There are too many types of plastic bags. The custom-made plastic bags we usually recognize may be just handbags. For example, supermarket shopping bags. There is a plastic bag called a composite bag. As the name suggests, it is composed of several layers of materials. It is much more complicated than vest bags and the like, and is often used in industrial and food packaging.
Composite bags are usually composed of three layers of materials, and the characteristics of different layers are as follows:
Outer layer: enhance the mechanical strength, heat resistance, printing performance and optical performance of the bag.
Middle: highlight the main functions of the composite structure, such as barrier performance, fragrance retention performance, etc.
Inner layer: mainly the sealing performance, followed by the pressure resistance, drop, and sealing performance of the packaging materials.
So, to understand the characteristics of different levels, let's talk about the characteristics of materials at different levels. The types and characteristics of the composite bags are as follows:
BOPP: High tensile strength, but low tear strength, good chemical stability, non-toxic and tasteless, and excellent water resistance.
CPP: high transparent bag, good gloss, high stiffness, so the shelf display effect of packaged products is good, high temperature resistance, can be cooked at more than 100 degrees.
BOPET: Tensile strength is one of the best among all plastic films. It has a very high barrier to air and odor. It is one of the fragrance-preserving materials.
BOPA: Tensile strength, tear strength, impact strength and rupture strength are among the best in plastic materials.
PE: The largest amount of plastic film, with good flexibility, high elongation and low cutting hardness.
VMPET / VMCPP: high barrier performance film, excellent fragrance retention and light shielding properties, can prevent food from oxidative deterioration.
EVOH: It has excellent gas barrier properties, good fragrance retention and chemical resistance, and is suitable for packaging of oily liquids and toxic volatile products.
AL: Aluminum foil material, the barrier performance is very good, opaque, moisture-proof, and air-proof.
Different materials are used for different product packaging. For more production processes of composite bags, please pay attention to Huasheng plastic bag manufacturers. Customized plastic bags contact customer service, personalized solutions are customized on demand!