The share of plastic packaging and plastic packaging products in the market is increasing, especially for composite plastic flexible packaging, which has been widely used in food, medicine, chemical industry and other fields, among which food packaging accounts for the largest proportion, such as beverage packaging. , Frozen food packaging, cooking food packaging, fast food packaging, etc. These products have brought great convenience to people's lives.
Film type
PVA coated high barrier film
The PVA coated high-barrier film is obtained by coating PVA with nano-inorganic materials on a polyethylene film and printing it on a plastic film at a cost-effective price.
Under the premise of cost, the barrier performance is not only better than EVOH five-layer co-extruded film, but also the packaging cost is greatly reduced. This not only ensures all the quality requirements for the aseptic packaging of the packaged goods, but also significantly reduces food processing. The cost of the company's aseptic packaging can be used to package beverages, fruit juices, milk, soy sauce vinegar, etc.
Biaxially oriented polypropylene film (BOPP)
Biaxially oriented polypropylene film is produced by co-extruding polypropylene particles to form a sheet and then stretching it in both longitudinal and transverse directions. Due to the orientation of the stretched molecules, the physical stability and mechanical strength of the film are achieved. , Good air tightness, high transparency and gloss, tough and wearable, is currently the most widely used printing film, generally using a thickness of 20 ~ 40 μ m, the most widely used is 20 μ m. The main disadvantage of acrylic film is poor heat sealability, so it is generally used as a composite film outer film, such as polyethylene film composite dampness, transparency, strength, stiffness and printability are ideal, suitable for dressed dry foods.
Since the biaxially oriented polypropylene film has a non-polar surface, high crystallinity, and low surface free energy, its printing performance is poor, adhesion to ink and adhesive is poor, and the surface needs to be printed before printing and compounding. deal with.
Low-density polyethylene film (LDPE)
Low-density polyethylene film is generally made by two processes of blow molding and casting. The thickness of cast polyethylene film is uniform, but due to higher cost and lower cost, it is the most widely used. Low-density polyethylene film is a kind of Translucent, shiny, soft texture film, with excellent chemical stability, heat sealability, water resistance and moisture resistance, freeze-resistant, boiled. Its main drawback is poor barrier to oxygen, commonly used in The inner film of composite flexible packaging material is also the most widely used and most used plastic packaging film, accounting for about 40% of the consumption of plastic packaging film.
Because the polyethylene molecule does not contain polar groups, and the crystallinity is high, the surface free energy is low. Therefore, the printing performance of the film is poor, and the adhesion to the ink and the adhesive is poor, so it is required before printing and compounding. Perform surface treatment.
Polyester film (PET)
Polyester film is a film material made from polyethylene terephthalate, extruded by extrusion, and then biaxially stretched. It is a colorless, transparent, glossy film. Excellent performance, rigidity, high hardness and toughness, puncture resistance, friction resistance, high temperature and low temperature resistance, chemical resistance, oil resistance, airtightness, and good fragrance retention. It is one of the commonly used barrier composite film substrates. However, the price of polyester film is relatively high, and the general thickness is 12 μm. It is commonly used as outer layer material for cooking and packaging.
Nylon film (PA)
Nylon film is a very tough film with good transparency, good gloss, tensile strength, high tensile strength, good heat resistance, cold resistance, oil resistance and organic solvent resistance. Wear resistance, excellent puncture resistance, and soft, good oxygen barrier, but poor barrier to water vapor, moisture absorption, moisture permeability, poor heat sealability, suitable for packaging hard items, such as greasy Sex foods, meat products, fried foods, vacuum packaged foods, steamed foods, etc.
Cast polypropylene film (CPP)
Cast polypropylene film is a polypropylene film produced by casting process. It can be divided into ordinary CPP and cooking grade CPP. It has excellent transparency, uniform thickness, and uniform longitudinal and transverse performance. It is generally used as a composite film. Layer material. Common CPP film thickness is generally between 25~50μm. After being compounded with OPP, the transparency is better, the surface is bright, and the hand feels strong. This kind of material is used in general gift bags. This film also has good heat sealing. The thickness of cooking-grade CPP film is generally between 60 and 80 μm. It can withstand 121°C, high-temperature cooking for 30 min, oil resistance, airtightness is good, and the heat seal strength is high, in general meat packaging Layers are cooking grade CPP film.
Aluminized film
At present, the most widely used aluminized films are polyester aluminum film (VMPET) and CPP aluminum film (VMCPP). The aluminized film has both the characteristics of plastic film and metal characteristics. The role of aluminum plating film surface is blackout , Anti-ultraviolet radiation, both to extend the shelf life of the content, but also increased the brightness of the film, to some extent instead of the aluminum foil, but also has low cost, beautiful and better barrier properties, therefore, the aluminized film in the composite packaging The application is very extensive.