在加工时，聚合物熔体与加工机械表面易产生摩擦，这些摩擦使熔体流动性降低，而且严重的摩擦会使薄膜表面变得粗糙，缺乏光泽或出现流纹等。

In the process, the surface of the polymer melt and the processing machinery is easy to produce friction, the friction reduces the melt flow, and serious friction will cause the film surface becomes rough, the lack of luster or rhyolite etc..

因此，提高润滑性、减少摩擦、降低界面粘附性能的润滑剂就显得非常重要了。同时润滑剂除了能改进流动性，还可以起熔融促进剂、防粘连和防静电剂、爽滑剂等作用。润滑剂的用量一般在0.5%~1%，选用时应注意：考虑聚合物的流动性能的内外平衡；外润滑剂的熔点应与成型温度相差10℃~30℃左右，才能形成完整的薄膜；

Therefore, it is very important to improve lubricants, reduce friction, and reduce the adhesion properties of the interface. In addition to the lubricant can improve the fluidity, it can also play the role of melt accelerator, anti adhesion and antistatic agent, skid agent and so on. The amount of lubricants is generally 0.5%~1%. When selecting, we should pay attention to the internal and external equilibrium of the flow properties of polymers, and the melting point of external lubricants should be 10 ~30 or about the same as the molding temperature, so that a complete film can be formed.

在生产中选择润滑剂时，应使之达到以下要求：

When the lubricant is selected in production, it should be made to meet the following requirements:

1.润滑效能高而持久；

1. the lubrication efficiency is high and lasting.

2.与树脂的相容性大小适中，内部、外部润滑作用的平衡；不喷霜、不易结垢；

2. the compatibility of the resin is moderate, the internal and external lubrication of the balance, no spray frost, not easy to scale;

3.表面引力小，粘度小，在界面处的扩展性好，易形成界面层；

The 3. surface has small gravitational force, small viscosity and good expansibility at the interface, and it is easy to form the interface layer.

4.尽量不降低聚合物的各种优良性能，不影响塑料的二次加工性能；

4. not to reduce the excellent properties of the polymer, and do not affect the two processing properties of the plastic.

5.本身的耐热性和化学稳定性优良，在加工中不分解、不挥发；

5. itself has good heat resistance and chemical stability, and it does not decompose and volatilize in processing.

6.不腐蚀设备，不污染薄膜，没有毒性。

6. does not corrode the equipment, does not pollute the film, and has no toxicity.

润滑剂可分为外润滑剂和内润滑剂两种。

Lubricants can be divided into two kinds of lubricants and internal lubricants.

外润滑剂的作用主要是改善聚合物熔体与加工设备的热金属表面的摩擦。它与聚合物相容性较差，容易从熔体内往外迁移，所以能在塑料熔体与金属的交界面形成润滑的薄层。

The effect of the external lubricant is mainly to improve the friction between the polymer melt and the hot metal surface of the processing equipment. It is poor in compatibility with polymer and easy to migrate out of the melt, so it can form a lubricating thin layer at the interface of the plastic melt and the metal.

内润滑剂与聚合物有良好的相容性，它在聚合物内部起到降低聚合物分子间内聚力的作用，从而改善塑料熔体的内摩擦生热和熔体的流动性。

The internal lubricants have good compatibility with polymers. They play a role in reducing polymer intermolecular cohesion within polymers, thereby improving the internal friction heat generation and melt fluidity of plastic melts.