2:20 PM , Posted in Sand Casting Processes
Sand Casting Processes
Bottom board is placed either boundary moulding from or on the floor making the surface even. The drag moulding flask is kept upside down on the bottom board. Dry facing sand is sprinkled over the board. Rest of the drag flask is completely filled with back up sand and uniform the rammed to compact the sand. The remaining of sand should be done properly. So as to compact it to hard , which makes the escape of gases difficult not to lose.
So that mould could not have enough strength . After the ramming is over , the excess of sand in the flask is completely scraped using a flat bar to the level of the flask edges. Now with a vent wire which is a wire of 1-2mm diameter with a pointed end, vent holes are made in the drag to he full depth flask as well as to the pattern to facilitate the removal of gases during casting solidification. This complete the preparation of the drag.
For case B:
We finished the drag flask is now rolled over to the bottom bolt exposing the pattern and cope of the pattern is placed over the dragged pattern.
For case C:The cope flask on the top of the drag is rotated aligning again with the help of the pins. A screw pin for making the screw passage. The sand is thoroughly rammed and excess sand scrap and vent holes are made over all in the cope as in the drag. The screw pin and the riser pin are carefully with drawn from flask the mould is now ready.