Plating Ground loop, elastane and the draft between them

Ground Yarn Count tex

Ground Loop Length mm

Elastane Count dtex

Draft Ratio x

Ground loop length divided by elastane fed

Elastane Tension at Draft cN

Fabric & Target Stitch density and the content being aimed at

Courses /cm

Wales /cm

Target Elastane Content %

Elastane Content

— %

By mass, from the loop geometry of both yarns

Loop, Weight Split & Power

Deviation from Target: — %
Elastane Loop Length: — mm
Extension the Elastane is Held At: — %
Fabric Weight: — g/m2
Ground Yarn Contribution: — g/m2
Elastane Contribution: — g/m2
Retraction Force: — cN/cm
Elastane Feed Speed Ratio: — x
Elastane Count: — tex

Content here is calculated from loop geometry and is a machine-setting target, not a declared figure: label content must trace to a chemical analysis under the ISO 1833 series, and the two will differ because of finishing losses, elastane relaxation and the tolerance the analysis itself carries. The retraction force is the elastane contribution alone at the stated tension and ignores the ground structure's resistance and the large effect of heat setting, which is applied specifically to reduce elastane stress; treat it as a comparative figure between settings rather than a predicted fabric power. Elastane tension at draft is entered rather than derived because elastane stress-strain behaviour is strongly non-linear and hysteretic, and no linear modulus reproduces it usefully across the plating range. Stitch density is the greige figure and moves substantially through relaxation and finishing, which shifts fabric weight and both yarn contributions together but leaves the content ratio roughly intact.

Elastane Plating Draft, Content Percentage & Retraction Force — free, with the formula and a worked example, at Textile School.