A vibration mill is a size reduction equipment that applies the process of continuous impaction in carrying out its size reduction function. The grinding container is made up of a tube that is held in a frame that is supported by means of springs which is filled to approximately 80% total volume with porcelain or stainless steel balls.
During milling, the entire body of the mill undergoes a small but frequent vibration that is generated by an eccentric motor and size reduction occurs by repeated impact. This vibration is usually, but not necessarily, in a vertical plane.
Vibration mills are similar to ball mills in that particles of the materials are crushed between porcelain or metal balls and the mill body.
Drugs and excipients are readily ground to less than 5 mm, the grinding time being considerably less than is required in normal ball milling. As a result, the efficiency of the comminution process in vibratory milling is a good deal than it is in conventional ball milling.
Advantages of Vibration Mill
- Suitable for hard abrasive grinding stocks
- Unlike tumbling mills, the porcelain in the vibrating mills move only a few millimetres through a complex path, shearing and impacting the materials between them.
- Higher grinding rate in the range of fine particles.
Disadvantages of Vibration Mill
- Not suitable for thermolabile material
References
- Brook R.J. (1991). Concise Encyclopedia of Advanced Ceramic Materials. Pergamon Press Plc, UK.
- Hiroaki Masuda, Ko Higashitani, and Hideto Yoshida (2007). Powder Technology: Handling and Operations, Process Instrumentation, and Working hazards. CRC Press, Taylor and Francis Group, LLC.
- Michael E. Aulton, and Kevin Taylor (2013). Aulton’s Pharmaceutics: The Design and Manufacture of Medicines fourth edition. Elsevier Ltd, NY.
Wow, I had no idea that there were so many advantages to using vibration mills for milling. Although, I suppose it makes sense since there is a higher grinding rate for particles. That is definitely something to keep in mind if I ever need to do any milling for the projects that I’ve been working on lately.