用计算机辅助设计/计算机辅助制造/计算机辅助工程（CD/CAM/CAE）系统协同塑料加工诸如这一趋近获得了更多的重要性。

The following discussion will highlight some of the basic concepts involved

in plastics shaping operations. It will emphasize recent developments relating to the analysis and simulation of some important commercial processes, with due consideration to elucidation of both thermo-mechanical history and microstructure development. More extensive reviews of the subject can be found in standard references on the topic (1~6).

下面的讨论将重点放在包括塑料成型操作一些基本概念上。适当考虑说明热机械过程

和微结构发展，将强调最近关于分析和一些重要商品加工模型的进展。在上端（1～6）的标准参考中能够找到本主题更广泛的综述。

As mentioned above, shaping operations involve combinations of fluid flow and

heat transfer, with phase change, of a visco-elastic polymer melt. Both steady and unsteady state processes are encountered. A scientific analysis of operations of this type requires solving the relevant equations of continuity, motion, and energy (i.e. conservation equations).

如上面提到的，成型操作包括液体流动和热传递，对于相态变化，还包括粘弹性聚合

物的熔融。稳定和非稳定状态加工是相冲突的。这种典型操作的科学分析需要解决相关连续、运转和能量平衡（如守恒方程）。

——Austarita G , Nicolas L. Polymer prscessing and

properties

New York: Plenum press 1984, 1~3

UNIT 29 Synthetic Plastics

第二十九单元 合成塑料

It would be difficult to visualise our modern world without plastics. Today they are an integral part of everyones lifestyle with applications varying from commonplace articles to sophisticated scientific and medical instruments. Nowadays designers and engineers readily turn to plastics because they offer combinations of properties not available in any other materials. Plastics offer advantages such as lightness , resilience , resistance to corrosion , colour