Fraunhofer Institute shows sustainable solutions

Düsseldorf, Germany — There were 18 different German Fraunhofer institutes exhibiting at K 2019, most of them focusing on sustainable solutions.

For example, Potsdam-Golm, Germany-based Fraunhofer IAP Institute for Applied Polymer Research addresses alternative means of producing carbon fibers.

Carbon fiber is traditionally produced by carbonization of nonmelting solution spun polyacrylnitrile (PAN) fiber precursors at around 1,600° C (2,912° F). But IAP's solvent-free ComCarbon technology makes melt-spun PAN copolymer fibers at around 60 percent lower cost.

IAP works on natural fiber-based precursors such as hemi-cellulose, glucan, lignin (CarbaCell process) and a "green" carbon fiber spun and converted at IAP.

IAP's process post-treats the fibers in an ultrahigh temperature oven for a few seconds at 2,700-2,900° C (4,892-5,252° F). This stretches the fibers, causing them to align along the fiber axis.

IAP has also worked on biofunctional polymers by integrating active enzymes into polyethylene, as well as developing plastic cell culture plates with a freeze-dried glycopolymer coating for cultivation and detachment of mammalian cells.

Other sustainability-focused exhibits at K 2019 included:

• Fraunhofer ICT Institute for Chemical Technology showed examples of two different directions in development of automotive hybrid passenger car seat backrests.

One of these involves use of recycled carbon-fiber-reinforced nylon 6 sheet, with a direct long-fiber-reinforced thermoplastic compound applied for tailored selective reinforcement and steel connection structures.

The other approach is the Bio4Self project's use of bio-based self-reinforcing polylactide sheet with tailored application of PLA compound for selective reinforcement, again along with steel connection structures.

• Reinforced plastic cladding of various particle foam sheets.

• A lightweight electric motor using flat wires to allow space for an internal cooling channel. The technology allows sufficient heat loss so that an aluminum housing can be replaced by a less conductive but lighter weight phenolic compound.

• Halle/Saale, Germany-based Fraunhofer IMWS Institute for Material and System Microstructures showed an "OrganoSandwich" OSW-3D-Shell made by combining continuous glass fiber over Thermhex polypropylene honeycomb cores, supplied by ThermHex Waben GmbH in Halle/Saale.

• Bremen, Germany-based IFAM Institute for Production Technology and Applied Material Research presented modification of silicone by vacuum UV light as a means of overcoming disadvantages of silicone rubber surfaces, in terms of high or low friction, dust attraction or repellency and improved haptics, to give a smooth feel.

• Aachen, Germany-based Fraunhofer ILT Institute for Laser Technology showed a 4 by 50 microliter polycarbonate microfluidic chamber treated with a 1,940-nanometer wavelength thulium-fiber laser, as well as a cyclo-olefin copolymer microfluidic demonstrator with its channels laser welded with 100-200 microns seam width.

In work with the IKV Institute of Plastics Processing in Aachen, ILT has laser microstructured a magnesium beam to improve bond strength when the beam is overmolded with 30 percent glass-fiber-reinforced PP to form a hybrid plastic/metal beam.