The plastics we usually use are not pure substances. It is made of many materials. Polymer (or synthetic resin) is the main component of plastics. In addition, in order to improve the properties of plastics, various auxiliary materials such as fillers, lubricants, plasticizers, colorants and stabilizers are added to the polymer to make plastics become plastics with good properties.

　　1. 润滑剂

　　1. Lubricants

　　使用润滑剂防止塑料在成型过程中粘在金属模具上，使塑料表面光滑美观。常用的润滑剂有硬脂酸和钙镁盐等。

　　Lubricant is used to prevent plastics from sticking to metal moulds in the forming process, so that the surface of plastics is smooth and beautiful. Commonly used lubricants are stearic acid and calcium magnesium salts.

　　2. 着色剂

　　2. Colorants

　　着色剂能使塑料具有各种鲜艳美丽的颜色。有机染料和无机颜料是常用的着色剂。

　　Colorants give plastics a variety of bright and beautiful colors. Organic dyes and inorganic pigments are common colorants.

　　3、稳定剂

　　3. Stabilizers

　　为了防止合成树脂在加工和使用过程中受到光热分解和破坏，延长使用寿命，在塑料中加入稳定剂。常用的有硬脂酸盐、环氧树脂等。

　　In order to prevent the photothermal decomposition and destruction of synthetic resins in the process of processing and use and prolong their service life, stabilizers were added to plastics. Stearate and epoxy resin are commonly used.