Design and Development of Young Coconut Peeling Machine

Abstract

The research was to design and develop a young coconut peeling machine. The study was consisted of design, facrication, testing and evaluation. The machine comprised transmission component using B belt, coconut fruit holder, knife control set, knives, 1 hp. 220 v. 50 hz electric motor.
Testing was divided into 3 tests a) testing to determine physical properties of young coconut fruits. Results showed a graph relating penetrating force by a plunger F, with deformation of a young coconut fruit D. The graph was featured by two straight line between noloading point and rupture point. The slope of the second straight line was slightly less than the first one. there was not any yield point on the F-D graph. Penetrating force and moisture content M of young coconut fruit varied excellently as modulus of elasticity E over 5 different maturity stages (ie. One-layer flesh, one and a half layer flesh, two-layer flesh, overripe, black and hard husk). Equations of relationship werre F = 65.39E + 30.25 N (R2 =0.99) and M = 10.46E + 109.5% (R = 0.97). E ranged from 1.3 MPa of one- layer flesh to 2.4 MPa of black and hard husk. B) testing of the first prototype showed that optimal young coconut fruit rotation was 300 rpm. Optimal knife angle to peel shoulder was &2= 65, B2= 65. Hardened mild steel was optimal knife blade. The first peeling machine prototype was improved to the second one of 70 kgs. weight with 0.75 kW. electric motor drive. C) testing of the second prototype revealed that the machine could peel of averagely 172 young coconut fruits per hour with 3% green skin remain and skin fiber < 0.6% at 0.65 kw-hr electrical power consumtion. The peeled fruits were well accepted by merchants. Economic analysis indicated that when totalcost was 0.13 baht/fruit. Pay back period was 1.7 month for 240 working days/year and 0.50 baht aof wage per fruit