1. Definition of Plastic Packaging Bags Plastic packaging bags are thin films made from various polymers (such as PE, PP, PA, PVC, EVA, PLA, etc.), processed through processes such as film blowing, casting, printing, and bag making. They are bag-shaped packaging materials used for packaging food, daily necessities, industrial products, electronic products, clothing, and other items. They can be transparent, translucent, or opaque, and can also be color printed and multi-layer laminated according to requirements.
2. Common Plastic Packaging Materials Different plastic bags use different materials depending on their purpose:
PE (Polyethylene): Includes LDPE and HDPE. Soft, good toughness, commonly used for food packaging.
PP (Polypropylene): High transparency, high stiffness, often used for food packaging.
PA (Nylon): High barrier properties, puncture resistance, mostly used for vacuum bags.
CPP, BOPP: High transparency, good heat resistance, suitable for baking and candy packaging.
PVC: High transparency, mostly used for daily necessities packaging.
EVA: Soft, low-temperature resistant, often used for ice packs, etc.
PLA: Biodegradable and environmentally friendly material.
3. Main Characteristics of Plastic Packaging Bags Lightweight and low cost: Economical and practical, it is the most commonly used packaging form globally.
Controllable transparency: Can be made highly transparent (for good display effect) or opaque (to protect privacy and contents).
Good sealing performance: Can prevent dust, moisture, pollution, and reduce contact with air.
Strong durability: Tensile and tear-resistant, protecting the contents inside.
Highly customizable: Size, thickness, color, printing, and bag type can be customized as needed.
Excellent oil and water resistance: Particularly suitable for food and daily necessities packaging.
4. Main Functions of Plastic Packaging Bags Protective function: Prevents contamination, damage, moisture, and oxidation.
Storage function: Used for storing, freezing, and transporting goods.
Display function: Transparent packaging can enhance product display effect.
Sealing function: Extends product freshness (such as food bags).
Portability function: Shopping bags and tote bags are convenient to carry.
Marketing function: Can be printed with logos, patterns, and descriptive text.
5. Common Applications of Plastic Packaging Bags Food packaging: Frozen food, vegetables, fruits, snacks, bread, etc. Daily necessities packaging: tissues, laundry detergent refill bags, health products, etc.
Clothing packaging: flat bags, zipper bags, tote bags.
Industrial and logistics: courier bags, electronic component bags, anti-static bags.
Medical and hygiene: medicine bags, medical waste bags.
Household use: garbage bags, food preservation bags, storage bags.
6. Common Plastic Packaging Bag Forms (Bag Types) Flat bag (most common)
Ziplock bag
Adhesive strip bag
Side seal bag
Center seal bag
Four-side seal bag
Square bottom bag (gusseted bag)
Tote bag
Roll bag / Reel bag
Pre-opened bag
Vacuum bag (Nylon PA)
7. Manufacturing Process of Plastic Packaging Bags Film blowing / Casting → Plastic film production
Printing (customizable in color)
Lamination (improves strength and barrier properties)
Slitting
Bag making (heat sealing and forming)
Inspection and packaging
