The different cleaning operations generally perform on casting are enumerate and discuss under:
1. Rough Cleaning
2. Surface Cleaning
4. Finishing 1. Rough cleaning Rough cleaning contain removal of gates of risers. The follow points are worth-noting.
• In case of a pliable material casting, rough cleaning might be done by mechanical cut-off machines (using band saws abrasive cut-off wheels, and metal shears).
• Gating system of a brittle material casting might be busted off by crash as castings are dumped and vibrated in shake-out or knockout devices.
• Lest of steel castings, extremely large risers and sprues might be removed with cutting torches.
• In case of risers being large and cast of oxidation-resisting alloys, powder cutting (in which a stream of iron powder in introduce into oxygen torch flame) is working. 2. Surface cleaning Surface cleaning includes cleaning of inner and outside surfaces while sand, scale and other adhering materials are mixed up. This kind of cleaning occupy the subsequent procedures: a. Tumbling This process is carried out by a barrel similar to machine call tumbling mill, which removes sand, scale and various fins and wires. b. Blasting Sand blasting is perform through using coarse sand as abrasive and air as carrying medium. Grit or sand blasting is carried out by throw metallic particle through centrifugal force as of a quickly rotating wheel. c. Other Surface Cleaning Methods The follow methods support in surface cleaning:
Various polishing procedures
Buffing 3. Trimming Trimming involve removal of fins, gate and chaplets, riser pads, wires and other like unwanted appendage to casting which are not a part of its final dimensions.
It involves the follow procedures: i. Chipping Chipping is use to eliminate pins, gates and riser pads, wires etc. It can be carried out by hammer and chisel or with pneumatic chipping hammers. ii. Grinding Grinding is working to remove excess metal and is carried out, through moveable grinders, stand grinders and swing frame grinders. 4. Finishing It is afterward stage of cleaning. In definite cases cleaning is whole after trimming process, but others might required extra surface finishing, eg., buffing, machining, polishing etc.