Result
- RPM at Ø 90 mm (core)
- 707 min⁻¹
- RPM at Ø 600 mm (full roll)
- 106 min⁻¹
- Web speed
- 3.33 m/s
How it is calculated
How do you calculate surface speed?
Surface speed in m/min = π × diameter in m × RPM. Example: a 90 mm core at 500 RPM = π × 0.09 × 500 = about 141 m/min.
How do you calculate RPM from surface speed?
RPM = surface speed ÷ (π × diameter). At 200 m/min a 90 mm core turns at about 707 RPM, a full 600 mm roll at only about 106 RPM.
Why does the RPM change at a winder?
The web runs at a constant speed while the roll diameter grows, so the drive has to keep lowering the RPM – from the core to the full roll.