Støbssand

Støbssand, also known as foundry sand or molding sand, is a granular material used to create molds for metal casting. Its primary function is to form a cavity that precisely replicates the desired shape of the final cast object. The composition of støbssand is crucial for its performance and typically includes a binder that holds the sand grains together. Common binders include clay, bentonite, or organic materials. Water is often added to activate the binder and achieve the necessary plasticity for mold making.

The properties of støbssand are critical for successful casting. It must be able to withstand the high temperatures of molten metal without degrading or causing defects in the casting. The sand needs to have good permeability to allow gases to escape from the mold cavity during pouring, preventing blowholes. Furthermore, it requires sufficient strength to maintain its shape under the pressure of the molten metal. After the casting has solidified and cooled, the sand mold is broken away, and the støbssand can often be reclaimed, cooled, and reconditioned for reuse. This recycling aspect makes it an economically viable and environmentally conscious choice for many foundry operations. Various types of støbssand exist, tailored to specific casting processes and metal types, influencing factors like grain size, shape, and binder content.