This document describes a method and apparatus for filling large collapsible shipping containers. The key points are:
- The container is first pressurized with air or an inert gas to expand it fully before filling to utilize the container's full capacity.
- While pressurized, filling material is conveyed into the container through a nozzle connected to the container opening using a flexible sleeve or sock to form an airtight seal.
- A rotary gas lock valve allows filling material to pass into the container while preventing loss of pressure during filling. Maintaining pressure ensures the container stays fully expanded during the filling process.