Smoothness

1. Check that basis weight and moisture profiles are as uniform as possible across sheet.
— consider using more hardwood and fillers.
2. Raise moisture level out of dryers.
— calendering is ineffective on too dry a sheet.
— use steam in calender rolls.
3. Uneven or insufficient wet press loading contributes to poor sheet smoothness or flatness.
— dirty or worn felts can disrupt the sheet surface and should be replaced.
— check condition of felts, particularly bottom wet felts.
4. Increase refining for improved formation if other tests and conditions permit.
5. Use smoothing press.
6. Check operation of sweat dryer.
7. Increase ash content of sheet to improve finish if other tests will permit.
8. Check press configuration and condition of oscillating doctors.
9. Check for press felt marking and reduce loads at press as much as possible.
— will need to raise load at calender stack.
10. Check calendering operation.
— increasing temperature or number of nips is beneficial to finish.
11. Check crown and loading of press rolls.
— regrind if needed.
12. Ensure gradient drying in early part of dryer section.
13. Check for dirty dryer cylinders, rolls, and doctors.
— clean where needed.
14. Reducing the level of internal sizing or raising moisture level of sheet into size press will permit greater pick-up at size press.
15. Increase size press solids and/or pick-up if other tests allow.
— reduce press loading to keep size on surface.
— make sure press is loaded evenly.