变化引起的变化。(3) 为了确保稳定的热吸收与传播的平衡，注塑机融化注射要严格保持一个稳定的温度。周围温度对模具具有很大的影响，一般会影响到熔体的对流系数内的死亡率的改变，所以最好建立在模具表面的温度传感器，是在任何时候观察表面的温度，保持稳定。(4) 变化的热交换效率，具有模具经过很长一段时间在水管冷却的规模，然后出现在界面的减少导热系数应及时清除水垢。1.2精密模具的设计与制造 模具设计是好还是坏，是为了确保塑料零件的尺寸精度的前提下，为了提升精密注塑模具的精度，在设计电脑辅助分析是必要的过程中，特别是浇注系统和热流，空调系统模具温度分布的分析。应用程序应该尽可能的仿真软件的使用和接近实际的负载条件下，熔体在模具中浇注，冷却，和其他非稳态过程仿真分析。 模具制造质量是保证塑件尺寸精度的关键，精密模具的主要特点是除了抛光的制造和装配业务，无需人工处理。模具一般加工和手工加工的比例约为6:4至7:3，加工精密模具和手工加工比为9:1。 模具材料及热处理是精密模具在成型过程中的保护，在国家的模具温度，甚至模具部分低温回火，高温熔化生产，将重复部分回火而使硬度低，代价也应该残余奥氏体的体积膨胀所造成的。因此，一般回火温度至少应该成型加工，增加一倍以上的模具温度和低温处理进行了妥善，以消除残余奥氏体。 在成型精密零件的高精密产品，精密模具装配积累在子表面精度以及平行度应达到微米级的方向。模具应具有足够的强度，硬度和耐磨性，坚硬耐磨的压力下注塑变形。为了实现上述处理可以是三维精密加工中心，数控机床的CAD / CAM / CAE技术和其他新技术的应用。1.3 使用精密模具设计收缩率 热塑性塑料成型收缩率不稳定，模具设计，产品腔大小的尺寸精度难以识别和控制。因此，在塑料模具设计中应该了解的特点和收缩造成网站收缩率的差异部分的形状，然后用必要的补偿措施。上高精密塑料部件可以在设计制造，模具简单，前测成型的实际收缩率的各个部分，这样可以大大提高零件的尺寸精度。1.4 设计精密模具的浇口 浇口的大小，位置和数量，尺寸精度的影响部分。但由于浇口的射流的影响，对于厚壁部件不适用。由于浇口位置及熔体流动距离的影响，熔体流动过程更大的收缩。很多过程可以缩短，但增加焊接的标记。浇口配件的设计应在规定的尺寸和材料的选择和使用的软件，以帮助完成实践经验。 2. 最佳的精密注塑成型工艺参数的设置 。 选择最佳的成型工艺参数，以减少塑料的收缩率。塑料收缩是指塑料热收缩、弹性恢复、塑性变形、塑性变形后收缩的综合反映，通常是由于造成老化或引起分子链重排引起的，具体表现为线性收缩率和体积收缩率的变化共同收缩值表示。 热塑性塑料注塑制品收缩的挥发性，特别是水晶注塑成型产品更加明显，不仅取决于由于化学结构的结晶度，而且也由于冷却过程参数（冷却速度，熔体温度，模具温度，产品厚度）的模具型腔尺寸和设计确定的尺寸精度控制的产品和困难的影响，目前迫切需要注意的参数对注射成型塑料收缩率的影响规律。不同厚度上存在的差异普遍认为由以下两个因素导致： 首先，高压熔模使模具型腔导致较小的变形材料的弹性模量变形后扩充。一般来说，质量控制和准确性，可以很好的尺寸精度，并在较高的温度，模具熔体粘度低，粘度较小的梯度，在一定的螺杆背压，精密零件的质量，可以精确地控制。但是，液晶聚合物（LCP），只需要较低的模具温度，这是因为冷LCP的情况下，将迅速冷却后非晶态。 增强或塑料填充，热容量下降刚度增加显着降低收缩和纤维填料含量或更高，较小的收缩率。晶体精密塑料制品也受到压力。为压力注射压力（P1），保压压力（P2）和摄食压力（P3），以加快结晶过程，结晶的P1，P2，P3的增加，在上升趋势中的作用的结晶。压力为P1，提高结晶度的结晶，增加收缩率上升P2和P3，一方面是因为增加的结晶收缩率增加的程度，另一方面增加P2的更大的压力，融化，类型腔已完全压实塑料; P3 - 饲料增加增加，有效地防止回流，有利于减少收缩。因此，塑料件的收缩率是共同作用的结果，与收缩的P1，P2，P3的，先增大后减小增加。 精密塑料件，不仅需要稳定的尺寸公差，但还需要严格的机械性能。这些特征主要取决于熔体热的冷却阶段 - 机械的历史进程中的作用。模具温度和冷却时间对产品的质量和对生产力有直接的影响。研究发现，模具温度，冷却时间的产品尺寸精度不延长已显着改善，只有在一定的时间内，经过了突出的作用。在冷却过程一般在这样一个关键时刻，有两个冷却，冷却时间，在第一点，虽然生产的产品也更高的准确性，但它是不是最稳定的状态，和第二点的时间冷却降温相对较长时间，然而，该产品使最稳定的状态。 3、 使用精密注塑机替换传统注塑机 精密注塑机注入功率一般较大，除了这样的喷油压力和注射，以满足在速度方面的要求，压力本身将是对注塑产品提高精度的一个特定的角色。精密注塑机控制系统一般都具有控制精度高，它是由产品本身的要求。精度高，可以保证控制注射工艺参数具有良好的准确度、精密度的产品，从而避免由于波动过程参数的变化。因此，精密注塑成型机一般的喷射，注射压力，注射速率，背压和螺杆转速的工艺参数惊醒了多层次的反馈控制。其精密注塑模系统其要求有足够的刚性，精度否则产品将是一个下降的弹性变形模型。第二压铸模具系统必须能够准确地控制大小，或过大或过小的精密产品的模型，将有不利的影响。因此，在设计，它应该被认为是模具的刚性，刚度，以及作为一个模型系统，以精确控制的精密产品，尤其是平板薄壁产品的大小。 当模具较大，必须面向列偏转检查。精密注塑机还必须能够精确的温度控制的液压回路工作，努力防止油因温度变化引起的粘度和流动的变化，进一步注射工艺参数波动而使产品将失去其准确性。3.1 零件成型周期时间一致性 典型注塑机一般有三种方式：手动、半自动和全自动。作为诸多因素的影响，每一组前两种模型成型周期时间可能不懂，它将影响温度和材料，从而影响到部分精度，在精密注塑模应尽量使用自动模式。3.2新型精密注塑机螺杆温度控制和设计 注塑机缸自动调温周期，材料的密度和粘度的变化，从而影响零件的质量和尺寸精度的周期性波动，冲模接近注塑机喷嘴，因此，温度喷嘴的模具零件也有很大的影响。现代注塑机配备一种特殊工艺控制软件来控制温度波动的趋势，这是比例积分微分（P ID）控制。 至少从酒桶里的一点透视温差电话，为P ID参数优化可以完全消除温度的波动。 塑料质量和稳定性的塑料配件、注射机组是非常重要的。塑料件的质量和稳定性，注塑机组非常重要的。塑料股是一个重要的判断标准：注射量，塑料率，注射速率，当时在塑料单元的聚合物。由于塑料零件质量，尺寸精度误差的一个非常重要的影响，它应该是注塑机精密注塑控制。提高测量精密注塑成型机的最有效方法是使用技术来实现螺杆直径最小，尤其是光的部分。测量相对螺丝的长度和总长度的螺丝小，在塑料材料的单位，在时间也越来越短。螺纹类似扩大的材料，可避免停留更长的时间，使螺杆和稳定运行。罗深沟宽度比相对较小，它创造了很多特别有效的小直径螺杆工程塑料部分。熔体均匀性和不小的压缩比降低，这是因为从很浅槽，螺引起很强的剪切速率的结果。饲养设计的难度，必须确保所有的聚合可以均匀地喂。考虑到需要，周期更短，塑料率也必须足够大，在饲料中的设计，必须有效地解决之间的矛盾。此外，如果采用两个阶段的注射螺杆，可以实现精确控制注射的误差，这就需要通过测量中检测到的球形阀熔体注塑机在底特律射出成型机。 前微处理器控制的注塑成型工艺不能获得通过注射精密电压比较已成功解决。通过电压比较器允许发射器和其他敏感了非常精确的电压信号传递，当出现设定点后立即传送到微处理器控制，以便及时信号的真正价值，为了操作程序周期，异步不时通过直接传输信号的过程中消除，大大提高了控制精度。 4、 精密成型技术4.1注塑压缩成型应用（ICM）技术 ICM技术是指模具开启一定距离的条件下开始注射，注射到一定量后，模具开始闭合对型腔内的熔体实施压缩，模具完全闭合时注射终止，然后保压、冷却直到取出制品。注射压缩成型是通过压缩行为来压实制品，使得制品的表面具有均匀的压力分布，这样压实的制品尺寸精度高且稳定，变形小。它是在模具开启的情况下将熔体注入型腔的，因而流动通道大，所需的注塑压力很低，并且减小或消除了由保压引起的树脂分子取向和制品的内应力，从而提高制品的尺寸稳定性。ICM技术的柔性与控制能力都较一般的注射模有较大的提高。因此利用这项技术可以生产更高精度的制件，尤其是高精度的圆柱状制件。4.2 高速注射成型高速灌装注射成型方法融化的速度比传统的10到100倍的速度，熔体在模腔内产生高剪切流，降低粘度，注射速度，减缓塑料表面硬化，从而改善薄膜成型产品壁厚度的限制，抑制过度的成型压力，以及由于低电压的移动模式，产品减轻压力。薄壁的精密产品，我们可以使用注射螺杆在从熔体在螺杆的能量吸收向前后停止运动，通过高速扩张融化全腔来实现。 4.3无高压注射成型 无高压注射成型技术是指塑料熔体高速，高压充填到模具，然后在喷嘴针阀关闭自动补偿合同的不同部分熔化塑料模具型腔产品，这些产品可以大大减少翘曲。然而，这种方法需要事先估计的包装收缩，因此需要注入更高的模腔压力值，我们需要的夹紧力也很高。 窗体顶端4.4其他智能控制技术精密注塑成型加工条件，在连续监测和精确控制的实施过程中是非常重要的。随着计算机技术的发展，已广泛应用于电脑注塑。其中，统计过程控制（SPC），P ID技术，模糊逻辑控制（FCC），网络控制中心（NNC）的方法和模型的基础上的骨干网络规模控制的反向处理。5. 结论 在高精密塑料制品，高性能的要求日益精密注塑成型技术是前进的动力，人们对精密注塑的原则，精密注塑技术的认识不断深化是基础进展。随着新材料，新工艺和新设备已经出现，特别是在塑料加工计算机，精密注塑技术的广泛应用，以创造良好的条件。作为这些技术的合理运用，我们将能够生产高精尖产品。参考文献：1罗卫华，等. 工程塑料应用, 2002, 30 (8) ： 272张友根. 塑料技术, 1990 (1) ： 173奚永生. 精密注塑模具设计. 北京：中国轻工业出版社, 1997.4林鹏. 模具技术, 1998 (1) ： 705王松杰，等. 塑料加工, 2002, 37 (3) ： 406陈洪，等. 精密塑料成型. 北京：国防工业出版社, 1999.7孙奇志，等. 塑料科技, 1996 (6) ： 138Liu C. Polymer Engineering and Science, 1996, 36 (1) ： 19周坤鲁，等. 工程塑料应用, 2003, 31 (1) ： 3110戴文利，等. 高分子材料科学与工程, 1995, 11 (5) ： 9711Yang S Y, et al. Advances in Polymer Technology, 1996, 15 ( 4) ：28912Chen Shia2chung, et al. Advances in Polymer Technology, 2003, 22(4) ： 30613朱锡坤，等. 模具工业, 2001 (11) ： 3714Kleinebrahm. M. Kunstoffe Plast Europe, 1998 (1) ： 1215胡海青. 工程塑料应用, 2000, 28 (10) ： 1816Mikell K. Plastics Technology, 2001 (4) ： 5417许航. 机电元件, 2002, 22 (2) ： 5618许忠斌，等. 中国塑料, 2003, 17 (4) ： 6119Yang S Y, et al. Advances in Polymer Technology, 1996, 15 ( 3) ：20520Masaki Y, et al. Polymer Engineering and Advance, 1998, 38 (9) ：158721Peter Pokorny, et al. InjectionMoulding, 2001, 91 (7) ： 2222吴大鸣，等. 中国塑料, 2003, 17 (2) ： 1Precision injection molding technology of progressAbstract: The polymer precision injection molding technology, impact on precision injection molding of factors, including the precision molds, injection molding machine control accuracy, precision injection process control and other computer control technology. These factors were discussed, and give the relevant solutions, finally introduces some advanced molding technology.Key words: precision injection; injection molding machine precision injection technology; Precision Injection MoldIn recent years, as electronics, telecommunications, medical, automotive, and other industries of the rapid development of the high-precision plastic products, and high-performance requirements of growing precision molding technology to continue to progress, new technologies continue to emerge. Precision injection molding products not only require high dimensional accuracy, and low warpage, to write good, but there should also be excellent optical properties. Injection molding is the most important one of the plastic molding methods, including plastics plastics, injection, packing, cooling, and some of the basic process, thus affecting the precision injection molding of many factors. 1, precision moldsTo produce sophisticated products, precision molds is essential. Die Die in general, the accuracy of the temperature control, mold and die design precision manufacturing, use of plastic shrinkage rate impacts. 1.1 Precision Mold temperature controlIn general precision injection molding of parts, control mold temperature is to increase productivity. However mold temperature control for precision injection molding of great impact, it affects parts of the contraction, shape, crystallization, such as stress, hot and cold circuit design mold temperature distribution at the request reasonable, precise control accuracy, a die temperature of the best and Lengshuiji control. Mold temperature control and cooling time on the products and their impact on performance of the following factors:(1) melt plastic injection molds and a two-cycle time will be produced in the mold temperature difference fluctuations, and should therefore be to minimize the volatility differential peak.(2) the heat transfer heat through the concrete and die in the transfer out of the media, mold is changed, the media control is the key, the general import and export of its cooling water temperature difference is less than 1 c Application of theory to calculate the average temperature, which can guarantee the stability of heat transfer. Media flow and heat transfer are interlinked, mould surface temperature can be used to control the media flow sensor to compensate for environmental temperature changes caused by mold temperature changes.(3) To enable stable by the heat absorption and dissemination of balance, the injection molding machine to melt injection to strictly maintain a stable temperature. Die surrounding temperature on the mold had a great impact on the general will be affected to die within the melt convection coefficient of change, so the best set up in the mold surface temperature sensor, die at any time observation of the surface temperature, and keep it stable.(4) changes in the efficiency of heat exchange with mold after a long time in the cooling water pipes and Youban appears in the scale, then the interface to reduce the thermal conductivity should furring timely clearance.1.2 Precision Die Design and ManufactureDie design is good or bad is to ensure the dimensional accuracy of plastic parts premise, in order to enhance the accuracy of precision injection mold, in the process of designing a computer-aided analysis is necessary, especially for gating system and the flow of heat-conditioning systems mold temperature distribution the analysis. Applications should be as much as possible the use of simulation software and close to the actual loading conditions to melt in the mold simulation analysis in the pouring, cooling, and other non-steady-state process.Die manufacturing quality assurance plastic parts Size is the key to accuracy, precision die is the main characteristic of the manufacturing and assembly operations in addition to polishing, are no manual processing. Die general machining and manual processing ratio is about 6:4 to 7:3, and the machining precision molds and manual processing ratio of 9:1. Die materials and heat treatment is the protection of precision molds in the molding process, the die temperature in the state, which even the mould parts tempered by low temperature, high temperature melt production and will repeat parts tempering ifij-fl! lower hardness, Consideration should also be given retained austenite caused by the volume expansion. Therefore general tempering temperature should be at least molding processing, more than double the die temperature and low-temperature processing is carried out properly in order to eliminate residual austenite. On the high-precision products for Molding precision parts, assembly accumulated precision die in the direction of the accuracy of the sub-surface as well as the parallel degree should achieve micron level. Mold should have sufficient strength, stiffness and abrasion resistance, in the injection molding deformation under the pressure of hard wear. To achieve the above processing can be three-dimensional precision machining centers, CNC machine tool and application of CAD / CAM / CAE and other new technologies.1.3 precision molds design shrinkage rate of useThermoplastic plastic molding shrinkage volatile, to mold design, identify and control products cavity size dimensional accuracy difficult. Therefore, in plastic mold design should understand the characteristics and contraction caused by the shape of the parts of the difference in the rate of contraction site, and then uses the necessary compensation measures. On the high-precision plastic parts can be manufactured in the design before simple mold, measured molding to the various parts of the actual shrinkage rate, this can greatly enhance the dimensional accuracy of parts. 1.4, the design of precision molds gateGate type, size, location and quantity of all affected parts dimensional accuracy. At the gate of the jet, but the effects of poor feeding, thick-walled parts do not apply. Gate position and the flow of impact melt flow distance, the longer the process of the greater contraction. Multi-gate process can be shortened, but increasing weld marks. Gate parts should be designed in accordance with the size and the choice of materials and the use of software to help finalize practical experience. 2, the best precision injection molding process parameters setChoose the best molding process parameters to reduce plastic shrinkage rate. Plastic is that the contraction of the heat shrinkable plastic, elastic recovery, plastic deformation, contraction after contraction and a comprehensive reflection of aging, usually caused by absorbent material or molecular chain rearrangement caused, the specific performance linear shrinkage rate and volume contraction rate changes in value of common contraction said. Thermoplastic plastic injection molding products shrinkage volatile, particularly for crystalline plastics injection molding products even more obvious, and not only depend on the degree of crystallinity due to the chemical structure, but also by the process of cooling parameters (cooling rate, the melt temperature, mold temperature , product thickness) the impact of the mold cavity size and design determine the size precision control products and difficulties, there is an urgent need to be aware of parameters on the injection molding of plastic shrinkage rate of the impact of the law. Part of the difference in thickness is generally believed that the two factors:First, high-pressure melt the mold cavity caused minor deformation of a die when the elastic modulus material after the expansion. Generally speaking, quality control and accuracy can be very good dimensional accuracy, and at a higher temperature, mold low melt viscosity, viscosity smaller gradient, in a certain screw back pressure, the quality of precision parts can be accurately controlled. But for liquid crystal polymer (LCP), it just needs a lower mold temperature, it is because cold LCP case will be promptly after cooling amorphous.LCP have low melting heat and orderly structure of the state, in the liquid crystalline state to change between crystalline solid, smaller changes, when fully cooling, the liquid - solid transition is almost complete in an instant. Die in the colder, when a cavity, the cavity material and the bulk of gate has been cured, it is very difficult stage compression added melt, thus parts and the size of the cavity size of the deformation is very close. Plastic amorphous than crystalline plastics low shrinkage with a mixture of contraction rate of low-polymer materials, elastomers at the same time as the increase of the content, materials shrinkage rate decrease. The enhanced or plastic filling, heat capacity decrease stiffness increased significantly reduce shrinkage and fiber filler content or higher, the smaller the rate of contraction. Crystalline precision plastic products also affected by pressure. As pressure crystallization of the role of injection pressure (P1), the packing pressure (P2) and the feeding pressure (P3) to speed up the crystallization process, crystallization of the P1, P2, P3, the increase in upward trend. For P1, the pressure to improve the crystallization of the degree of crystallinity, the contraction rate of increase rose P2 and P3, on the one hand because of the degree of crystallinity increased shrinkage rate increase, on the other hand increased to P2 more pressure to melt, the type cavity has been fully compacted plastic; P3-feed increased to increase, and effectively prevent reflux is conducive to reducing shrinkage. Therefore, the plastic parts of the shrinkage rate is the result of both, with the shrinkage of P1, P2, P3, the first increases and then decreases increased.Precision plastic parts require not only stable size tolerances, but also require strict mechanical properties. These characteristics mainly depend on the cooling phase of the melt in the heat - mechanical role of the historical process. Mold temperature and cooling time on the quality of products and have a direct impact on productivity. Study found that,given the die temperature, the dimensional accuracy of products with the cooling time is not the extension has been significantly improved, and only in a certain period of time, after a prominent role. In general cooling process in such a critical point in time there are two cooling, cooling time in the first point although production products also higher accuracy, but it is not the most stable state, and the second point-in-time cooling cooling relatively long time, However, the products enable the most stable state. 3, using precision injection molding machine to replace conventional injection molding machinePrecision injection molding machine generally larger injection power, in addition to such injection pressure and injection to meet the requirements in terms of speed, power itself will be on the injection products improve the accuracy of a certain role. Precision injection molding machine control systems generally have high control precision; it is requested by the products themselves. High accuracy can be guaranteed control of injection process parameters has good accuracy, precision products in order to avoid fluctuations due process parameters change. Therefore precision injection molding machine generally of the injection, injection pressure, injection rate and pressure-pressure, back-pressure and screw speed process parameters such as a multi-level feedback control. Precision Injection requirements of its modulus system have sufficient rigidity, accuracy or products will be a model for the elastic deformation decreased. Second-Die-Die of the system must be able to accurately control the siz