4D evaluated the ability of silicon dioxide (SiO2) nanoparticles as a spray-applied waterproofing solution to provide aftermarket waterproofing and fire protection to fabrics used in clothing, shelters and rucksacks. As envisioned, the easy application of SiO2 products would allow the military to apply the product to fabric already in inventory, thereby providing a cost-effective means of improving fabric performance. In order to ensure the performance of the SiO2 product, 4D planned and executed a comprehensive set of test in accordance with the protocol and methods recommended by the American Association of Textile Chemists and Colorists (AATCC) and also by the American Society for Testing Materials (ASTM). Testing included: Water Repellency Spray Test; Water Resistance Rain Test; Water Resistance Impact Penetration Test; Absorbency; Aqueous Liquid Repellency, and; Standard Test Method for Flammability of Apparel Textiles.
Testing included machine washing and drying of fabrics in accordance with AATCC test specifications for a total of 25 cycles, with analysis of test samples after each 5 wash/dry cycles. Performance assessment for Nomex flight suit fabric, Army Combat Uniform (ACU) fabric and Combat Vehicle Crewmen (CVC) Coveralls was performed and reported.