Lubricants play a very important role in the processing of thermoplastic polymers for improving the processing and application properties of products. Then, because the polymer processing process is very complex, which has a lot of influence on the lubrication, such as the polymer structure, processing machinery, molding method, processing conditions, product shape, the interaction between composite components, and so on. At the same time, considering the required performance of the final product, the selection of the lubrication system in the design must start from the whole formula and comprehensively consider various factors. The following are the selection points of lubricants for PVCL processing and molding:
(1) Processing machinery calendering focuses on the external lubrication, extrusion, injection molding focuses on the internal lubrication.
(2) Compared with homopolymers, copolymers use more external lubricants.
(3) The type and dosage of compounding agent
1. Compared with soft products, the amount of lubricant should be increased for hard products
2. It is necessary to pay attention to the lubricity of stabilizers, and the order of lubricity is as follows: sulfur containing organotin < organotin < inorganic stabilizer < liquid composite stabilizer < metal soap. Sulfur containing organotin needs to be used with External Lubricant in the formulation; organotin needs to be used with external lubricant or internal and external lubricant; inorganic stabilizer and liquid compound stabilizer need to be used with internal and external lubricant, and metal soap needs to be used with external lubricant.
3. When the amount of filler is large, the Internal Lubricant should be used more.
4. Pay attention to the balance between internal lubrication and external lubrication.
The appearance should consider spray frost, color drift, migration and so on. The surface should consider the printability, gloss and so on. Mechanical strength should consider strength, interlayer exploitation...
