The differential speed and narrow space between the rollers develop high shear over the materials.
This shear causes crushing of aggregates particles and also distributes the drug uniformly throughout the semisolid base.
Construction of Triple Roller Mill
It consists of three parallel rollers of equal diameters. These are made up of hard abrasion resistant material, normally stainless steel.
The pressure and gap between the rollers are independently adjustable.
A hopper is arranged between the first two rollers. A scrapper is attached to the last roller.
Working of Triple Roller Mill
The rollers are rotted at different speeds. In practice, the first roller (receiving roller) rotates at a slower speed compared to the second roller. Similarly second roller speed is less than that of third roller (discharged roller).
The feed is passed through the gap between the first and second roller. The aggregates and particles are crushed and then abraded by the rubbing action of the roller, which is developed due to different speed of rotation.
A film of appreciable thickness of the feed is produce. The material passes from slow rotating to fast rotating roller.
Between second and third roller, the gap is small and produces a thinner film of feed. The speed of the third roller is increased to compensate the reduction of cross-sectional area. In the thinning film, more crushing and more abrasion are developed.
Finally the scrapper removes the material completely from the last roller which can be collected immediately into the receiver or transported through a suitable conveyor.
Uses/Applications of Triple Roller Mill
It is uses for production of fine or thinner film, on by large particle feed.
Advantages of Triple Roller Mill
Triple roller mill is suitable for continuous process extremely uniform dispersion obtained.
Low Temperature Operation: The superior surface contact with the cooled rollers allows the temperature to remain low, even during extensive dispersion work.
Uniform Particle Size: These mills produce more uniform particle sizes, resulting in better product quality.
Less Heat Generation: Compared to bead mills, triple roller mills generate less heat due to their low operating speed. This is beneficial for temperature-sensitive products, maintaining product quality.
Disadvantage of Triple Roller Mill
Roller may cause the abrasion and speed maintain is key tasks.
