Screw Extrusion Additive Manufacturing (SEAM): Fast, granulate-based 3D printing enables load-bearing plastic structures in vehicles.
Granulate-based plastic processes create new perspectives for low-cost manufacturing of highly durable products in closed material cycles. Fraunhofer IWU demonstrates with a highly resilient shelf and a vehicle frame how SEAM can pave the way for individual shaping, low material costs, and high load-bearing capacity in transportation applications.
The SEAM system consists of an extrusion-based plasticising unit for processing plastic granules, and a hexapod. The hexapod, a tiltable 6-axis parallel kinematics, is equipped with a metal build platform. The hexapod motion system is characterised by high dynamics, low moving masses, and high positioning and path accuracy, making it ideal for controlling the movement of the extruder.
SEAM is synonymous with new products and manufacturing possibilities on an industrial scale – it allows for large production quantities at competitive costs in a short time. The system also contributes to the circular economy as it can use granules obtained from recycled thermoplastics without devaluing the plastic from the previous product. Used shelves can thus become highly resilient new shelves or load-bearing frames for E-scooters in a second life.
MAXIMISING CARRYING CAPACITY
Battery electric vehicles significantly reduce CO2 emissions in the transportation sector. However, the added weight of high-voltage storage systems comes at the expense of allowable payload unless lightweight solutions can be found elsewhere. Fraunhofer IWU and MOSOLF Special Vehicles suggest a smart solution for simultaneously reducing weight while optimising cargo space: a 3D-printed rear shelf. Using the Mercedes Vito as an example, the shelf and its fittings can save 26.5kg compared to the previous retrofit solution.
The payload capacity of the shelf system remains fully unchanged. Nevertheless, the new shelf must provide flexible transportation for traffic control, patrol duties, or police personnel transport at large-scale operations. The newly developed shelf seamlessly fits the vehicle’s exterior, requiring no additional reinforcements or attachments, thus optimising the cargo space in the rear. The new upper compartments offer even more storage space, thanks to an 8% enlarged storage area. Naturally, the shelf is as safe as the standard retrofit version.
DYNALIGHT PROJECT
Electrically powered cargo scooters will play a crucial role in future emissions-free short-distance transportation. Saving vehicle weight means more payload capacity. However, safety should not suffer at the hands of weight optimisation. The designers of the Innvelo Cargo-Scooter from Chemnitz research institution ICM first banked on a steel frame. The partners in the DynaLight project now suggest a robust plastic solution - printed with SEAM technology like the rear shelf for the battery-electric van. The new plastic frame saves around 10% in weight and costs. Naturally, it is just as practical as the old one: delivery services can transport a crate of beverages or a thermobox on the carrier, with a total payload capacity of about 200kg, including the rider. Partners in the DynaLight project include Fraunhofer IWU, the Chemnitz Institute for Machine and Plant Construction e.V. (ICM), and Sauer Creations.
Dr. Martin Kausch and Roberto Seyfert are at Fraunhofer IWU.
