Stretch film is a kind of packaging material which is now more popular. Because of the different products produced by different manufacturers, the materials and the production process, the function and effect of the product will be different, and the continuous progress and improvement will be followed. It also has the advantages of high strength, good longitudinal ductility, strong resilience, good lateral tear resistance, good puncture resistance, good self-adhesive function, odorless, non-toxic, etc. Then let us briefly introduce Its physical policy:
    1. Tensile force: After stretching the film to a certain ratio, the ratio of the tensile force to the F-force value for a certain period of time is adhered to. Stretch film
    2. Viscosity: Adhesion between two films in the case of stretching or unstretching.
    3. Permanent deformation: the ratio of the added length to the original length after stretching the film to a certain ratio.
    4. Elastic recovery: After the certain ratio of stretching, the time must be adhered to, and the ratio of the restored standard to the original standard after release.
    5, anti-piercing: used to indicate its ability to resist needle piercing.
    6. Transmittance, haze: The stretch film has good transparency in its application.
    The physical principle of stretching film, that is to say, its functional advantages, so that in order to better ensure the application of the product, we need to analyze its function, what is its interest? What is the defect? What do you need to pay attention to when using? These are all very helpful in our future, so we must understand all aspects of understanding.