1. Difference 1: different melting point
PE：92℃
PET：250－255°C
Difference 2: different physical properties
PE: odorless, non-toxic, feel like wax. It has excellent low temperature resistance (the lowest operating temperature can reach ~ 100 ~ ~ 70 ° C) , good chemical stability, and can resist the attack of most acids and bases (not acid with oxidation properties) . Insoluble in common solvents at room temperature, small water absorption, excellent electrical insulation.
Pet: milky or yellowish, highly crystalline polymer with a smooth, glossy surface. It has excellent physical and mechanical properties in a wide temperature range, long-term service temperature can reach 120 ° C, excellent electrical insulation, even at high temperature and high frequency, its electrical properties are still good, but corona resistance is poor, creep resistance, fatigue resistance, friction resistance, dimensional stability are very good.
3. Difference 3: different processing methods
PE: polyethylene according to the polymerization pressure can be divided into high-pressure method, medium-pressure method, low-pressure method;.
PET: polyester polyester is made by polycondensation of terephthalic acid with ethylene glycol, following the general rule of linear polycondensation. Polyester polyester production, has developed transesterification and direct esterification of two synthesis technology.
PET benefits:
1. have good mechanical properties, impact strength is 3 ~ 5 times of other films, good folding resistance.
2, oil-resistant, fat-resistant, acid-resistant, alkali-resistant, resistant to most solvents.
3. It can be used for a long time in the temperature range of 55-60 °C, and can withstand the high temperature of 65 ° C and the low temperature of -70 ° C for a short time.
4. Low permeability of gas and water vapor, good gas barrier, water, oil and odor.
5, high transparency, can block ultraviolet, good gloss.
6, non-toxic, tasteless, good health and safety, can be directly used in food packaging.