METHOD FOR THE PRODUCTION OF A YARN SPOOL-HOLDER TUBE, DEVICE FOR MAKING SAME, SPOOL-HOLDER TUBE THUS OBTAINED AND USE METHOD FOR SAID SPOOL-HOLDER TUBE

摘要

The invention relates to a cardboard tube which is applied against a rotatin g former by means of a narrow marginal end zone thereof having a hollow rim. Said rotating former is provided with a concave surface that is designed to form a perimeter step that extends inward by constriction of said narrow marginal zone. The diameter of the vertical face of said step is equal to th e internal diameter of the aforementioned cardboard tube. Simultaneously, a force is applied against said hollow rim that is sufficiently strong in orde r to crush the hollow part of same and to apply the wall thereof against the inner face of the projecting end wall of the cardboard tube which is shaped by the action of said rotating former.