Foreign production of the main raw materials for polyethylene (PE), domestic production mainly polypropylene (PP), is the ethylene polymerization of a thermoplastic resin. In industry, it also includes ethylene with a small amount of α-olefin copolymers. Polyethylene odorless, non-toxic, feel like wax, with excellent low-temperature resistance (the minimum temperature can reach -70~-100℃), good chemical stability, resistance to most of the acid and alkali erosion (not resistant to the oxidation of acid), at room temperature insoluble in the general solvents, water absorption is small, electrical insulation performance is excellent, but polyethylene for environmental stress (chemical and mechanical action) is very sensitive, thermal aging resistance is poor. The properties of polyethylene vary depending on the molecular structure and density. The products of different densities (0.91~0.96g/cm3) can be produced by using different production methods. Polyethylene can be used in general thermoplastic plastic molding methods (see plastic processing) processing. Use is very wide, mainly used to make films, containers, pipelines, monofilament, wire and cable, daily necessities, and can be used as television, radar and other high-frequency insulating materials. With the development of petrochemical industry, the production of polyethylene has been developed rapidly, which accounts for 1/4 of the total plastic output. 1983, the total production capacity of the world polyethylene is 3.65Mt, the capacity of the installation is 16Mt.
A thermoplastic resin produced by polymerization of propylene. There are three kinds of configurations, such as regulations, regulations and regulations, and industrial products are mainly composed of such regulations. Polypropylene also includes propylene and a small amount of ethylene copolymer. Usually translucent colorless solid, odorless and non-toxic. Because of the structural regularity and high crystallization, so the melting point of up to 167 ℃, heat-resistant, products available steam disinfection is its outstanding advantages. Density 0.90g/cm3 is the lightest general-purpose plastic. Corrosion resistance, tensile strength 30MPa, intensity, rigidity and transparency are better than polyethylene. The disadvantage is low temperature impact resistance, easy aging, but can be overcome by modifying and adding antioxidant respectively.
Woven bag color is generally white or gray white, non-toxic tasteless, physical injury to people generally small, although it is made from a variety of chemical plastics, but its environmental protection is stronger, and the recovery intensity is greater;
The use of woven bag is very wide, mainly used in the packaging and packing of various items, and it has wide use in industry;
Plastic woven bags are polypropylene resin as the main raw material, extruded, into flat wire, and then woven, bag-making.
Composite plastic woven bag is made of plastic woven cloth as the base material, which is compounded by flow extension method.
Used for packing powdered or granular solid materials and flexible articles. The composite plastic woven bag is divided into two bags and three bags according to the main material.
The sewing method is divided into bottom bag, seam bottom bag, inserting pocket, adhesive sewing bag.
The effective width of the bag is divided into 450, 500, 550, 600, 650, 700mm, and the special specifications are agreed by both the supply and demand sides.