Thermal properties of polyethylene polyethylene heat back, as the temperature rises, the formation of crystals gradually partial derogation partial formation of crystals dissolve when the polyethylene to melt, then the temperature is the melting point. Until now LLDPE into almost all of the traditional polyethylene market, covering film, molding, pipe and wire and cable. Because polyethylene has a melt flow calibration efficiency than the molecular weight calibration easy, and therefore generally a melt index (MI), or melt flow index (MFI) to express the particular nature of the molecular weight of the polyethylene. LLDPE succeed guide radical reaction initiator complexing agents, as well as lower cost of low-pressure gas-phase polymerization children instead of the higher cost of high pressure reaction device, in a relatively short period of time, then its particularly good performance and low The cost has been replaced in many areas LDPE. LLDPE melting point of 120 ~ 125 ℃, between HP-LDPE and HDPE. At low temperature polyethylene soft and natural with satisfactory toughness, crisp analysis of its low temperature, which related to its molecular weight. When the same molecular weight, temperature is lower melt viscosity. When higher molecular weight polyethylene, its brittle temperature decreased, its limit is -140 ℃. Polyethylene mobility and increase the load fluctuation at the time of temperature rise, mainly affected by the molecular weight, degree of increased density polyethylene, the degree of increase in the formation of crystals having a melting point also will increase, so the density not the same degree of polyethylene having a melting point of not the same. In the molten condition, the polyethylene melt viscosity is a function of molecular weight, and it increased with increasing molecular weight. Because the melting point range than the HP-LDPE LLDPE narrow, so a good performance LLDPE film heat-sealed, heated bonding strength is also high. Density polyethylene with different degrees and are not the same soft and toughness at room temperature. Because LLDPE melting point than HP-LDPE is high, so the plate-type products may be at a higher temperature releasing, and fast and clean. LLDPE different copolymerizable monomer, which decrease the melting point of the level of carbon atoms with comonomers varies more carbon atoms, higher melting point multiplication. LLDPE in the 20th century, the era of the 70 industrialized UnionCarbide business, which represents the polyethylene reactants and technology of significant political reform, polyethylene significant expansion of the product range.