APPARATUS FOR TRANSVERSELY STRETCHING A FOIL OF PLASTIC MATERIAL

摘要

A film of plastic material formed as a continuous web (1) is transversely stretched in a continuous process. The apparatus provides for two side gripping assemblies (5,5) spreading the web edges, each assembly comprising a first and a second group of rolls (6, 8) adjacent to each other and with their axes parallel. The rolls of the first group (6) are driven by a motor whereas the rolls of the second group (8) that are substantially tangent to the former are provided with at least one friction belt (9) to engage the foil edges at the tangency areas. The apparatus further provides means (15, 18) for supplying the foil to the diverging assemblies while maintaining it at a predetermined temperature and cooling the transversely stretched foil immediately after the diverging assemblies.