The compact drag finishing systems from Roesler produce high quality surface finishes for a wide variety of parts like medical implants, gear components, drill bits and milling tools, work piece fixtures, tablet presses or various toothed components. The Roesler drag finishers allow the simultaneous surface finishing of up to 32 parts without these parts ever touching each other. And with their variable immersion depths and rotational speeds they achieve metal removal rates that are up to 40 times higher than those achieved in conventional vibratory finishing systems.
For components undergoing a prior geometric grinding step and, therefore, having a relatively high initial surface roughness, the subsequent drag finishing operation must usually be specified as a three-stage process: Prior to the fine finishing and polishing stages the parts undergo a pre-grinding phase with fast cutting ceramic grinding media. The sequence and the processing times of this multistage process are specially programmed, and the programs are stored in the system PLC. The first two steps – the pre-grinding with ceramic media and the fine finishing with plastic media – are wet processes involving the constant dosing of water and cleaning compounds into the work bowl. The subsequent high gloss polishing stage with specially prepared polishing media is a dry operation. To minimize the parts handling times between the various process stages, the Roesler drag finishers are equipped with easy-to-exchange work piece fixtures. The fine grinding plastic media, especially developed for such drag finishing applications, produces extremely fine surface finishes that can be as low as Rz = 0.2 μm.
Since drag finishing is a mechanized system with fixed process parameters, it guarantees high-quality and absolutely repeatable surface finishes irrespective of the part geometries and part quantities. The grinding and polishing media, used in this process and specially developed and manufactured by Roesler, are precision grinding and polishing tools for fine finishing the most delicate work pieces and can be exactly adapted to the most challenging surface finishing applications. Moreover, this finishing technology is highly eco-friendly: The media and metal fines can be removed from the process liquid with Roesler centrifuges, and the cleaned process liquid can thus be re-used for the finishing process.
The drag finishing process can be easily adapted to the most stringent requirements regarding the dimensional accuracy and surface finish of the treated parts and – compared to conventional finishing methods -- produces significant quality improvements with, at the same time, substantial time and cost savings.
Drag finishing is found in many industries, among others it is used as the final step in the manufacturing process for medical implants, turbine blades for stationary or airplane turbines, a wide range of different gear components, all kinds of work piece fixtures and drill bits & milling tools.