METODO Y APARATO PARA LA FORMACION DE UNA LAMINA DE MATE- RIAL TERMOPLASTICO DELGADO CON ONDULACIONES EN UNA PRODUC- CION CONTINUA.

摘要

Method for continuously forming a corrugated web of thermoplastic material in which the corrugations extend diagonally across the web. The web is first softened by heat and then passed to a molding belt which moves in an endless path while supporting and advancing the web in a longitudinal direction. The molding belt is provided with grooves corresponding to the corrugations in the web. The corrugations are formed initially by poking the softened web progressively into the grooves without stretching the web to any substantial degree. The thus initially formed corrugations are thereafter drawn into the grooves and retained therein by applying suction to the bottom side of the molding belt.