Kestrel Sport Denmark: Swim School Programme Wash Durability Evaluation
Kestrel Sport is a Denmark-based brand whose swim school programme is one of its most demanding programmes. Durability is where most functional claims fail. We washed the silver ion antibacterial knit fifty times under domestic conditions and re-measured after every ten cycles for Kestrel Sport.
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 | 175 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
Method
Washing ran at 30 degrees with a standard reference detergent and no softener, then tumble dried on low. This mirrors what customers actually do rather than what a care label optimistically suggests.
Performance by cycle
The fabric started at bacterial reduction above 99% and held above 90% of that value through 30 cycles. The decline after cycle 40 was gradual, which is the behaviour we want: a slow change, not a sudden failure.
Evaluation session with the Kestrel Sport team
Appearance
Pilling stayed at grade 4 or above and there was no visible shade shift against the retained reference. Surface comfort after washing mattered most to Kestrel Sport, so hand was scored by a panel at every interval.
Conclusion on service life
On this evidence the garment keeps its function for a full retail season of weekly washing, and ISO 20743 remains a valid claim for that period.
Test records and inspection notes for the Swim School Programme
Scorecard
| Criterion | Result |
|---|---|
| Function after 30 washes | 4.7 / 5 |
| Appearance retention | 4.4 / 5 |
| Pilling grade | 4.8 / 5 |
| Hand retention | 4.6 / 5 |
| Shade | 4.5 / 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 Denmark
Verdict and recommendation
Fifty cycles is a reasonable service life for this product class, and the silver ion antibacterial knit stayed inside tolerance throughout. Care wording should be printed exactly as tested. 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.
