Paper360 - March/April 2015 - (Page 28)

millwise | SPECIAL FEATURE WINDER ALIGNMENT Precision Alignment of Winders Winder speeds must increase to keep pace with higher operating speeds of paper machines. At high speeds, any misalignment of the winder can have a detrimental effect on operation and production rates. MYRON SMITH and ROGER CROSS The alignment of winders within stringent tolerances is necessary to achieve optimum operating speeds while minimizing roll defects and web breaks. Precision two dimensional optical and three dimensional metrology tooling and alignment techniques are both very capable of achieving the tolerances required for faster, more efficient winder operations. Optical tooling and the techniques specific to it, has a long proven track record of providing positive results with respect to inspections and realignment efforts on winders. However, newer three dimensional metrology tooling, such as laser trackers and the techniques specific to it, will provide identical results with the added capabilities of providing three dimensional documentation of the actual, to scale, Figure 1. Baggy edges. Source: OASIS Alignment Services, Inc. 28 Paper360º MARCH/APRIL 2015 geometry of the rider roll/core chuck relationship to the winder drums. Likewise, it can detail the actual, to scale, geometry of the sectional rolls to the slitter section components. Using either of these types of equipment, specialized inspection techniques can provide considerable speed increases while significantly reducing waste and roll winding defects. MISALIGNMENT AND qUALITY The following examples illustrate how misalignment can adversely affect product quality and contribute to roll defects: * Misaligned winder components often produce the baggy edges shown in Figure 1, wrinkles, web tracking problems and frequent web breaks. * Dishing, shown in Figure 2, can occur when rider roll, winder drum, or core chuck misalignment causes the product to move incrementally in the axial direction. This continuous movement creates dish-shaped ends on the roll. * Interweaving, shown in Figure 3, is the result of misalignment in the rolls following the slitters. Here, two adjacent strips of the slit web overlap during winding so that the adjacent rolls intertwine. This often can't be separated and such rolls must be scrapped. * Offsets, shown in Figure 4, are "steps" in the edge of the roll formed by rider roll misalignment that produces non uniform nip loads. They can also be caused by tension variations in the web, causing the web to shift due to the guiding action of the misaligned rolls. Figure 2. Dishing. Source: OASIS Alignment Services, Inc.

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