Production requirements for polyethylene packaging materials

Polyethylene packaging materials are usually produced by a blown film process, which requires flexographic printing and slitting after the blown film is completed. Heat sealing performance is an important physical index for evaluating polyethylene packaging materials. Excellent heat sealing properties ensure that the material has a wide heat sealing temperature range on the automatic packaging line, which is conducive to increasing the packaging speed, and is not sealed during refrigeration and transportation. rupture.

For this reason, a low-density polyethylene having a narrow molecular weight distribution is used in the heat-sealing layer to improve the heat-sealing property of the polyethylene packaging material. The LDPE heat sealing temperature range is wider, and the heat sealing strength is significantly higher than that of the ordinary LLDPE. However, the disadvantages are poor fluidity, poor processing, and low melt strength. Therefore, it is necessary to add a certain amount of LDPE to improve the bubble stability and improve the extrusion processing performance.

The automatic packaging machine requires a low friction coefficient between the polyethylene packaging material and the metal to ensure smooth movement without affecting the production efficiency. If the friction coefficient is large, the heat seal will be pleated, and the pleated film will be thickened and heat sealed. Poor, the pleats will rupture and leak when falling and static pressure. Therefore, strict requirements are imposed on the content of additives in the printing surface of the polyethylene packaging material and the heat sealing layer, and it is necessary to add an appropriate amount of the opening agent and the slip agent.www.xmlfilm.com