Self-supporting zipper bags are usually made of the following materials:

Plastic Materials

• Polyethylene (PE):
  • Low Density Polyethylene (LDPE): It is soft, flexible and has good transparency. Bags made of LDPE have good toughness, are not easy to break, and have certain moisture resistance, which can well protect the items in the bag. It is often used in self-supporting zipper bags for packaging food, daily chemical products, etc.
  • High Density Polyethylene (HDPE): HDPE is harder and more rigid than LDPE, and has better wear resistance and tensile strength. Self-supporting zipper bags made of HDPE can bear heavier items and are often used to package hardware products, industrial supplies and some products that require higher strength packaging.
• Polypropylene (PP): PP material has high hardness, good transparency and heat resistance. Self-supporting zipper bags made of PP can be used in some occasions that require high temperature resistance, such as packaging some food that needs hot filling or sterilization. In addition, PP material also has good chemical stability and is not easy to be corroded by general chemicals.

Composite Materials

• PE/PP Composite: By combining the characteristics of PE and PP, the self-supporting zipper bag made of PE/PP composite material has both the softness and flexibility of PE and the hardness and heat resistance of PP. This kind of composite material can improve the comprehensive performance of the zipper bag and is suitable for packaging a variety of products.
• PE/Aluminum Foil Composite: The combination of PE and aluminum foil makes the self-supporting zipper bag have excellent barrier properties. Aluminum foil can effectively block light, oxygen and moisture, and PE provides good sealing and flexibility. This kind of composite material is often used in the packaging of high-end food, medicine, electronic products and other items that have high requirements for preservation and protection.
• Paper/Plastic Composite: The outer layer is paper, which gives the bag a certain texture and printability, and is convenient for printing various patterns and texts for product promotion and identification. The inner layer is plastic, which provides waterproof and sealing functions. This kind of composite material is environmentally friendly to a certain extent and is often used in the packaging of some cultural and creative products, light industrial products, etc.
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