Measuring Broccoli Stalk Cutting Forces

Abstract

A hydraulic system with a piezoelectric load cell mounted between the blade and the cylinder rod was used to measure the forces associated with the high speed (9 to 25 cm/s) cutting of broccoli stalks. High speeds were used in order to model a more realistic cutting process. An experiment was conducted to test the apparatus and to measure broccoli stalk cutting forces. Additional objectives were to determine if the knife speed and certain stalk dimensions had significant effects on the cutting force. Broccoli stalks were cut at three different knife speeds. The hydraulic system provided nearly instantaneous movement of the knife at a constant speed, and the transducers and associated instrumentation were capable of measuring knife forces and displacement at the required speed. The cutting force was significantly affected by the blade speed, with the lowest force (73.40 N) occurring at the highest speed (25.63 cm/s). The cutting force was also affected by the perpendicular stalk diameter and the stalk area.