Blowroom & Carding
Sixteen per cent noil that is only 55% selective is expensive fibre bought at a cheap price.
— kg/h
Lap consumption less noil, across all heads
Noil is quoted on the lap fed, which is the industry convention; quoting it on the sliver delivered gives a larger number for the same machine and the two are frequently confused between mills. Production assumes all heads run and are fed equally - a head with a broken lap reduces output and shifts the effective noil, since the noil percentage is measured on what actually passed. The short-fibre balance needs all three percentages measured to the same length threshold and on the same instrument; short fibre content below 12.7 mm and below half an inch are different quantities, and mixing an HVI-derived feed figure with an AFIS-derived noil figure will not close. Total draft is from the combined lap mass to the delivered sliver and includes the draft in the draw box after combing.
Comber Feed, Noil Extraction & Short-Fibre Balance — free, with the formula and a worked example, at Textile School.