PE and PP are the English abbreviations for raw materials. The chemical name of PE is linear polyethylene, which is divided into two types. One type of transparent zipper bag is high-density linear polyethylene, which we usually call PO-HDPE, and the other is low-density linear polyethylene, which is what we usually call PE-LDPE. Low-density linear polyethylene is divided into two types-LDPE and LLDPE (we will call them the main material and the secondary material respectively, but these two materials will be used together when making plastic bags). The chemical name of PP is polypropylene, and there is no further division.

The raw materials of bubble bags, pearl cotton, and bone bags are all PE materials, which are synthetic materials of LDPE and LLDPE. Transparent zipper bags generally use PE plastic bags in factories, such as electronic and electrical factories, hardware factories, plastic factories, clothing factories, shoe factories and so on. PE plastic bags are widely used. The film used by farmers for spring plowing is also of PE material. The PE plastic bag looks transparent, smooth, and very soft. It does not make much noise when rubbed and has toughness (this is the function of LLDPE).

The PP plastic bags are mostly used for gift and finished clothing packaging. The ready-to-wear packaging bag with a layer of double-sided tape at the mouth is usually a PP plastic bag. PP plastic bags are very transparent and smooth, but they are tough and crisp. They make a loud noise when rubbed and leave obvious creases when they are folded in half. Folded PE plastic bags do not. Because PP material has good transparency, it is very high-grade when used for packaging gifts. PP is very similar to OPP, but its transparency is not as good as OPP. PP plastic bags have a relative advantage over OPP plastic bags in price. In the past, the price of PE material was higher than that of PP material, but in recent years, I don't know why, PP material is more in demand than PE material, and the price has exceeded that of PE material.

In the past two years, the cost of making plastic bags for transparent zipper bags has increased a lot due to the rising oil prices. As for the PO plastic bag, because of its particularity, the PO material can be very thin and thin. According to the technology we have at present, the smallest can be 0.007MM. The PE and PPzui can only achieve 0.02MM thinness. PP can't even be so thin. Although PO has a relative advantage in price, because PO plastic bags are not transparent and are almost white, the application range of PO is limited to a certain extent.