The word "standard setting" amounts to a dyke of a contradiction in the world of surface treatment. Especially then in delicate processes such as cleaning or deburring, the à change turns out to be standard. The machine settings are "case-specific" and are determined by the material and design of the product.
Vincent Raman of specialist Rösler explains a special application that drove their straight vibratory machine technologically more than a few steps ahead. The surface treatment of an exceptional product required equally exceptional process parameters, all the more so because a combined process of cleaning and deburring in a single pass was opted for.
The case includes a custom-made, tubular ledge used for sanitary applications, and more specifically as embedded profiles in shower floors. The degree of finishing is therefore also high: each of these pieces is aesthetically brushed, giving the surface an attractive pattern of lines. Moreover, this is followed by the final finish with a durable PVT coating.
The stainless steel profile features a number of drill holes and has a square tube cross-section with a side of barely 8 mm. The latter immediately makes the cleaning and deburring process quite a task. After all, the quality of all subsequent steps depends on it. Residual, loose but often invisible burrs after PVT coating irrevocably lead to an unsellable product. Also, the entire surface of the workpieces must be impeccably clean and, above all, grease-free. If not, the overall adhesion of the PVT finish is compromised.
Rösler therefore came up with a revolutionary, combined deflashing and cleaning process: on the one hand, a round, non-abrasive ceramic grit with a diameter of 3 mm was chosen for the machine filler, so that the square tube profile could be filled with the grit smoothly and to the furthest corners. In addition, to adapt the efficiency of the deburring to the small inner diameter of the pieces, an increased oscillation frequency was opted for. Thus, the drive motor reaches no less than 3600 rpm, where an average value of 1500 rpm is normally sufficient for the majority of applications.
The entire process gains additional clout because it occurs from beginning to end in the presence of a strongly alkaline soap solution. Thus, a double effect is achieved in one process step. Applying this combined method also simplifies the subsequent inspection of the parts, because two different process steps were now united in a single one.
For the application of smaller granules at an increased vibration frequency, Rösler went to get the mustard from one of its other activities: the AM division. In this technology branch, the use of mini-beads is in fact a necessity. This is because the often highly complex, unique design requires smaller grains that reach even the most inaccessible cavities of workpieces, but at the same time do not get stuck in them either. Moreover, this type of grit produces very little friction. However, an appropriately higher speed is always required, otherwise the treatment gives little or no result. The effect ultimately rests on the speed of the medium, and not on its force impact.
Rösler can be visited during Blechexpo in Hall 10, Booth 10609.
Neem dan rechtstreeks contact op met Rösler Benelux BV.