Analysis of punching force during random-velour needling

Random-velour needling technology uses not only a modified needle loom in which the bed-plate is replaced by a moveable brush conveyor but also specially designed needles known as fork needles are employed. In this study, in order to measure the net force exerted on fork needles and contributing forces due to factors such as vibration, inertia and resistances of brush and fibrous matt, a twin force measuring unit was developed. It was found that the magnitude of the contributing forces is strongly related to factors such as loom vibration, needle inertia and rigidity of both the conveyor surface and the fibrous matt. Quantification of the net punching force and the related factors are of vital importance in the engineering design of fork needles and random-velour looms, which in turn leads to production of high performance products at lower costs.