Goldeworks International Supplies Vac Pack macines. In essence the workings of a vacuum packer are very simple. The vac machine consists of a hermetically sealed chamber from which all or part of the air is extracted by a pump consisting of rotating blades that absorb and expel air. A vac bag under the lid is then sealed with a heat produced by thermal strips. In some models it is also possible to create a vacuum and seal the bag inside a box chamber (called a chamber machine) and in others it is possible to drawer a vacuum from a pouch whose open pocket is placed under a lid of a machine and heat sealed whilst under vacuum pressure (called an external suction vacuum sealer).