The Nonwovens Innovation and Research Institute (NIRI) has developed a new platform technology to enhance the performance of a broad range of nonwoven products, also suitable for multiple high-performance applications.  Ross Ward, Chief Commercial Officer at NIRI, demonstrates how the technology is already being used in a COVID Capture project, for PPE that captures and immobilises SARS-CoV-2 to prevent viral transfer between healthcare staff and patients.  He explains the process and its relevance for numerous sectors, such as air filtration, wastewater filtration, automotive, pharmaceuticals and HVAC.
 
The impacts of the SARS-CoV-2 pandemic are far-reaching. While significant progress has been made in vaccine development and clinical treatments for COVID patients, even with the roll-out of vaccines and the increase in population immunity it remains vital to reduce virus transmission to protect the public, frontline staff and vulnerable people from the current and mutated variants of the virus.
 
Ross explains the rationale underpinning the Covid Capture project. “In hospitals, increased environmental contamination with SARS-CoV-2 can be found in areas where PPE is removed,” he says. “Improvements to personal protective equipment materials could reduce the risk of dissemination of the virus into the environment and the risk of transfer between staff and patients in the healthcare setting.  NIRI’s technology is designed to capture and immobilise COVID-19 and to prevent the cross infection from contaminated PPE and other products such as HVAC filters, thus protecting key workers and patients.”
 
To develop the technology specific to the Covid Capture project, NIRI used their new filtration platform technology – and an overview of the general process is detailed, below.  For this project, NIRI first identified a range of strategies for binding different functional groups onto the surface of the fibres. This allows the optimal binding strategy to be selected for the specific adsorbent molecule. The success of the project development to date means that COVID-Capture PPE is now being prototyped for clinical trial evaluation.
 
As noted, NIRI’s new filtration platform technology has applications – whether in product development consultancy or through licence – across a wide range of sectors and product types. 
 
“The nonwoven adsorbent technology is developed for the selective filtration of molecules, compounds and particles from gaseous and liquid environments,” Ross explains. “Harnessing NIRI’s technical expertise, with over 750 projects completed for more than 350 clients across over 30 sectors, the development of this new platform technology has been possible due to the extensive facilities we have at NIRI, including complete prototyping equipment such as drylaid, wetlaid, spunmelt, electrospinning and filament spinning and bonding techniques.  The evaluation and optimisation of filter performance is, likewise, critically dependent upon our complete analytical services which allow us to tailor and modify the nonwoven architecture and factor in other functional performance requirements.  The engineered nonwoven can be tailored, depending on the nature and volume of unwanted material to be filtered, and on the specific application, carrier fluid and separation performance requirements.”
 
When designing an adsorbent filter for a specific application, there are key considerations: the nature of the contaminant and level of contamination; the nature of the application itself, and fluid dynamics such as dwell time, adsorption kinetics and required performance.  Thus, NIRI carefully considers the material, nonwoven architecture and binding strategies in the first stage of the process – the development of the base filter substrate.  It is then possible, by considering the nature of the application and carrier fluid, to select and apply surface activation technology which serves as an anchor and binding site for linker chemistries.  This surface activation technology can be an array of treatments, such as chemical and plasma techniques.  Ross notes,
 
“It’s important at this stage to consider the spacial arrangement and number of binder sites required, and to tailor the surface activation process accordingly. Too many binding sites or multiple sites too closely spaced and the adsorbent components may inhibit one another.  Insufficient binding sites and there is a risk that the filter will not remove all the contaminants.  “
 
The next stage of the process is to bind the adsorbent molecule, which is specifically designed for interacting with an adsorbate or contaminant.  When the contaminated fluid passes through the filter substrate the contaminant or adsorbate is captured. 
 
In addition to the COVID Capture project, NIRI has utilised the new platform technology to enhance its Sanguis universal plasma filter, and is already exploring applications in wound-care, air filtration and wastewater filtration.  The company has seen significant investment and expansion, with more than 20 additional staff joining in the last year, including principal scientists, senior innovation engineers and technicians.  Consistent investment in new technology underpins the development of the new filtration platform technology and the company growth and expansion are enabling NIRI to help more clients grow their businesses, accelerate innovation and develop their next generation of nonwoven products.