Polyethylene (PE) is mainly produced in foreign countries, and Polypropylene (PP) is mainly produced in China. It is a kind of thermoplastic resin made by polymerization of ethylene. In industry, copolymers of ethylene with a small amount of α – olefins are also included. Polyethylene is odorless, nontoxic, waxy, with excellent low temperature resistance (the lowest temperature can reach – 70 ～ – 100 ℃), good chemical stability, resistant to most acid and alkali erosion (not resistant to oxidizing acid), insoluble in general solvents at room temperature, low water absorption and excellent electrical insulation; but polyethylene is very sensitive to environmental stress (chemical and mechanical action) The heat aging resistance is poor. The properties of polyethylene vary from variety to variety, mainly depending on the molecular structure and density. Different densities (0.91-0.96 g / cm3) of products can be obtained by different production methods.
Polyethylene can be processed by the molding method of general thermoplastic (see plastic processing). It is widely used in making films, containers, pipes, monofilaments, wires and cables, daily necessities, etc. it can also be used as high-frequency insulating materials for TV, radar, etc. With the development of petrochemical industry, the production of polyethylene has developed rapidly, and the output accounts for about 1 / 4 of the total plastic production. In 1983, the total production capacity of polyethylene in the world was 24.65 MT, and the capacity of the plant under construction was 3.16 Mt.
Polypropylene (PP)
A thermoplastic resin obtained by polymerization of propylene. There are three configurations of isotactic substance, random substance and syndiotactic substance. Isotactic substance is the main component of industrial products. Polypropylene also includes copolymers of propylene with a small amount of ethylene. Usually translucent colorless solid, odorless non-toxic. Due to its regular structure and high crystallization, the melting point is as high as 167 ℃, and the products can be sterilized by steam. The density is 0.90g/cm3, which is the lightest general plastic. Corrosion resistance, tensile strength 30MPa, strength, rigidity and transparency are better than polyethylene. The disadvantages are poor low temperature impact resistance and easy aging, which can be overcome by modification and adding antioxidant respectively.
The color of woven bags is generally white or gray white, non-toxic and tasteless, and generally less harmful to human body. Although it is made of various chemical plastics, its environmental protection is strong, and its recycling strength is large;
Woven bagss are widely used, mainly for packing and packing various articles, and widely used in industry;
Plastic woven bags is made of Polypropylene resin as the main raw material, which is extruded and stretched into flat filament, then woven and made into bag.
Composite plastic woven bags is made of plastic woven cloth by tape casting.
This series of products are used for packing powder or granular solid materials and flexible articles. The composite plastic woven bags is divided into two in one bag and three in one bag according to the main material composition.
According to the sewing method, it can be divided into sewing bottom bag, sewing edge bottom bag, inserting bag and adhesive sewing bag.
According to the effective width of the bag, it can be divided into 350, 450, 500, 550, 600, 650 and 700mm, and the special specifications shall be agreed by the supplier and the demander.
Post time: May-10-2021