Kestrel Sport New Zealand: Swim School Programme Laboratory Test Report
Kestrel Sport is a New Zealand-based brand whose swim school programme is one of its most demanding programmes. This report documents the laboratory qualification of the silver ion antibacterial knit supplied to Kestrel Sport for its swim school programme. Every figure below was produced on bulk fabric, not on an approval swatch.
Kestrel Sport: Silver Ion Antibacterial Knit in use during daily pool sessions for children and adults
Evaluation background
The programme covers training swimsuits, swim shorts and rash guards, used for daily pool sessions for children and adults. The environment is chlorinated water and repeated drying cycles and the requirement written into the brief was chlorine resistance with reliable shape retention. Fabric was selected on that basis rather than on price alone.
Fabric under evaluation
| Parameter | Value |
|---|---|
| Fabric | Silver Ion Antibacterial Knit |
| Composition | nylon spandex with silver ion filament |
| Weight | 250 GSM |
| Width | 160 cm |
| Primary function | stops the bacteria that turn sweat into odour |
| Target | bacterial reduction above 99% |
| Test method | ISO 20743 |
| Additional note | performance retained after 30 home washes |
| Certification | OEKO-TEX Standard 100 |
Silver Ion Antibacterial Knit close-up showing the fabric surface
Samples and conditioning
Three bulk lots were sampled at random and conditioned for 24 hours before testing. Results are reported as the worst of the three, which is the number a brand should plan around.
Test methods
The primary method was ISO 20743, supported by dimensional change to AATCC 135, pilling to ISO 12945-2 and colour fastness to ISO 105-C06.
Evaluation session with the Kestrel Sport team
Results
The fabric reached bacterial reduction above 99%, with performance retained after 30 home washes. All supporting tests passed the agreed limits, and the report carries the lot numbers so the results can be reproduced.
Interpretation
Numbers only matter against the use case. For swim school programme the relevant result is that the fabric keeps stops the bacteria that turn sweat into odour after conditioning, which is what protects the wearer during daily pool sessions for children and adults.
Test records and inspection notes for the Swim School Programme
Scorecard
| Criterion | Result |
|---|---|
| Primary function | 4.9 / 5 |
| Dimensional change | 4.5 / 5 |
| Pilling grade | 4.6 / 5 |
| Colour fastness | 4.3 / 5 |
| Consistency | 4.7 / 5 |
“Fifty washes later the fabric still performs. That is what convinced our buying team.” — Kestrel Sport Technical Team
Packed bulk rolls before shipment to New Zealand
Verdict and recommendation
The bulk fabric met every agreed target. The lot is released and we recommend repeating the same test set on each future delivery of the silver ion antibacterial knit. For Kestrel Sport the practical next steps are to keep the current specification for the repeat, retain the shade standard, and issue ISO 20743 results with every lot so any claim can be supported with data.
