Antiviral and Antimicrobial Treatments in Textiles

Gopinath  Rout 

Plant Head 

Himalaya Cotton Yarn Ltd 

Antiviral and antimicrobial treatments enhance textiles by incorporating agents that inhibit or kill viruses, bacteria, and fungi on fabric surfaces. These finishes are increasingly used in healthcare, apparel, and protective gear for better hygiene.

Key Agents

Common materials include silver and copper nanoparticles, which disrupt viral envelopes or microbial DNA/RNA. Zinc compounds, triclosan, and sodium pentaborate pentahydrate (SPP) provide broad-spectrum effects, reducing virus titers like adenovirus and poliovirus by up to 60%. Natural options such as tea tree oil or aloe vera extracts offer eco-friendly alternatives with sustained activity post-sterilisation.

Application Methods

Treatments use padding (pad-dry-cure), exhaust soaking, spraying, or plasma activation for even agent distribution. Nanoparticles like ZnO or Cu are often bound via sol-gel processes for durability over washes. Spun-in additives integrate agents during fiber production for long-term efficacy.

Effectiveness

Silver-based finishes like HeiQ Viroblock deactivate enveloped viruses (e.g., SARS-CoV-2, coronaviruses) within 2-5 minutes and inhibit bacteria. Copper pigments retain antiviral action after 15 washes, while zinc excels against resistant bacteria like MRSA.

Commercial Examples

• HeiQ Viroblock: Uses silver and vesicle tech for masks and apparel.
• Klopman's Vektron: Offers barrier fabrics for hygiene-critical uses.
• Recent 2023-2025 launches: Milliken and Toray target healthcare.

Silver nanoparticles (Ag NPs) stand out as the most effective antimicrobial agents for cotton fabrics due to their broad-spectrum activity against gram-positive and gram-negative bacteria (S. aureus and E. coli), often achieving over 99% reduction.

Why Antiviral & Antimicrobial Textiles Are Needed

• Control odor-causing bacteria
• Prevent cross-contamination
• Reduce virus survival on fabric surfaces
• Improve hygiene, safety, and product value

Major Applications

• Medical & hospital textiles
• Protective wear (PPE, masks)
• Sportswear & innerwear
• Home textiles (bedsheets, towels)
• Uniforms & workwear
• Transport textiles (seat covers, curtains)

Difference: Antimicrobial vs. Antiviral

Most antiviral finishes also provide antimicrobial effects, but not vice versa.

Common Antimicrobial & Antiviral Agents

A. Silver-Based (Ag⁺, AgNP)

• Broad-spectrum antimicrobial & antiviral
• Highly effective
• Used in medical & premium textiles
• Pros: Strong efficacy; long durability.
• Cons: High cost; regulatory scrutiny (eco-toxicity).

B. Copper-Based (Cu, CuO)

• Excellent antiviral activity (COVID-19 proven)
• Cost lower than silver
• Pros: Fast virus inactivation; good durability.
• Cons: Fabric discolouration risk; oxidation issues.

C. Zinc-Based (ZnO)

• Moderate antimicrobial & antiviral
• Popular in apparel
• Pros: Skin-friendly; cost-effective.
• Cons: Lower efficacy vs. Ag/Cu.

D. Quaternary Ammonium Compounds (QAC)

• Disrupt microbial cell membranes
• Pros: Low cost; easy application.
• Cons: Limited wash durability; less effective against non-enveloped viruses.

E. Chitosan (Bio-based)

• Derived from crustacean shells
• Pros: Eco-friendly; good antimicrobial.
• Cons: Weak antiviral; poor wash fastness unless cross-linked.

F. Graphene & Photocatalytic Agents (TiO₂)

• Advanced technology
• Mainly for R&D and high-end products

Application Methods in Textile Processing

1. Fibre/Dope Level (Best Durability)
   Add agent during polymer extrusion; common in polyester, nylon.
2. • ✔ Wash durability: 50–100 washes
   • ✖ High development cost
2. Yarn/Fabric Finishing (Most Common)
   Pad–dry–cure; exhaust method.
3. • ✔ Flexible & economical
   • ✖ Wash durability depends on the binder
3. Coating/Lamination
   Used for medical textiles; masks, gowns, and curtains.
4. • ✔ High surface efficacy
   • ✖ Affects breathability

Wash Durability

Testing & Certification

• Antimicrobial: AATCC 100, ISO 20743, ASTM E2149
• Antiviral: ISO 18184 (mandatory for antiviral claims)

⚠ Without ISO 18184, antiviral claims are not acceptable in export markets.

Commercial & Leadership Perspective

From an operations and cost-control angle:

• Cost addition: ₹5–25/kg fabric (depends on chemistry)
• Best ROI products: Innerwear, medical textiles, hotel & hospital linen
• Avoid over-engineering: Antiviral finish for daily wear only where customers are ready to pay

“Antimicrobial finish controls hygiene; antiviral finish controls risk perception. Both must convert into customer value, not just technology.”