Seam Slippage Solutions for Swimwear: Comparison of Options
Three working routes exist for seam slippage in swimwear. This page compares them by performance, cost and risk.
Option A: change the yarn
Changing fibre composition usually gives the largest improvement. It costs more and needs a new minimum quantity, but less than 6 mm opening at 60 N is easier to hold over time. Because the fabric stays wet, stretched and chemically exposed for hours, target checks are made on a worn sample rather than flat fabric alone.
Option B: change the structure
Adjusting knit density is cheaper and faster. The trade-off is a narrower operating window, so process control becomes more important. Keep ISO 13936-2 seam slippage named in the tech pack so every lot is measured the same way.
Option C: change the finish
Finishing delivers fast results and can be added late. The risk is wash durability, so check performance after 10 and 20 washes. Where swimwear is worn for pool training and beach use, set tolerances around that range of movement.
Cost comparison
Indicative cost impact: bonding equipment adds unit labour cost. Testing adds little, while the cost of a rejected shipment is far higher. Any change to nylon and polyester knits at 190-230 GSM with high elastane requires re-testing against less than 6 mm opening at 60 N before bulk is released.
Recommended route
For pool training and beach use the practical route is normally raise stitch density and use ball-point needles combined with add a softener that increases yarn mobility then re-set. Confirm with ISO 13936-2 seam slippage before releasing bulk. Past reports from ISO 13936-2 seam slippage help the mill reproduce the same recipe on the next order.
