What's the performance of PE plastic film?
Thermal property. The melting point of polyethylene is proportional to the degree of crystallization and the size of the grain. Therefore, the melting point of LLDPE is 10-15 degrees higher than that of LDPE. Here, even if the same number of LLDPE, the higher the carbon number of the copolymer monomer, the higher the melting point. This rule is also suitable for softening point of VEKA. The heat sealing property of the film is corresponding to the full heat sealing temperature. The heat sealing temperature of LLDPE is 10-15 degrees higher than that of LDPE, and LLDPE is narrower than the melting point of LDPE, so the film has good heat sealing performance.Cold tolerance of LLDPE, the relationship between catalytic temperature and melt flow rate of LLDPE brittle temperature than LDPE, HDPE are low, which indicates that the resistance to low temperature.
Physical and mechanical properties. The tensile properties of LLDPE and LDPE ratio, tensile quantity, tensile yield strength, especially the tensile strength and elongation at break, generally from the stress-strain curve obtained when the fracture area of the energy required, as the index of rigid resin. Obviously, LLDPE good rigidity, it can be considered as the reason for tethering LLDPE molecule.The relationship between stiffness and density: the lower the density, the worse the rigidity (i.e. softer). For the same density, the impact strength of LLDPE would be better than that of C4, and the impact strength of C6 and C8 copolymer polymers would be higher.The physical and mechanical properties of LDPE films are obviously better than those of LDPE. Their softness, toughness, cold resistance and puncture resistance are better than those of LLDPE films.
Melting property. The melting property depends on the relative molecular weight, relative molecular weight distribution and long branch chain. The relationship between flow rate and shear rate of LDPE and LLDPE Hu also melt: HDPE LLDPE behavior with narrow molecular weight distribution is similar to that of the ratio of the melt viscosity of LDPE is high, so the extrusion molding extrusion load increases, the heat is increasing.The melting tension of LLDPE is lower than that of LDPE, and the relaxation time of melting stress is short. It can be observed that the extrusion film from the "T" type die head has a big necking, and the parison has a great degree of elongation during the molding process. Due to the short relaxation time of the melt stress, the residual stress in the injection molding material is small, so the shrinkage is small and the warpage is small.
Heat sealing property. LLDPE film has good heat sealing property. As long as the minimum sealing temperature is reached, it has good heat sealing strength, and has strong sealing and anti pollution ability.
