SHELL MOLD CASTING

Shell Process—In this process, sand is pre-coated with a phenolic novalac resin containing a hexamethylenetetramine catalyst. The resin-coated sand is dumped, blown or shot into a metal corebox or over a metal pattern that has been heated to 450-650F (232-343C). Shell molds are made in halves that are glued or clamped together before pouring. Cores, on the other hand, can be made whole, or, in the case of complicated applications, can be made of multiple pieces glued together.

In a Shell Mold Casting, a shell of sand forms the mold cavity. The sand is much more thin and weighs less than the molds commonly used in sand foundries.The materials that can be used with this process are aluminum, cast irons, and copper alloys. Parts made can be connecting rods, Gear Housings, Lever arms etc.

Benefits of the shell process include:
• an excellent core or mold surface resulting in good casting finish;
• good dimensional accuracy in the casting because of mold rigidity;
• storage for indefinite periods of time, which improves just-in-time delivery;
• high-volume production;
• selection of refractory material other than silica for specialty applications;
                               

Shell Mold Casting 01                      Shell Mold Casting 02

Shell Mold Casting 03                               Shell mold