Overview
Kaolin is used for filling rubber to improve its mechanical strength and resistance to abrasion. For this purpose, the clay used must be extremely pure kaolin and exceedingly fine grained.
SPECIFICATIONS FOR RUBBER GRADE KAOLIN
Physical Properties
| Parameter | Specifications |
| Apperance | Off White Powder |
| Moisture | 1.50% max |
| Brightness (ISO) | 75 % (+/- 1.0%) |
| Residue (by wet sieving) (300 Mesh BSS) |
1.o % (+/- 0.20%) |
| Bulk Density | 0.28 – 0.31 gm/cc (Untapped) 0.38 – 0.41 gm/cc (Tapped) |
| pH | 7 – 8 |
| Oil Absorption (Linseed Oil) |
42 ml / 100 gm |
Chemical Properties
| Parameter | Specifications |
| SiO2 | 46.50% +/- 01.00% |
| Al2O3 | 37.00% +/- 01.00% |
| Fe2O3 | 00.55 +/- 00.35% |
| TiO2 | 01.00% +/- 00.15% |
| CaO + K2o | 0.55% +/- 00.20% |
| Na2O | 00.25% +/- 00.10% |
| L.O.I | 13.00% +/- 00.50% |