Nonwovens Research

Research

Research spans fibre science, nonwoven fabric manufacture and nonwoven materials and technology. The research aims to create knowledge, understanding, methods and tools that contribute to improving nonwoven processes and materials. This work is linked to numerous application areas including: hygiene, medical devices, filtration, packaging, personal and property protection, energy generation, water and food security, reducing disease transmission, clothing and domestic products, defence industries, civil engineering and building, automotive and transport, agriculture, aquaculture and horticulture.

Some of the major research themes are summarised below:

Hygiene Materials

Research activities address demands in both single use and durable hygiene materials. This includes improving liquid handling and transport properties, conformability, odour control, barrier properties, mechanisms of particle removal during wiping surfaces, fibre-lotion interactions, antimicrobial chemistry, comfort and end of life disposal challenges such as improved dispersibility of wipes and continence control and ostomy products during flushing. The process-structure-property modelling paradigm underpins much of the research in this area. Modelling of the structure-dependent directional permeability in nonwoven materials, in-plane liquid transport and droplet penetration through thickness are areas of interest. These models have enabled linkage of liquid handling properties with measurable aspects of the fabric structure and this is enabling process as well as product developments in the hygiene industry. Collaborations include those with the University’s Centre for Computational Fluid Dynamics, the University of Leeds’ Skin Research Centre and the School’s of Healthcare and Chemistry.

Active Delivery & Storage Fabrics

The research aims to improve the targeted delivery of chemical and biochemical agents for healthcare, drug release in medicine, liquid filtration and personal care. The controlled release of chemical and biochemical agents from the surface of fibres and from nonwovens can be achieved by exploiting established diffusion, polymer swelling, fracture or degradation approaches amongst others. We are also studying local microstructural engineering of fabrics to introduce local variations in specific permeability in both monolithic and three-dimensional materials.

One of the outcomes in this area is a family of hydroentangled internally micro-channelled (Hydrospace) nonwovens that are pre-loaded with actives and which facilitate guided delivery. Storage of actives and the direct injection and encapsulation of beads, nanoporous silica gels, SAPs, waxes, metal or ceramic particles to functionalise such fabrics has also being studied.

Protective Fabrics

This research is principally concerned with:

  • Light-weight fabrics and flexible protective garments in which nonwoven materials form part of the garment assembly: impact resistant, stab and cut resistant materials, exo- and endothermic vapour permeable fabrics, chemical protection membranes and nanoporous thermal insulation materials.
  • Insecticidal materials that do not rely on biochemical mechanisms to induce a lethal response. This research aims to reduce the reliance on neurotoxic insecticidal chemicals in mosquito nets that are currently used to combat malaria and disease transmission by biting insects.
  • Durable materials suitable for clothing and other high attrition areas continues to pose challenges for nonwoven materials. Research in this area addresses fundamental aspects concerned with the mechanisms of pilling and abrasion in nonwovens, colouration and functional finishing of nonwovens including modelling of the dye transport mechanisms, structural patterning and visual surface effects, engineering of fabric and garment elasticity, garment assembly and construction including consideration of block design.

Biomedical Fabrics & Tissue Engineering Scaffolds

Design and manufacture of textile fibres and fabrics for integration in medical devices is at the heart of this activity. Current projects span blood filtration, drug delivery, advanced woundcare, tissue repair and regeneration, grafts and continence management. The work involves collaboration between the NRG, the Institute of Medical and Biological Engineering, Dental Institute at Leeds and the NHS. Research involves production of new biomaterials such as functionalised collagen in various forms such as hydrogels, fibres, films and fabrics for use in medical devices and clinical procedures. It also involves development of methods to improve cell infiltration and viability in three-dimensional scaffolds, rapid customisation of scaffold structures to meet individual patient needs and improved methods of nonwoven scaffold manufacture. The group is a contributor to activities in the The WELMEC Centre of Excellence in Medical Engineering and the MeDe Innovation Centre.

Wound Care Materials

Research interests include alternative antimicrobial chemistry suitable for incorporation with fibres to control biofilm formation, control of moisture vapour transmission, development of alternative biomaterials as wound contact layers, odour sorption, diagnostic dressing design and engineering and superabsorbents. Understanding and modelling of the liquid transport and distribution within woundcare materials is an important area both in respect of functional performance and infection control. Novel methods of managing exudate and other fluids within the dressings is an important aspect of the work particularly with respect to chronic woundcare and negative pressure therapies. NRG is the founding member of the Clothworkers Centre for Textile Materials Innovation for Healthcare (CCTMIH) that manages a large programme of research that includes wound care device development.

Filter Media

The work spans liquid, air and gas filtration. The interaction of nonwoven filter media with aqueous fluids as well as fuels, beverages, blood and other liquids is studied to improve filtration performance and to understand underlying mechanisms. Research includes the development of improved sorption media for removal of target species such as uremic toxins in blood and other fluid streams where contaminants need to be selectively removed. The influence of fabric structure on filtration performance and the selection of appropriate raw materials and surface chemistries are core activities. The roles of specific permeability, pore size distribution, average pore size and surface finishing are experimentally explored to improve overall filtration performance. Other research interests are in the filtration of oil aerosols and the factors affecting recontamination of the airflow as well as engineering of high permeability triboelectrically charged dry-laid filter media in air filtration.

Composites

The formation, structure and properties of composites reinforced with nonwoven materials is an important development area and is particularly focused toward light RTM (Resin Transfer Moulding) applications. High and low modulus reinforcements and flow media are being studied, reinforced with glass and with recovered high modulus fibres including carbon, recovered glass and aramid. The structure-property relations of surface energy modified bast fibre composites and those reinforced with more unconventional biological materials is an additional research interest. Other composite interests are in the area of nonwoven breather membranes.

Sustainable Industrial Materials

This research is directed at improving the understanding and knowledge needed to address challenges particularly in the automotive and transport, composites, building and construction industries. Significant progress has been made that has already led to industrially-relevant outcomes.

Research interests are focused in three main areas:

  • Improved dry processing techniques for mixed fibre waste and short particles to enable the formation of industrially-applicable nonwoven materials.
  • The processing, structure and property relationships of sustainable crop-fibre based nonwoven materials (including wool and hair, bast fibres, regenerated natural polymers, wood pulp, stem and leaf material and carbonised particles.
  • Approaches for the recycling, reuse and conversion of recovered fibres for industrial processes and products to enable better use of environmental and economic resources (including wear2 technology).

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