Now more and more places are using self-supporting zipper bags, especially for food, such as dried fruit packaging bags, laundry detergent self-supporting bags, etc., so what are the main materials used for self-supporting zipper bags?

1, polyethylene (PE)Polyethylene is a high molecular polymer of ethylene. It is a thermoplastic. Polyethylene is a milky white waxy solid, lighter than water, softer, good water resistance, low temperature resistance, odorless, non-toxic, according to its density. It can be divided into high-density, medium-density, low-density polyethylene, and linear low-density polyethylene.

2, polypropylene (PP)Polypropylene is a by-product of petroleum refining, propylene, which is the smallest known plastic; non-toxic, odorless, high transparency, good mechanical properties, surface strength, friction resistance, chemical corrosion resistance, and moisture resistance; The impact resistance value is large above room temperature, and the raw material source of polypropylene is wide, the price is cheap, and the performance adaptability is wide. It is widely used in the food industry, and is mostly used to make films and composite films. It has good transparency and surface gloss, and can withstand120It can be made into packing boxes, blow molded into plastic bottles, and can be made into some machine parts by adding some fillers.

3, polystyrene (PS)Polystyrene is a colorless, transparent, non-extensible thermoplastic; non-toxic, tasteless, odorless, good coloring, moisture permeability is greater than polyethylene, low hygroscopicity, stable size, good gloss; processing performance Good, low cost; mechanical properties increase with the increase of molecular weight; low temperature resistance, can withstand—40℃ low temperature; good indoor aging resistance; good tolerance to alcohol organic solvents and mineral oil, and good acid and alkali resistance.Due to its superior performance, low price and wide application, polystyrene can be made into films and containers, and is widely used in the food industry; the shrinkage rate can reach60~70, is a good material for making shrink wrap.