Plastic films come in a variety of types, each with its own unique characteristics. These films differ in their ability to resist moisture, air, oil, heat, and various other properties. Here are some of the differences and special features of various plastic films:
1. Moisture Barrier: Some plastic films possess excellent moisture barrier properties, which makes them ideal for foods, medicines, and other products that must remain dry. These include films made from polyethylene terephthalate (PET), polypropylene (PP), and ethylene-vinyl alcohol (EVOH).
2. Air Barrier: Certain films are specially engineered to keep air out, delivering oxygen barrier protection for foods like snacks, coffee, nuts, and cheese. Oxygen-sensitive products are protected from getting stale or losing flavor. Films that provide an excellent air barrier include those made from PET, PP, and EVOH.
3. Oil Barrier: Films that have excellent oil barrier properties can protect products from contamination and damage. These include films made from polyester (PET), polyethylene (PE), and polyamide (PA).
4. High Tensile Strength: When a film is exposed to tension, it must remain intact without breaking or stretching. Films that have high tensile strength include those made from polyester (PET), polyethylene (PE), and polypropylene (PP).
5. High-Temperature Resistance: Some films can withstand high temperatures of up to 400°F. These include films made from polyimide, polyetherimide, and polyamide.
6. Low-Temperature Resistance: Films that can withstand subzero temperatures can be used for frozen food packaging, medical supplies, and other applications. These include films made from polyethylene (PE), polypropylene (PP), and ethylene vinyl acetate (EVA).
7. Printable: Films that can be printed on are best suited for labeling, brand identification, and packaging designs. Printable films include those made from polyester (PET), polypropylene (PP), and biaxially-oriented polypropylene (BOPP).
8. Heat Sealable: Some films can be heat-sealed to provide a strong bond between packages. These include films made from polyethylene (PE), polypropylene (PP), and coextruded or laminated structures.
In conclusion, plastic films are an essential component of modern packaging, and each type has its unique characteristics and capabilities. By understanding the differences between these films, users can choose the most appropriate materials for their needs.