1. Protection function
As a packaging material, plastic film is an important and basic function for the protection of commodities. If the plastic film does not have a reliable protective effect on the packaged goods, causing damage or devaluation of the goods, then it will lose its use value as a packaging material. The protective functions of plastic films for commodities are diverse. Different commodities and different packaging forms have different requirements for the protective functions of plastic packaging films.
2. Mechanical protection
Prevent the leakage of the product in the package or the damage and contamination of the product by foreign substances entering the package. The performance indicators that directly reflect the mechanical protection function of the plastic film are mainly the mechanical strength of the polyethylene film, such as tensile strength, tear strength, falling impact strength (dropping impact), and puncture resistance.
3. Good welding strength
Welding strength is also a necessary condition for polyethylene film to reliably protect products. If the weld seam strength is insufficient, the weld seam will become the Achilles heel of the plastic film bag, and the plastic bag will lose its protective effect on the goods due to the crack of the weld seam.
