IGD, the Fraunhofer Institute for Interfacial Engineering and Biotechnology in the joint project Chito Tex is researching harmless bio-based alternatives to chemicals used in textile processing.
The Institute is working on utilizing side streams from the animal feed manufacture for the production of chitosan.
The biopolymer is supposed to be used as a sizing agent in the processing of yarns or for the functionalization of textiles.
Chitin is a component of insect shells and animal feed produces it in large quantity. Insects can be bred cheaply and reproduce quickly making them a sustainable source of protein. If the shells and skins of these insects can also be utilized, this will contribute to sustainability and economic efficiency of the whole feed production.
The potential is enormous since the larvae shed their skin several times.
Substitute for harmful fluorocarbons
Firstly, the chitin is separated from components of the insect skins such as minerals and proteins. Chitosan can be used as a sizing agent due to its properties to form films. It reduces friction in weaving machines and further prevents the roughening and breaking of yarns in the weaving process. Later, the sizing agent is washed out again or remains on the yarns.
Secondly, a possible application is functionalization of textiles that is finishing of the textile fabrics with specific properties like using the functional amino group to link hydrophobic molecules with the chitosan achieving water repellent properties if applied to textiles.
