Development of Technological Restrictions When Operating Disc Polymer-Abrasive Brushes

Abstract

Polymer-abrasive brush rotating tools are increasingly used for finishing operations in automated manufacturing. Given this, studying the process of their fibers’ wear has become important; and such a type of wear as the detachment of a whole fiber at the point of fixing has not been investigated in detail up to now. This phenomenon can lead to the disruption of stable equipment operation and the catastrophic wear of brushes. Therefore, it is a relevant task to search for and identify those limitations that could prevent fibers from detachment. This study involved the disc and cylindrical polymer-abrasive brushes as the most common in production. The current study has established that the detachment occurs at an unfavorable combination of the processing regimes and brushes’ parameters at rotations close to the limits specified by the manufacturer. When checking the temperature level at the fiber anchoring point, it was determined that the heating of the fibers in this region during operation was not enough to melt the polymeric base of the fibers and detach them. It has been established that the reason for the detachment of fibers is the accumulation of fatigue changes, which significantly accelerate under the limit modes. Studying the cyclical durability of fibers has made it possible to determine the ratios of critical processing modes to the tool parameters, which lead to the fatigue destruction of fibers at their fixing point. The following technological restrictions have been defined to warrant that fibers are not detached: ‒ it is not recommended to use circumferential cutting speeds exceeding 40 m/s; ‒ the tension during operation should not exceed 10 % of the fibers’ overhang magnitude. These limitations ensure the integrity of the tool, its high durability, as well as the stability of the process of parts’ finishing machining under an automated mode