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    The full name of PE is Polyethylene, and PE release film is a widely used polymer material made by polymerizing ethylene. PE release film is divided into high-density polyethylene, medium density polyethylene, and low-density polyethylene. Low density polyethylene is relatively soft and is often polymerized under high pressure; High density polyethylene has the characteristics of rigidity, hardness, and mechanical strength, and is often polymerized under low pressure. High density polyethylene can be used as containers, pipelines, and high-frequency electrical materials for radar and television. The commonly used material is low-density (high-pressure) polyethylene. Polyethylene is wax like and has a smooth texture like wax. When not dyed, low-density polyethylene is transparent while high-density polyethylene is opaque. Polyethylene is a highly polymerized chain formed by the addition and polymerization reactions of ethylene (CH2=CH2), connected by repeated - CH2- units. The performance of polyethylene depends on its polymerization method; High density polyethylene (HDPE) is obtained by Ziegler Natta polymerization of organic compounds under moderate pressure (15-30 atmospheres) catalytic conditions. Under these conditions, the polymerized polyethylene molecules are linear and have long molecular chains, with molecular weights reaching several hundred thousand. If the free radical polymerization is carried out under high pressure (100-300MPa), high temperature (190-210 C), and peroxide catalyzed conditions, the resulting product is low-density polyethylene (LDPE), which has a branched structure.
  Polyethylene is insoluble in water and has very low water absorption. Even for some chemical solvents such as toluene and acetic acid, it only slightly dissolves at temperatures above 70 ℃. However, particulate polyethylene can melt or solidify with temperature between 15 ℃ and 40 ℃, and melt and absorb heat as the temperature increases; When the temperature drops, it solidifies and releases heat. Moreover, due to its low water absorption, low moisture resistance, and excellent bonding properties, it is an excellent building material.
Characteristics and Applications
  LDPE (High Pressure Low Density Polyethylene): Non toxic, odorless, odorless, forming semi transparent spherical or cylindrical particles, excellent low temperature resistance, chemical properties, good extensibility, electrical resistance, but poor moisture resistance and flammability. Density: 0.910-0.9408G/CM3 (grams/cubic centimeter), suitable for processing methods such as extrusion, vacuum forming, injection molding, compression molding, and transfer molding. Crystallinity of 55-65%, melting point of 108-126 ℃.
HDPE (Low Pressure High Density Polyethylene): Non toxic, odorless, odorless white powder or cylindrical or semi-circular particles, with wear resistance, tolerance, impermeability, flammability, and poor flexibility. The melting point is about 130 ℃, and the relative density is 0.941-0.965. Has good heat and cold resistance. Good chemical stability, high rigidity and toughness, good mechanical strength, dielectric properties, and good resistance to environmental stress cracking.
  Density: 0.941-0.9708G/CM3 (grams/cubic centimeter), mainly used for vacuum forming, manufacturing various bottles, cans, barrels, industrial storage tanks, etc., hollow packaging.
LLDPE (linear low-density polyethylene): odorless, odorless, non-toxic powder or particle, high hardness and wear resistance, good heat sealing and thermal viscosity. Density: 0.91-0.940G/CM3 (grams per cubic centimeter); Mainly used for manufacturing films, it can also be used for injection molding and vacuum forming. Compared with LDPE, it has the advantages of high strength, good toughness, strong rigidity, heat resistance, cold resistance, etc. It also has good resistance to environmental stress cracking, tear strength, and can resist acid, alkali, organic solvents, etc.
  PE release film is a polyethylene plastic with stable chemical properties. It is commonly used to make food bags and various containers, and is resistant to acid, alkali, and salt water solutions. However, it should not be wiped or soaked with strong alkaline detergents.
PE release film is divided into high-density, low-density, and linear PE, and is commonly used in various plastic films and plastic fabrics for daily applications.
PE pipes include medium density polyethylene pipes and high-density polyethylene pipes. Divided into SDR11 and SDR17.6 series based on wall thickness. The former is suitable for transporting artificial gas, natural gas, and liquefied petroleum gas in gaseous form, while the latter is mainly used for transporting natural gas. Compared with steel pipes, the construction process is simple, has a certain degree of flexibility, and most importantly, does not require anti-corrosion treatment, which will save a lot of processes. The disadvantage is that the equipment is not as good as steel pipes. During construction, special attention should be paid to the safety distance of thermal heating, and it should not be exposed to the air and sunlight. It is also sensitive to chemicals to prevent damage caused by leakage of sewage pipes. Specific gravity: 0.94-0.96 grams per cubic centimeter; Molding shrinkage rate: 1.5-3.6%; Molding temperature: 140-220 ℃.
Material performance
  Excellent corrosion resistance, electrical resistance (especially high-frequency), can be chlorinated, modified by irradiation, reinforced with glass fiber, and has a high melting point, rigidity, hardness, and strength of low-pressure polyethylene. It has low water absorption, good electrical performance, and radiation resistance; High pressure polyethylene has good flexibility, elongation, impact strength, and permeability; Molecular weight polyethylene has high impact strength, fatigue resistance, and wear resistance. Low pressure polyethylene is suitable for making corrosion-resistant parts and edge parts; High pressure polyethylene is suitable for making films, etc; Molecular weight polyethylene is suitable for making shock-absorbing, wear-resistant, and transmission parts.
Release film forming
  Crystalline material has low moisture absorption and does not require sufficient drying. Its flowability is sensitive to pressure and is suitable for high-pressure injection during molding. The material temperature is uniform, the filling speed is fast, and the pressure is sufficient. It is not advisable to use a direct gate to prevent uneven shrinkage and increased internal stress. Pay attention to selecting the gate position to prevent shrinkage and deformation; The shrinkage range and shrinkage value are large, the directionality is obvious, and it is easy to deform and warp. The cooling speed should be slow, and the mold should be equipped with a cold material hole and a cooling system; The heating time should not be too long, otherwise decomposition and burns may occur; When soft plastic parts have shallow side grooves, they can be forcibly demolded; Possible melt rupture may occur, and it is not advisable to come into contact with organic solvents to prevent cracking.
Polyethylene is an important downstream product of ethylene, accounting for 70% of polyolefin consumption, 44% of total thermoplastic general-purpose plastic consumption, and 52% of ethylene production.
  Polyethylene is basically divided into three categories, namely high-pressure low-density polyethylene (LDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE). Thin film is its main processed product, followed by sheets and coatings, hollow containers such as bottles, cans, barrels, and other injection molded and blow molded products, pipes and wires, cable edges and sheaths, etc. Mainly used in departments such as packaging, agriculture, and transportation.