Linear strip brushes
Linear strip brushes are used for:
- accident-prevention barrier in machine tools
- barrier for chips, dusts, fumes
- scraping of surfaces
- soundproofing of moving machine parts
Linear strip brushes have variable base thickness B as shown in the table. The length L is unrestricted, as the brushes are continuously produced from strip. For the total height H, the limitations given in the table apply.
Linear strips with double tapes are not normally produced.
Linear strips dimensions (mm)
Two types of profile are available for the installation of the linear brush, which is made of sturdy zinc-coated iron sheet. Type (a) must be welded to the metal support, while type (b) must be mounted with screws. The available dimensions are shown in the table. The standard length is 1000 mm.
- A: aluminium
- AN: black anodised aluminium
- S: zinc-coated iron
- X: stainless steel
Dimensions Type guide (a)
Dimensions Type guide (b)
Linear strips can also be used to reduce noise in machines that have moving parts and therefore cannot be shielded with rigid elements.
In order to find out the degree of acoustic insulation of the strip brushes, we constructed a special test apparatus, where the noise source was a compressed air nozzle. The results are shown in the table, where R is the degree of sound insulation expressed in dB(A).
It can be seen that sound insulation is highest with smooth filaments and lowest with wavy filaments, regardless of the material. These results can only be achieved by carefully installing the brushes and making sure that there is contact between brush and surface.
Linear strip sound insulation [dB(A)]
|PA 66 0.30 plain||8.2|
|PA 66 0.50 plain||7.1|
|PA 66 1.0 plain||5.7|
|Steel plate 1.1x0.25||5.1|
|PA 66 0.30 wavy||1.5|
|Brass 0.30 wavy||1.2|
|Wavy AR 0.30 steel||0.7|
|Wavy AR 0.50 steel||0.7|
The special feature of the brush is that the work surface is made up of millions of individual elements, which are the ends of the individual filaments.
This gives the brush an adaptability that no other element, however deformable, can have.
It depends on various factors. In a nutshell, it can be said that 2 mm is a good compromise. The important thing is that the filaments of the brush work “at the tip” and not on the side.
Depending on the materials used and the dimensions, there is a tensile limit load that a single bunch can withstand.
Beyond this limit the bunch comes off, therefore the brush must be calculated according to the use. This limit can be greatly increased by building “sewn” or “tied” brushes by hand, where a continuous steel wire is placed instead of a single anchor element.
There is no single answer. Speaking for example of cylindrical brushes, the strip brush is generally cheaper when dimensions are important (e.g. over one meter in length). For small dimensions, punched brushes are certainly more suitable and convenient.
It can only happen if the brush has a manufacturing defect, like any other type of object (e.g. a roller made with silicone flakes, one of which is defective and breaks).
When it is important that no contamination occurs, it is advisable to use synthetic (non-natural) fibers with a diameter greater than or equal to 0.15 mm.
Virtually all degrees of hardness can be had, from very soft to very hard. In fact, the hardness is given by the combination between the diameter of the filament, its free length and the density of the bunches.
Of course, we can provide FDA or FOOD GRADE certifications and filament traceability.
Unfortunately not, as it is the machine + brush assembly that must be ATEX certified, not just the brush.
It is however possible to provide the materials that the certifier requires, eg. conductive bases, conductive filaments etc …
Generally speaking it is possible, but it is necessary to evaluate if it is economically convenient, and it is not always. Furthermore, in the case of a punched brush, it is not advisable to regenerate the brush more than twice in order not to reduce the holding of the bunches.