The plastic film is of polyvinyl chloride, polyethylene, polypropylene, polystyrene and other resin films for packaging, and as a coating layer.
To analyze the following seven characteristics and uses plastic film:
Biaxially oriented polypropylene film (BOPP)
Biaxially oriented polypropylene film is the 1960s developed a transparent flexible packaging materials. It is a production line with a special polypropylene material mixed with a functional additive, melt-kneaded, formed into a sheet, and then formed into a film by stretching. BOPP film not only has a low density of the original PP resin, good corrosion resistance, heat resistance and good benefits, and good film optical properties, high mechanical strength, a rich source of raw materials.
In addition, the film can also be applied to the preparation of electricians, microporous film of high value-added functional products, so the prospects for the development of BOPP film is very broad. By 2004, China's BOPP film production line capacity of 1.9 million tons, the actual output of about 1.76 million tons.
PVA coating of high barrier plastic film
High barrier composite film of polyvinyl alcohol, based on the film with high barrier properties of polyethylene plastic substrate, a water-soluble polyvinyl alcohol modified in liquid coating formed on the substrate. Since the polyvinyl alcohol barrier composite film has good barrier properties, and meet environmental requirements, so the market prospect of this kind of packaging material is very light, there is a broad market space in the food industry.
Low density polyethylene film (LDPE)
LDPE is at high pressure radical polymerization of ethylene and synthetic resin obtained, so called "high-pressure polyethylene." Branched molecules with different lengths on LPDE branched main chain, in the main chain per 1000 carbon atoms with from about 15 to 30 ethyl, butyl or longer Di branches. Since the molecular chain contains more branched-chain length and therefore lower density of the product, soft, low temperature resistance, good impact resistance, good chemical stability, under normal circumstances acid (except strong oxidizing acid outside) , the corrosive effect of alkali, salt, has good electrical insulation properties.
Applications LDPE film is also very broad, such as packaging. Polyethylene packaging film variety, its performance varies, the performance of a single monolayer film composite membrane performance complementary, as the main material for food packaging. Second, the polyethylene film is also applied in the field of civil engineering, such as geomembrane. It can play the role of water in civil engineering, and has a very low permeability. Is applied on agricultural plastic sheeting, can be divided into films, film, bitter covering film, silage film.
Polyester film (PET)
Polyester film (PET), a thermoplastic engineering plastics. Using extrusion method into thick slices, and then by two-way stretch film material. The characteristics of the polyester film is excellent mechanical properties, high stiffness, hardness and toughness, puncture resistance, abrasion resistance, high temperature and low temperature resistance, chemical resistance, oil resistance, air tightness and preserving flavor is good, is a common barrier one composite film substrate, but poor resistance to corona. The higher price of the polyester film, thickness is 0.12mm, made common outer packaging food packaging materials, printing is better. Because of the complexity and difficult to judge the polyester film, to the customs control to bring some difficulties.
Nylon plastic film
Many chemical name nylon polyamide (PA), nylon current industrial production species in which the main varieties used to produce films as nylon 6, nylon 12, nylon 66 and the like. Nylon film is a very tough film, good transparency and good gloss, tensile strength, high tensile strength, but also has good heat resistance, cold resistance, oil resistance and organic solvent resistance, abrasion resistance, excellent puncture resistance, and relatively soft, good oxygen barrier properties, but poor water vapor barrier, moisture absorption, moisture permeability is large, poor sealing, suitable for rigid packaging materials, such as greasy food, meat, fried foods, vacuum-packed food, cooking food.
Cast polypropylene film (CPP)
The cast film is quenched by melt casting the production of a non-stretch, non-oriented cast film. It is characterized by production speed, high output, film transparency, gloss, thickness uniformity is good, excellent in the performance balance. Because it is cast film, the follow-up work such as printing, laminating, etc. is extremely convenient, widely used in textiles, flowers, food, daily necessities packaging.
Aluminized plastic film
Both feature aluminized plastic film, but also has the properties of the metal. The role of aluminum film surface shading, anti-ultraviolet radiation, both to extend the shelf life of the contents, but also improves the brightness of the film, instead of the aluminum foil from a certain extent, also cheap, beautiful and good barrier properties. Thus, in aluminized composite packaging in a wide range of applications, mainly used in biscuits and other dry, puffed food packaging, as well as some pharmaceuticals, cosmetics packaging.