If parts have sharp edges and projections, first wrap the part in two to four laps of nylon sheet film or tubing. These layers of film can be secured with PVC tape. After the part has been wrapped, enclose it in the first barrier bag and seal it. It is important to restrict the motion of the part within the bag. After all of the air has been evacuated, seal the opening, over-bag and repeat the evacuation procedure.
Automatic equipment is also available as an option.