| 摘要 |
PURPOSE:To prevent the blow of a molten metal by embedding a pattern for a casting consisting of polyolefin resin foam into molding sand and providing a vent port to the upper part of a casting mold. CONSTITUTION:The pattern 5 for a casting consisting of the polyolefin resin foam, as well as a runner 3 and a gate 4 made of the same material are adhered by an adhesive agent, etc. and thereafter the assembly is installed together with a pattern for the vent port placed atop the pattern and a sprue 2 made of a clay pipe in a molding flask. After the molding sand 1 is packed to the periphery and is solidified, the pattern of the vent port is removed from the molding sand 1 to form the vent port 6. The gas is thereby released into the atm. and the blow of the molten metal is prevented. |
