Audited Supplier
HDPE
PP
Transparent Plastic Sheet
Bags
200kg
China
Product Description
Introduction:
High pressure-low density polyethylene (HP-LDPE, abbreviated as LDPE) has been industrialized for more than 70 years, although with the discovery and development of olefin polymerization catalysts, the variety and output of polyethylene have increased. progress, but high-pressure polyethylene still occupies an important position. Ethylene is polymerized into high molecular weight polyethylene by free radical mechanism under high temperature and high pressure, which has the following characteristics:
(1) The ethylene polymerization process is a strongly exothermic process. The heat of polymerization of ethylene is about 93.5kJ/mol (or 3.3kJ/g), and the specific heat capacity of ethylene at 235MPa and 150~300ºC is 2.51~2.85J/(g·ºC). The polymerization of 1% ethylene will increase the temperature by 12~13ºC. If the temperature is too high, it can also cause ethylene to decompose.
(2) Under high pressure, ethylene has been compressed to a gas-tight phase with a density of 0.5g/mL, which is similar to a liquid that cannot be compressed any more. At this time, the distance between ethylene molecules is significantly shortened, thereby increasing free radicals and ethylene molecules. The collision probability is high, so the polymerization reaction is prone to occur.
(3) The free radical activity of the growing chain at high temperature is large, and the chain transfer reaction is easy to occur, and the obtained polymer has a linear structure with many branches. Usually there are 20~30 branches per 1000 carbon chain atoms, the crystallinity is 45%~65%, and the density is 0.910~0.925g/mL. It is light in weight, flexible, and has good low temperature resistance and impact resistance.
Application field
Scope of application of low density polyethylene: suitable for food packaging such as seasonings, cakes, sugar, candied fruit, biscuits, milk powder, tea, fish floss and so on. Tablets, powders and other pharmaceutical packaging, shirts, clothing, knitted cotton products and chemical fiber products and other fiber products packaging. Packaging of daily chemical products such as washing powder, detergent, cosmetics, etc. Due to the poor mechanical properties of the single-layer PE film, it is usually used as the inner layer of the composite packaging bag, that is, the heat-sealable substrate of the multi-layer composite film.
High pressure-low density polyethylene (HP-LDPE, abbreviated as LDPE) has been industrialized for more than 70 years, although with the discovery and development of olefin polymerization catalysts, the variety and output of polyethylene have increased. progress, but high-pressure polyethylene still occupies an important position. Ethylene is polymerized into high molecular weight polyethylene by free radical mechanism under high temperature and high pressure, which has the following characteristics:
(1) The ethylene polymerization process is a strongly exothermic process. The heat of polymerization of ethylene is about 93.5kJ/mol (or 3.3kJ/g), and the specific heat capacity of ethylene at 235MPa and 150~300ºC is 2.51~2.85J/(g·ºC). The polymerization of 1% ethylene will increase the temperature by 12~13ºC. If the temperature is too high, it can also cause ethylene to decompose.
(2) Under high pressure, ethylene has been compressed to a gas-tight phase with a density of 0.5g/mL, which is similar to a liquid that cannot be compressed any more. At this time, the distance between ethylene molecules is significantly shortened, thereby increasing free radicals and ethylene molecules. The collision probability is high, so the polymerization reaction is prone to occur.
(3) The free radical activity of the growing chain at high temperature is large, and the chain transfer reaction is easy to occur, and the obtained polymer has a linear structure with many branches. Usually there are 20~30 branches per 1000 carbon chain atoms, the crystallinity is 45%~65%, and the density is 0.910~0.925g/mL. It is light in weight, flexible, and has good low temperature resistance and impact resistance.
Application field
Scope of application of low density polyethylene: suitable for food packaging such as seasonings, cakes, sugar, candied fruit, biscuits, milk powder, tea, fish floss and so on. Tablets, powders and other pharmaceutical packaging, shirts, clothing, knitted cotton products and chemical fiber products and other fiber products packaging. Packaging of daily chemical products such as washing powder, detergent, cosmetics, etc. Due to the poor mechanical properties of the single-layer PE film, it is usually used as the inner layer of the composite packaging bag, that is, the heat-sealable substrate of the multi-layer composite film.
