The dosage of lubricant is generally 0.5%~1%, and attention should be paid to the following:
● If the flow performance of the polymer has met the needs of the molding process, the role of external lubrication is mainly considered to ensure the balance between inside and outside;
● Whether the external lubrication is effective should be based on whether it can form a complete liquid film on the plastic surface layer at the molding temperature, so the melting point of the external lubricant should be close to the molding temperature, but it must be 10°C~30°C to form a complete film;
● Does not reduce the mechanical strength and other physical properties of the polymer.
When selecting lubricants in production, they should meet the following requirements:
● High and long-lasting lubrication efficiency;
● Compatibility with resin, moderate size, balance of internal and external lubrication; No frosting, not easy to scale;
● The surface gravitational force is small, the viscosity is small, the expansion at the interface is good, and the interface layer is easy to form;
● Try not to reduce the excellent properties of the polymer, and not affect the secondary processing performance of the plastic;
● It has excellent heat resistance and chemical stability, and does not decompose or volatilize during processing;
● No corrosion of equipment, no contamination of the film, no toxicity.
However, the simple use of a lubricant, often difficult to achieve the purpose, the need for several lubricants to be combined, compound lubrication development is very fast, in the selection, you can look at the role of lubricants from multiple angles.
