Vibrofinishing

The vibrofinishing (or tumbling) is a mass finishing process which allows to modify the surface roughness of objects (usually metal parts) in order to improve their appearance and functionality.

This type of technology allows to optimize the processing costs through the flexibility of the equipment required and the reduced labor costs.

 

The vibrofinishing (or tumbling) is achieved by combining the following three systems:

 

  • a tank kept in continuous oscillation by a suitable electric motor

  • an "abrasive agent", consisting of media at different degree of abrasion and form

  • the workpieces to be treated

 

The simultaneous interaction of the three systems allows to the abrasive media to modify the surface appearance in a gradual and uniform way.

 

 

The vibrofinishing can be split into four different mechanical phases:

 

  1. Deburring: removal of sharp edges created during the production of the article - in this phase a ceramic abrasive (consisting of abrasive material only) is mainly used for hard materials, or a plastic abrasive (with organic binder) for softer materials

  2. Smoothing: during this phase the edges are “compacted” and the roghness is reduced - this operation is performed mainly by plastic abrasive, preferable for its modular action compared to those ceramic

  3. Polishing: further reduction of the degree of roughness to obtain a bright surface - it’s usually performed by a low degree of abrasion media (porcelain - high density) in combination with polishing pastes / liquid additives

  4. Burnishing: type of polishing that allows to achieve a shiny surface without changing the roughness - this process is performed with stainless steel media, which allow short working times

 

The efficiency of these steps can be optimized by assisting the mechanical action with chemical additives: with the addition in the working system of suitable chemical products (liquid or powder), it’s possible to perform the following actions:

  • Pickling      

  • Passivation

  • Descaling

  • Deoxidation