The efficient removal of sand from the complex cored internal passages of castings has always been an ongoing problem with sand casting processes. Conventional processes used for sand removal from castings have been hammering, vibration or a combination of both. All of these produce a considerable amount of noise and air-born contamination and require expensive noise and dust containment systems.
In the CGI casting process, sand removal is accomplished by attrition and shake out. Inherent in the process is the requirement to separate the silica used for the cold box cores from the greensand used for the mold. Once successfully separated they can both go to their respective recycling systems for reclamation and reuse. However, a large percentage of silica and greensand are lost due to cross contamination. The waste product is ultimately dumped somewhere at a considerable cost to the foundry…and to the environment.
Reshamca LLC is a proponent of foundry processes that utilize new sand removal and reclamation processes that use fluidized bed handling to totally eliminate any motion of components through the bed. For countries that have poor domestic silica sand resources, it’s essential to have the capability to reclaim up to nearly 100% of the precision sand to have a competitively priced product and provide for the best environmental situation.
The latest systems that Reshamca LLC has successfully applied to lower capital and operational costs use:
- A modular system that can be expanded as production increases
- Robots to put castings and pallet into a position in the bed where they remain for the total de-core time
- Robots to carry the castings from bed to cooling area
- No retained internal sand
Cast mold removed from flask by manipulator Core with casting placed on sand removal pallet
Core & casting on pallet moved to fluidized bed 600-degree sand is removed and reclaimed
The real economic advantage of fluidized bed for sand removal and reclamation is the use of one thermal operation that achieves two separate process requirements of the component. Reclamation of silica sand is a major advantage based on sand costs and quality.
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