Halden Works Denmark: Odor-Free Warm-Up Hoodies Built on Built-In Antibacterial Masterbatch Yarn
Halden Works is a Denmark-based activewear label whose gym hoodies programme sells directly to consumers and through selected retail partners. The team asked us to rebuild the fabric from scratch because a scented finish masked the smell for two washes and then stopped working. The target was a permanent mechanism rather than a fragrance.
Halden Works: odour-control swatch set for the gym hoodies programme
The challenge
The smell built up at the back panel and the cuffs, where sweat sits longest during a session. The previous fabric was a standard synthetic knit with no odour strategy, so bacteria broke the sweat down on the fabric and the smell became permanent after a few weeks. A retailer review that questioned the wording of the claim made the problem urgent: the brand needed a fix before the next bulk booking, not a new supplier search.
The fabric solution
We built the programme around Built-In Antibacterial Masterbatch Yarn on a polyester filament knit base. The mechanism matters: the active agent is locked inside the fibre so it cannot be washed off the surface. Keeping the base at brushed back fleece with 5% elastane and 300 GSM meant the hand, the stretch and the cover stayed exactly where the design team wanted them, because odour control changed the chemistry and the construction rather than the silhouette.
Wear trial and fit approval of the polyester filament knit fabric
Development and implementation
- Week 1: brief agreed, sweat zone mapped, target set as above 99% bacterial reduction retained after 50 washes by JIS L 1902.
- Week 2–3: laboratory knits produced and tested; add-on level adjusted until the target was met with margin.
- Week 4–5: wear trial on finished gym hoodies, assessed after eight hours of wear.
- Pre-production: wash durability confirmed at 50 washes or more, care wording written as standard laundering with no special requirement.
- Bulk: fixed recipe, consolidated dye lots, JIS L 1902 repeated on every lot.
Specification delivered
| Parameter | Value |
|---|---|
| Product | Warm-Up Hoodies |
| Base construction | brushed back fleece with 5% elastane, 300 GSM |
| Odour-control system | Built-In Antibacterial Masterbatch Yarn |
| Performance target | above 99% bacterial reduction retained after 50 washes |
| Test method | JIS L 1902 |
| Service life | 50 washes or more |
| Added cost | an 8% yarn premium |
| Certification | OEKO-TEX Standard 100, REACH compliant inputs |
Results
Smell-related returns fell by 71% inside one season, and the style moved onto a fixed repeat recipe with test reports issued per lot. The odour value was re-measured on bulk fabric rather than on the approval sample, so the result reflects what customers actually received. The programme is now on its third repeat with the same recipe.
“Two seasons on, the odour value is still there. That is why the style stayed in the range.” — Halden Works Product Team
Inline inspection and packing before the gym hoodies shipment
Key takeaway
Sweat is almost odourless; bacteria create the smell. Treating the bacteria and moving the moisture at the same time solved a problem that neither approach had solved alone. For Halden Works, that turned a recurring complaint into a feature the brand could sell.
