It is not common to accompany material development by a Life Cycle Assessment (LCA) during the research and development phase. It is the aim of the study at hand to present environmental aspects of the manufacturing of different polypropylene composites by injection moulding in comparison to the neat polypropylene. The process analysis following two injection-moulding experiments revealed that the total specific energy consumption of injection moulding of seven different materials and on different scales ranges from 1.6 MJ/kg to 3.5 MJ/kg. On the level of an ex-ante LCA from cradle-to-factory gate, injection moulding can be rated from being a negligible to an important contributor.