GMBOND™ Process: An Environmentally Friendly Sand Binder System

Automotive engineers are challenged with increasing fuel economy in transportation vehicles by reducing weight. Aluminum castings are replacing cast iron components as one way to reduce weight in cars. Many of the aluminum castings produced for automobiles today are made with a sand core to form the internal cavity of the automotive component. Currently, the most popular choice of sand binder system in core making is the phenolic urethane cold-box binder system. This system, however, was not designed for use at aluminum pouring temperatures.

The collapsibility of a phenolic urethane cold-box core is not sufficient for expedient shakeout in an aluminum casting. Because of this, many aluminum castings must undergo secondary core removal processes. This reduced shakeout effectiveness limits the designer in the casting geometries available and adds cost to the part. The protein-based binder system was designed to replace current binder systems as an environmentally friendly sand binder and to improve the shakeout characteristics of the sand core.

Detailed benefits of the protein-based binder process include excellent shakeout effectiveness, recyclability, and cost savings because of the reduced solid waste and labor expenditures. More applications for aluminum casting replacements will become available as the awareness of this new process grows. Dissemination of the state of technology of the protein-based binder process to the automotive engineer would allow for more timely advancement of casting design and metal casting technology.