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FREE CONTENT: Treatment for odour-capturing wound dressings

A treatment that has been proven to reduce malodours (such as putrescene and cadaverine) from chronic wounds when incorporated into nonwoven dressings has been launched by Aqdot of Cambridge, UK.  

Called AqFresh, the treatment is based on cucurbiturils, which are barrel-shaped molecules with a hydrophobic cavity and polar portal that capture and hold odour molecules. They cannot be felt in the bandage and Aqdot says that, unlike existing anti-odour solutions, AqFresh works in wet environments (such as chronic wounds). It explains that current odour-control technologies, such as charcoal, only work when dry, while silver is relatively ineffective and relies on antimicrobial action to which bacterial resistance is increasing. In testing conducted by the company, nonwovens treated with AqFresh generated 78% less malodour than a non-treated nonwoven when putrescene is added to them.

The treatment, which is available as a powder, can be applied to nonwovens using a dry-powder-impregnation process developed by Fibroline of Ecully, France.  

Fibroline has developed four variations of its process(1). In its basic configuration (called D-Preg) a scattering unit deposits dry powder onto a porous substrate travelling below. The substrate and powder then pass between two electrode plates, which are connected to a low-current, high-voltage generator that produces an alternating electrical field in the intervening space. The alternating field first electrically charges the dry particles in the powder and then attracts them, pulling them into the substrate. Fibroline says that no heat is required and there is no rise in temperature during processing, which takes place at room temperature. T-Preg is a version of D-Preg tailored for high running speeds (from 50–500 m.min–1) and is particularly suitable for hygeine applications. S-Preg allows users to deposit powder at a rate as low as 5 g.m–2 in a pre-determined pattern and can be used in cleanrooms. Finally, Y-Preg can be used to impregnate yarns and is suitable for use with coiled cartridge filters.

Aqdot says that AqFresh helps patients overcome any social embarrassment and isolation they may experience owing to the smells created by their chronic wounds. Further to putrescene and cadaverine, AqFresh can capture isovaleric acid (from sweat), trimethylamine (from urine) and skatole (from faeces).

The company runs its odour tests using trained assessors selected according to the ISO 8586 standard(2) (from the International Organization for Standardization (ISO) of Geneva, Switzerland) for their ability to discriminate and describe malodours. They undergo training and a quarterly assessment using validated polymeric standards provided by a qualified supplier. The panel carry-out the odour tests to evaluate the impact of the treatment. The panellists evaluate the intensity of the odour based on a scale from 0 to 6 (not detectable to extremely strong odour) and the hedonic tone from -4 (extremely unpleasant) to +4 (extremely pleasant).


(1)Dry powder impregnation takes the heat out of processing, https://www.technical-textiles.net/node/74288

(2)ISO 8586:2012, Sensory analysis — General guidelines for the selection, training and monitoring of selected assessors and expert sensory assessors, https://www.iso.org/standard/45352.html


Tel: +44 (1223) 928000.
Email: [email protected]

Jérôme Ville, Chief Executive Officer, Fibroline.
Tel: +33 (4) 2829-8540.
Email: [email protected]

Joric Marduel, Chief Technology Officer, Fibroline.
Tel : +33 (4) 2829-8536. Mobile/cellular: +33 (6) 8161-0548.
Email: [email protected]