Paper360 - March/April 2015 - (Page 36)

millwise | JUMBO ROLLS iroll helps Irving Paper Boost Jumbo set Throughput More even tension profiles cut winder wrinkling, reduce breaks and cull. Jumbo roll set count raised from two to four. MARK WILLIAMSON Irving Paper in Saint John, New Brunswick, has conclusively improved wound roll throughput and hardness uniformity on its PM1 line that produces mainly SCA+ grades with basis weights from 42 to 67 g/m2. Using a new polyurethane-covered Valmet reel drum and integral iRoll nip load and reel hardness profile measurement and controls, the mill now produces considerably larger jumbo reels with good profiles, even sheet tension and improved winder productivity. Mark Chatterton, paper mill operations manager, summarizes the successful project, "We are making more good-quality wound rolls and winder efficiency has been increased. The iRoll has been a success story, a real plus for us." GOOD STRUCTURE IS CHALLENGING Many SCA producers would agree that it's challenging to make a well-structured jumbo reel with good hardness profiles once a certain reel size threshold is reached. That is because the effects of air entrapment become significant after so many wraps on a parent reel. SCA+ sheets, which are dense and have very low porosity, do not effectively allow the air entrapped between the winding layers to escape evenly, and that has a cumulative effect on sheet tension, causing wrinkling and winder breaks. Valmet's Dr. Heikki Kettunen explains the practical papermaking reasoning: "Profile errors affect the accumulation of air under the topmost layer of paper. In many cases, one can run with a stable air bubble before the nip. However, if the top layers of paper are not stabilized, an air bubble hitting against the tight part of the roll easily creates foldovers and wrinkles." With those wrinkling effects, winder production often falls behind, and the familiar sight of full reel spools in the aisles signals low productivity. The solution is often unwanted but necessary: that is, to limit the number of sets in the jumbo-which then increases the losses from bottom and surface broke. PM1 is equipped with a Valmet OptiReel Plus with iRoll. 36 Paper360ยบ MARCH/APRIL 2015

Table of Contents for the Digital Edition of Paper360 - March/April 2015

Guest Editorial
Over the Wire
TAPPI's Centennial: A Celebration 100 Years in the Making
Precision Alignment of Winders
Single-stream Waste Processing
iRoll at Irving
Fully Automated Continuous Digester
Twin Roll Press Upgrade
TAPPI Journal Summaries
Effluent Treatment
Microfibrils to Transform Paper Furnish
Consolidation Watch
Knowledge Builder
New Energy Windfall
Power from Waste
Safety Survey
Association News
Online Exclusives
Advertisers Index

Paper360 - March/April 2015