Krauss Maffei develops Hybrid thermoforming Injection Moulding process for the automotive industry

Krauss Maffei of Munich Germany, a world leader in plastics processing machinery has developed a hybrid thermoforming injection process, in conjunction with Audi AG, Bond Laminates, the Institute for Composite Materials, Jacob Plastics Group and Lanxess, under a German government supported project. The “SpriForm” process is for lightweight structural components used particularly in the automotive industry but with other potential applications such as the aircraft industry, leisure craft, agricultural machinery etc.

It combines the advantages of thermoplastic injection moulding and thermoforming of continuous fibre-reinforced, semi-finished products (organic sheets) for applications in structural lightweight components. The organic sheets are slab-like in shape and the reinforcing fibre is impregnated with a polyamide (PA) matrix. The sheet for an impact protection application is comprised of six 0.5mm fibre layers and a  PA6 matrix.

In the fully automated SpriForm production cell, individual sheets pre-heated by an infrared oven are robotically inserted into an injection mould where they are fixed in place by an infrared oven. Simultaneously, a finished part on the other side of the mould is removed. The newly inserted sheet is then formed and back injected with ribs and its edges are fully over moulded. Krauss Maffei has applied its injection moulding compounder to the production cell so that the fibre content and length can be adjusted according to the part requirement (up to 60% is possible).

Fibre composite technology is becoming more popular in lightweight automotive construction and the proportion of plastics as an automotive material will continue to increase.