PE resin is tasteless, nontoxic white powder or particle, the appearance is milky white, the water absorption rate is low, less than 0.01%, the PE film is transparent, and decreases with the increase of the crystallinity. The permeability of PE membrane is low.
However, it is highly porous and is not suitable for fresh-keeping packaging and is suitable for moisture proof packaging.
The mechanical properties of PE are generally low, tensile strength is low, creep resistance is not good, and impact resistance is good. Impact strength: LDPE>LLDPE>HDPE, other mechanical properties LDPE<LLDPE<HDPE.
PE environmental stress cracking resistance is not good, but it improves with the increase of relative molecular mass.
The heat resistance of PE is not high, and it is improved with the increase of molecular weight and crystallinity. PE has good low temperature resistance, and the embrittlement temperature can generally reach below -50 degrees Celsius. PE has a large coefficient of expansion, which is the largest in plastic.
The order of PE different varieties is LDPE>LLDPE>HDPE. PE thermal conductivity in plastic is the highest. The thermal conductivity of different PE is HDPE>LLDPE>LDPE.
PE has no polarity, so it has excellent electrical performance, high dielectric strength and can be used as high voltage insulation materials.
PE is an inert polymer and has good chemical stability.
The LDPE films are used for food, daily use, vegetables, shrinkage, self-adhesive, trash bags and other agricultural plastic mulch film, greenhouse film, preservative film, etc
LLDPE film has good extensibility, good stretchability, puncture resistance and shrink film. It is mainly used for packaging film, garbage bags, fresh-keeping film, self mucous membrane and ultrathin plastic film.
EVA film can be used in packaging film and agricultural film, such as heavy packaging film, frozen packaging film, food packaging film, composite membrane, insulation film, heat shrinkable film, self mucous membrane and barrier preservation film. EVA agricultural film’s heat preservation, light transmittance, aging resistance and drip free properties are superior to those of PE film.