What are the material composition of rice plastic packaging bags?

The plastics used in rice plastic packaging bags are all laminated with multi-layer plastic films, including: 1.Polyethylene (referred to asPE)It is a thermoplastic resin obtained by polymerization of ethylene. In industry, also includes ethylene and a small amountα-Olefin copolymers. Polyethylene is odorless, non-toxic, feels like wax, and has excellent low temperature resistance (the minimum operating temperature can reach-100~-70°C), good chemical stability, and can resist most acids and alkalis (not resistant to acids with oxidizing properties).”polyethylene”Flexible and tough, lighter than water, non-toxic, with superior dielectric properties. It is flammable and continues to burn after leaving the fire. The water permeability is low, and the organic vapor transmission rate is relatively large. The transparency of polyethylene decreases with the increase of crystallinity. At a certain crystallinity, the transparency increases with the increase of molecular weight. The melting point range of high density polyethylene is132-135℃, the melting point of low-density polyethylene is low (112℃) and a wide range. Insoluble in common solvents at room temperature, low water absorption, excellent electrical insulation.70Above ℃, it can be dissolved in a small amount in solvents such as toluene, amyl acetate, and trichloroethylene.In terms of processing: polyethylene can be processed by blow molding, extrusion, injection molding and other methods, and is widely used in the manufacture of films, hollow products, fibers and daily sundries.made into thin film:It can be widely used as packaging materials for various food, clothing, medicine, chemical fertilizers, industrial products and agricultural films. It can also be processed into a composite film by extrusion for packaging heavy objects.1975In recent years, high-density polyethylene film has also been developed. It has high strength, low temperature resistance, moisture resistance, and good printability and processability. The biggest use of linear low-density polyethylene is also to make films. Its strength and toughness are better than low-density polyethylene, and its puncture resistance and rigidity are also better. Although the transparency is poor, it is still slightly better than high-density polyethylene. .PEThe film has strong chemical stability and certain acid and alkali resistance at room temperature, and is insoluble in any solvent. It is often the first choice for the inner material of food packaging bags. 2.Polyester film (referred to asPETfilm)It is characterized by high temperature resistance, good printing, easy processing, good voltage resistance and insulation, and can pass fireULcertified94VTM-2Certification, environmental protection has passedSGS,ROSHIt is a film material made of polyethylene terephthalate as raw material, extruded into thick sheets, and then biaxially stretched. It is a colorless, transparent, glossy film with excellent mechanical properties, high rigidity, hardness and toughness, puncture resistance, friction resistance, high and low temperature resistance, chemical resistance, oil resistance, air tightness and fragrance retention. Good, it is one of the commonly used barrier composite film substrates. However, the price of polyester film is higher, and the general thickness is0.12mm, commonly used as the outer material of retort packaging, good printability. 3.Polyamide (referred to asPA)The main chain of the system is a polymer containing many repeating amide groups. This type of high molecular polymer is commonly known as nylon. Compared with ordinary plastics, polyamide has the advantages of wear resistance, toughness, chemical resistance, heat resistance, cold resistance, easy molding, self-lubricating, non-toxic, easy to dye, and the biggest feature of the film is low oxygen transmission rate. The packaging container is conducive to the long-term storage of the product without air leakage and moisture deterioration. In terms of vacuum packaging, it is one of the necessary basic materials. Among all varieties of polyamides, the biaxially oriented nylon film is mainly used for food packaging; its advantages are high puncture strength, impact strength, friction strength, and bending strength, and it has good gas barrier properties. The disadvantage is that it has poor heat sealing properties. , when used, it is often used as a composite product with a substrate film with good heat sealing properties.It is used for frozen food packaging, mainly because of its high film strength, good puncture resistance, and excellent cold resistance.It is used for seasoning packaging of soup and noodle liquid, mainly because of its high strength, good puncture resistance, and especially oil resistance.It is used for cooking-resistant food packaging, mainly using its oil resistance, heat resistance, good gas barrier property, and puncture resistance. 4.Biaxially oriented polypropylene film (referred to asBOPP)Its production is to first make the melt of high molecular polypropylene into a sheet or a thick film through a long and narrow machine head, and then in a special stretching machine, at a certain temperature and a set speed, simultaneously or step by step A film made by stretching in two vertical directions (longitudinal and transverse) and undergoing appropriate cooling or heat treatment or special processing (such as corona, coating, etc.). BOPPBecause of its high transparency and gloss, excellent ink and coating adhesion, heat-sealing strength, water vapor and grease barrier properties, ultraviolet barrier properties, pearly high-end appearance, high barrier properties and low static electricity. It is commonly used as the basic material for bag making and printing composites of packaging bags.The material of the packaging bag container is closely related to the chemical properties. The above is a part of the basic material film of the common food packaging bag. Such as kraft paper, aluminum foil,CPP,YOPPIt is also one of the composite materials for rice packaging bags.