Abstract: An improved process and apparatus for molding expandable polystyrene ("EPS") beads. The process comprises the steps of: (a) introducing the beads into the mold cavity; (b) isolating the mold cavity from the ambient environment; (c) purging the mold cavity of any ambient air and moisture; (d) pulsing steam into the mold cavity among the beads to melt and fuse the beads; (e) pulsing cooling mist into the mold cavity and directly among the melted and fused beads; and (f) removing the melted and fused beads from the mold cavity. The invention also comprises an apparatus for accomplishing this process and a computer program for controlling and directing the apparatus to perform the process.

Abstract: A device for executing a method of molding expandable thermoplastic polymer beads in a mold to form articles of foamed material comprising: pulsing steam through at least one of the cavities to contact and expand the beads in the cavity for a finite period of time and drawing the steam amongst the beads by providing reduced pressure to at least one of the cavities for the same period of time; and pulsing mist through the expanded beads by providing mist to at least one of the cavities and drawing the mist through the expanded beads by providing reduced pressure to at least one of the cavities for the finite period of time of predetermined duration to form articles of foamed material.

Abstract: A method of molding expandable thermoplastic polymer beads in a mold to form articles of foamed material comprising: pulsing steam through at least one of the cavities to contact and expand the beads in the cavity for a finite period of time and drawing the steam amongst the beads by providing reduced pressure to at least one of the cavities for the same period of time; and pulsing mist through the expanded beads by providing mist to at least one of the cavities and drawing the mist through the expanded beads by providing reduced pressure to at least one of the cavities for the finite period of time of predetermined duration to form articles of foamed material.