Design and assessment of mandrel pipe dies

An integrated programme, developed for the design, optimisation and assessment of pipe mandrel dies, is presented and experimentally assessed. The work is divided into three parts. First, the general strategy adopted to solve the problem and the methodology used to characterise the polymer are discussed. Design and simulation case studies are used to illustrate the procedure for designing a die and to determine the influence of the operating conditions on the extrudate dimensions, respectively. Finally, the predictions are compared to the experimental data obtained using a modular instrumented die. The errors associated with the final pipe dimensions, total pressure drop, extrudate-swell and with the maximum throughput inducing good extrudate surface characteristics were generally within 3-6% of the values measured.