Features Fiber length (95 %) 2–20 μm, average degree of polymerization 400–500 specific surface acc. to Blaine 15000 cm 2 /g ≤ 20 ppm Fe, 6 ppm Cu, 7 ppm P; dichloromethane extract ≤ 0.25% residue on ignition at 850°C ≤ 1500 ppm available as glass plates, POLYGRAM®...