Atomic Layer Deposition on Fabrics for Flame Resistance

An atomic layer deposition process for coating a wool-synthetic fabric sample with alumina was developed. Samples were processed at 65 degree C and 0.49 mBar, typically for 1000 cycles resulting in a nominal oxide thickness of 100 nm. Samples were characterized by both internal laboratory and commercial indicative flame resistance tests to test its efficacy. It was shown that untreated samples burnt to completion on removal of the ignition source, but in the case of atomic layer deposition treated samples, the flame on the fabric extinguished rapidly on removal of the ignition source, leaving the sample intact after the test. Thermal gravimetric analysis showed that successful fire resistance treatment was achieved by addition of alumina with less than 1% weight of the fabric. Therefore, it can be concluded that atomic layer deposition growth of oxides offers significant advantages in the area of fire resistance treatment, since in addition to its effectiveness, treated fabrics exhibit a negligible increase in weight, remain flexible, breathable and do not undergo any change in colour or palpable texture.