Paper Machine Speed Calculator

The speed formula is production times 1,000,000 divided by (trim width times GSM times 1,440 minutes per day times efficiency), so trim width and basis weight both sit in the denominator alongside efficiency. Widening the trim or running a heavier basis weight lets the machine hit the same daily tonnage at a lower speed, since more paper mass is being laid down per meter of travel.

Efficiency represents overall machine uptime accounting for downtime, breaks, and grade changes — it's a fraction, from 50-100%, that scales down effective production time rather than a measure of drive speed. It's floored at 50% because modeling lower efficiency would produce an unrealistically extreme required speed for typical tonnage targets, and capped at 100% because real paper machines never run at nameplate speed continuously.

The calculator assumes a fixed 20-ton reel weight, converts that to linear meters of paper using trim width and basis weight (reel weight divided by trim width times basis weight), then divides that length by machine speed to get minutes between reel changes. Since 20 tons is a common but not universal reel size, scale the result proportionally if your mill runs a different standard reel weight.

The calculator applies a fixed 1.5% draw to compute press-section speed, reflecting the convention that press sections run slightly faster than the wire to maintain sheet tension as paper transfers between sections. The real draw percentage varies by machine and grade, so the 1.5% figure is a typical starting point for checking drive settings, not your actual tuned value.