The reason is that film blowing machines are used in packaging, agriculture, construction, medical, electronics,  consumer goods, environmental and other related fields. 

1. Packaging Industry
Food Packaging, Consumer Goods Packaging, Industrial Packaging

2. Agricultural Industry
Greenhouse Film, Mulch Films, Protective Films

3. Construction Industry
Waterproof Membranes, Protective Films

4. Medical Industry
Packaging for Disposable Medical Supplies

5. Electronics Industry
Anti-static Films, Protective Films

6. Consumer Goods Industry
Plastic Bags and Shopping Bags, Film Materials

7. Environmental Industry
Trash Bags and Recycling Bags

8. Other Industries
Apparel and Textile Packaging, Toys and Gift Packaging