Reel quality at the stack

1. Maintain an even basis weight and correct pressing.
— a proper understanding between machine operators is needed concerning wet end versus calender changes.
2. Maintain even moisture (moist paper compresses more).
— the sheet temperature to the calender should be monitored.
3. Make certain that there are no hot bearings.
— install anti-friction bearings if they are not already in use and if the machine justifies it.
4. Keep calender rolls in good condition and properly ground.
— if the machine is an old one, check that the chill depth has not been reached by grinding.
5. Provide correct crowning for nip load required.
— the use of variable crown rolls greatly facilitates roll building in situations where many grades and weights are processed on the same equipment.
— use the minimum nip relief required to compensate for the doctor and outboard bearing effects.
6. Provide adequate cooling air of sufficient velocity and low enough temperature.
7. Except for the bottom and intermediate calender rolls, eliminate the use of doctors, and use air showers instead.
8. Temperature controllable rolls, using a circulating glycol system, provide a more uniform caliper profile.
Note: It should rarely be necessary to stop the calender. Clean the stack by using air hoses and cleaning solutions piped to the stack.