HYTAC® materials may be polished to a smooth surface finish condition. A properly polished plug will reduce scratching and aid in plug life/reduce sheet stick to the plug.
Syntactic foams are a variety of combinations of epoxy, plastic and hollow glass microspheres. The same properties that make these foams the top choice for plug assist can create challenges in polishing. The goal of sanding is to smooth microscopic peaks to eliminate potential scratching, prepare the plug for use and to modify surface area for different frictional performance.
Thermoset Epoxy Syntactic foams (HYTAC-W, WF, WFT, FLX, FLXT and C1R) may be wet or dry sanded using random motion. When following CMT machining/turning guidelines, most users find 220 grit sandpaper provides the appropriate roughness as a starting point. Finer and finer grits may be used for finish rubs until desired the desired surface finish is achieved.
Thermoplastic Syntactic foams (B1X and XTL) may also be polished, but a good starting surface is critical. A surface that has been damaged in the machining process cannot be fixed by sanding. After following CMT machining/turning guidelines, most users find 400 or 600 grit sandpaper provides the appropriate starting point, though many move up to 1200 and 1500 for an ultra-smooth finish. HYTAC® B1X should always be dry sanded. Download our polishing guide for details.
CMT continues to work with our partners in industry and academia to develop new techniques for polishing HYTAC®. If you have a tip to share, please let us know!