There are various types of films used in food packaging, each with its unique characteristics and application scenarios. Here are some common types of films used for food packaging and their characteristics:
Polyethylene (PE) film:
? Features: PE film is one of the most widely used plastic packaging films, with good toughness, moisture resistance, and heat sealing performance. It is easy to process and shape, and is inexpensive.
? Application: It is widely used for general moisture-proof packaging of food, medicine, daily necessities, and metal products, as well as packaging of frozen food. Among them, low-density polyethylene (LDPE) film is mainly used for fresh-keeping packaging of fresh items such as fruits and vegetables; High density polyethylene (HDPE) film is commonly used to make shopping bags, garbage bags, and various food packaging bags due to its good strength, toughness, and heat resistance.
Polypropylene (PP) film:
? Features: PP film is divided into unstretched film and biaxially oriented film (BOPP). Untretched PP film has good transparency, glossiness, moisture resistance, heat resistance, and oil resistance; BOPP film has higher transparency, glossiness, and mechanical strength.
? Application: Widely used for packaging of food, pharmaceuticals, textiles, and other items. BOPP film has replaced or partially replaced glass paper in food packaging due to its excellent performance.
Polyester (PET) film:
? Features: PET film has excellent physical and chemical properties, dimensional stability, transparency, and recyclability.
? Application: Mainly used in the packaging of dry and puffed foods such as biscuits, as well as the outer packaging of some pharmaceuticals and cosmetics.
Nylon (PA) film:
? Features: Good transparency, good heat resistance, cold resistance, oil resistance, and organic solvent resistance, excellent wear resistance and puncture resistance, and relatively soft with excellent oxygen resistance.
? Application: Suitable for packaging hard items such as greasy food, fried food, vacuum packaged food, meat products, steamed food, etc.
Polyvinylidene chloride (PVDC) film:
? Features: PVDC film is a high barrier film with excellent moisture resistance, airtightness, and fragrance retention, as well as excellent resistance to strong acids, alkalis, chemicals, and oils.
? Application: Mainly used for making composite films to maintain the flavor of food for a long time.
Ethylene vinyl acetate copolymer (EVA) film:
? Features: EVA film has good low-temperature heat sealing and inclusion sealing properties, making it an excellent sealing film.
? Application: Commonly used as a heat sealing layer for composite films, but single-layer EVA films are generally not directly used for packaging food.
Polyvinyl alcohol (PVA) coated high barrier film:
? Features: It has excellent oxygen barrier performance, fragrance retention performance, and is an environmentally friendly material.
? Application: Can be used for packaging beverages, fruit juice, milk, soy sauce vinegar, etc.
Edible packaging film:
? Features: Made from edible materials such as lipids, proteins, polysaccharides, and other natural macromolecules, it can be biodegraded without any pollution.
? Applications: such as glutinous rice paper used on candy packaging, corn baking packaging cups for ice cream packaging, etc.
Antibacterial food packaging film:
? Characteristics: It has the ability to inhibit or kill surface bacteria.
? Application: Antibacterial effects can be achieved by directly contacting packaging materials containing antibacterial ingredients with food, or by controlling the growth of microorganisms through the selective permeability of packaging materials.
In summary, there are various types of films used in food packaging, and the specific choice of film depends on factors such as the type of food, shelf life requirements, packaging methods, and cost considerations.
