Sigma Kneaders comprises of a double ~U~ shaped container welded and machined together inside which rotate two ~Z~ shaped Sigma Blades in opposite directions at 2 different RPM i.e. 30/60 RPM. The clearance between the blades and the walls of the container are kept to the minimum to ensure maximum efficiency in the kneading and mixing action. The shafts of the Sigma Blades are fitted in bearing blocks which are each provided with roller bearing, steel glands, Teflon/rubber seals for smooth and leak less running. Lubricating points are provided for continuous lubrication of the shafts. A hinged type cover with locking bolts is provided for charging the kneader. The Kneader is mounted on a sturdy base frame fabricated out of ISMC section and free from vibrations. The machine is provided with a normal M.S. Jacket arrangement which can be heated by steam / hot water / thermal fluid and or cooled by circulating cooling water.