In collaboration with  project partners CG Tec, Cordenka, ElringKlinger, Fiber Engineering and Technikum Laubholz, DITF, the German Institutes of Textile and Fibre Research Denkendorf, is developing a new fibre composite material called Cellun with reinforcing fibres made of cellulose.

Cellun enables the replacement of glass or carbon fibres in the production of industrial moulded parts and its matrix is a thermoplastic cellulose derivative that can be processed using industrial processing methods such as hot pressing or pultrusion.

Organosheets are increasingly being used within the fast-growing segment of lightweight fibre composite construction and organosheets are pre-consolidated semi-finished sheet products with a matrix of thermoplastics and various reinforcing fibres in a wide variety of textile designs. The thermoplastic matrix allows the organosheets to be processed using industry-established ‘fast’ processes such as hot pressing, thermoforming, injection moulding or pultrusion. The processes produce highly recyclable and functionalised components with reproducible quality.

The textile reinforcement of organosheets currently consists mainly of glass, carbon, basalt or aramid fibres which have high stiffnesses and tensile strengths, but are energy-intensive to manufacture and recycle and can only be recycled in an increasingly low-grade condition.

Cellun is a much more sustainable alternative. For its production, the reinforcing component combines non-fusible cellulose fibres and thermoplastic derived cellulose fibres as the matrix to form a hybrid roving. The regenerated cellulosic reinforcing fibres are from Cordenka and the HighPerCell cellulose fibres were developed at DITF.

Cellun is now being further developed as part of a joint project funded by the German Federal Ministry of Economics and Climate Protection (BMWK). A further focus will be on the complete recycling of the material after the end of life. Two different approaches are being researched to this end – it is possible to thermally reshape Cellun moulded parts without any loss of quality and also to chemically separate the material into its individual components again.

www.ditf.de