3M™ GLASS BUBBLES SCOTCH™ K-20 60lb BAG
K20 glass bubbles have a density of 0.2 g/cc and an isostatic crush strength of 500 psi.
These hollow microstructures not only displace a lot of volume at very low weight but also add an abundance of processing and product enhancements. Of the many fillers now available to composites manufacturers, microspheres, also called microballoons, are the most versatile. To the naked eye, the small, hollow spheres appear like fine powder. Ranging from 12 to 300 μm in diameter (by comparison, a human hair is approximately 75 μm in diameter), microspheres pack a lot of functionality into a very small package. Integrated into composite parts, they provide a variety of product enhancements and process improvements — including low density, improved dimensional stability, increased impact strength, smoother surface finish, greater thermal insulation, easier machinability, faster cycle times, and cost savings. Composite manufacturers, already adept at making the most of their materials, regularly exploit these benefits sometimes all at once.