Advanced thermo-mechanical recycling of colored thermoplastic textile waste (Recotex)

The textile industry is a crucial sector for the development of a circular European economy. As the textile market is dominated by synthetic polymers (more than 50% polyester, followed by polyamide and polypropylene), untapped ways for recycling and reuse of previously unused thermoplastic waste streams need to be explored.

While thermo-mechanical recycling is already an established process for certain thermoplastic waste streams, e.g. recycling polyethylene terephthalate from bottles into fleece, it is not yet implemented on a large scale for textile fiber-to-fiber recycling. This whilst there is increasing pressure from the EU to move to a "textile-to-textile" recycling model.

In addition, colored textile waste poses a major challenge to recycling processes, as removal of colorants is a complex problem, that is currently only addressed using resource-intensive (chemical) recycling technologies and not yet solved at industrial scale.

This project will assist in increasing the recycling rate of colored synthetic textile waste, especially waste that is not currently recycled into high-value fiber materials and products due to their color, and mainly used as fuel (thermal recycling). This will be performed through two strategies:

The first strategy is the development of an alternative thermo-mechanical method (coextrusion). This will be performed using bicomponent (bico) melt extrusion technology: the colored waste material is encapsulated in virgin or light-colored recycled plastic as core component.

The second strategy is to gain insight and acquire knowledge on the effect of colorants and dyeing processes on recyclability, also considering a design-for-recycling perspective for use of dyestuffs in textile production. Being able to estimate the achievable color range of a given waste stream is crucial to the later use and economic potential of the recycling process, reaching required color evenness and color matching.

Research will be performed by Centexbel (Belgium) and Hochschule Niederrhein FTB (Germany), supported by FKT (association of the German textile and fashion industry).