The material selection:

BOPP: High tensile strength, but low tear strength, good chemical stability, non-toxic, tasteless, odorless, good water resistance.

CPP: High transparency, good luster, high stiffness, thus packaging goods shelf display effect is good, high temperature, can withstand more than 100 cooking.

BOPET: Tensile strength is all the plastic film in the higher, to the air, the smell of the high barrier, is one of the aromatic materials.

BOPA: Tensile strength, tear strength, impact strength and fracture strength are better in plastic materials.

PE: A large amount of plastic film in a variety, good flexibility, high elongation, and low hardness.

VMPET/VMCPP: High barrier film, excellent preservation and light shielding, can prevent food oxidation and deterioration.

EVOH: It is suitable for oil and grease liquids and toxic volatile products.

AL: Aluminum foil, very good barrier material, not light, not wet, not air.

According to the common structure of packaging, it is composed of three layers. The characteristics of different layers are as follows:

(1) outer layer: to enhance the mechanical strength, heat resistance, printing performance and optical performance of the bag.

(2) intermediate layer: highlight the main functions of the composite structure, such as barrier, shading, incense retention, etc.

(3) inner layer: mainly used for sealing, followed by the packaging material pressure, drop, airtight performance.