Investigation of automated nibbling as an alternative cutting technology for the machining of fiber-reinforced polymersWednesday (29.04.2020) 15:40 - 16:00 Room 2
Today, milling is the most frequently used process for contour machining and trimming operations of fiber-reinforced polymers (FRP) on an industrial scale. Disadvantages of this process are dust generation as well as machining-related damage such as delamination. An alternative technology for the processing of FRP, with the potential of overcoming these disadvantages, is a punching process with feed, the so-called nibbling. This hand-guided process, known from sheet metal processing, has so far only marginally been mentioned for the processing of FRP materials. The aim of this study is to investigate the correlation of process parameters like stroke frequency with feed forces, machining induced damage as well as workpiece cutting edge quality. In order to achieve these objectives, the hand-held nibbling tool was integrated into a machining center to ensure automated and reproducible machining of FRP. Slot nibbling tests were carried out on glass (GFRP) and carbon (CFRP) fiber-reinforced sheet molding compounds (SMC). Force measurements serve as characteristic values to assess the fundamental mechanism. The evaluation of the workpiece cutting edge quality as well as surface damage such as delamination, matrix spalling and fiber fraying are carried out by the use of microscopic imaging. The results show fundamental characteristics of nibbling FRP. Since the underlying cutting mechanism differs significantly from milling, dust generation can be considerably reduced by nibbling. The work provides a basis for highly productive, automated nibbling of FRP.