METHOD FOR THE PRODUCTION OF LOST CASTING MOLDS MADE OF EXPANDED FOAM BEADS FOR THE FULL MOLDING METHOD, PREFERRED FOR THE PRODUCTION OF SERIES CASTING PARTS, AND DEVICE THEREFOR

摘要

1. Process for producing consumable casting models comprising expanded foam-material beads, for full mould casting, preferably for making mass-produced castings, in which a finebeaded unfoamed propellant-containing initial product, in particular polystyrene, is prefoamed, and in which the prefoamed foam-material beads are introduced into a foaming mould preferably corresponding to the contour of the casting to be produced and are there warmed by introducing a heat transfer medium, in particular steam, and postfoamed, characterized in that in each mould foaming procedure an underpressure is produced when the heat transfer medium is introduced at a draw-off side of the mould cavity of the foaming mould which is opposite the introduction side and the heat transfer medium is drawn off thereby, the introduction side and draw-off side are changed repeatedly and after the change drawing off is continued until substantially clean fresh heat transfer medium comes to the draw-off side.