A COMPARISON BETWEEN MACROSHEAR REDUNDANCY AND LOADING EFFECTS IN 2-ROLL AND 3-ROLL ROTARY TUBE CONE PIERCERS

Very high levels of redundant macroshear strains generated in the obli que rotary-piercing processes are detrimental to the quality of the bl ooms produced. Although the situation is improved when cone-type rolls are used, the question of the choice of the particular piercing syste m still remains. In this paper, using lead and internally-marked wax b illets, an experimental comparison is drawn between the redundant-macr oshear effects, and also between the force parameters in 2- and 3-roll tube cone rotary piercers. The optimal rolling conditions are indicat ed, and the respective advantages and disadvantages of the two systems are discussed. (C) 1997 Elsevier Science S.A.