Valve bag

摘要

A method for closing a valved sack having one or more layers of flexible material. The valved sack has a filling opening which is closed after filling the valved sack. The filling opening is formed by opposite layers of material, which when closing the valved sack, are on top of one another and are undetachably joined. The method involves closing the filling opening by joining the layers of material which are on top of one another by plastic deformation without applying heat. A valved sack formed by the method is also described.