The Bugdugle Blog Network

CNC

2008-Jun-3 - Lost Foam Casting Process

Posted in Metal Casting
Injecting Polystyrene in a Mold: Polystyrene contains pentane as a blowing agent and is commonly used for beads. The beads are pre-extended, stabilized and then blown into the mold to form pattern sections. A steam cycle forces the beads to expand fully, after this the fuse together and then it undergoes an in-mold cooling cycle. The final shape if very complex, then it is molded in sections. A cluster is formed by aging and gluing together the shaped foam sections.

Preparing Final Mold (Investment) fo Lost Foam Casting: Gates and Raisers are generally attached to the pattern, they are also the part of the casting as this helps reduce the shrinkage. Pouring, dipping or spraying are the different methods used for coating the foam cluster with ceramic investment. The reason for this coating is that it forms a barrier and helps to prevent the molten metal to penetrate or cause sand erosion while pouring. Structural integrity of the casting is protected thanks to the coating. The cluster when dried is backed up with un-bonded sand and is placed in a flask. Proper and uniform compaction is then achieved by performing mold compaction using a vibrating table. After all this process and after proper compaction, the mold is ready to be poured.

Automatic pouring is the preferred method in Lost Foam Casting. This is the most critical process and also a bit difficult than the traditional foundry practice. As there are no parting lines or fins to remove the cleaning is easier and requires far more less time and operations in the Lost Foam Casting process.

<- Last Page :: Next Page ->

About Me



«  November 2008  »
MonTueWedThuFriSatSun
 12
3456789
10111213141516
17181920212223
24252627282930

Friends

Powered By Bugdugle Blog Hosting