The Shell Molding process produces cost savings solutions for difficult shapes, pressure vessels, weight sensitive parts, and castings requiring superior surface finishes. Shell Molding casting includes the following steps:
| 1. Sand is pre-coated with a resin that bonds the sand grains together. 2. A tool, or pattern, is coated with the resin coated sand. 3. The coated pattern is heated, curing or hardening the sand. This part of the process bonds the resin and sand creating a hard surface shell that is .5” to 1” thick. 4. The hardened shell mold is stripped from the pattern. This creates one half of the cavity that will be used as the mold. The process is repeated to create the other shell mold half. 5. Two shells are glued together to form the cavity that holds the molten metal. 6. Once the mold is created it is loaded onto the conveyor line and molten metal is poured into it. 7. After the mold goes through a cooling process, the sand shell is stripped from the casting. 8. The sand is recycled and the part is ready for finishing applications which are provided at the same facility.
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Advantages of Shell Molding include:
- Reduces or eliminates machining
- Produces consistent weight capabilities (+ / - 2%) (dimensionally more accurate from a weight aspect)
ideal for weight sensitive applications.
- Provides excellent dimensional tolerances (+ / - 0.5mm)
- Improved surface finishes
- Cost reduction for core elimination
- Provides weight reduction with direct material cost savings
- Delivers superior tooling life therefore significantly reduces tooling costs
- Reduced machining cycle times
Revstone’s Vassar facility specializes in Gray Iron Shell Mold castings for Automotive, Heavy Truck, Industrial, and Construction industries. With a capacity of 40,000 melt tons per year, Revstone can produce castings that range from .23kg up to 23 kg in weight. Near net shape and as cast details allow for many advantage over alternative casting processes. Other capabilities include: | |  |
-Cast tolerances as low as +/- 0.3 mm to +/- 0.75 mm.
-Machine stock allowances of 1.0 mm to 1.5 mm.
-Draft angles as low as 0.25 to 1.0 degrees.
-Complex designs coupled with reduced stock provide for many manufacturing advantages.
-CAD engineering and process/product development combine to produce successful cast solutions.
There are few, if any, foundries that combine these capabilities, providing for limited competition. Core competencies at Revstone Metavation’s Vassar facility include:
-In-house sand coating that provides cost/quality effectiveness
-High capacity equipment allows for higher production capability
-Pre-machined parts
-Process control and preventative maintenance on equipment
Revstone companies that specialize in this process include:
- Revstone Metavation
For more information or to request a quote for your shell mold casting business, please contact:
- Doug Averill - daverill@revstone.com