Process
Process
The Process offers substantial advantages over existing casting technologies such as:
Precision
Millions of castings with absolutely no difference between the first & the last piece can be produced, since EPS foam patterns can be made by simple injection moulding process with no abrasion between the foam and the aluminium tool. This technology enables excellent casting soundness & superb dimensional accuracy
Minimal Machining
Perhaps the biggest advantage of this technology is the drastic reduction in machining costs since numerous holes & complex cavities can be made in as cast condition. This leads to tremendous saving in the cost of wasteful machining. An estimated weight saving of between 10-30% can be achieved by converting existing sand casting components to the LFSS process.
Design Flexibility
EPS is very light & insensitive to temperature & hence even thin & thick wall patterns can be produced. Further, complex shapes can be formed by glueing pattern sections thereby allowing significant design freedom & scope to produce complex shapes which cannot be produced by conventional methods.
Precision
Millions of castings with absolutely no difference between the first & the last piece can be produced, since EPS foam patterns can be made by simple injection moulding process with no abrasion between the foam and the aluminium tool. This technology enables excellent casting soundness & superb dimensional accuracy
Minimal Machining
Perhaps the biggest advantage of this technology is the drastic reduction in machining costs since numerous holes & complex cavities can be made in as cast condition. This leads to tremendous saving in the cost of wasteful machining. An estimated weight saving of between 10-30% can be achieved by converting existing sand casting components to the LFSS process.
Design Flexibility
EPS is very light & insensitive to temperature & hence even thin & thick wall patterns can be produced. Further, complex shapes can be formed by glueing pattern sections thereby allowing significant design freedom & scope to produce complex shapes which cannot be produced by conventional methods.
Elimination of Cores
EPS patterns are simply glued together to obtain cavities instead of any need to use any intricate cores & thus all defects related to cores & undesirable protrusions in cavities are eliminated. This also enables complete elimination of the need to keep draft angle allowances.
Superior Surface Finish
The hardened ceramic shell prevents contact between molten metal & sand resulting in excellent surface finish. Ra values up to 3.2 are achieveable with this process.
Environment Friendly
The process is relatively clean, pollution free & enables excellent plant conditions conductive to quality production. The carbon footprint in this process is considered to be the least among all known foundry processes
Elimination of Cores
EPS patterns are simply glued together to obtain cavities instead of any need to use any intricate cores & thus all defects related to cores & undesirable protrusions in cavities are eliminated. This also enables complete elimination of the need to keep draft angle allowances.
Superior Surface Finish
The hardened ceramic shell prevents contact between molten metal & sand resulting in excellent surface finish. Ra values up to 3.2 are achieveable with this process.
Environment Friendly
The process is relatively clean, pollution free & enables excellent plant conditions conductive to quality production. The carbon footprint in this process is considered to be the least among all known foundry processes
Comparision of Sand Moulding, Lost Wax & Lost Foam Sintered Shell Process
| Sand Casting Process | Lost Wax Process | Lost Foam Sintered Shell Process | |
|---|---|---|---|
| Pattern Material | Metallic or Wooden | Wax | EPS – Expandable Polystyrene |
| No. Of Pattern Halves | 02 (Min) + Side Cores for complex geometry | Single | Single |
| Pattern Usage | Multiple | Single Use | Single Use |
| Core Material | Baked Sand | No Cores | No Cores |
| No. Of Cores | Multiple | No Cores | No Cores |
| Pattern Weight | Heavy | Heavy | Light |
| Pattern Material Temperature Sensitivity | NA | Sensitive | Insensitive |
| Moulding & Compaction Process | Manual or Machine Moulding (Pneumatic or High Pressure) | Wax Pattern is coated with Ceramic slurry & allowed to harden. Coated Wax Pattern is heated to remove Wax & hard ceramic shell is obtained. Ceramic Shell is heated further to obtain a hard sintered ceramic shell. | EPS Pattern is first coated with Wax followed with Ceramic Slurry & allowed to harden. Coated Pattern is heated to blow off EPS & Hard Sintered Ceramic Shell Mould is obtained in one go. Ceramic Shell Mould is compacted in vacuum assisted Mould. |
| Metal to Mould Interface | Sand Mould | Sintered Ceramic Shell Mould | Sintered Ceramic Shell Mould |
| Shell Thickness | NA | More | Less |
| Pre-Heating of Ceramic Shell before metal Pouring | NA | Required | Not Required |
| Pattern Thickness Range (Casting Wall Thickness) | Difficult to cast very thin sections | Better than Sand Moulding & Similar to Lost Foam Process | Better than Sand Moulding & similar to Lost Wax Process |
| Complexity | Difficult to cast very thin sections | Better than Sand Moulding & Similar to Lost Foam Process | Better than Sand Moulding & similar to Lost Wax Process |
| Design Freedom | Less | Good | Very High |
| Dimensional Accuracy & Surface Finish | Good | Excellent | Excellent |
Metafore Castings Private Limited
Survey No 421/P4, Kundi Village, Taluka & District Valsad, Gujarat – 396375
Get In Touch
info@metaforecastings.com
+91 9512000591