A rigid, hollow cylindrical insert is designed to be located and to remain in the end portion of a deformable plastic tube. The end portion of the tube is situated between thin film layers with the insert aligned with an edge to be sealed. The assembly is placed between the mating pressure dies to be...http://www.google.es/patents/US4650452?utm_source=gb-gplus-sharePatente US4650452 - Method for joining a tube to a collection pouch
