广东工业大学 模具专业英语2 09E2-6.pptVIP

作业1：翻译下面短文( p.57) These polymers set after being melted to a liquid state by heating; hence the term thermosetting plastic. This process of solidifying is known as curing. During curing all the small molecules are chemically linked together to form one giant network molecule. Hence they are distinguished from the linear polymer (thermoplastics)by being called network polymers. 参考译文 这些聚合物通过加热被熔化为液态后再变为固态，因此采用术语热固性塑料。凝固的过程称为固化。固化时所有小分子通过化学反应连接起来形成巨大的网状分子。因此它们区别于线状聚合物（热塑性塑料） 而正如其名———网状聚合物。 作业2：翻译下面短文( p.57) The change from the liquid state to solid is irreversible, and further heating results only in chemical breakdown; not melting. All the common thermosetting plastics are synthetic resins like epoxide, melamine, phenol, polyester for example, which in the hard state are invariably glassy and brittle in nature. Their structure is based upon carbon like the linear polymers. The silicones, however, are another family of materials whose structure is based upon silicon, not carbon. They are usually grouped with the common thermosetting plastics, the properties of some of which the commonly used either to improve or modify the mechanical or chemical properties of the resin, or in order to give cheaper material. 参考译文 从液态到固态的转变是不可逆的，进一步加热只能导致化学分解，而非熔化。所有的常见热固性塑料都是合成树脂，比如象环氧化物、三聚氰胺、酚、聚酯，硬态时它们性质类似玻璃、易碎。象直链多聚物它们的结构以碳为基础。然而，硅树脂却是基于硅而非碳的另一类物质。它们和常见的热固性塑料归于一类。图11.8表给出了部分材料的属性。请注意：常采用填充材料去提高或改善树脂的力学性能或化学属性，或为了得到更廉价的材料。 专业名词及术语 ??lend itself to v.?有助于 high frequency preheating 高频预热 radio frequency methods 射电频率法  第六讲 阅读课文:Production of Plastic  11.8 MOULDING OF THERMOSETTING PLASTICS  11.8 MOULDING OF THERMOSETTING PLASTICS Compression Moulding This is the traditional moulding method which has been used in the plastics industry for many years. The process is superficially similar to the hot pressing of metals in so far that the plastic is placed into a heated 11.8 MOULDING OF THERMOSETT