Periodic Reporting for period 2 - REACT (REcycling of waste ACrylic Textiles)
Periodo di rendicontazione: 2020-12-01 al 2022-09-30
Saving resources is one of most important challenges, also for textile industry.
Recycling, instead of landfill or incineration when a good is end-of-life, is a clear objective for all, but not easy. One of the major problems is to have secondary raw material similar to the virgin one, because of contamination, treatments to recycle, and so on, that lowen obtainable product performance.
The general objective of the REACT project was to develop a process to recycle waste from acrylic fibres both post-industrial and post-consumer, removing finishes and chemical substances added to improve fabric performances.
REACT focused in a small market segment that involves the outdoor fabrics. In particular, awnings, umbrellas and furniture. It is a precise market sector, but it can be used as a case study.
The goal was to remove more than 90% of the undesirable chemicals present in acrylic outdoor fabrics in order to produce a new yarn with recycled acrylic fibre, through a mechanical recycling. The new yarn must have the highest rate of recycled content, even 100%. The chemicals removed and all sewage impurities obtained from removal steps must be treated to avoid their environmental spread with the objective to remove 99% of chemicals in wastewater. The process to be developed must allow reducing the amount of acrylic incinerated or landfilled by at least 30%, introducing in the meantime in the market a secondary raw material.
The project was divided in several phases to:
- study a system for the recovery of the fabrics;
- investigate an effective removal method to achieve the objectives of the project;
- study the fabrics treatment and the wastewater treatment;
- use the treated fabrics in mechanical processes to recycle, in order to develop recycled yarn and fabrics, to be used to create prototypes for laboratory and real environment testing.
The overall purpose of the REACT project was also to contribute to European sustainability, also setting recommendations to design and manufacture textile materials for recyclability and standard methods and examples to recycle textile waste.
Recycling, instead of landfill or incineration when a good is end-of-life, is a clear objective for all, but not easy. One of the major problems is to have secondary raw material similar to the virgin one, because of contamination, treatments to recycle, and so on, that lowen obtainable product performance.
The general objective of the REACT project was to develop a process to recycle waste from acrylic fibres both post-industrial and post-consumer, removing finishes and chemical substances added to improve fabric performances.
REACT focused in a small market segment that involves the outdoor fabrics. In particular, awnings, umbrellas and furniture. It is a precise market sector, but it can be used as a case study.
The goal was to remove more than 90% of the undesirable chemicals present in acrylic outdoor fabrics in order to produce a new yarn with recycled acrylic fibre, through a mechanical recycling. The new yarn must have the highest rate of recycled content, even 100%. The chemicals removed and all sewage impurities obtained from removal steps must be treated to avoid their environmental spread with the objective to remove 99% of chemicals in wastewater. The process to be developed must allow reducing the amount of acrylic incinerated or landfilled by at least 30%, introducing in the meantime in the market a secondary raw material.
The project was divided in several phases to:
- study a system for the recovery of the fabrics;
- investigate an effective removal method to achieve the objectives of the project;
- study the fabrics treatment and the wastewater treatment;
- use the treated fabrics in mechanical processes to recycle, in order to develop recycled yarn and fabrics, to be used to create prototypes for laboratory and real environment testing.
The overall purpose of the REACT project was also to contribute to European sustainability, also setting recommendations to design and manufacture textile materials for recyclability and standard methods and examples to recycle textile waste.
The REACT project developed a model to collect, classify and sort textile waste, with logistic and business aspects. Waste samples have been identified and characterized in order to correctly address treatments to remove chemicals and recycle.
A forecasting method based on NIR spectroscopy has been has been tuned to identify and classify collected waste, creating a database for the identification of chemicals or other contaminants on treated fibres. Correct identification of chemicals allow to chose, for each waste, the best treatment for removal.
Three categories of finishing and substances have been identified and the Partnership investigated treatments to remove these categories.
Experiments done so far over the three categories have already demonstrated that is possible to reach a removal rate of 90-95%.
To evaluate a finish removal process, the amount of any finishing component on the acrylic fabric substrate before and after this process have been compared by means of FTIR-ATR analysis.
Also wastewater streams from the removal processes have also been treated to avoid any harmful impact on the environment. The streams were studied to improve treatability and increase reuse options and treated through conventional anaerobic, aerobic and combined anaerobic-aerobic biodegradation techniques (target achieved: remove 99% of chemicals in wastewater).
The REACT project experimented with mechanical recycling (fraying and carding), spinning and weaving, mainly to evaluate how mechanical processes can influence the tensile properties and performance of fabrics with recycled fibres. Fabric prototypes have been made with recycled fibers.
In parallel, a Life Cycle Assessment was carried out to evaluate the change in the environmental impact of the recycling process developed in the project.
A forecasting method based on NIR spectroscopy has been has been tuned to identify and classify collected waste, creating a database for the identification of chemicals or other contaminants on treated fibres. Correct identification of chemicals allow to chose, for each waste, the best treatment for removal.
Three categories of finishing and substances have been identified and the Partnership investigated treatments to remove these categories.
Experiments done so far over the three categories have already demonstrated that is possible to reach a removal rate of 90-95%.
To evaluate a finish removal process, the amount of any finishing component on the acrylic fabric substrate before and after this process have been compared by means of FTIR-ATR analysis.
Also wastewater streams from the removal processes have also been treated to avoid any harmful impact on the environment. The streams were studied to improve treatability and increase reuse options and treated through conventional anaerobic, aerobic and combined anaerobic-aerobic biodegradation techniques (target achieved: remove 99% of chemicals in wastewater).
The REACT project experimented with mechanical recycling (fraying and carding), spinning and weaving, mainly to evaluate how mechanical processes can influence the tensile properties and performance of fabrics with recycled fibres. Fabric prototypes have been made with recycled fibers.
In parallel, a Life Cycle Assessment was carried out to evaluate the change in the environmental impact of the recycling process developed in the project.
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.
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.