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Improved rope runs with minimum changes, two-machine case study

In this case study, two paper machines were rebuilt to improve their rope runs. The rope systems were made much more reliable by making a minimum of changes. Valmet changed the transfer philosophy from tear-off to tail-release. The results were less fouling of return runs and less debris.

LWC machine forming fabric MD ridging problem, a case study

Distortions in fabrics, such as ridges, cause basis weight profile problems. In this case study, the culprit was found to be a tiny speck of rust - which created a large and expensive problem.

Suction couch and press roll packing strip problems, a case study

A paperboard mill suffered from unexplained grooving and chipping in thesuction roll sealing strips. The fog shower was identified as a culprit.

Uhle boxes - care, handling, cleaning, maintenance and adjustment

Reliable operation of a press section uhle box requires attention to care and handling, as well as routine maintenance. Blades and covers are susceptible to costly damage if improperly handled and maintained.

Chronic dryer drive oscillation and worn couplings, a case study

The clack-clack-clack noise warned of heavy oscillation in the drive, subjecting the machine to potentially damaging duress. The only known cure was a shutdown and restart, costing the mill productivity and dollars. The shift supervisor calls in a drive technician for assistance...

Winders require a consistent preventive maintenance program (PMP)

Sheet breaks at the winder can bring the entire papermaking process to a stop. To prevent this, the winder needs constant attention through a sound preventive maintenance program (PMP).

Apron lip mapping and repair avoid production quality problems

Apron lip damage usually comes in the form of nicks, scratches or dents. These minor abrasions can trap fibers from the pulp or cause distortions in the flow of the headbox jet, which jeopardizes sheet formation. Preparation before apron repairs can improve maintenance safety and save money.

Problematic retention aid system leads to press wreck, case study

Papermaking is as much a chemical process as it is a mechanical one. A fine paper machine lost retention aid flow when the pump shut down. The resulting imbalance caused a press wreck when the pump was restarted. Multiple lessons were learned.

Reel process audits can reduce broke and defects near the spool

Reel equipment can take a beating during normal operation. Periodic inspections of the reel equipment are recommended to develop a baseline with regard to its process variables and mechanical condition.

Size press roll wear causes reel wrinkles and culls, a case study

A P&W paper machine suffered from excess wear on the back edge of the bottom size press roll. The problem was traced to the size press synchronization shaft. When the shaft was replaced, the roll wear problem went away.