Polyethylene (PE) is one of the five main synthetic resins. It is the most productive and most imported synthetic resin variety in China. Polyethylene is mainly divided into three categories: linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE) and high-density polyethylene (HDPE).
Formability of PE plastic bag
1. The crystalline material has low moisture absorption, does not need to be fully dried, has excellent fluidity, and is sensitive to pressure. High pressure injection should be used when molding, with uniform material temperature, fast filling speed, and moderate pressure. Direct gate is not suitable for preventing uneven shrinkage and increasing internal stress. Pay attention to the location of the gate to prevent shrinkage and deformation.
2. The shrinkage rate and shrinkage rate are large, the direction is obvious, and it is easy to deform and warp. The cooling rate should be slower, the mold should be equipped with a cold cavity, and there should be a cooling system.
3. The heating time should not be too long, otherwise it will decompose and burn.
4. When the side groove of the PE plastic bag part is shallow, it can be demolded forcibly.
5. Melt fracture may occur, so it is not suitable to contact with organic solvents to prevent fracture.
Namely high-pressure low-density polyethylene (LDPE), high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE). PE plastic bags are its main processed products, followed by sheets and coatings, hollow containers (such as bottles, cans, barrels and various other injection and blow molding products), pipes and wires, and cable insulation and sheathing. Mainly used in packaging, agriculture and transportation sectors.