注塑成型设备机械课程毕业设计外文文献翻译/中英文翻译/外文翻译

中国地质大学长城学院  本科毕业设计外文资料翻译  系     别：         工程技术系          专     业：   机械设计制造及其自动化    姓     名：          贾朋渤          学     号：        05211628          2015 年  4 月  1 日  外文资料翻译译文  近年来，随着塑料工业的飞速发展和通用与工程塑料在强度和精度等方面的不断提高，塑料制品的应用范围也在不断扩大，如：家用电器、仪器仪表，建筑器材，汽车工业、日用五 金等众多领域，塑料制品所占的比例正迅猛增加。一个设计合理的塑料件往往能代替多个传统金属件。工业产品和日用产品塑料化的趋势不断 上升 塑料工业的机械和装备的水平对该工业的发展起着关键作用。比起传统的塑料挤出机，单螺杆塑料挤出机有他积极的优势，通常他能加工出高分子量、高粘度热塑性好的塑料。其中有高生产率低熔点、高熔体强压力的塑料有利于化学降解，产品质量高，因此是最佳的塑料生产这使得单螺杆塑料挤出机生产经济，特别适用于稳定的挤压。  所谓注塑成型（ Injection Molding）是指，受热融化的材料由高压射入模腔 ，经冷却固化后，得到成形品的方法。该方法适用于形状复杂部件的批量生产，是重要的加工方法之 一。  注射装置是使树脂材料受热融化后射入模具内的装置。从料头把树脂挤入料筒中，通过螺杆的转动将熔体输送至机筒的前端。在那个过程中，在加热器的作用下加热使机筒内的树脂材料受热，在螺杆的剪切应力作用下使树脂成为熔融状态，将相当于成型品及主流道，分流道的熔融树脂滞留于机筒的前端（称之为计量），螺杆的不断向前将材料射入模腔。当熔融树脂在模具内流动时，须控制螺杆的移动速度（射出速度），并在树脂充满模腔后用压力（保压力）进行控制。当 螺杆位置，注射压力达到一定值时我们可以将速度控制切换成压力控制。  螺杆的回转航程和固定筒壁的相互作用是挤出机的泵出过程中必要的参数。为了运输塑料材料，其摩擦在螺杆的表面要低，但在固定的筒壁要高。如果达不到这个基本标准，塑料可能会随着螺杆旋转，而不是在轴向 /输出方向上移动。在输出区域，螺杆和机筒的表面通常都覆盖着的溶解物以及来自溶解物和螺杆通道之间的外力，而其除了  处理有极高粘性的材料时都是无效的，如硬质  PVC 材料和有超高分子量的聚乙烯。溶解物流在输出部分是  受内摩擦系数（粘度）影响，尤其是当模具提供了一 个高阻力的熔体流时。   常见且更多使用的单螺杆型使用的是传统设计，即机筒和螺杆保持基本一致的直径，包括具有例如减小螺  杆通道体积，有连续可变速度、压力控制，和通风（挥发）系统的挤出机。一些特殊的设计使用了圆锥或  抛物线外形的螺杆，用以达到特殊的混合和捏合效果。它们可以包含偏心的核心，根据不同坡度变化的动  程，揉捏转子，适应性的核心环，和间歇的轴向运动。桶内可能有螺纹，可伸缩的螺杆形状以及进料设备。   一个成功的挤出操作需要密切注意很多细节，如（ 1）进给材料的质量和在适当温度下的物质流，（ 2）足以  融化、但不 会分解聚合物的温度曲线，以及（ 3）不会分解塑料的启动和关机。   应采取措施，防止促进塑料表面上水分的胶合和湿气的吸收凝结，如颜料浓缩物中的色素。料斗干燥机已被  证明在干燥塑料中非常有用。它们还可以在操作中提高挤出机受加热和熔解能力限制的输出的能力。图  显示了与加热输入挤出机所需的熔化塑料，有或没有料斗干燥机作为预热器时相关的不同。挤出机使塑料  熔体均匀熔化，并使之通过与产品的横截面形状关联的模具口。所形成的  TP 的熔体（挤出的）是冷了却的，或是加热的 TS 熔体，因为它是向下放置的进而得以远离模具出口或是通过 下游设备拔出。   注射成型是塑料加工中最普遍采用的方法。该方法适用于全部热塑性塑料和部分热固性塑料，制得的塑料制品数量之大是其它成型方法望尘莫及的，作为注射成型加工的主要工具之一的注塑模具，在质量精度、制造周期以及注射成型过程中的生产效率等方面水平高低，直接影响产品的质量、产量、成本及产品的更新，同时也决定着企业在市场竞争中的反应能力和速度 。  外文原文  In recent years, with the rapid development of plastics industry and general and engineering plastics in the intensity and precision, continuous improvement, the application of plastic products is also expanding, such as: household electrical appliances, instruments, construction equipment and automobile industry, Japan with hardware and many other fields, the proportion of plastic products is rapidly increasing.  A well-designed plastic parts can often replace the more traditional metal parts.  Household products plastic industrial products and the rising trend. The level of working equipment plays a pivotal role in the development of the plastic industry.The processing of very high-molecular-weight and high-viscosity thermoplastics in single-screw extruders today is usually done only in extruders with a positive-advantages over conventional extrusion. Among these are high output at low melting temperatures and high melt pressures; reduced shear of the plastics, which makes this system energy-saving and very economical; gentle plastic of the plastics; on thermal or chemical degradation, hence optimum product quality; and particularly stable extrusion so that output, pressure and melting temperature surges are prevented. Called Injection Molding (Injection Molding) refers to the heat melting the material by the high-pressure injection mold cavity, cooled after curing, are molded method.  This method is suitable for mass production of complex shaped parts, is an important processing methods. Injection device is heated to melt the resin material after the injection mold device.   From the resin material to squeeze into the first barrel, by turning the screw will melt delivered to the front barrel.  In that process, the role of the heater heating the resin material to machine cylinder to heat, shear stress in the screw under the action of a molten resin, forming the equivalent of goods and main channel, shunt molten resin stuck in the front barrel (called measure), the constant screw the material injected into the cavity.  When the molten  resin flows in the mold, to control the screw speed (injection speed), and in the resin after cavity filled with a pressure (holding pressure) control.  When the screw location, injection pressure reaches a certain value, we can speed control switch pressure control.  The essential parameter in the extruders pumping process is the interaction between the rotating fights of the   screw and the stationary barrel wall. For the plastic material to be conveyed, its friction must be low at the screw surface but high at the barrel wall. If this basic criterion is not met, the plastic will probably rotate with the screw   and not move in the axial/output direction.   In the output zone, both screw and barrel surfaces are usually covered with the  melt, and external forces between   the melt and the screw channel walls have no effect except when processing extremely high viscosity materials   such as rigid PVC and ultrahigh molecular weight PE. The flow of the melt in the output section is affected by the   coefficient of internal friction (viscosity), particularly when the die offers a high resistance to the flow of the melt.   The usual and more popular single screw types use conventional designs with basically uniform diameters of the screw and barrel. Examples include extruders that have decreasing screw channel volume, continuous variable speed, pressure control, and a venting (devolatilization) system. Special designs use conical or parabolic screws for   special mixing and kneading effects. They can include eccentric cores, variable pitch superimposed flights of different pitch, kneading rotors, fitted core rings, and periodic axial movement. Barrels may have internal threads,telescopic screw shapes, and feeding devices.  A successful extrusion operation requires close attention to many details, such as (1) the quality and flow of feed material at the proper temperature, (2) a temperature profile adequate to melt but not degrade the polymer, and (3) a startup and shutdown that will not degrade the plastic.   Care should be used to prevent conditions that promote surface condensation of moisture on the plastic and   moisture absorption such as by the pigments in the color concentrates. Hopper dryers have proven very useful in drying plastics.  They can also enhance extruder capacity in operations where the output is limited by the heating and melting capacity of the extruder. The relative difference in heat input required from the extruder to melt the plastic, with and without the hopper dryer used as a preheater. The extruders form a homogeneous plastic   melt and force it through a die orifice that is