METHOD AND ARRANGEMENT FOR THE MANUFACTURE OF CYLINDRICAL TUBES

摘要

For the purpose of producing a packing container a web of laminated material is used, which material includes a base layer of foamed polystyrene, and two outer layers of homogeneous polystyrene. In order to seal the edge zones of the material web into a tube a part of the base layer of one of the edge zones is removed and the other edge zone is inserted into this cut off part between the remaining end parts of the outer layers and is heat-sealed to the outer layers. The so achieved sealing is tight and durable and superior to the known overlap sealing. The seal is also more pleasing from the aesthetic point of view.