The difference between PP and PE

PE and PP are abbreviations for raw materials. The chemical name for PE is linear polyethylene, and there are two kinds of PE. One is high-density linear polyethylene, which we usually called PO- HDPE, the other is a low-density linear polyethylene, as we usually called PE- LDPE. LDPE is divided into two types --LDPE and LLDPE (we will call them main and secondary materials respectively, but they are used together in plastic bags). The chemical name for PP is polypropylene, and there is no further division.

Bubble bag, pearl cotton, a bone bag of raw materials are PE material, that is, LDPE and LLDPE composite material. General factory plastic bags are PE plastic bags, such as electronics factory, hardware factory, plastic factory, clothing factory, shoe factory and so on. PE plastic bags are widely used. The film farmers use for spring plowing is also made of PE material. PE plastic bags are transparent, smooth, soft, quiet, and flexible (LLDPE is responsible for this). And PP plastic bags are used for gifts and finished clothing packaging. The bag mouth has a layer of double-sided adhesive sealing garment packaging bag is usually PP plastic bag. PP plastic bag is very transparent, also very smooth, but relatively tough, flat, rubbing when the sound is very big and fold up will leave obvious creases. Folded PE plastic bags are not. Because PP material transparency is good, used for packaging gifts is very grade. PP is similar to OPP, but not as transparent as OPP. PP plastic bags have a comparative advantage over OPP plastic bags at price. In the past, PE material price is higher than PP material, but in recent years, I do not know what reason, PP material is tighter than PE material, the price also exceeds the price of PE material.

In the past two years, due to the rise in oil prices, the cost of making plastic bags has increased a lot. As for the PO plastic bag, because of its particularity, PO material can be very thin. According to our current technology, the thinnest can be 0.007mm. While PE and PP can only be 0.02mm thin. PP can't even be this thin. Although PO has a comparative advantage in price, because the transparency of the PO plastic bag is not high, almost white, limited the scope of application of PO to a certain extent.