Chapter 12 Roll forming of sheet materials

Abstract

Roll forming is one of the most versatile forming processes, capable of producing a wide range cross-sections from sheet materials by passing a strip of material through successive pairs of rolls. The scope of this secondary deformation process can even be further advanced with the addition of suitable auxiliary operations. The first part of this chapter gives a brief introduction to the process itself in the context of metallic sheets and explains the basic concepts of roll forming. The latter part shows the possibility of roll forming continuous fibre-reinforced thermoplastic (FRTP) sheets and identifies the important parameters influencing the success of the process. The inlet temperature of the strip, the cooling rate and the fibra architecture appear to have the most significant effects on the product quality in relation to fibre buckling, product curvature and material spring-back or spring-forward. The in-situ measurement of membrane strains in the product, while roll forming FRTP sheets, shows a distribution similar to that obtained in metallic sheets. The deformation zones under various roll stations appear to be generally larger in the case of composite sheets; however, the effects of different geometric parameters again seem to follow the trend obtained with metallic sheets.