Flatlock Seam How It Changes with Construction and Elastane Content
Flatlock Seam does not stay constant when construction changes. Understanding the direction of change helps during development.
Effect of knit structure
Loop length and density move results first, usually before any yarn change is made. Working figures for Flatlock Seam normally sit around used next to skin in mainstream production. Note flatlock machines on the tech pack so nobody tests against an older revision.
Effect of elastane content
More elastane raises recovery but changes the value measured by flatlock machines, so retest after any blending change. Record elastane content alongside Flatlock Seam, because blends shift the measured value. A result outside used next to skin usually points to process drift rather than to the fibre itself.
Effect of finishing
Heat setting and softeners shift results, which explains differences between a hand sample and bulk. Keeping reference values for Flatlock Seam lets suppliers quote without extra sampling rounds. Ask for conditioning details together with flatlock machines, since both affect the reading.
Typical range
Working values stay around used next to skin for mainstream activewear. Working figures for Flatlock Seam normally sit around used next to skin in mainstream production. Note flatlock machines on the tech pack so nobody tests against an older revision.
Development advice
Change one variable at a time, then verify against flatlock machines before moving to the next sample round. Record elastane content alongside Flatlock Seam, because blends shift the measured value. A result outside used next to skin usually points to process drift rather than to the fibre itself.
