Patent ID: 8051628

Claim:
A method for gas filling of a duct in a container of a collapsible type, said duct being defined by a first and a second side wall of the container, wherein said first and second side walls are joined along a common connecting portion, and said duct comprises an inlet arranged in the first side wall, said method comprising the steps of clamping the container between an abutment and a gas module, said gas module being axially movable towards the abutment, wherein said gas module comprises a groove formed in a surface, facing the abutment, of the gas module, and clamping the first side wall comprising said inlet is positioned in such a manner that the groove is located radially outward from said inlet, and wherein the second side wall is allowed to bulge in response to a gas flow supplied to the duct through said inlet to form a passage for filling the same with said gas flow, connecting said groove with an environment outside of the gas module, supplying through an outlet in the gas module a gas flow to said duct through said inlet, whereby the groove connected with the environment prevents build-up of a pressure above atmospheric on the side, facing the gas module, of said first wall surrounding said inlet, and after completion of the gas filling, sealing the duct.