What is the name of the black film covered on the bracket at the bottom of the box?

Packaged film. The black film covered on the bracket at the bottom of the packaging box is pe black winding film stretching film 50cm industrial cling film tray packaging film self-adhesive film wrapping film. Winding film, also known as stretch film and heat shrinkable film, is the earliest PVC winding film produced in China. It is self-adhesive with PVC as the base material and DOA as the plasticizer.