Get A Free Quote! Contact Us Now! It is a shelf which can be positioned inside the vacuum chamber in substitution of the horizontal ones already present. It allows to vacuum pack liquids in bags, thanks to a pure physical action: the force of gravity keeps the liquid at the bottom of the bag, thus allowing the vacuum pump to suck the air which instead will occupy the top of the bag. In order to carry out this action, the bag must be only half-filled and one must pay attention to the temperature reached as in vacuum conditions the liquid boiling point is lowered.