Wire life, short

1. The fourdrinier table must be accurately lined up and in good mechanical condition.
— all drainage devices must be firm and set at uniform height.
— see that stretcher and automatic tension controls do not bounce.
2. A major cause of short wire life is poor condition of forming table and general housekeeping.
— pay careful attention to fourdrinier cleanliness.
(a) ensure that no accumulation of fiber can fall off on inside of forming fabric as a lump
(b) maintain doctors in good condition.
— prevent accumulation of stock on carrying rolls and breast roll.
— first outside roll is critical to avoid wire damage from lumps.
— doctor angle is important (25 – 30 degree) to ensure proper scraping without chattering.
— doctor load is matter of trial and error but excessive loads must be avoided.
— oscillation is a wise precaution for any and all doctors.
— breast roll doctor should be checked frequently to avoid marking the fabric or carrying excess water around the roll.
(c) check for holes in pans, rusty bolts or shower valves.
— uneven flow around shower valves can cause flakes of metal to break off and go through showers.
3. Eliminate abrasive fillers, e.g., calcium sulfate.
4. Check wire tracking, guiding, tension, load and slippage.
— ensure uniform tension across machine.
— do not run forming fabric too slack.
5. Maintain shower temperature and pH the same as that of the stock.
— ensure that edges are not blinded from fresh water edge showers.
6. Use low coefficient of friction suction box tops.
— check for uneven wear of suction boxes.
7. Use fewer suction boxes with bigger holes.
— reduce vacuums to prevent freezing or hanging of forming fabric on a suction box.
8. Eliminate grit from furnish (centrifugal cleaners).
— check for nicks and burrs on forming board, suction box covers, and foils.
9. Use wire life extenders.
10. Obtain proper split of drive load to ensure that fabric does not slip over couch.
11. Run with lowest practical flatbox vacuum.
— ensure that the flow is free from boxes to seal tank.
12. Check setting of forming board to ensure adequate room for uniform, minimum breast roll discharge.
13. Check condition of wire return roll system.
— inspect doctors, doctor loading, showers, bearings, and excessive shower water pressure.
14. Check for wear streaks from deckle rulers or headbox cheeking pieces that are set too low.