Polypropylene film is PP. Polypropylene film is a kind of film with good physical stability, mechanical strength, air tightness, high transparency and gloss, toughness and abrasion resistance. Polypropylene film is currently the most widely used printing film. The main disadvantage of biaxially oriented polypropylene film is poor heat sealability, so it is generally used as the outer film of composite film. For example, it is ideal for moisture resistance, transparency, strength, stiffness and printability after compounding with polyethylene film. Contain dry food.
Polypropylene (PP) has a high melting point and excellent comprehensive properties. It is one of the most promising thermoplastic polymer materials today. Compared with other general thermoplastics, it has low price, small specific gravity, yield strength, tensile strength, surface It has excellent mechanical properties such as strength, outstanding stress crack resistance and abrasion resistance, good chemical stability, easy forming and processing, and a wide range of applications.It has been widely used in chemicals, electrical appliances, automobiles, construction, packaging, etc. industry. At present, the packaging market, from food to miscellaneous goods, mostly uses plastic films instead of paper as flexible packaging materials. The plastic film used for commodity flexible packaging must meet the requirements for protection, workability, convenience, and economy of commodity packaging materials, have appropriate strength, have barrier properties, stability, security, aesthetic transparency, and economic convenience Sex.
Polypropylene film can be divided into CPP film and BOPP film according to different processing technology, and the relevant situation is as follows:
CPP film features
CPP film and polypropylene film produced by casting process. CPP film can be divided into general-purpose, metallized and retort-type films. The general 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 cast by using a special process and special specifications of polypropylene material, which requires a high level of film Heat-sealing strength; cooking type has higher heat resistance requirements. Random copolymers are usually used as raw materials, and the initial heat-sealing temperature is higher.
CPP film is a non-stretched, non-oriented, extruded film.It has light weight, high transparency, good flatness, good rigidity, strong mechanical adaptability, excellent heat sealability, moisture resistance and heat resistance, and is smooth. Good properties, high film-making speed, uniform thickness, moisture resistance, oil resistance, heat resistance and cold resistance, easy to heat seal, its resistance and packaging machinery applicability are superior to polyethylene films. It has excellent optical properties and can be used for automatic packaging. This technology has been introduced in China since the 1980s, with a large investment market and high added value. CPP film can be used in the packaging of food, medicine, stationery, cosmetics and textiles after bag making. It is the most used in food packaging. CPP film is used to package heat-sterilized food, condiments, soups, etc .; it can also be used on the surface, compartments and auxiliary films of stationery products, such as leaflets, protective films for photos and collectibles, and various labels and tape .
BOPP film and features
BOPP film is a polypropylene film produced by biaxial stretching technology. BOPP film can be divided into: antistatic film, which is obtained by coating antistatic agent on the substrate or mixing antistatic agent into polymer; Anti-fogging BOPP film, which has good fresh-keeping effect, has been rapidly developed in the field of packaging products, which is obtained by stretching the free-cut BOPP film in the longitudinal or transverse direction; the porous BOPP film modified by inorganic matter is filled with inorganic substances. Made of mixed polypropylene; and BOPP film that is easy to print.
BOPP film is a kind of flexible packaging material developed in the 1960s, and it is also a kind of highly transparent packaging material with excellent performance. Due to the molecular segment orientation, the crystallinity is increased, so tensile strength, tensile elastic modulus, impact strength, tear strength, tortuous life, etc. can be significantly improved, and a tough film with high stiffness can be obtained. In addition, it has good moisture resistance, high gloss, good transparency, good gas barrier, moisture resistance, light weight, non-toxic, odorless, good dimensional stability, wide range of use, good printability, good electrical insulation, excellent It has the advantages of quality stability and processability, and its comprehensive performance is superior to transparent films such as moisture-proof cellophane and polyethylene film. It is known as “the packaging queen” by the packaging industry. Antistatic BOPP film is used for packaging of small foods such as carp fillets; easy-to-print BOPP film can be used for packaging cereals; easy-cut BOPP film can be used for soup and medicine packaging; inorganic-filled modified porous BOPP film is used for Packaging of deoxidizers and moisture barriers. The BOPP shrink film produced by the secondary stretch flat film method has good shrinkability, high shrinkage, improved tensile elastic modulus, and high gloss. It is often used in the packaging of cigarettes.