Other than the grinding belt running on contact wheels and working nicely on flat areas of the workpiece, flap wheels are mainly in use with workpieces requiring a specific flexiblility, because this flexiblility is the main advantage of the flap wheel. Flap wheels are mainly not used because of their abrasive character, but for the fine surface treatment, for smoothing and pre-polishing and to obtain surfaces which can be galvanized.
The radially assembled flaps – completely assembled one after the other in case of Schleifbold® KV or in packs with the more flexible version Schleifbold® KF – are made of high-quality cloth and according to their application either made of X- or J-cloth. For workpieces requiring a very extreme flexibility even slotted cloth-versions are used.
Flap Wheels supplied by KEMPER-KONTAKT are produced with a plastic hub. The arbor hole is standardized and can be reduced down to the variety of arbor dia. being in the market by inserts being fixed in the plant already. It is for this reason not necessary to handle additional flanges which are costly and due to the nut being fixed on them dangerous for the workpiece in case complicated grinding processes are concerned. In case of flap wheels made by KEMPER-KONTAKT the nut is hidden in the hub as far as the smaller flap wheels are concerned.
Flap wheels with arbor hole are used on grinding lines, rotary table grinding machines and flexible spindle machines as well as on simple spindle heads. The most optimal operating speed is between 20 and 36 m/sec.
Shaft mounted flap wheels are used on hand tools such as straight grinders, flexible spindle machines and others.
Special regard has to be given to the fact that with flap wheels, compared with grinding belts, a finer finish will be obtained. This is due to the fact that with a flap wheels the cloth itself is working, not only the grit. In case the same result as with belt grinding must bei obtained, the cloth of the flap wheels has to be one step more coarse than the belt.
If flap wheels are used at rotation speeds near the lower limit value, the working pressure should be reduced in order to avoid damage of the flap wheel. Furthermore it is absolutely neccessary to pay attention to the correct direction of running. In case workpieces are automatically transported, the wheel must run in the opposite direction. If case grinding oil is used in connection with a flap wheel, a more uniform and soft grinding pattern as well as a higher lifetime of the flap wheel will be achived.
Schleifbold® F, FR and FMS, consisting of folded flaps, are particularly designed for grinding processes in areas of angles, grooves or notches. Since they are working on the cut edge, even these processes are optimized and highly accelerated. They are working on stationary grinding machines (Schleifbold® F), angle grinders (Schleifbold® FR) and even simple hand-tools like straight grinders etc. (Schleifbold® FMS).
