Antimicrobial Textile Testing – Advanced Performance

Textiles are part of our everyday experience but little do we realize the amount of technology and application expertise that goes into providing their features and performance attributes, particularly formulating for the addition of antimicrobial performance.  

Although one of the strongest fibers, Kevlar still requires antimicrobial treatment for protection against microorganisms.

Kevlar (Dupont TM) – One of the highest strength fibers Kevlar (para-aramid polymer) is often knit or woven into materials designed for providing bullet proof protection; that being said fungi can still reside on the material as it becomes aged. Anti-microbial auxiliaries can be added to the fibers or incorporated into the binder of the material to provide lasting protection.

As part of the product testing that we perform in our laboratory we like to say that we test ‘fibers to finished products” for microbial performance and durability attributes.    Having extensive experience formulating for the application and development of microbial performance for textiles against bacteria, fungi and algae, has given us the perspective that considerations small and large must be taken into account when attempting to produce these features for advanced durability and product performance.

Fibers – being made of synthetic (ex. polyester, nylon etc.) or natural (ex. wool, cotton, rayon)  material are made to provide specific characteristics, and then woven, knit, or simply spun (non-woven) into a textile material.  There can be several treatments of the fibers before during or after this process; adding colors, weaving types, knitting , and different attributes such as (moisture management, antibacterial, antifungal, abrasion properties etc.) can be added to the fibers and incorporated into the product at this stage.

Finished Products – Manufacturing of a textile requires the fiber product as a starting material, but the ultimate aim is the finished product.  The application and treatment of the whole cloth can again undergo several process steps including dyeing, texturizing,  padding, spraying, hot molding in addition to other auxiliary chemistries  ( again to add features such as moisture management, antibacterial, antifungal, abrasion properties etc.) and more depending on intended use of the material or required product performance.

The challenge is in selecting the appropriate additive that fits both the manufacturing process (requirements) and the product performance requirements of the finished product for advanced durability.

Once completed, the product should be tested to validation both the proper application and performance benefits in addition to demonstrating the durability needed for superior product performance.  Amazingly factors such as ultra violet light (UV), moisture, soiling, and washing  can all have detrimental effects on antimicrobial properties in textiles.

Trade organizations such as  AATCC, ISO and ASTM provide standard methods that can test bacterial, fungal and algal performance.  Certain agencies such as the US Military require specific tests such as the MIL-STD 810 for demonstration of appropriate antifungal performance.   Some of the requirements may incorporate a durability component to the antimicrobial test but some do not which can lead to misleading interpretations of a products performance if not appropriately tested.