Foreign production is mainly polyethylene (PE), domestic production is mainly polypropylene (PP), is a kind of thermoplastic resin produced by ethylene polymerization. Industrially, it also includes copolymers of ethylene with small amounts of -olefin. Polyethylene odorless, non-toxic, feel like wax, has excellent low temperature resistance (the lowest use temperature can be up to -70 ~ -100℃), good chemical stability, can withstand most of the acid and alkali erosion (no oxidation of acid), room temperature insoluble in general solvents, small water absorption, excellent electrical insulation performance; But polyethylene is sensitive to environmental stresses (chemical and mechanical effects) and has poor resistance to thermal aging. The properties of polyethylene vary from species to species, mainly depending on the molecular structure and density. The products with different density (0.91 ~ 0.96g/cm3) can be obtained by using different production methods. Polyethylene can be processed by the general thermoplastic molding method (see plastic processing). It is widely used in the manufacture of film, container, pipe, single wire, wire and cable, daily necessities, etc., and can be used as high-frequency insulation materials for TV, radar, etc. With the development of petrochemical industry, polyethylene production has been rapidly developed, the output of about 1/4 of the total plastic production. In 1983, the total production capacity of polyethylene was 24.65Mt, and the capacity of plant under construction was 3.16Mt.
Polypropylene (PP)
A thermoplastic resin prepared by polymerization of propylene. There are three configurations of isochronous, unregulated and interchronous products, and isochronous products are the main components of industrial products. Polypropylene also includes copolymers of propylene and a small amount of ethylene. Usually translucent colorless solid, odorless non-toxic. Because the structure is neat and highly crystallized, so the melting point up to 167℃, heat resistance, products can be used steam disinfection is its outstanding advantages. With a density of 0.90g/cm3, it is the lightest universal plastic. Corrosion resistance, tensile strength 30MPa, strength, rigidity and transparency are better than polyethylene. The disadvantage is the low temperature impact resistance and easy aging, which can be overcome by modification and addition of antioxidant respectively.
The color of woven bag is generally white or gray white, non-toxic and tasteless, generally less harm to human body, although it is made by a variety of chemical plastics, but its environmental protection is stronger, and the recycling strength is larger;
Woven bags are widely used, mainly used for packing and packing of various articles, widely used in industry;
Plastic woven bag is made of polypropylene resin as the main raw material, which is extruded and stretched into flat silk, then woven and bag-making.
The composite plastic woven bag is based on the plastic woven cloth, which is made by the rolling method.
This series of products are used for packing powder or granular solid materials and flexible articles. The composite plastic woven bag 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 bottom bag, inserting pocket and bonding sewing bag.
According to the effective width of the bag, it can be divided into 350, 450, 500, 550, 600, 650 and 700mm. Special specifications shall be agreed by both parties.
Post time: Sep-28-2020