Perfectly crafted in house moulds are made on automatic moulding machines are placed in Green Sand and CI or SG molten matter is poured into. The moulds then are placed on knock out hammer and sand is recycled through automatic sand plant. The drawn casting is then sent for shot blasting and thereafter for grinding and finishing. The castings are drawn to the minimum machining margins. The plant has the Capacity to draw 20 ton of casting per day.
Manufacturing Process :
Core making :
By Co2 Process : A process for hardening molds or cores in which carbon dioxide gas is blown through dry clay-free silica sand to precipitate silica in the form of a gel from the sodium silicate binder. Here the cores are essentially painted with in inner base and then ignited for proper drying.
By Shell Process : Process in which clay-free silica sand coated with a thermosetting resin or mixed with resin is placed on a heated metal pattern for a short period of time to form a partially hardened shell. The bulk of the sand mixture inside the resulting shell is removed for further use. The pattern and shell are then heated further to harden or polymerize the resin-sand mix, and the shell is removed from the pattern. These are generally painted in water base Zircon mix paints, prepared in the same way as graphite paints but is important that these cores are dried completely after painting.
By Molasses Process : A solution of water and molasses sprayed on sand molds to strengthen mold surface and yield a fine finish layer.
By No Bake Process : Molds/cores produced with a resin bonded air setting sand. Also known as the air set process because molds are left to harden under normal atmospheric conditions. Here the painting can be water base or spirit base graphite and then spray painted - torched or ignited as the case may be.
By Green Sand Process
Facing sand is used for covering the Pattern and then backing sand is used for moulding which is mixed with the proper bonding agent, onto the pattern. This is done in moulding machines using sand prepared in sand mixers with coal dust, Dextrine (if required), Bentonite and water.
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 Pattern with facing sand, backing sand is added. Once the sand sets in the moulding box, squeeze board is placed above the box and is squeezed into simultaneous jolting for a minute or so. Then the squeeze board is moved out and box is relieved from the Pattern. The mould is checked for proper condition and for pouring. The Cope and drag boxes are made separately with cope box having down spare and air vents.
Chemical Composition as under :
Cast Iron Composition :
|Grade||C %||Mn %||Si %||S %||P %|
|FG - 200||3.4-3.5||0.40 Max||1.90-2.10||0.06||0.12|
|FG - 400||3.40-3.80||0.50-0.60||1.80-1.90||0.050||0.11|
|FG - 450||3.50-3.70||0.60-0.80||1.90-2.20||0.06||0.12|
|FG - 350||3.60-3.90||0.60-0.80||2.00-2.20||0.05||0.10|
|Grade||C %||Mn %||Si %||S %||P %||Magnesium|
During the process of moulding, the sand prepare is also checked in the laboratory for moisture, Permeability, Green Compression strength & Computability so as to attain the quality sand. Also chemical composition test of Carbon, Manganese, Silicon, Sulphur and Phosphors and magnesium are performed.