These additives are 40 percent stronger than 3M’s previous leading high strength glass bubbles and, at 17 microns, are approximately half their size. 3M™ Glass Bubbles iM30K have a density of 0.6 g/cc and an isostatic crush strength of 28,000 psi.
3M™ Glass Bubbles S38HS have a density of 0.38 g/cc and an isostatic crush strength of 5500 psi. The S Series glass bubbles have smaller particle sizes than the K Series. The S38HS has a higher crush strength than the S38 glass bubble.