In the field of industrial packaging, stretch film is one of the most common materials used to secure palletized goods. Many users often prioritize the thickness of the film when making a purchase, believing that thicker films are more durable. However, in practical use, the tensile properties, retraction force, and puncture resistance of the film often have a more critical impact on the packaging effect. Understanding the technical logic behind these surface features can help establish a more accurate understanding of selection.

The core material of mechanical PE wrapping film is polyethylene (PE), which works by mechanically stretching the film to produce pre tension, wrapping it around the surface of the goods, and tightly fixing the goods using the film's own retraction force. The performance of the film mainly depends on the molecular structure of the PE raw material, the additive formula, and the blown film process. There are significant differences in tensile strength, elongation at break, and viscosity among different grades of PE resin. Although the thickness of the film is an intuitive parameter, the actual packaging effect depends more on the stretching ratio of the film - the degree to which the film can be stretched before it breaks. A higher stretching ratio means that sufficient wrapping force can be achieved with less film material, while reducing packaging costs. In addition, the viscosity of the film (usually achieved by adding thickening masterbatch) determines the degree of adhesion between layers, directly affecting the stability of the packaging.