Lot Properties Available cotton

Lot A Micronaire mic

Lot B Micronaire mic

Lot A Staple Length mm

Lot B Staple Length mm

Lot A Strength g/tex

Lot B Strength g/tex

Laydown Target Mix

Target Micronaire mic

Bales in Laydown no.

Within-Lot Micronaire SD mic

Micronaire Tolerance ± mic

Lot A Share of Laydown

— %

Proportion needed to reach the target micronaire

Blend Properties

Bales from Lot A: — no.
Bales from Lot B: — no.
Blend Staple Length: — mm
Blend Strength: — g/tex
Laydown Micronaire SD: — mic
Tolerance in Sigma: — σ

Micronaire averages linearly and staple length does not — a blend of short and long fibre spins like neither, because the short-fibre content and length distribution drive drafting behaviour rather than the mean. Treat the blended staple figure as a bookkeeping average and judge the mix on span length and short-fibre index. A fraction outside 0 to 100% means the target lies beyond both lots and cannot be reached by mixing them. Bale-to-bale variation within a lot is also the number this rests on and it must be measured, since HVI data on every bale is what makes a controlled laydown possible at all.

Cotton Bale Micronaire & Staple Blending Laydown Calculator — free, with the formula and a worked example, at Textile School.