Weifang Bangtai polymer materials Co., Ltd. -- precautions for selecting lubricants

There are many kinds of lubricants, the common external lubricants are paraffin, stearic acid and its salts; the internal lubricants are relatively low molecular weight PE, PTFE, PP, etc. These low molecular weight polymers are not only excellent internal lubricants, but also good external lubricants. Sometimes, the effect of one kind of lubricant is not ideal, and several kinds of lubricants are needed to be used together, resulting in a compound lubricant, which can play various roles. Better results. The amount of lubricant is generally 0.5% - 1%.

When selecting lubricants, the following principles should be followed:

1. If the fluidity of the polymer can meet the needs of the molding process, the main consideration is whether the external lubricant can meet the process requirements and whether it is easy to demould to ensure the internal and external balance.

2. Whether the external lubrication is ideal or not depends on whether it can form a complete liquid film on the plastic surface when it is forming. Therefore, the melting point of the external lubricant should be close to the molding temperature, but it should be noted that there is a difference of 10-30 ℃, so as to form a complete film.

3. The compatibility with the polymer is moderate, the internal and external lubrication is balanced, without frost spraying and scaling.

4. The lubricant has excellent heat resistance and chemical stability, does not decompose in processing, does not volatilize, does not corrode equipment, does not pollute products and has no toxicity.