The nonwovens industry is currently undergoing a huge transformation. In part this is due to environmental goals, such as the EU’s target to become the first carbon-neutral continent by 2050. This transformation requires the expertise and collaboration of engineers from many different fields, such as materials, textile, chemical, and mechanical engineering, in order to introduce novel materials
Steven Neill, Chief Technology Officer at NIRI, examines the development of biopolymer technology and highlights the prototype-scale laboratory facilities that help make these new materials commercially viable with lower financial risk.
Responsible Manufacturing
Reducing CO2 emissions globally includes addressing those generated from polymer and nonwoven fabric production, converting and product assembly processes, and end-of-product life concerns. Manufacturers have a growing obligation to focus on various production factors, such as selecting raw materials, shifting to renewables, reducing overall energy usage, handling pre-consumer waste during the manufacturing process, and cutting down on water-intensive processes while better managing wastewater. Manufacturers must also consider the longer-term product lifecycle, including reuse, recycling, and returning materials to the production cycle or natural ecosystem.
A new direction for growth
The shift from fossil fuel-derived materials to alternative materials is transforming the nonwovens industry, but it comes with various challenges, such as adapting novel materials to conventional processing techniques or adapting current processing techniques to novel materials. Biopolymers’ growth and development offer a clear alternative to fossil fuel-derived plastics applicable across multiple sectors. Biopolymers, in their natural form, have been in use throughout history, largely animal-, plant-, or mineral-based, as natural fibres and binders. Alternative biopolymers for fibre/filament formation include a range of options, such as reconstituted/regenerated polymers from agri-resources, polymers from microbial production (PHA, PHBV), polymers synthesised from agri resources into biopolymers (PLA, PCL, PBAT, PBS, PGA), and polymers synthesised from bio-resources into conventional polymers (bioPET, bioPP, bioPE, bioPA).
By using prototyping-scale equipment, NIRI’s experts can determine the parameters and performance of biopolymer-based materials and the resulting fabrics.
Steven Neill, Chief Technology Officer at NIRI
The appropriate web formation technology for each of the biopolymer options varies, including carding, airlaying, wetlaying, meltblowing, and spunbonding. While these processes are well-established, there are significant challenges involved in introducing new materials into any sector or product line. One of the challenges is achieving trouble-free processing and conversion of novel materials using conventional equipment. The current alternative approach is to adapt conventional equipment to achieve trouble-free processing. Whichever route is pursued, novel materials must meet the specifications and performance demands of the materials and products they are meant to replace to be commercially viable.
Optimising Material Properties through Blending and Additives
One way to overcome these challenges and achieve the desired performance is to combine materials with the required properties into a blend that brings out the best of both materials. Alternatively, process or performance additives can be added during raw material preparation or processing. Blending can occur during the polymer preparation stage (compounding) by mixing different fibre types before carding, airlaying or wetlaying. In wetlaying, process additives can be added to the fibre slurry. Performance enhancers in non-fibrous forms such as powders can be added during the fibre laydown process or into the formed webs.
Enhancing Processability and Efficiency through Prototyping-scale Laboratories
Steven emphasises the significance of NIRI’s investment in laboratory technology when examining these process options. NIRI’s laboratories have unique, prototyping-scale equipment that allows them to evaluate the processability, explore polymer combinations with processing and performance additives, and optimise process conditions for biopolymer extrusion into filaments, spunbound, and meltblown nonwoven fabrics. NIRI can also meet the demand to match the specification and performance properties of novel materials to conventional fabrics and products. Prototyping machines on a laboratory scale enable cost-effective and time-effective changes to be made to the prototypes. This approach results in a rapid succession of adaptations that are less intensive in material use, leading to effective optimisation that provides confidence before more costly pilot and production trials take place.
The expansion of chemical recycling to include biopolymers is necessary to meet the drive towards more sustainable practices and the critical need to decarbonise.
Steven Neill, Chief Technology Officer at NIRI
After successfully forming nonwoven webs, they require bonding. NIRI’s extensive range of bonding techniques, including mechanical (which consolidates webs into fabrics without requiring additional materials), thermal, and chemical, can be used to assess bonding of carded, airlaid, and wetlaid webs made from novel biopolymers. Bicomponent fibres are the most common form of bonding agents used in thermal bonding. NIRI’s experts collaborate with clients on various trials to coextrude combinations of biopolymers into biocomponent fibre form, assess adhesion to fibres, and determine behaviour during thermal bonding and bonding performance. In chemical bonding, binders are applied onto the formed fibre webs, forming chemical bonds and aiding fabric strength. The main requirements for binders include compatibility with diverse application methods such as spraying, coating, printing, and saturation, affinity to fibres, and bonding strength.
Steven Neill, Chief Technology Officer at NIRI, emphasises the importance of prototyping-scale laboratory equipment for bonding:
“NIRI’s prototyping-scale bonding equipment is suitable for assessing the processability of binders, exploring polymer combinations, and optimising process conditions for bicomponent biopolymer extrusion into filaments, as well as the implementation of bonding techniques. NIRI’s analytical facility can be used to test the specifications and performance properties of biopolymer prototypes according to industry standards. NIRI’s experts can quickly communicate the outcomes of the testing to the prototyping team, make necessary adjustments, and form optimised prototypes to test again. By using prototyping-scale equipment, NIRI’s experts can determine the parameters and performance of biopolymer-based materials and the resulting fabrics. Clients can also use NIRI’s facilities and expertise to implement low energy and less water-intensive processes, assessing their impact on the parameters and performance of alternative fabrics and conducting rapid optimisation. Finally, NIRI’s experts can explore managing waste reintroduction into production, including pre-consumer waste, and assess their impact.”
Sustainable End-of-Life Management for Nonwoven Products
A crucial consideration in the nonwovens industry is the end-of-life management of the products. Nonwovens are typically designed for durability, semi-durability, or disposability, depending on the application. The choice of end-of-life strategy depends on factors such as the material composition and production methods used. The nonwovens sector has long-established mechanical recycling infrastructure that can manage the collection and recycling of conventional polymers, as well as biobased alternatives such as PET, PP, PE, and PA. However, as the use of biopolymers expands across different sectors, waste collection and recycling infrastructure will need to grow to extend the products’ service life by recycling and reusing the materials before they reach the end of their life.
Looking ahead to the future of bioplastics, Steven Neill, Chief Technology Officer at NIRI, notes that:
“Chemical recycling has the potential to achieve true circularity of polymeric materials, allowing them to be reintroduced into the same extrusion processes as virgin materials. Although reasonably developed for conventional polymers like PET and PP, the expansion of chemical recycling to include biopolymers is necessary to meet the drive towards more sustainable practices and the critical need to decarbonise.
NIRI’s facilities and expertise can offer manufacturers a cost-effective and quick way to explore novel materials while ensuring they meet the performance and specification requirements of existing products. With sustainability as a driving force in nonwovens, NIRI can help address vital aspects of the journey towards achieving a Net Zero future.”
About the author
NIRI’s Chief Technology Officer, Steven Neill, has over 20 years commercial experience in textiles, coatings and nonwovens NPD. He is responsible for the technical delivery of NIRI’s consultancy services. Steven manages the innovation process within the organisation and ensures technical excellence. He also promotes continuous improvement at an individual and organisational level.
Steven also heads up the development of NIRI’s IP portfolio including strategic partnerships and JV programmes. Steven has an MBA focussed on improving organisational creativity and innovation. He gained a 1st class honours degree in Textile Technology from the University of Leeds. He also received best finalist award and Textile Institute Textile Technology Examination prize.
To find out more about NIRI’s biopolymer expertise and prototype-scale laboratory facilities contact us:
E: enquiries@nirigroup.com T: +44 (0)113 350 3829
