Temperature and pressure are the two most important factors; if they are not controlled, undesired results can be obtained, such as defective parts or even the melting of the sheet from which the parts are formed. Vacuum thermoforming consists of holding the semi-finished product in a structure and heating it until it reaches a gomoelastic state in order to place it on the mold cavity so that it adapts to its geometry. The air is removed by vacuum, which pushes the sheet against the walls and contours of the mold.