Unerringly to the ideal tool brush

The application-oriented design of technical brushes is determined by many factors. When designing and configuring driven tool brushes, these must be taken into account in order to find the right brush solution.

As tools for surface and production technology, technical brushes are used in many industries today. Depending on the design, they are used for deburring, shaping, structuring or cleaning. Kullen-Koti's wide range of products offers the right brush solution for almost every task. Read here which special factors have to be considered when designing and configuring driven tool brushes.

Movement, shape and pace

Topics of kinematics and geometry usually come up at the beginning of the decision-making process when designing a tool brush. The focus here is on the question of whether the brush in the specific application executes a linear or a rotating movement - and at what speed it rotates, oscillates, vibrates, pushes or rubs. It must also be clarified at this point whether the kinematics of the application require a change of direction. If one wants to achieve that the brush produces the same effect bi-directionally, its trim must not have an inclined position. The drive power available on the machine or device side and the resulting kinematic-mechanical loads for the brush system - for example, when the maximum speed is reached - must also be taken into account.

Closely related to this is the consideration of three further factors: the achievable circumferential speed, the outer diameter and the overall diameter of the brush. Although higher circumferential speeds can be achieved by increasing the outer diameter, the decisive factor for the process efficiency of the tool brush is ultimately the size relationship of the brush to the machined workpiece and its surface. More precisely, the diameter of the trim has a great influence on the brushing effect at the contact point of trim and surface. This relationship leads directly to other aspects of the fill geometry: How high should or may the fill stand and how strong should its elements be? With wires, filaments and fibers of larger diameters, higher fillings can be realized without the risk of kinking; with thinner elements, on the other hand, the filling can be made denser, so that a larger number of filling tips act on the surface.

Processes, media and machines

Especially when used in industrial and automated production environments, the way in which the tool brush is implemented in a machine or production cell must be considered at an early stage. The focus is usually on two questions: Does the installation space or protective enclosures limit the size of the brush? And how is the brush picked up or clamped - in other words, how is the mechanical machine-brush interface designed? Depending on the specifications of machine builders, clamping device manufacturers or users, tool brushes can be fastened to axle holes, bores, detent grooves or in other ways. Kullen-Koti's portfolio offers numerous alternatives here.

At this point, it is also highly relevant whether the brush is used as part of a dry or wet process. If, for example, process-accompanying media such as cooling lubricants or oil are used, it is essential to ensure that the trim and body material of the brush are suitably resistant. The same applies if the brush comes into contact with solvents, acids or alkalis before, during or after use. In this case, the chemical resistance factor must be included in the design. And in application environments with a corrosive effect, all components of the brush must be adapted to this. This is done by galvanizing metallic surfaces or by using stainless steel and engineering plastics.

Heat and UV radiation

Further design criteria, which usually result from the immediate operating environment of the brush, are the factors temperature and UV light. It is therefore necessary to take into account the maximum temperatures reached on the surface to be brushed and the temperature values prevailing in the environment of the brush. In the case of Kullen-Koti brushes, either only the fill or the entire brush system can be made heat-resistant.

The UV light factor can usually be neglected when using tool brushes, as they are mostly used indoors. And yet: brush trimmings that are exposed to strong sunlight can be equipped with UV-resistant filaments as a precaution.

Material and surface

Many questions in the design of brushes revolve around the nature of the materials and surfaces to be treated. The aspect of material hardness is particularly decisive here. If the tool brush is used for processing very hard materials, the hardness of the fill must be adjusted accordingly. Soft materials usually do not tolerate aggressive filaments. In concrete terms, the following picture emerges: smooth, crimped, knotted or stranded steel and metal filaments are primarily suitable for hard materials and can be gradually adapted very well to the specific application. Smooth or corrugated filaments made of plastic are less aggressive and can be designed to be both abrasive and non-abrasive. Gentle and soft trimmings, on the other hand, are usually made of horsehair, goat hair or pig bristles, which do not become statically charged.

Moreover, one should not neglect to take a close look at the surface at the moment of processing. If the surface is sticky or greasy, it is advisable to make the trimming thinner to avoid clumping or sticking of the trimmings. The question of whether the surface changes its condition during processing by the tool brush can also be important in this context.

Many industries, many brushes

Beyond the basic factors that play a role in the design of tool brushes, numerous other aspects result from the special requirements of various industries. In food technology, for example, only trimmings made of stainless steel wire or selected plastics are permitted almost without exception. They must comply with the relevant standards of this industry. It is not only the fill that must be designed to conform to foodstuffs standards, but the entire brush as well as its holders, shafts and brackets. When plastic trimmings are used in food processing technology, their color is also highly relevant, because trim residues in the food can be detected more easily with high-contrast colors.

Another example of industry-specific brush design can be found in woodworking technology. Here, steel wire trimmings with a brass coating are usually used - for example, for the specific structuring of wood surfaces. The reason for this is that the tannic acid contained in the wood would quickly cause corrosion on bare, uncoated steel wire.

The list of typical industry requirements for the design of tool brushes could be continued with numerous other examples. In any case, it can be of great advantage, especially for newcomers, process optimizers or even quality managers, to seek advice from an experienced manufacturer. In order to pave the way for customers and users to make a confident product decision, Kullen-Koti has developed its own system of services, which is presented as a five-step program that can be individually tailored. In this context, service modules based on a certain know-how transfer are of particular importance. This is because it is often precisely this that yields findings that lead to quality optimization and efficiency improvements in manufacturing processes. (OM-05/23)

Author

Julius Moselweiß, Freelance Trade Journalist, Darmstadt

Contact

Kullen-Koti GmbH
Halskestraße 9
72766 Reutlingen (Germany)
Tel.: +49 (0)7121 142-0
Fax: +49 (0)7121 142-260
www.kullen.dewww.koti-eu.com

About Kullen-Koti

The family-owned Kullen company was founded in 1913 and has developed over the decades into one of the leading international manufacturers of technical brushes. Since 2012, it has been part of the Dutch Koti Group and has been operating under the name Kullen-Koti GmbH with headquarters in Reutlingen. The product range includes a large variety of different designs and variants of technical brushes.

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