Thermoforming research at the IKT plastics technology institute at Stuttgart University is putting the emphasis on upcycling of used material.
An “UpFilT” project, developed with 3D printing filaments from thermoforming scrap material, could allow processors to use material in higher-value products.
Researchers use the UpFilT filaments to 3D print additional features such as reinforcement ribs on thermoformed parts. This involves laying the thermoformed part on a support that follows its contour and printing with a printing head mounted on an articulated arm robot.
Stuttgart University’s ISW machine tools and production equipment control engineering institute applied robotics to eliminate 3D support structure material. Langenargen, Germany-based thermoforming processor SE Kunststoffverarbeitung GmbH & Co. KG is also an UpFilT project partner.
A heater on the 3D printing head pre-heats the thermoformed part. Movement pre-programming maintains the distance required to the thermoformed part, depending on 3D printed material thickness needed.
Another IKT project involves a “thermoforming with integrated design elements” process used to obtain more complex thermoformed parts for enhanced design freedom, toward that achieved by injection molding.
The process combines thermoforming and welding to provide integrated functional plastic elements such as ribs, screw bosses or snap-fit hooks, without resorting to post-thermoforming processes such as back injection molding or other joining techniques. This is achieved by placement of locally pre-heated plastic inserts into the thermoforming mold, which are then welded to the hot thermoformed part during thermoforming.