BEYOND THE STREAM TABLE: OTHER GEOSCIENCE EDUCATION APPLICATIONS FOR GROUND MELAMINE PLASTIC

This project discusses the use of melamine plastic as an alternative to mineral sand for teaching geoscience. Many physical geomodels use mineral sand as a substrate due to its low cost and widespread availability. However, the bulk density (ca. 1,300 kg/m³) of sand tends to make the models heavy and difficult to transport, especially if the material is wet. Mineral sand’s specific gravity (ca. 2.65) does not easily allow for studies across wide spatial scales (e.g. Reynold’s Numbers). To accommodate this, many models mix the sand with fine coal particles to demonstrate hydrodynamic sorting. In addition, the hardness of mineral sand often wears down model hardware such as pumps and fittings.

Melamine plastic is a thermoset resin, which means it can’t be re-melted once it has set, but used melamine is often cryogenically frozen and ground it into a granular material that is commonly sold as an air-abrasive for stripping paint off soft surfaces. Melamine is much softer (Moh’s hardness 3) than mineral sand, so it won’t likely scratch lab tables or lab equipment. It also has a much lower specific gravity (ca. 1.48 – 1.52) and bulk density (ca. 700 kg/m³) compared to mineral sand. The material will accept some “fiber reactive” dyes to emphasize sediment-sorting patterns.

One manufacturer, Little River Research and Design, uses melamine as the mobile bed material in their stream tables. Upon receiving an Em2 model for my lab, I realized that ground melamine would make an ideal replacement for mineral sand when teaching other subjects. In addition to geomorphology, I will provide examples of using melamine sand for teaching hydrogeology, soil mechanics, physical sedimentology, and even special effects cinematography.