A Xebec range of abrasive deburring brushes made from heavy duty aluminium oxide (alumina) fibres has been introduced for use on static platforms such as machining centres, mills, drilling machines and special-purpose machine tools but, according to supplier NCMT, they are equally suitable for mounting on industrial robots. Versions are also available for hand-held power tools.
These Japanese-made tools from Xebec Technology, which can be from 6 to 100 mm diameter, comprise rods consisting of 500 alumina blue fibre filaments measuring 25 microns in diameter. The self-sharpening cutting action is on the tip only, there being no abrasive effect on the sides of the rods.
The thicker blue fibres have been added to the existing range of white, red and pink fibre Xebec brushes. White brushes previously provided the highest deburring and finishing action, with their one thousand 15-micron filaments. Machining performance using the blue variety is much higher, with double the abrasive power allowing burrs of 1 mm to be tackled, such as those produced during hobbing or pressworking. On flat surfaces, processing performance is said to be four times higher.
Dozens or hundreds of parallel rods, depending on tool size, go to make up a hollow, cylindrical tool rather like an elongated cup. The rods are prevented from unduly splaying under centrifugal force by a metal sleeve whose inside diameter is approximately the same as the outside diameter of the tool. Only a short length of the fibre rods protrudes from the end of the sleeve at any given time, which is retracted by hand as necessary to compensate for rod wear. Periodic offsets also have to be entered into the machine tool control.
NCMT claims the product design bears out Xebec's assertion that these precision deburring, deflashing, finishing and polishing tools are more akin to end mills than wire brushes which are relatively crude in their application. Moreover, the manufacturer claims that its method of growing the fibre filaments ensures that the alumina content is very high at 70% by weight, compared with just 30% in conventional, abrasive-impregnated nylon wires.
Despite their high metal removal rate, the tools wear slowly due to the high alumina content and also as a result of their resistance to high temperatures as well as to water- and oil-based coolants. The tools are equally capable of cutting dry.
Author: Celia Cadwallader