Patternless, Rapid, Sand Mold Prototyping for Casting

Product: Patternless, Rapid, Sand Mold and Core Prototyping for Casting
Development Stage: Proof of Concept Completed
Primary Inventors: Hemant Bohra, PhD, Sam Ramrattan, PhD, Industrial and Manufacturing Engineering 
Scientific Publication: Bohra et al., AFS Transactions 13-1456     
License Status: Available for Licensing         
Patent Status: US 9,901,977
Reference:  2013-003

There exists a need for ever more accurate parts and products to be created, and to be created quickly and efficiently. One way of doing this is to use rapid prototyping technologies. Rapid prototyping uses three-dimensional (3D) computer aided design to quickly fabricate a part or, alternatively, a sand mold for casting a part from metal. Currently there are many limitations with rapid prototyping to create sand molds and cores for casting parts: speed, accuracy, consistency, strength, and cost.

At WMU, sand mold, rapid prototyping has been significantly enhanced to overcome many of the drawbacks with present prototyping devices.

Technology Description

WMU’s sand mold prototyping invention is an innovative device and method for rapidly producing patternless, sand molds and cores, utilizing specialized, bonded sand in a hybrid, 3D layering and CNC machining system.

The resin coated, black carbon, shell sand used in the process is quickly and inexpensively sintered into layers with a non-laser light source because the black sand efficiently absorbs light energy. Because of its greater energy absorption, the black, carbon shell sand allows for thick layers to be created with each cycle of the layering process. This decreases the build time, resulting in higher throughput.  In addition, the sand resin is not flammable, allowing for safe transport and long term storage of the resulting molds and cores.

Each sand layer is sintered and machined, in contrast to present systems that only sinter layers or that machine the entire mold after all of the layers have been sintered.  Each layer is easily and accurately machined because the carbon sand acts as a lubricant for the CNC machining tool, prolonging its operating lifetime.  The mold is then ready for use for metal casting, or it can be coated for increased durability when casting certain metals.

With this process, the device rapidly creates smooth, sand molds with exact tolerances from CAD drawings. The device makes feasible design testing of very accurate, complex castings that can replace multiple part castings, and that are beyond the capabilities of any other device currently on the market.

Potential Benefits 

•    Rapid creation of molds for complex castings
•    Extremely accurate molds with smooth surfaces
•    Carbon sand resin binding system is not flammable
•    Carbon sand is readily available
•    Low operating cost

3D Mold Prototyping


D. Clark Bennett 
(269) 387-8218
Director of Technology and Innovation Advancement