Fibre modification is a research field in which researchers aim at developing and applying technologies to impart new properties to natural fibres such as those in paper, in order to increase their functionality. Research areas in this field include many different technologies, amongst which the chemical modifications of fibres are widely used. One important sector of application of the chemical modifications is the treatment of wood for giving it enhanced properties such as higher mechanical properties, water impermeability, less hygroscopicity, bacterial and fungal resistance. Transferring and adapting the technical knowledge on fibre modification available for the wood sector to the recycled paper sector is an innovative use of these chemical treatments which has been the subject of studies that have been carried out within an EU co-funded project called Fibre+.[1]
The project Consortium included members representing Paper and Packaging European Associations (CEPI, FEFCO), and research institutes specialized in the wood and paper for packaging sector and paper and packaging companies. The focus of the project was on chemical modification of the paper made recycled fibres, investigating the possibility to transfer wood fibre modifications technique from the wood sector to paper and packaging sector. The aim was to enhance the properties of papers and of the packaging, as the recycling process causes the deterioration of fibres.
The chemical modification of recycled fibres aimed at the creation of a new generation of packaging papers characterized for being more recyclable, less hygroscopic, stiff and durable. The high recycling rate of papers in Europe (which is at the level of 72%) and the consequent importance that recycling has for the circular economy, were at the basis of this study. Paper products form part of an integrated carbon cycle based on the photosynthetic conversion of water, carbon dioxide, nutrients and solar energy into renewable wood-based biomass. Once consumed, paper may be recovered and used again either as a source of secondary fibres, to produce recycled paper or as bio-fuel. Fibre packages or corrugated containers made from corrugated board were the ones that were dealt with in the project, as they are considered as being the most prominent structural application of paper.