What are the four kinds of plastic bags commonly used

What are the four kinds of plastic bags commonly used?
1, high-pressure polyethylene plastic bags
High pressure polyethylene, also known as low density polyethylene (LDPE), Cheng translucent state, plastic bag products transparency is generally better than low pressure polyethylene. There are three main uses:
A. Food packaging: pastry, candy, fried goods, biscuits, milk powder, salt, tea, etc.
B. Fiber packaging: shirts, clothing, cotton, chemical fiber products;
C. Packaging of daily chemical products.
2, low pressure polyethylene plastic bags
Low pressure polyethylene, also known as high density polyethylene (HDPE), due to its high crystallinity, transparency is not good, generally translucent state, transparency is worse than HDPE high pressure polyethylene plastic bag products. There are four main uses:

A. Garbage bag, germ bag;
B, convenience bag, shopping bag, tote bag, vest bag;
C, plastic bags;
D, woven bag inside bag

3. Polypropylene plastic bags
Polypropylene plastic bag of polypropylene relative to polyethylene, its crystallization will weaken the need, especially random polypropylene, crystallization is weak, the transparency of plastic bag products is very high.
Mainly used for packaging textiles, cotton, clothing, shirts and so on.
The first three plastic bags are not easy to stain or print because of the non-polar reason of their material structure, so they need surface printing treatment.

4. Polyvinyl chloride plastic bags

PVC plastic bags, from PVC resin blow molding processing, compared with the first three plastic bags, the material structure of the introduction of chlorine element this substance, making its crystallization effect is very weak, the transparency of the product is high, at the same time, due to the addition of chlorine element, making the material itself with a certain polarity, easy to print coloring. Its main use is in two aspects:
A. Gift bag;
B. Bags and bags, bags for needle and cotton products, bags for cosmetics;