英语翻译第一部分：Injection MoldingMany different processes are used

英语翻译
第一部分：Injection Molding
Many different processes are used to transform plastic granules,powders,and liquids into final product.The plastic material is in moldable form,and is adaptable to various forming methods.In most cases thermoplastic materials ore suitable for certain processes while thermosetting materials require other methods of forming.This is recognized by the fact that thermoplastics are usually heated to a soft state and then reshaped before cooling.Thermoses,on the other hand have not yet been polymerized before processing,and the chemical re-action takes place during the process,usually through heat,a catalyst or pressure.It is important to remember this concept while studying the plastics manufacturing processes and the polymers used.
Injection molding is by far the most widely used process of forming thermo-plastic materials,It is also one of the oldest.Currently injection molding accounts for 30% of all plastics resin consumption.Since raw material can be converted by a single procedure,injection molding is suitable for mass production of plastics articles and automated one-step production of complex geometries.In most cases,finishing is not necessary.Typical products include toys,automotive parts,household articles,and consumer electronics goods.
Since injection molding has a number of interdependent variables,it is a process of considerable complexity.The success of the injection molding operation is dependent not only in the proper setup of the machine variables,but also on eliminating shot-to-shot variations that are caused by the machine hydraulics,barrel temperature variations,and changes in material viscosity.Increasing shot-to-shot repeatability of machine variables helps produce parts with tighter tolerance,lowers the level of rejects,and increases product quality (i.e.,appearance and serviceability).

注塑成型运用许多不同的工艺将塑料颗粒、粉末以及液体转换成最终产品.塑料材料处于可模压形态,适用于各种成形方法.
大多数情况下,热塑材料适用于某些工艺过程,而热固性材料则需要其他成形方法.我们要明白这个事实即热塑材料通常被加热到软化状态,然后在冷却前再成形.另一方面,热固材料在加工之前仍未被聚合,在加工过程中通常通过热,催化剂和压力作用出现化学反应.牢记这个概念对于研究塑料加工工艺和所使用的聚合体是重要的.
注塑成型是至今为至使用最为广泛的热塑材料的成型工艺,同时也是使用时间最久的一种.现在注塑成型占所有塑料树脂消费量的30%.因为原材料只需经过一个工序就能转换,所以注塑成型适合于塑料件的批量生产和加工具有复杂几何外形的自动化一步生产.在大多数情况,不需要精加工.代表性产品有玩具、汽车零部件、家居用品和消费类电子产品.
因为注塑成型有许多独立的变量,所以是一个相当复杂的工艺.注塑成型成功与否不仅仅取决于机器变量的正确设置,还要消除由机器液压系统、桶的温度变化、材料粘度变化所产生的重复性变量.增加机器变量的重复性有助提高于产品零件公差精度,合格品的等级和产品质量（即外观和适用性）.