SKZ Plastics Center and INNOVENT e.V. jointly develop innovative sol-gel coatings for plastic welding that are PFAS-free, wear-resistant, and energy-efficient.

This “PTFE-Sub” research project was launched in August 2026. Its goal is to create sustainable alternatives to established polytetrafluoroethylene (PTFE)-based coating solutions without compromising on performance or process reliability.

Performing a heating-element butt weld on PA-U 12 pipes using a PTFE-coated heating element.

Limits in conventional PTFE-based materials

PTFE coatings and PTFE-glass fabric films have proven their worth in numerous plastic welding applications. In particular, they provide good non-stick properties in heating-element butt welding of plastic pipes made of polypropylene (PP) or polyethylene (PE) and window profiles made of polyvinyl chloride (PVC). PTFE is also used as a material for welding shoes in hot-gas extrusion welding.

However, PTFE-based solutions are increasingly reaching their limits: Their comparatively low wear resistance leads to frequent maintenance and replacement intervals. In addition, PTFE and other PFAS-containing materials are coming under increased scrutiny due to potential future regulatory restrictions.

Developing high performing alternatives

The PTFE-Sub project addresses precisely this issue. It aims to develop innovative sol-gel coatings that combine high temperature resistance, outstanding non-stick and sliding properties, and significantly improved wear resistance.

In addition, the new technology is intended to enable easy repair or recoating of the tools, thereby further extending their service life.

The research focuses on novel sol-gel systems that are specifically tailored to the requirements of various welding processes through the use of suitable additives.

In addition to developing the coatings, extensive test setups are being established to investigate wear, non-stick, and sliding properties under realistic conditions. Furthermore, the coatings are to be validated in practical welding trials using PE and PVC components.

Numerous benefits across multiple applications

This results in numerous benefits for users – longer tool service life, lower maintenance costs, and greater process reliability. At the same time, the use of PTFE fabric films and PTFE welding shoes, which are difficult to recycle, is to be replaced by durable alternatives.

The research results are aimed in particular at small and medium-sized enterprises in the fields of plastics processing, piping construction, window manufacturing, apparatus and container construction, and surface technology.

Furthermore, the project partners see potential for applications in other industrial sectors where temperature-resistant and non-stick surfaces are in demand.