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Biobased textile coating and finishing

Centexbel develops antibacterial and antifungal textiles based on biological coatings & finishes

In the Bio-AmiCoFitex project finalised at the end of 2014, Centexbel developed bio-based antibacterial and antifungal textile finishes and coatings complying with the criteria of the new biocide regulation that urges the textile to apply non-hazardous alternative biocides. Biocides are used to prevent the growth of microorganisms.

Because microorganisms have the undesired effect of creating unpleasant smells, transmitting infectants and provoking material degradation, biocides have to be added to those textiles that are subject to the growth of microorganisms.
However this has to be done in a delicate balance, in respect of human and environmental safety while being effective against bacteria, algae and fungi.

Indeed, biocidal products often contain substances of very high concern and have allergic, carcinogenic, neurotoxic or endocrine disruptive effects.
Therefore we have explored the implementation of renewable materials with antibacterial or antifungal properties starting from materials that are also present in food and beverages or used in food processing.
This new approach to develop antimicrobial coatings for textiles is based on the application of natural resources. The development of non-toxic, flexible and durable antimicrobial coatings only requires a minor optimisation and up-scaling and is thus in reach of SMEs.
Antimicrobial coatings can be applied in sportswear, carpets, socks, bedding and upholstery, table linen, outdoor textiles, and other application areas.

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Materials used in textiles need to be constantly improved and respond to the consumer’s growing environmental awareness.
One of the strategies to reduce CO2 emission (Kyoto) is to replace petroleum based products with CO2 neutral biopolymers.
Centexbel introduced biobased binders and additives in coating formulations for textiles and developed waterbased soy polymer and PLA coating formulations. The optimised waterbased formulations are compatible with anionic and non-ionogenic additives (e.g. repellents). Sodium alginate was used as a viscosity modifier. Renewable plasticizers improved the flexibility of the coating.

We then functionalised textiles with biobased antibacterial additives and evaluated the antibacterial efficacy of the treated textiles according to ISO 20645, agar diffusion plate test.

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Antibacterial effect of textiles treated with biobased products. +: Inhibition of growth and -: no inhibition of growth.

The concentrations are dry weight concentrations (w/w) of the antibacterial additive onto the textile.

Results

Chitosan and a mixture of thymol and carvacrol proved effective against the tested Gram- and Gram+ bacteria, whereas thymol and carvacrol showed synergistic effects.

Acknowledgement

Research performed in the framework of Cornet and funded by IWT (IWT-120273)