Mass finishing

Mass finishing is a material removal process for treating the surface of predominantly metallic workpieces. The workpieces to be processed are put into a container as bulk material together with an abrasive medium (so-called chips) to which an aqueous solution (compound) is usually added. An oscillating or rotating motion is induced in the process container to create a relative movement between the workpiece and the abrasive medium, and this in turn causes material to be removed from the workpieces, especially at the edges. 

OTEC is the specialist in mass finishing technology, especially when high-precision edge rounding, deburring and high-quality surfaces are called for. Decades of experience, a comprehensive and well-equipped laboratory and state-of-the-art machines and processes are the basis for solving our customers problems.  Special technologies enable OTEC machines to achieve high-precision processing results. A precision finish, in fact. For example, when processing tools, the cutting edges can be rounded to an accuracy of exactly 1 µm or the working parts of injection systems can be smoothed to the exact dimensions required.  

In terms of mass finishing, OTEC specializes in two types of machine. The first of these employs the disc finishing process:

In this process, the workpieces are put as bulk material into a process container together with an abrasive medium. The base of the container (the disc) is free to rotate like a turntable. When the disc is set in motion (whilst the wall of the container itself remains stationery), a vortex is generated which creates a highly efficient grinding effect. Only OTEC possesses the special techniques to enable these machines to process very thin workpieces (< 0,4 mm) and to use fine-grain abrasives such as quartz. This is why the disc finishing machines (CF series) are espcially suitable for the deburring, edge rounding and polishing of intricate and delicate workpieces. This technique is especially suitable for applications in:

• the jewelry industry (for grinding and polishing to a high shine)
• the watchmaking industry (e.g. for grinding the working parts of watch movements and clasps and polishing them to a high shine)
• the textile industry (e.g. for the deburring, rounding amd polishing of threading components) 
• medical devices (e.g. for the deburring, rounding and polishing of bone plates). For medical devices there are special versions of the machines tailored to the industry's specific requirements.
• the automotive industry (e.g. for finishing the parts of fuel injection systems)
• the metalworking industry in general
• the plastics industry

Secondly, OTEC manufactures machines for the drag finishing process:

In this process, high-quality workpieces are clamped in so-called drag finishing machines and describe a planetary motion through an abrasive medium. For this process, OTEC has developed special techniques to fulfil a wide variety of customer requirements. The use of a dual drive system with two electric motors enables workpieces, including the cutting edges of carbide drills, to be rounded uniformly, giving a considerable increase in tool life. By positioning the holders at an angle, the quality of polishing on the face of the workpiece, e.g. in the case of forming tools, can be improved considerably.

Drag finishing machines from OTEC are available for both wet and dry processing. 

The drag finishing process is especially suitable for applications in:

• the toolmaking industry (e.g. for rounding cutting edges and polishing the chip flutes of carbide tools to a high shine)
• forming tools (for smoothing and polishing the pressing and forming surfaces)
• the pharmaceutical industry (for repolishing the contact surfaces of tabletting tools)
• motor racing (e.g. for smoothing and polishing of cog wheels, valves and cam followers)
• the watchmaking industry (e.g. for grinding watch cases in stainless steel, gold and ceramics and polishing them to a high shine)
• medical devices (e.g. for grinding knee implants and polishing them to a high shine)
• the metalworking industry (e.g. for smoothing high-speed spindles)