| 摘要 |
PURPOSE:To make possible the use of a polyolefin resin foam for a pattern in consumable pattern casting in which the pattern made of the polyolefin resin foam for a casing is used by attaching gas vent ports communicating with the atm. to a runner and/or the bottom surface of the pattern. CONSTITUTION:The pattern 1 is formed of the foamed-in-place molding of an ethylene-propylene random copolymer by a bead method and is adhered to a runner 3 and gate 4 made of the same material by a vinyl acetate resin adhesive agent. The assembly is installed together with a sprue 2 into a molding flask 7 and is attached with the patterns for the gas vent port 5 on the side face of the runner 3, the gas vent port 5' at both top ends of the runner 3 and the gas vent port 5'' having a prescribed angle of inclination from the bottom surface of the pattern 1 on the counter sprue side. Furan sand is packed to the periphery thereof and is solidified. The patterns for the ports 5, 5', 5'' are thereafter removed and the casting mold is formed. |
