The drum filling under vacuum is prepared: the lid will be closed, the vacuum in the vacuum drum and the density of the inliner will be checked. The peephole allows to see the filling process. This is an example for possible fillings which depends on material and the used nozzle. In time-lapse modus you see the air-free filling under vacuum. Possible intermediate air supply (material sinks down) with adjustable parameters prevents a frothing of the filled material.