What are the classifications of polypropylene films?

Polypropylene film can be divided into CPP film, BOPP film and IPP film according to different processing techniques. The relevant information is as follows:

CPP film and characteristics

CPP film and polypropylene film produced by casting process. CPP film can be divided into general type, metallized type and retort type film. The universal type is a commonly used CPP film material, and the film can be adjusted within a certain range; the metallized type is a high-end CPP film product, which is made of polypropylene materials with special processes and special specifications, requiring the film to have a higher Heat sealing strength: The retort type has higher requirements for heat resistance. Random copolymers are usually used as raw materials, and the initial heat sealing temperature is higher.

CPP film is a non-stretched, non-directional cast-extruded film with the characteristics of light weight, high transparency, good flatness, good rigidity, strong mechanical adaptability, excellent heat sealability, moisture resistance and heat resistance, and smoothness. It has good properties, high film-making speed, uniform thickness, moisture-proof, oil-resistant, excellent heat and cold resistance, easy heat sealing, and its wrap resistance and packaging machinery applicability are better than polyethylene film. It has excellent optical properties and can be used for automatic packaging.

This technology has been introduced in China since the 1980s. Its investment market is large and its products have high added value. CPP film can be used for packaging food, medicine, stationery, cosmetics and textiles after bag making, and is used in the largest amount in food packaging. CPP film is used to package heat-sterilized food, condiments, soups, etc.; it can also be used for the surface layer, interlayer and auxiliary film of stationery products, such as loose-leaf and protective film for photos and collections, and can also be used to make various labels and sample tapes .

BOPP film and characteristics

BOPP film is a polypropylene film produced using biaxial stretching technology. BOPP film can be divided according to its function: anti-static film, which is obtained by coating an anti-static agent on the substrate or mixing the anti-static agent into the polymer; Anti-fog BOPP film, which has good fresh-keeping effect and has developed rapidly in the field of packaging products, is obtained by stretching the easy-cut BOPP film in the longitudinal or transverse directions; inorganic-filled modified porous BOPP film, which is made by inorganic-incorporated Made from mixed polypropylene; there is also an easy-to-print BOPP film.

BOPP film is a flexible packaging material developed in the 1960s. It is also a highly transparent packaging material with excellent performance. Due to the orientation of the molecular segments and the increase in crystallinity, the tensile strength, tensile elastic modulus, impact strength, tear strength, flexural life, etc. can be significantly improved, and a strong and tough film with high stiffness can be obtained. In addition, it has good moisture resistance, high gloss, good transparency, good gas barrier, moisture-proof, light weight, non-toxic, odorless, good dimensional stability, wide range of use, good printability, good electrical insulation, and has excellent It has the advantages of quality stability and processability. Its comprehensive performance is superior to transparent films such as moisture-proof cellophane and polyethylene film. It is known as the "Queen of Packaging" by the packaging industry. Anti-static BOPP film is used for packaging of snack foods such as carp fillets; easy-to-print BOPP film can be used for packaging cereals; easy-to-cut BOPP film can be used for packaging soups and medicines; inorganic-filled modified porous BOPP film is used for Packaging of deoxidizer and moisture-proof agent. BOPP shrink film produced by the double stretch flat film method has good shrinkage, high shrinkage rate, increased tensile elastic modulus, and high gloss. It is often used in cigarette packaging.

IPP film and characteristics

IPP is a polypropylene film produced using down-blowing water-cooled blown film technology. The optical properties and film thickness deviation of IPP film are slightly lower than those of CPP and BOPP, but the process is simple and the cost is low. It can be packaged by simply sealing at the upper and lower ends. The thickness of packaging film is generally 0.03 ~ 0.05mm. Films with excellent strength at low temperatures can be obtained using copolymer resins. The modified IPP film has low-temperature high impact resistance, high slipperiness, high transparency, high impact strength, good toughness, and anti-static properties. It includes a single-layer polypropylene film, which can be a homopolymer or a copolymer; a multi-layer co-extruded blown film, which is generally made from two raw materials: homopolymerized isotactic polypropylene and copolymerized. IPP is mainly used for packaging of fried snacks, bread, textiles, folders, record sleeves, sea vegetables, sports shoes, etc.

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