Reusable Protection Against Droplet Infections

A new study demonstrates how reusable, water-repellent cleanroom suits can be used as medical protective clothing. Whether protective garments and equipment can be reused against droplet infections is currently part of public debate. However, despite rising infection incidence and associated supply bottlenecks, the medical community has hesitated to respond. This is due to the need to first establish that traditional disposable garments provide reliable protection compared to reusable textiles. A new study on the wettability of coated cleanroom garments takes an important step forward. [caption id="attachment_122586" align="aligncenter"] Properly coated cleanroom textiles form round droplets with wide contact angles[/caption]   As part of a research collaboration, the materials examined demonstrated excellent liquid-repellent properties as required to protect against infectious droplets. The contact angle method, which was the focus of the study, proved valid and can be used as an easily accessible method for testing medical protective clothing. The study involved KRÜSS, a Hamburg-based measurement equipment manufacturer, as well as Dastex Reinraumzubehör GmbH & Co. KG and OHB System AG, which played a key role in initiating the work.  

How cleanroom suits become droplet-resistant protective clothing

The textiles being examined are actually used in satellite production, primarily for cleanroom clothing where they protect the environment. For potential medical use, a hydrophobic PTFE coating was applied to the fabrics. This modification ideally prevents infectious droplets from wetting and absorbs them so they either fall off the surface or evaporate. Detection of such hydrophobic properties is a typical concern in contact angle measurement technology, in which KRÜSS specializes.  

Practical wetting tests confirm good hydrophobic properties

Initially, the fabric was confirmed to have excellent liquid-repellent behavior on the basis of larger water droplets. To further investigate protection in contact with coughing or sneezing patients, high-speed small droplets were applied to the materials. Microscopy-based contact angle measurements also showed good protective effects in this case and could be verified even at the individual fiber level. Reusability was also demonstrated. After 120 wash cycles, no deterioration in water-repellent material properties was detected.  

Contact angle measurement as a valid test method for protective clothing

Until now, the protective effect of medical garments could only be determined in specialized laboratories. In contrast, coated textiles for other uses are usually tested using ad hoc methods that are not particularly scientifically sound. On the other hand, contact angle measurements are not only valid for characterizing hydrophobic textiles, but can also be performed quickly, easily and in a mobile manner. In parallel, scientists at the Helmholtz Zentrum Geesthacht at DESY, together with quality analysis (Nürtingen) and Volume Graphics (Heidelberg), visualized the round shapes of non-wetting droplets in high-resolution computed tomographic studies. There is still much work to be done before medical facilities can switch to reusable protective clothing. However, it is certainly beneficial for ecological reasons alone and when supply bottlenecks are a concern. Doctors and nurses could benefit from more comfortable and breathable protective garments. The study results will be presented online by Dr. Thomas Willers from KRÜSS on 18 February 2021 at the World Textile Coating Congress. A medical publication is first planned in the Norwegian journal Dagens Medisin.   Source