Milling Poly Methyl Methacrylate Granules to Micro Size for Medical Applications

Poly methyl methacrylate (PMMA) is a synthetic polymer used in different medical and manufacturing applications. Milling is essential in resizing PMMA granules from millimeter to micro-scale size of 10 μm to 100 μm, the scale needed for dental restorations, human dentures, and bone cement applications. In this study, several techniques are employed to downsize PMMA granules such as grinding machines, ball milling machines, and grater tools for micro sizing. Results are compared to achieve a more efficient and precise method. In addition, the size of the produced grains is further tested using the vibrating sieve shaker. Results clarify that crushing, grinding and ball milling can resize PMMA granules to a smaller size up to 0.5 millimeters. However, ball milling produces powder with impurities due to the wastes of balls' friction with PMMA granules when using aluminum balls. Using graters produce thin and equal PMMA particles size but with changed chemical and mechanical properties due to the polymerization process. The experimental work clarified that putting PMMA granules in a crushing tool for 5 minutes and then putting the crushed PMMA powder in a ball milling machine for 6 hours at 300 rpm produced powder with the required micro pure PMMA particle size. The novelty of the work comes from resizing PMMA granules with two simple methods for producing pure PMMA powder without impurities.