Co2tex

The establishment of commercially viable elastic filament yarns made from CO2-containing TPU.

motivation

The greenhouse gas carbon dioxide (CO2) is an abundant, recyclable and – compared to many biogenic raw materials – inexpensive educt for the production of specific polymers. Technologies exist for using CO2 in the production of polyols that can be used e.g. for the polymerization of thermoplastic polyurethanes (TPU). TPU yarns are a melt spinnable alternative for conventionally dry-spun elastanes and have several advantages e.g. no need for solvents in processing. First elastic filament yarns from CO2-TPU have already been spun on pilot scale plants and transferred to textile demonstrator applications. However, the developed TPU-yarns currently have a particular tackiness, which create challenges in further processing and thus makes industrialisation difficult.
Elastic filaments are used in 80 % of all clothing products and are thus a globally significant economic and ecological factor.

Aim

The aim of the project “CO2Tex” is the establishment of commercially viable elastic filament yarns made from CO2-containing TPU. At the end of the project we expect to process these yarns as easy be processed as easily as possible with existing industrial plants into yarns as well as textile pre- and end- products.

CO2TEX VISUALIZED

APPROACH

In order to develop a stable and reproducible melt spinning process for TPU-yarns containing CO2, modifications are being made to spinning plants. These include the investigation of spinnerets, filament cooling, godet surfaces and winding technology. In addition, spin finishes are adapted to the process and tested.. The developments are scaled up from technical to industrial scale. If the production of suitable yarns is possible, the process chain for the production of sports and medical textiles is investigated and adapted. This includes the processes of covering, knitting and finishing. Finally, the use of TPU-yarns containing CO2 is evaluated ecologically and economically by life-cycle-assessment (LCA).

Results

In the framework of the project CO₂Tex, the upscaling of the melt spinning of elastic multifilament yarns made from CO₂-containing or partially bio-based thermoplastic polyurethanes (TPUs) has been investigated. The range of the covered technological readiness levels (TRLs) has ranged from the formulation of the technology concept (TRL 2) to the system prototype demonstration in operational environment (TRL 7). Three main challenges of the former state of the art melt spinning of CO₂-containing TPU could be successfully overcome:

The yarn-yarn and yarn-component adhesion, which interfered with processing, has been reduced sufficiently.
The insufficient mechanical yarn characteristics in terms of stretch have been improved, the available elongation at maximum force is now between 300 % and 600 % depending on the yarn count.
First application areas for industrialisation and commercialisation have been tested and determined by the prototyping of knitted textile fabrics, covered yarns, lifestyle compression stockings and sport shoe uppers.

Book: Jan Thiel, Thomas Gries: “Elastic Yarns and Textiles”

Project Partners

GET IN TOUCH

Dr. Lukasz Debicki lukasz.debicki@ita.rwth-aachen.de

Jan Thiel, M.Sc. Jan.Thiel@ita.rwth-aachen.de

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