Overwrapping film, film pre-stretching device and overwrapping method

摘要

A film wrap is submitted to stretching under tension of 10-20 N/mm<2> of the initial cross section, is wound onto a bobbin and allowed to relax under a tension of 10-90%, preferably 10-50% of the stretching tension. The film is wound onto a cardboard or plastic centre. Also claimed is the stretching machine consisting of the means (35) to stretch the film (36); a guide system (40, 41, 35, 37) and a storage bobbin (38) with a means (42) to partially relieve the tension after stretching and prior to winding onto the storage bobbin.