The REACT project has achieved important results.
NIR chemometric method
The current automatic processes for the separation of textile fabrics by type of fiber are based on NIR spectroscopy, without taking into account any substance added to increase the performance of the fabric. The partnership enhanced the detection capabilities of NIR spectroscopy.
By analyzing NIR spectroscopy data with chemometric methods we can extrapolate further information to find an identification system to separate acrylic fabrics by type of finishing present to route the material for the proper finishing removal process. The results of the model applied to this system led to an identification absent from errors of the type of finishing.
Furthermore, the method will be able to give indications on the percentage of finishing removed, allowing a quality control process following the treatments.
The method addresses the lack of information on the possible presence of chemicals of concern which is a significant barrier to achieving higher recycling rates, making chemicals easier to be classified in waste streams and simplifying treatment or removal, ensuring another level of health and environmental protection.
Effective processes for removing chemicals and finishing
The REACT project investigated a series of chemical-physical processes to remove the fluorocarbon, melamine and acrylic resins present on the fabrics, studying alternative ways with the aim of finding a process that can remove at least 90% of the contaminants from the acrylic fiber. The best method identified is a combination of successive acid and basic treatments, followed by washing with clays. This chemical-physical-mechanical combination made it possible to remove approximately 99%, 93% and 99% respectively of melamine, fluorocarbon and acrylic resin for the three types of finishing identified.
The process developed on a laboratory scale has been tested on a pre-industrial scale, through the use of a wool dyeing machine, suitably modified for the required needs.
Assuming the same removal rate in the pre-industrial process, the final product that can be sent to the market will have a high purity since most of the substances will be removed. This result makes it possible to reprocess a portion of the acrylic waste, avoiding that 30% of the end of life materials are disposed in landfills or incinerated.
LCA acrylic awning
A LCA study of the entire life cycle of a virgin material in a cradle-to-grave situation has been carried out. The results obtained from these studies show that the most significant impact by textiles derives from the polyacrylonitrile production, from the fabric manufacturing and the end-of-life on the whole awning. In particular, the manufacturing of the polyacrylonitrile fibre and of a few chemical agents used in the finishing (i.e. the resins) contribute more than the other parts considered in this step. As the production processes for both materials are affecting the resource indicator, the environmental performance related to these activities could be favoured by using recycled material.
Starting from the saving of resources, the introduction of such an innovation can lead to a positive improvement for other impact indicators when some activities will no longer take place due to the recycled material.
Additionally, the end-of-life stage could take advantage as well from the recycling of materials and register higher benefits when recycling processes are introduced.
