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Green Sand Mold process - is commonly used in the casting of aluminum, brass/bronze, and iron
products. The term "green sand" is known principally because of the
moisture content within the sand. The sand undergoes a "mulling" process
in which various clay and chemical additives that act as binders are
blended with the sand, which results in a compound which is suitable for
the sand molding process. This prepared sand mixture is then compressed
around the pattern at specific pressures and temperatures, to ensure it
will maintain its shape throughout the remainder of the casting process.
The blended sand and binders are compacted around the pattern, taking on
the shape of the desired casting.
No-Bake Sand Casting process
- consists of sand molds created using a wood, metal or
plastic pattern. Sand is mixed with a urethane binder and deposited into
a box containing the pattern (and all necessary formers and inserts) for
pouring. The sand mixture sets hard in a short time, and the mold is
then removed from the pattern. Cores for forming internal passages in
the castings are made using the same process. The No-Bake casting
technique creates molds with excellent dimensional stability. The
casting surface finish is also improved over other sand casting
processes.
Semi-permanent mold casting
process - produces Aluminum alloy castings - using re-usable
metal molds and sand cores to form internal passages within the
casting. Molds are typically arranged in two halves - the sand cores
being put into place before the two halves are placed together. The
molten metal flows into the mold cavity and surrounds the sand core
while filling the mold cavity. When the casting is removed from the mold
the sand core is removed from the casting leaving an internal passage in
the casting. The re-usable metal molds are used time and again, but the
sand cores have to be replaced each time the product is cast, hence the
term semi-permanent molding.
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