The molding process involves taking the loose expanded beads and forming them into a solid mass. ACH Foam Technologies' shape & block molded products are formed using a state-of-the-art vacuum-assisted mold. By utilizing a system of load cells, the computer is capable of controlling the exact weight of beads introduced into the mold cavity. Once the cavity is filled, the computer uses a vacuum system to evacuate residual air from it. The vacuum is relieved by live steam, which flows over the entire mass of beads in the cavity. This vacuum-rinsing process softens the polymer structure of the bead surface and is immediately followed by the pressurization of the mold cavity with more live steam. The latent heat from the steam and subsequent pressure increase cause the beads to further expand. Since this is a confined environment, the only way the beads can expand is to fill up any voids between them causing the soft surfaces to fuse together into a polyhedral-type solid structure. The computer releases the pressure after it reaches its predetermined set point. The loose beads are now fused into a solid mass.