Electromagnetic Barrel Finishing
The machining of medical product surfaces (implants, prosthetic components, and instruments) made of metal (on metal-cutting machines) is the next stage in a long and complicated process of their manufacturing. Just the surface quality and structure of the prosthetic products mainly define their consumer propertiesthe key one of which lies in the biological compatibility with the living human body. The most careful attention to this technological stage of prime importance is paid at our ABM Technology Specialized Medical Product Plant wherein all necessary manufacturing conditions are created for this purpose with the state-of-the-art and cutting-edge equipment as of today being concentrated.
Such main methods of surface processing applicable in the industrial production as grinding and honed finishing are least of all suitable in the area of medical metal product manufacturing. The metal processing methods proven in the jewelry production got a more widespread use in our specific sphere. This is due to the substantial similarity both in applicable materials and in sizes, geometrical complexity of the shape requiring accuracy of manufacturing.
One of these processing methods having come to us from the jewellery is an electromagnetic barrel finishing. The method got a widespread use in processing of surfaces of small-sized metal parts with a complicated geometrical shape. Judging by its resulting effect on small-sized parts, a barrel finishing is equivalent to grinding of large-sized parts in the industrial production. While applying a barrel finishing method:
• the surfaces are cleaned of contamination and corrosion deposits;
• the sharp edges and burrs are rounded;
• metal surface is hardened by cold working (cloudburst process)
The principle of electromagnetic barrel finishing method lies in the cleaning of metal part surface by way of multiple strokes on it with hard-alloy needles being in a fast-moving flow of liquid medium and their points positioned in the direction of a part being processed with the help of high intensive electromagnetic field. In simple terms, a part being processed is put in a tank (barrel) with liquid (usually, a soapy water solution) with some handfuls of metal hard-alloy needles being poured therein. When the processing is commenced, a liquid in the barrel is put in a fast circulatory motion imparting speed and striking force to hard-alloy needles. In their turn, the needles are optimally positioned (with their points directed to a part being processed) by available magnetic field generator. As the result, the needles begin to deliver multiple strokes on the surface of a part being processed penetrating into the most complicated areas of its geometrical shape simultaneously removing from it the contamination and oxidation deposits, partially chippings with the sharp edges and burrs being rounded.Concurrently, a soapy solution concentrates and takes away removed chippings and contaminants along with a foam being whipped.
With all relative simplicity of this processing method, the most careful attention in our manufacturing area is paid to the quality of equipment. To carry out the operations of an electromagnetic barrel finishing, the most high-technology equipment manufactured bySwiss KKS Ultraschall AG being an undisputed leader in this market segment is used at the ABM Technology Medical Product Plant.
However, regardless of its high efficiency, there is a significant limitation for an electromagnetic barrel finishing (in the conditions of our works) – this method of surface processing usually “licks off” the sharp edges, including the cut threads. That is why, in the ABM Technology Plant, the method of electromagnetic barrel finishing is categorically not used on threaded implants and prosthetic components. Conversely, a barrel finishing of prosthetic components without threaded elements consistently demonstrates excellent results.