Dirt

In the sheet:
1. Screening equipment not operating efficiently.
— check screens.
— reset to permit an increased flow of rejects.
2. Check operation of each cleaner along with the inlet and outlet pressure for each stage of cleaning.
3. Check dirt counts of all pulps being used.
— if dirt is in the stock identify source and eliminate.
4. Determine location of pump or agitator packing failure and have it repaired.
5. Wash up stock system and machine.
6. Check for dirty recycled water to machine.

See also Dirt in the sheet .

On the sheet:
1. From foam spots.
— increase defoamer addition.
— if this does not reduce the spots, flush out.
2. Check for dirty wet felts.
3. Ensure paper carrier rolls or top press rolls and doctors are clean.
4. If dirty dryer felts are running too wet, raise dryer temperatures and clean the felts.
5. If dirty dryer felts are due to high temperature of lead dryers, reduce lead dryer temperatures and clean the felts.
6. Clean up oil, grease or water on dryer felts indicated by felt pattern showing up in dirty area.
7. Clean up dust in dryer hood that occasionally drops on sheet.
8. Clean dirt build-up on all doctors on each reel turn up, or as often as necessary, to prevent dirt dropping on sheet.
9. For surface size spots, check size press filters and/or screens.
— ensure that by-pass valves are closed.
— clean screens and/or filters as required.
1 0. Be more careful when using air hoses around calender stack.
11. Increase temperature of building air supply fans to prevent sweating of building or machine structural members.
12. Clean the filters to avoid dirty calender cooling air.