A PROCESS AND APPARATUS FOR THE MANUFACTURE OF PIPE TUBES WITH A SIZE EMBEDDED FOR THE PACKAGING OR EXPEDITION OF ARTICLES OR DOCUMENTS, AND PIPES OBTAINED THROUGH THE APPLICATION OF THIS PROCESS

摘要

A process and apparatus are provided for manufacturing cardboard tubes with incorporated closure for packing or sending articles or documents and tubes obtained by implementing this process. The process comprises the continuous formation of a cardboard tube on the rotary mandrel of a spiralling machine and cutting the tube into tube elements discharged by the machine. This cut out is provided in the form of a sinusoid with provision of appropriate fold lines. Thus tube elements are obtained, without waste of material, whose ends have two opposite tongues which may be folded back, the adjacent ends of two successive tube elements being offset by 90 DEG .