What is the difference between esd PP protective film and esd PE protective film?
ESD Polyethylene (PE), abbreviated as PE, is a kind of thermoplastic resin obtained by polymerizing ethylene. Industrially, copolymers of ethylene and a small amount of α-olefins are also included.
Polyethylene is odorless, non-toxic, feels like wax, has excellent low temperature resistance (minimum use temperature can reach -70～-100°C), good chemical stability,
Resistant to the erosion of most acids and bases (not resistant to acids with oxidizing properties), insoluble in common solvents at room temperature, low water absorption, excellent electrical insulating properties;
However, polyethylene is very sensitive to environmental stress (chemical and mechanical action) and has poor heat aging resistance. The nature of polyethylene varies depending on the species.
It mainly depends on the molecular structure and density. Different production methods can be used to produce products with different densities (0.91 to 0.96 g/cm3).
Polyethylene can be processed by the general thermoplastic molding method (see plastic processing). It has a wide range of uses and is mainly used to make films and containers.
Pipes, monofilaments, wires and cables, daily necessities, etc., and can be used as high-frequency insulation materials for televisions, radars, etc.
ESD PP is a semi-crystalline material. It is harder and has a higher melting point than PE.
Since the homopolymer PP is very fragile when the temperature of the PP is above 0C, many commercial PP materials are random copolymers with 1 to 4% of ethylene or
Higher ethylene content clamp segment copolymers. The polymeric PP material has a low heat distortion temperature (100C), low transparency, low gloss,
Low rigidity, but there is more impact strength. The strength of PP increases with the ethylene content. The Vicat softening temperature of PP is 150C.
Due to the high degree of crystallinity, this material has very good surface stiffness and scratch resistance.
PP does not have the problem of environmental stress cracking. In general, PP is modified by adding glass fibers, metal additives, or thermoplastic rubber.
The flow rate of PP has an MFR range of 1 to 40. PP materials with low MFR have better impact resistance but lower strength. For the same MFR material,
The strength of the copolymer type is higher than that of the homopolymer type. Due to crystallization, PP shrinkage is quite high, typically 1.8 to 2.5%.
And the uniformity of the shrinkage direction is much better than that of materials such as PE-HD. Adding 30% of the glass additive can reduce the shrinkage to 0.7%.
Homopolymer and copolymer PP materials have excellent resistance to moisture absorption, acid and alkali corrosion, and resistance to dissolution.
However, it is not resistant to aromatic hydrocarbons such as benzene solvents, chlorinated hydrocarbon (carbon tetrachloride) solvents, and the like.
PP is also not as resistant to PE as it is at high temperatures.