Polyethylene resin is a non-toxic, tasteless white powder or granule, with a milky white appearance, a wax-like hand, and low water absorption, less than 0.01%. The polyethylene film is transparent and decreases with the increase of crystallinity. Polyethylene film has low water permeability but high air permeability, which is not suitable for fresh-keeping packaging but suitable for moisture-proof packaging. It is flammable and has an oxygen index of 17.4. It has low smoke during combustion, with a small amount of molten droplets, yellow on the flame and blue underneath, with a paraffin odor. Polyethylene has better water resistance. The surface of the product is non-polar, and it is difficult to bond and print. It is improved by surface treatment. Many branches have poor resistance to light degradation and oxidation.
Its molecular weight is in the range of 10,000 to 100,000. Those with a molecular weight of more than 100,000 are ultra-high molecular weight polyethylene. The higher the molecular weight, the better the physical and mechanical properties and the closer to the required level of engineering materials. But the higher the molecular weight, the more difficult its processing. The melting point of polyethylene is 100～130℃, and it has excellent low temperature resistance. It can still maintain good mechanical properties at -60℃, but the use temperature is 80~110℃.
It is insoluble in any known solvents at room temperature, and can be dissolved in a small amount in toluene, amyl acetate, trichloroethylene and other solvents above 70°C.