#greensandmoulding #manufacturingprocess #polytechnic
Greensand moulding :
A two-piece pattern is used. One half of the pattern is placed on a moulding board. The drag box is placed around the pattern. 20mm layer of facing sand is first placed around the pattern.
Then the drag is filled up with green sand.
Ramming is done by rammer.
Sand is filled up to the top of the box.
Ramming is completed. Excess sand is removed by the strike-off bar. Vent holes are made.
Then the drag is tilted upside down.
Parting sand is placed on the upper side to prevent two pieces of Pattern from sticking to each other.
The cope box is placed correctly in position on the drag.
Sprue pin and riser pin are placed in position.
Then the cope is filled up with moulding sand.
Ramming is completed in the cope.
Vent holes are made. Sprue pin and riser pin are removed. The pouring basin is cut. Cope and drag are separated.
The top surfaces of cope and drag are smooth finished with a trowel...
Draw spike is driven into pattern pieces and shacked lightly. Pattern pieces are withdrawn slowly. Gate is cut to the mould.
Repair work is carried out in the mould if necessary.
Surfaces of the mould are coated with graphite to give a smooth surface to the casting.
The core is set in position.
The two moulds are assembled incorrect position.
A pouring weight is placed.
Now the mould is ready for pouring.