Vibratory Origins: Unveiling Vibratory History

By Sharmic Engineering
schedule31st Oct 23

Vibratory finishing is a widely used industrial mass finishing process that employs the use of vibration, abrasive media, and chemical compounds, to smooth, burnish, polish, or deburr surfaces of various materials.

Over the years, this unique technique has become an essential part of manufacturing and has attracted interest from researchers and historians exploring its origins and evolution. The exact beginning of vibratory finishing remains a subject of debate, and is widely contested, however there is evidence to suggest that its evolution and roots can be traced back, prior to the industrial revolution, possibly even to the forces of nature and the relentless erosion caused by water on rocks along the beaches and shorelines. 
 
To understand the potential connection between vibratory finishing and nature's erosion processes, it is essential to delve into the history of this remarkable technique. The concept of finishing, smoothing, and polishing surfaces is not a recent development but rather an age-old practice that has evolved with human civilizations. Ancient artisans would manually grind and polish materials using abrasive stones and sand, resulting in improved aesthetic appeal and functionality. It was not until the advent of the Industrial Revolution that the idea of some automation and improvement of this process began to take evolve more, first steadily then more rapidly. The constant search for efficiency and productivity led to the emergence of various mechanical methods. Firstly, by trying to implement the action of the sea, and copy a slide and roll movement, inclined barrels were employed, offering a degree of finishing on small parts, followed by horizontal barrels, which could be manufactured in greater sizes, and combined with hollow shafts and perforated doors enabled a more efficient technique and with greater outputs, to meet the demands of a changing industry. This barrelling technique, ultimately led to the introduction of lining inside the chambers as the finishing process was nonselective, resulting in destruction of the machines.

One major problem with barrelling was that the desired finish could not be seen without entry into the chamber of the barrel and therefore times were often greater than they needed to be, resulting in parts that were either not finished or in some cases finished beyond what was required. 

Vibratory finishing machines, very slowly emerged, firstly with a trough type machine, employing a foot motor with two eccentric weights on either side of the motor again trying clone the finishing action. The advantage of this machine was that larger parts could be processed, the disadvantage was that the parts still needed a degree of hand unloading, and if the weights on either side of the motor were not balanced then migration of the parts to the outside of the tub would happen and result in damage to the part being finished.So where does the circular vibrator and their techniques emerge from, here there is some disagreement among machine manufacturers, and that each manufacturer probably contributed towards its progression of what we see today. Patents were taken out by companies on aspects of the movements or features of the machines and due to lax laws were often infringed in countries that did not recognise their legitimacy.

In the UK techniques similar to finishing, were often employed in the pottery industry, such as the ball milling of powders, using ceramics, both natural and preformed types. One manufacturer invented the idea of employing vibration as a technique to manufacture ultrafine powders using a cylindrical alumina media and allowing the grains of ceramic to be crushed by the movement created by the action of vibration until the desired particle size was achieved. To achieve their objective, they required a manufacturer experienced in building machines to construct the plant, and hence a collaboration of ideas from both companies successfully produced the first circulate vibrators in the UK, and for which patents were taken out.

In the USA and Germany similar R and D produced machines similar in design but with a scroll type appearance and were designed to be used in the mechanical finishing industry, again patented. Over the years licences have been issued, infringed, cloned, by many manufacturers, hence we now have a global market of similar machines, all using the same techniques.The introduction of the circular vibrator with its eccentric weights, created a toroidal movement, thus allowing parts to be processed without damage, providing the machine load has been calculated correctly, as the parts in the mass are moving away from each other.

Most of the development of vibratory finishing machines has been in the creation of processes, although unloading techniques and chemical dosing systems have evolved, along with auxiliary equipment such as effluent control.

The vibratory finishing process once was regarded as something that was not needed, and hence shoved into the back shed or similar, however, now its regarded as an essential piece of equipment by most firms that use them, and the process is written into many specification manuals.The vibrator whilst offering most solutions to finishing problems, it does not offer the total solution. 

Recently advances in centrifugal finishing machines has enabled small jewellery and similar parts to be finished using the centrifugal action, with smaller loads and shorter cycles, however it should be remembered that the disadvantage of this action is the depreciation of the machine, and medias and therefore should be considered only if the vibrator cannot produce the result.