Abrasive peeling of pumpkin

Abstract

This paper presents new abrasive peeling methods for the pumpkin. The design of two innovative peeling devices, called abrasive pads and abrasive disks, are aimed at evenly peeling the varieties of pumpkin with uneven surfaces (i.e. Jarrahdale and Jap). The performance of the peeling process was evaluated for each method by using the Taguchi method and compared. High and equal peeling effect in convex and concave areas, and low peel losses, were the criteria of experiments. Optimization of the results of abrasive pads indicated the possibility of the peeling effect in concave and convex areas as 4.5 and 3.83 %/min respectively with peel losses of 0.14 %/min. These results were obtained in optimum conditions of independent variables involving 0° flap angle, overlap of 26.5 mm, 140 rpm of peeler head speed, and 10 rpm of vegetable speed. Higher peeling productivity compared to abrasive pads was achieved by using abrasive disks. Optimized results showed the peeling effect can approach 71.85 and 79.01 %/min in concave and convex areas, respectively with 1.02 %/min peel losses. The results were obtained in optimum conditions of independent variables of abrasive disks including abrasion grade of 24, vegetable speed of 5 rpm, peeler head speed of 1000 rpm, pushing force of 1.65 N, and with the specially shaped foams (shape A).