Evaluation of ratite skinning force in order to fix plant and mechanical solutions

Hide is the most requested product of ratite slaughter. The “first-rate” of the hide to assure its appreciation on the marketplace. The hide is tanned in South Africa and sold all over the world. Besides, the ostrich meat is considered a niche production in the marketplace thus allowing for another profit for the ostrich breeding. Theoretical analysis of skinning process has been carried out, and an automatic measurement system in order to record the drawing-force on the animal’s body during skinning tests, has been designed. The aim was to indentify the best animal position and provide values of drawing-force in order to design a specific machine for ostrich skinning. Experimental results partially confirm theoretical analysis; they point out that the angle of inclination of drawing-force with back-line is a parameter which mostly influences the value of drawing-force and that this influence tends to increase as the angle is near to 90° or exceeds this limit. In any case, the applied drawing-force must not exceed 350,0 daN. Therefore ostrich skinning should be done with vertical-drawing machines and the animal should be suspended by its wings at the rail, in relation to their anatomy structure and the tensile strenght of the hide. In the case of low working capacity (8-10 heads per hour) the animal could be skinned suspended by the legs, considering some limitations pointed out during experimental trials; technical, operating, ergonomic, health-hygienic limitations are accentuated if the workers involved are not enough able to ostrich slaughter.