Single point incremental forming of bilayer sheets made of two different thermoplastics

Abstract

A novel configuration of bilayer composite sheets containing different polymers is described and used for the first time in the single point incremental forming (SPIF) process. These bilayer sheets made of polypropylene (PP) and Santoprene are fabricated by hot welding, and shaped with cone-like geometry by SPIF. The bilayer configuration is such that only one of the containing polymers is in contact with the forming tool. During the SPIF processing, the bilayer sheets show a noticeable difference in the mechanical response, depending mainly on the polymer that is not in contact with the forming tool, which is related to a lower polymer softening. The performance of the bilayer sheets is compared against the neat polymers and a blend of these with a mass ratio of 1:1. The observed effect is introduced as a dual effect of properties that brings together in a single composite sheet, properties for a better performance in SPIF and wider functionality of the fabricated parts, evidenced by a lower material softening and higher mechanical strength, in comparison with the two individual polymers, and even better than the blend of both

Research funding: Consejo Nacional de Ciencia y Tecnología. Grant Numbers: 369647, 242269, 255837, 242269 and 255837; Instituto Tecnológico y de Estudios Superiores de Monterrey; Agency for Management of University and Research Grants; Ministry of Economy and Competitiveness; University of Girona; Rice University & Tecnológico de Monterrey