Heat-Shrinkable Bags from China - Quality Industrial Packaging by Leading Suppliers and Factory
What is a hot compressed bag?
Heat shrinkable bags, also known as shrink bags or PVC / POF shrink bags, is a packaging material made of special plastic film. When heated (usually using a hot windmill, syringe, or oven), it contracts evenly in one or both directions, thus tightening the contents of the interior to form a strong, transparent, and aesthetically pleasing protective film.
Working principle
The raw materials of the hot compressed bags have gone through a process of "prestretching" and "cooling and forming" before they leave the factory. This means that the plastic molecules are forcefully stretched and arranged when manufactured, and are cooled to secure in a stretched state. When you heat it again, these "frozen" molecular chains return to their original state of relaxation, causing the film to contract in size and tightly adhere to the product surface.
Main types and materials
1. POF (polyolefin)
Features: Most mainstream and eco-friendly.
- High transparency & toughness
- Non-toxic, food-grade standards
- Uniform shrinkage, smooth surface
Apps: Food, pharma, cosmetics, electronics.
2. PVC (polyvinyl chloride)
Features: Traditional low-cost material.
- Strong contractile force
- Lower price point
- May turn yellow over time
Apps: Industrial products, card packaging.
3. PET / PETG
Features: High-performance engineering plastic.
- Extremely strong & shock resistant
- Eco-friendly and recyclable
- Premium presentation
Apps: High-end electronics, batteries.
4. OPS (polystyrene)
Features: Hard, brittle material.
- Very high transparency & gloss
- Environmentally friendly
Apps: Pastries, fruit trays, stationery.
Application Areas
- Food & Bev: Bottled water, canned goods, biscuits.
- Personal Care: Shampoos, cosmetics, toothpaste.
- Pharmaceutical: Medication and health product boxes.
- Electronics: USB drives, batteries, small appliances.
- Tools & Hardware: Screwdrivers, wrenches.
- Printed Media: Waterproof book and magazine wrap.
How to use heat-shrinkable bags?
Bag should be 10-20% larger than the product to allow room for shrinkage.
Place the product securely inside the bag.
Use an L-shaped sealing machine or an **Impulse Sealer** to seal the opening.
Industrial: Use thermal shrinkage tunnels for mass production.
DIY: Use a heat gun (15-20cm distance). Do not use open flames.
