The use of technical brushes ranges from professional dental care, painting and polishing and even street sweeping. These not only differ in size and origin of the bristle material (including extrusions, synthetic fibers, but also natural horse or pig bristles), but also in their design. In addition to flat brushes, there are segmented, round, strip and knot wheel brushes – and each brush type has its special uses.
Independent of size, bristle type and brush type, many manufacturers of technical brushes throughout the world use machines made by Wöhler Brush Tech GmbH from the Westphalian city of Bad Wünnenberg. There are good reasons for this: Wöhler has been active in the brush industry for more than 75 years. The company provides a comprehensive system spectrum for manual or automated brush production that covers the entire process sequence – starting from injection molding (for bodies and fastening elements) and extrusion (for the bristles). Because the machines are completely modular in their design, they can be customized to specific requirements. This ensures responsive engineering processes. Based on customer need, fast production speeds can also be realized: With a system that produces 60 flat brushes per minute, Wöhler holds the unofficial "world record" for brush production performance capabilities.
One notices two things when observing such a machine in operation. Firstly: Brush production requires a host of coordinated motions, many of which are highly dynamic and have short strokes. Secondly: Fines and dust from the cut bristles require a well conceived selection of the bearing locations.
Here the Wöhler designers made a basic decision. On many different rotary and linear mountings, they use igus® plain bearings made of high performance polymers. Project Manager and Designer Martin Dören: "The bearings are maintenance-free despite the cutting dust, and no preventive maintenance is necessary. For this reason they are very easy for our customers to use. “
Using the example of a type FP 900 B machine currently in production, the range of the used igus® bearings can be well described. 40 stems for flat brushes are clamped on a central slewing ring. Martin Dören constructed the grippers from iglidur® bar stock: "We use bar stock which we process in-house. The grippers have a simple design – you do not need ball bearings or cam rollers – and extremely long-lasting. “
Here, iglidur® J is the "fast-and-slow-motion" specialist among the plain bearing materials. Wöhler employs iglidur® G more often. This versatile material is the all-rounder that provides medium to high loads, medium surface speeds and medium temperatures. Wöhler generally uses iglidur® J for linear bearings and iglidur® G for rotary and pivoting movements.
Thanks to the favourable experience, igus® plain bearing solutions are always an option when it comes to own range of used machinery and also for customer service. For example, Wöhler has retrofitted existing drive systems in a customer machine. Martin Dören: "The purchased parts included a toothed belt drive with recirculating ball guides, which is used in filament production. We have proposed to equip the axis with plain bearings, and our arguments have convinced the customer. “
Now the toothed belt drive is guided by linear bearings made from iglidur® J; Wöhler has even milled the bearing inserts from bar stock. The result is impressive: for a machine already in use, the axes have already covered 8000 km in just 55 days with no sign of wear! igus® Sales Consultant Marcus Kleine: "In such cases we calculate the fill weight and the service life very conservatively and recommend a practical test. " The test was completely satisfactory. Despite high acceleration and high speed, the iglidur® linear bearings prove their worth, which, admittedly, have to be used only for guidance and do not have to absorb transverse forces or torsion.
For the guidance of cylinders, Wöhler uses linear plain bearing bushings of the RJM/RJMP series at several bearing points of the FP 900 B flat brush making machine. Linear plain bearings from the drylin® T series have proved themselves in the format adjustments of several axes. In one instance – when the brushes are smoothed after application of the adhesive – you need relatively high forces and a clearance-free format adjustment. Here, the Wöhler designers use a drylin® lead screw lift table from the SLWE-PL series, which ensures high stiffness with a shaft diameter of 16 mm. Last but not least, the double rail guide drylin® W-1660 is also used in the Wöhler Brush Tech brush making machines.
The designers of the special machine builder are satisfied not only with the products, but also with the service of igus®. Martin Dören: "All bearing type series can be calculated online; also the price list is available online. And since I can download the appropriate CAD data immediately, no time is lost in the designing. “
Also helpful is the fact that the igus® homepage allows the comparison of different products and materials – a function that is often used: "We can quickly check whether there are technically better or even more cost-effective solutions. " For these reasons, the igus® homepage is one of those that are often called up in the design department of Wöhler Brush Tech:" We always check whether we can use igus® components in bearing points. “