Method of regulating the degree of pre-stretching a stretchable plastic film

摘要

1. Process for controlling the degree fo prestretching of a stretchable plastic film which passes over at least one prestretching roll before arriving at a use station, particularly for the purpose of wrapping loads, especially palletized loads, making it possible to avoid the sum of the elongation produced by the prestretching and of the additional elongation produced by the tension created in the film before it arrives on the load to be wrapped being greater than the breaking elongation, characterized in that it consists in - continuously sensing the tension in the part of the film included, when the direction of travel of the film is considered, between the last prestretching roll and the use station ; and - causing the speed of at least one prestretching roll to vary correspondingly to the sensed tension.