Differences Between Paraffin Wax, Microcrystalline Wax, Liquid Paraffin, and Polyethylene Wax

(1) Paraffin Wax:
    The main component of paraffin wax is straight-chain alkanes with only a small amount of branched chains. It is widely used as a lubricant and release agent for various plastics, with strong external lubrication effects and the ability to impart gloss to product surfaces. It is most commonly used in rigid polyvinyl chloride (PVC) extruded products. Since its dosage affects product strength (as shown in the figure below), the recommended dosage is 0.5-1.5 phr to ensure product strength.

(2) Microcrystalline Wax:
    Microcrystalline wax is mainly composed of branched-chain hydrocarbons, naphthenes, and some straight-chain alkanes, with a relative molecular weight of approximately 500–1000 (i.e., C35–C50 alkanes). It can be used as an external lubricant for plastics such as polyvinyl chloride (PVC). Its lubrication effect and thermal stability are superior to ordinary paraffin wax, and it is non-toxic. However, its gelation rate is slow, which affects the transparency of products.

(3) Liquid Paraffin:
    Also known as "white oil", liquid paraffin products with different freezing points are suitable for different applications. When used as a lubricant, liquid paraffin has a freezing point in the range of -15~35°C and is suitable as an internal lubricant for polyvinyl chloride (PVC), polystyrene (PS), etc., with high lubrication efficiency. It has good thermal stability, is non-toxic, and is applicable to injection molding, extrusion molding, etc. 

(4) Polyethylene Wax:
    A low-molecular-weight polyethylene (or partially oxidized low-molecular-weight polyethylene) with a relative molecular weight of 1500–5000. It can be used as a lubricant for polyvinyl chloride (PVC) and other materials, with stronger internal lubrication than other hydrocarbon lubricants. Suitable for extrusion and calendering processes, it improves processing efficiency, prevents adhesion of films, etc., and facilitates the dispersion of fillers or pigments in the polymer matrix.