The REACT project aims to mechanically recycle acrylic fabrics from the production or end-of-life of awnings and umbrellas. The main issue addressed by the project is the removal of the substances from the fabrics – in particular the finishing present in them – to ensure the required performance, to obtain a recycled material with high purity and without potentially hazardous substances.
To achieve this goal, the identification of the substances present on the fabric is crucial for the choice of the type of removal process to be applied. This characterisation is complex and time-consuming and requires a series of detailed analyses, some of which are destructive if these substances are not known, which add costs to the recycling process.
As part of the REACT project, CENTROCOT has developed a predictive method to respond to this challenge, using spectroscopic techniques currently employed in automatic sorting machines used to separate waste, which quickly identify the kind of fibre contained. Spectroscopic techniques identify the chemical characteristics of the whole fabric and are influenced by the quantity of material present; this poses the problem of recognising finishing and substances that are present in very small quantities in comparison to the fibre. Through chemometrics, only useful information can be extracted from the spectroscopic data to identify the type of chemicals present, excluding data from the fibre.
In the REACT project, a significant number of acrylic fabrics with different kinds of finishing were analysed by infrared spectroscopy: the kind of finishing and the quantity applied were thus identified. This led to being able to ‘train’ the chemometric model with accurate information, so that the model was subsequently able to identify small differences between the various fabrics analysed and create accurate and precise predictive clusters. The model designed for acrylic textiles makes it possible to recognise the finishing present. This makes it possible to separate fabrics in real time according to the finishing types present, and to allocate end-of-life fabrics to the appropriate treatment process. In addition, the same model can also be used to verify the effectiveness of finishing removal treatment. In other words, chemometrics becomes a core element of the REACT project: with it, it is possible to combine the effectiveness of treatments, the recognisability of the most problematic textiles, and time efficiency.