What effect does blow molding have with lubricant?What kinds of lubricant are commonly used?What should you pay attention to when choosing?
The function of lubricant is to reduce the friction between plastic macromolecules, improve the fluidity of polymer, reduce the friction between polymer and processing machinery, avoid the adhesion between them, and reduce the surface roughness of products.
According to the function of lubricant, it can be divided into internal lubricant and external lubricant.Internal lubricant refers to the good compatibility between the resin and the resin, which can improve the fluidity of melting materials and reduce the friction between melting materials.External lubricant refers to the addition of resin to reduce the temperature of plasticized molten material, reduce the friction between the molten material and the equipment surface, and prevent the molten material from sticking to the equipment metal surface.Internal and external lubrication is not absolute, in fact many lubricants have two types of lubricant functions, such as metal soap.
The common thermoplastic plastics that need to add lubricant include PVC, PP, PE, PS, PA, ABS, etc., among which, rigid polyvinyl chloride is the most prominent.The commonly used lubricants include metal soap, saturated hydrocarbons, fatty acids and their derivatives and fatty acid salts.If stearic acid (octadecanic acid), liquid paraffin (white oil), polyethylene wax (low molecular weight polyethylene), stearic acid amide, oleic acid amide.
The following problems should be noted when choosing lubricant.
(1) the lubricant should be compatible with the resin and other additives.
(2) the lubricant can be evenly dispersed in the resin without affecting the properties of the plastic products.
(3) it has no effect on the quality of plastic molded products and is conducive to improving the appearance of products
Quality and reduction of surface roughness;It does not decompose or deteriorate in the range of forming temperature
It depends on the temperature.
(4) lubricants of the same performance shall be selected with low price and abundant sources.