The process may be divided into two main stages: packaging and vacuum. In the first phase, the film is tubular formed and longitudinally sealed around the product. In the second phase, the vacuum and the transversal sealing take place. At the same time, one side is sealed outside the chamber and one side is sealed into the chamber. Changeovers from one package size or shape to another do not require any changes to the line; therefore the machine can run continuously, resulting in a significant reduction of cost and time while increasing productivity.