Journal of Advances in Science and Engineering 3 (2020) 14 – 23 Journal of Advances in Science and Engineering (JASE) J o u r n a l h o m e p a g e : www.sciengtexopen.org/index.php/jase Optimization of multiple performance responses of a fish feed pelletizer machine Osagie Ighodalo a , Sebastian O. Amiebenomo b, , Temabor Esabunor c a,b,c Department of Mechanical Engineering, Ambrose Alli University, Ekpoma, Nigeria 1. Introduction The lack of adequate feed to meet the nutrient requirements of cultivable fish species has been a challenge to fish farming in Nigeria [1]. As a result of this factor, the cultivated fishes do not attain market size at the right age [2]. Omitoyin [3] stated that indigenous farmers rely on imported fish feeds to meet their feed requirements. This results ———  Corresponding author. Sebastian O. Amiebenomo https://orcid.org/0000-0003-0955-9508 e-mail: sebastianamiebenomo@gmail.com 2636 – 607X /© 2020 the authors. Published by Sciengtex. This is an open access article under CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) in the astronomical cost of production due to the high cost of these imported feed given the devaluation of the naira and the attendant high foreign exchange rate. It was reported in [4] that an estimated 46% of quality fish feeds are imported into the country. This invariably affects the profit accruing to the indigenous fish farmer. In trying to remain in production and business, ARTICLE INFO ABSTRACT Article history: Received 3 March 2020 Received in revised form 11 May 2020 Accepted 16 May 2020 Available online 18 May 2020 This study details the assembling of a prefabricated fish feed pelletizing machine and optimization of some operational parameters such as die thickness, number of die holes, shaft speed and feed rate to produce high-grade fish pellets. The Taguchi methodology and Grey relational analysis (GRA) have been utilized to evaluate the multi-objective functions of interest such as pelletizing efficiency, throughput, energy requirements and pellets bulk density (g/cm 3 ). The pelletizer machine performance evaluation test was carried at 3 levels of die thickness (8, 6 and 12 mm), number of die holes (30, 25, and 35), and feed rates (145, 130 and 160 g/h). The test for the performance indicators was conducted using L9 orthogonal array experimental design. The test data were analyzed using the Taguchi scheme employing the signal-to-noise ratio response with effects deduced. The GRA was utilized to assess multiple responses by fusing the Taguchi technique with the GRA. Thus the multi-objective optimization was transformed to a single equivalent objective function. The results of Taguchi optimization revealed that die thickness was the most influential parameter for the various control factors. In addition, optimum parameter combination was obtainable at medium die thickness (8mm), medium number of die holes (30), low shaft speed (200rpm) and medium feed rate of 145g/h. Analysis of variance for grey relational grade (GRG) reveals that die thickness and feed rate are the dominant parameters. The confirmation test performed shows that the GRG is enhanced by 2.19%. https://doi.org/10.37121/jase.v3i1.71 Keywords: Grey relational analysis Multi response optimization Orthogonal array Pelletizer machine Taguchi methodology