Upcycling Filaments…

… from Thermoforming Production Waste.


Dr.-Ing. Armin Lechler

Institute for Control Engineering of Machine Tools and Manufacturing Units

University of Stuttgart


Upcycling by Means of Additive Manufacturing

UpFilT's project goal is to recycle cutting scraps from thermoforming into higher-value products using a novel additive manufacturing process. In this way, 3D printing in this field can be made more sustainable in the long term.

Recycling of Thermoformed Components

The production of thermoformed components generates large quantities of offcuts, which can only be partially recycled and reused in the state of the art. A large part of the waste is instead recovered by incineration. At the same time, thermoforming offers only very limited possibilities in the design of components, which is why thermoformed components often have to be supplemented in further work steps by gluing on separately manufactured functional elements. However, this not only increases the manufacturing effort, but also makes it much more difficult to recycle the component, as it is very difficult to separate the individual parts made from different materials and glued together.

Process-optimized 3D Printing Method for Upcycling

In the state of the art, the application of separate functional elements by bonding is almost without alternative, and the complete high-quality recycling of waste offcuts is not established for economic reasons. For complex components, the manufacturing effort is thus relatively high. The UpFilT project aims to reduce the increased manufacturing effort and the associated recycling problems to a minimum by developing a process-optimized 3D printing method. By upcycling the offcuts into a filament, components can be produced from a homogeneous material, while waste is reduced.

Project Objectives

UpFilt has two main objectives:

  • The efficient upcycling of offcuts into a high-quality filament for 3D printing with reproducible material properties.
  • The development of a process-optimized 3D printing method based on the Fused Filament Fabrication (FFF) process with the possibility to use the thermoformed components directly as a print bed.

UpFilT is a project of the Institute for Control Engineering of Machine Tools and Manufacturing Units (ISW) at the University of Stuttgart in cooperation with SE Kunststoffverarbeitung GmbH & Co. KG and the Institute of Plastics Technology at the University of Stuttgart (IKT).

The project receives funding from the Deutsche Bundesstiftung Umwelt.