Method and device for gas filling and sealing of a duct intended to be filled with gas and positioned in a container of a collapsible type, and container blank comprising such a duct
The invention relates to a method and a device for gas filling and sealing of a duct intended to be filled with gas and positioned in a container of a collapsible type. The duct is defined by two opposite side walls which are joined along a connecting portion and comprises an inlet arranged in one of the side walls. A part of the container that comprises the inlet is clamped between an abutment and a gas module which is axially movable towards the abutment. Clamping occurs in such a manner that one off the two side walls included in the duct is allowed, in response to a gas flow supplied from the gas module and entering the duct through said inlet, to bulge to form a free passage into the duct for filling the same with gas. After completion of the gas filling, the duct is sealed. The invention also relates to a container blank having a duct which is specially developed for the method and the device.
1. A container blank for a collapsible container, the container blank comprising:
two opposite side walls joined along a common connection portion and each facing a compartment, the compartment being configured to be filled with liquid foodstuffs, and
a duct defined by internal surfaces of said two opposite side walls and the connection portion, said duct forming a handle portion defined by external surfaces of said two opposite side walls and the connection portion,
the duct being configured to be filled with gas, the duct including:
a first segment configured to provide a geometry in the container after gas filling;
a second segment adjoining the first segment, said second segment having a substantially smaller cross-sectional area than a cross-sectional area of the first segment; and
a third segment adjoining the second segment, the third segment being configured to provide an inlet to the duct.
2. The container blank as claimed in claim 1 , wherein the inlet is a hole formed in one of the two side walls.
3. The container blank as claimed in claim 1 , further comprising duct means, the container blank being fillable through the duct means,
wherein the third segment is in communication with the duct means of the container blank.