Friedrichshafen, Germany — The largest, main exhibit at the booth of KIMW Kunststoff Institut Lüdenscheid molded a demonstration of a new DryFoam physical foaming process based on a carbon dioxide foaming agent. As with many inventions, the process evolved earlier in the year by coincidence when KIMW was looking at using compressed gas to dry thermoplastic granulates.
So when it was discovered that a large amount of the CO2 became absorbed in the plastic, the idea was born to feed the impregnated resin into an injection molding screw to see what would happen, resulting in the gas becoming released to form foamed material. A wide range of different thermoplastics has been trial molded, leading to lightweight parts.
"Quite honestly, we don't know how it works, and that is subject of basic research activities at various research institutes," said Stefan Schmidt, head of KIMW. "We also found that in evaluation of the foaming effect, it is necessary not just to make conclusions on, for example, ABS as a type of material, but to go into detail with investigations with different ABS grades as they all behave differently in the new foam process from one grade to another."
Schmidt added that KIMW takes a very pragmatic approach, taking both the right tooling and specific material into account before making statements on feasibility to its clients. KIMW has many samples to evaluate for customers; the work will go into early 2018.