What is pre stretch?How Is Film Prestretched ?

Pre stretch is the process that allows stretch film to be stretched before (pre) being applied to a load. The film threads past two rollers (Primary and Secondary) in which the second rollers' rotational speed is faster than the first, thus stretching the stretch film between the two.

Film is prestretched when it is elongated mechanically between the two film carriage rollers due to the gearing ratio and diameter of the rollers.

As the surface of the secondary roller is rotating faster than the Primary the film gets pulled between them and stretches.