Chlorine Resistance Solutions for Swimwear: Common Failure Causes and Fixes
Below are the failure patterns most often seen when chlorine resistance affects swimwear, with the correction for each.
Failure: hidden until worn
elastic loss and colour change after pool exposure usually appears after several sessions. Because it develops slowly, it reaches the customer instead of the inspection table. Because the fabric stays wet, stretched and chemically exposed for hours, target checks are made on a worn sample rather than flat fabric alone.
Cause one
standard elastane that degrades under chlorine. Keep ISO 105-E03 chlorine water named in the tech pack so every lot is measured the same way.
Cause two
acid dyestuffs sensitive to oxidation. Where swimwear is worn for pool training and beach use, set tolerances around that range of movement.
Cause three
insufficient fixing after dyeing. Any change to nylon and polyester knits at 190-230 GSM with high elastane requires re-testing against less than 15% modulus loss after 100 hours at 1 ppm chlorine before bulk is released.
Correction and prevention
Apply chlorine-resistant elastane such as high-temperature spandex first, then verify against less than 15% modulus loss after 100 hours at 1 ppm chlorine using ISO 105-E03 chlorine water. Lock the corrected settings into the bulk recipe so repeat orders behave identically. Past reports from ISO 105-E03 chlorine water help the mill reproduce the same recipe on the next order.
