Stage 1: Filling the mold.
- The required quantity of plastic material to be processed is introduced into the mold (finely ground thermoplastic powder or dispersions of thermoplastics in non-volatile solvents and some thermosetting resins) according to the weight of the final piece; it is mounted in an open and cold mold previously covered with demolding agent inside. Then the mold is closed and taken inside an oven to be heated.
Stage 2: Heating the mold.
- Once the mold is prepared, it is subjected to the application of heat and simultaneously rotated on two perpendicular axes in order to allow the material to gradually adhere to the internal wall and merge into a continuous mass. To form a porous three-dimensional network. Finally, by capillarity the viscous material fills the remaining pores.
Stage 3: Mold cooling.
- When all the plastic material has taken the internal shape of the mold, it is then cooled so that it hardens and is finished with the desired characteristics; during this stage the rotation continues, to guarantee uniformity in the conformation of the piece. As a cooling medium it is possible to use cold water dispersed in droplets on the surface of the mold (to achieve rapid cooling), a stream of air with condensed water vapor (with less rapid cooling) or cold air (achieving slow cooling) .
Stage 4: Emptying the mold.
- When the piece is finished, we proceed to remove it from the mold. This last stage, apparently very simple, may require high-tech methods when the manufactured parts have intricate designs or are large.