The first step in ordering packaging bags: characteristics and uses of 7 major plastic films

Plastic films are films made from polyvinyl chloride, polyethylene, polypropylene, polystyrene, and other resins, used to produce various types of packaging bags. Today, Shunxingyuan Packaging, a professional flexible packaging manufacturer, will focus on analyzing the characteristics and uses of seven major plastic films.

1. Biaxially Oriented Polypropylene Film (BOPP)

Biaxially oriented polypropylene film is a transparent flexible packaging material developed in the 1960s.

It is made by mixing polypropylene raw materials and functional additives on a special production line, melt blending them into sheets, and then stretching them into films.

BOPP film not only has the advantages of low density, good corrosion resistance, and good heat resistance of the original PP resin, but also has good optical properties, high mechanical strength, and abundant raw material sources.

The development prospects of BOPP film are very broad. By 2004, the production capacity of BOPP film production lines in China was 1.9 million tons, and the actual output was about 1.76 million tons.

2 PVA coated high barrier plastic film

Polyvinyl alcohol high barrier composite film is a film with extremely high barrier properties formed by coating a modified polyvinyl alcohol water-soluble liquid on a polyethylene plastic substrate.

Because polyvinyl alcohol high barrier composite film has good barrier properties and meets environmental protection requirements, the market prospects of this packaging material are very bright, and it has a broad market space in the food industry.

3. Low-Density Polyethylene Film (LDPE)

Low-density polyethylene is a synthetic resin obtained by free radical polymerization of ethylene under high pressure, also known as "high-pressure polyethylene". LPDE is a branched molecule with different lengths of branches on the main chain, with about 15-30 ethyl, butyl, or longer branches per 1000 carbon atoms on the main chain.

Due to the large number of long and short branches in the molecular chain, the product has low density, softness, good low-temperature resistance, good impact resistance, good chemical stability, generally resistant to acid (except strong oxidizing acids), alkali, and salt corrosion, and good electrical insulation properties.

The application fields of low-density polyethylene film are also very wide, such as the packaging field. There are many types of polyethylene packaging films, and their properties vary. Single-layer films have single properties, while composite films have complementary properties, making them the main materials for packaging bag products.

Especially Shunxingyuan Packaging has successfully made PE plastic bags have the industry advantages of high transparency, powder-free, and easy opening. They are widely used in clothing bags, hardware bags, and other series of products, Shunxingyuan Packaging produces PE plastic bags that appear pure without any impurities, no wrinkles, no stains, and the surface feels smooth, delicate, and has super strong toughness. In addition, Shunxingyuan Packaging's PE plastic bag technology is more advanced, the quality can be finely controlled, and it can meet the needs of high-efficiency production.

4. Polyester Film (PET)

Polyester film (PET) is a thermoplastic engineering plastic. It is made into thick sheets by extrusion and then into films by biaxial stretching.

Polyester film is characterized by excellent mechanical properties, high rigidity, hardness and toughness, puncture resistance, friction resistance, high and low temperature resistance, chemical resistance, oil resistance, good airtightness and aroma retention, and is one of the commonly used barrier composite film substrates, but it has poor corona resistance.

Polyester film is relatively expensive, with a thickness generally of 0.12 mm, commonly used as the outer layer material for food packaging. It has good printability. Due to the complexity and difficulty in judging polyester film, it poses certain difficulties for customs supervision.

5. Nylon Plastic Film

The chemical name of nylon is polyamide (PA). Currently, many types of nylon are produced industrially, and the main types used to produce films include nylon 6, nylon 12, and nylon 66.

Nylon film is a very tough film with good transparency and good gloss. It has high tensile strength and elongation strength, as well as good heat resistance, cold resistance, oil resistance, and organic solvent resistance. It has excellent wear resistance and puncture resistance, and is relatively soft, with good oxygen barrier properties.

However, it has poor water vapor barrier properties, high moisture absorption and permeability, and poor heat sealing properties. It is suitable for packaging hard items, such as oily foods, meat products, fried foods, vacuum-packed foods, and steamed foods.

6. Cast Polypropylene Film (CPP)

Cast film is an unstretched, non-oriented flat extruded film produced by melt casting and rapid cooling. Its characteristics are fast production speed, high output, good transparency, gloss, and thickness uniformity of the film, and excellent balance of various properties.

Because it is a flat extruded film, subsequent work such as printing and lamination is extremely convenient. It is widely used in the packaging of textiles, flowers, food, and daily necessities.

7. Aluminum-Coated Plastic Film

Aluminum-coated film has both the characteristics of plastic film and metal.

The role of aluminum coating on the film surface is to block light and prevent ultraviolet radiation, which extends the shelf life of the contents and improves the brightness of the film. To a certain extent, it replaces aluminum foil and also has low cost, good appearance, and good barrier properties.

Therefore, aluminum-coated film is widely used in composite packaging bags, mainly used in clothing packaging, cosmetics packaging, and food packaging.