Ceramic Mold Castings

The Bimac Corporation is one of a select few foundries in the United States to offer ceramic mold castings. Also known as the Shaw Process, Bimac was one of the early adopters of this process when the firm was founded in 1959. We can use permanent or rapid prototype patterns to produce large or small, short run precision parts using the ceramic mold process.

The Bimac Corporation utilizes an Ethyl silicate slurry molding process that employs a mixture of a graded refractory filler, hydrolyzed ethyl silicate, and a liquid catalyst which are blended together to form a slurry consistency. The slurry is then poured over a pattern and allowed to jell. After gelation, the mold is stripped and torched with a high pressure gas torch. The mold can then be cooled, assembled and fired prior to pouring.

Patterns can be made of various materials such as plaster, wood or metal and can be reused, which is how this process differs from the expendable (wax or plastic) process. Molds are torched and brought to a red heat in a furnace. The molds are allowed to cool prior to assembly for pouring. From time to time, the Shaw process and the lost wax process are combined to gain the advantages of each, and the Bimac Corporation often uses this approach. The complex pattern configurations, which are difficult or impossible to remove from the mold can be made of wax and placed into the regular pattern. This provides for the regular pattern to be stripped off and the wax to be melted and burned out later.

The following charts shows the comparison between investment casting and the ceramic mold process.