Green Sand Moulding
This is done in moulding machines using sand prepared in intensive sand mixers with coal dust, Dextrine (if required), Bentonite and water. In this type of Moulding, Facing sand is used for covering the Pettern and then backing sand is used for moulding in regular way.
After proper inspection of the Pettern and the match plate, if is mounted on the moulding machine and set for leveling tightness and listing of the moulding box from the match plate after making the moulds.
Once this is made ready moulding box is placed on the machine into match plate fix going inside the Lug Holes with buses. After covering the Pettern with facing sand backing sand is added and jointing of the machine is started. Once the sand sets in the moulding box, squeeze board is pleased that above the box and in squeezed into simultaneous jolting for a minute or so. Then the squeeze board is moved out and box relieved from the Pettern. The mould is checked for proper condition and placed on them for pouring. The Cope and drag boxes are made separately with cope box having down spare and air vents. During the process of moulding, the sand prepare is also checked in the laboratory for moisture, Permeability, Green Compression strength, Computability etc. So mat quality of the sand is maintained.