SINTX’s Silicon Nitride-Treated Polypropylene Fabric vs. Commercial Antimicrobial Masks

Nonwoven spunbond polypropylene fabric (SB PP) is used for a variety of applications including apparel, absorbents, filters, and medical personal protective equipment. It is also most commonly used as a layer in surgical masks. SINTX’s R&D team has successfully developed a novel method to infiltrate its silicon nitride antipathogenic powder, FleX SN-AP, into SB PP.

Several companies have developed and commercialized surgical masks containing antimicrobial agents. The majority of these commercial masks that claim antibacterial or antiviral properties contain antimicrobial agents such as metals or quaternary ammonium salts. In an effort to gage market competition, SINTX characterized masks that were commercially available in stores or online. Scanning electron microscopy (SEM) analysis of one such mask shows powder coating a fiber found on the proclaimed antiviral layer. Energy Dispersive X-ray Spectroscopy (EDS) analysis suggests the presence of zinc and copper in the powder seen on the fiber (see Figure 1).

Figure 1. SEM & EDS Analysis of Commercial Mask
SEM & EDS Analysis of Commercial Mask

While metals, such as zinc and copper, or quaternary ammonium salts are indeed antibacterial and antiviral, they can also be irritants and are considered environmentally hazardous. SINTX FleX-SN kills bacteria and inactivates viruses but does not damage mammalian (human) tissue cells59*, which makes it a unique solution.

Not only is our antimicrobial agent safer than antimicrobial agents used by other companies, but our process also produces much more evenly and heavily treated fabric. SEM analysis shows that SINTX’s treated layer has far better active ingredient coverage compared to other antimicrobial masks (Figure 2). While other commercial masks contain layers with sparsely treated fibers, SINTX’s treated fabric contains fibers that are almost completely covered with SINTX’s FleX-SN AP.

Figure 2. SEM analytical comparison of SINTX treated spunbond polypropylene vs. two commercially available masks for active layers.
SEM analytical comparison

The more covered the fabric is with an antimicrobial agent, the more efficacy it will have against bacteria and viruses. While fabric embedded with SINTX’s FleX-SN AP is still in the development phase, the initial results are promising for new antipathogenic fabric applications in the future.


*Go to for links to references.

Back To Top