An analysis of Digital ABS as a rapid tooling material for polymer injection moulding

Rapid tooling (RT) is an important application of additive manufacturing (AM). However, applications in this field are very dependent on the material that is available for use in AM processes. This work investigates the application of the new Digital ABS material from Stratasys in RT, focusing primarily on dimensional and surface stability during the injection process, and the influence the material has on the properties of the final moulding. Digital ABS was used to make inserts to inject standard specimens, which were compared with specimens produced using inserts made of two metallic materials (SAE 1045 steel and Zamak 8). Polypropylene (PP) was used to produce the specimens (50 shots). Insert surface quality and dimensional variations during injection were analysed. The influence of the material used on moulding properties was assessed by tensile, bending, impact and hardness tests and by measuring the crystallinity of the mouldings. The results show that in terms of dimensional and surface quality, the behaviour of Digital ABS during injection moulding was stable. The properties of mouldings produced with inserts made from digital ABS were only slightly different from those produced with inserts made from SAE 1045 steel and Zamak 8.