Packaging machine with coaxial valve

A method for operating a packaging machine, comprising:

• sealing packages in a sealing station of the packaging machine by sealingly attaching a cover film;
• and
• sucking a gas out of the packages before sealing the packages, comprising controlling a flow of the gas through a fluid line of the sealing station by moving a blocking body of a valve in a valve body of the valve along an axial direction, wherein the blocking body of the valve is flowed through by the gas along the axial direction in an at least partially opened position of the valve, but not in a closed position of the valve;
• wherein moving the blocking body during a working cycle of the sealing station comprises:
• first, keeping an opening degree of the valve at a first opening degree for a first period of time;
• then increasing the opening degree of the valve to a second opening degree for a second period of time;
• and
• then keeping the opening degree of the valve at a third opening degree for a third period of time, wherein the third opening degree is a lower opening degree than the second opening degree.

A packaging machine comprising:

• a work station for processing at least one packaging part, wherein the work station comprises a fluid line;
• and
• a valve for controlling a flow of fluid through the fluid line, wherein the valve comprises a valve body with a flow channel, and a blocking body which is movable in the flow channel along an axial direction between a closed position and an open position, wherein in the closed position a flow of fluid through the flow channel is prevented, and in the open position a flow of fluid through the flow channel is enabled, and wherein the blocking body is configured to allow fluid to flow through the blocking body in the axial direction in the open position of the blocking body;
• wherein the valve further comprises a preload element configured to pretension the blocking body into the closed position;
• wherein the preload element is provided in a preload element chamber of the valve body;
• and
• wherein the preload element chamber is in fluid communication with a fluid inlet of the valve.