Improving paper machine efficiency with iRoll
Parent roll defects due to CD profile errors often result in lower line efficiency and higher costs per ton. Likewise, web breaks or complaints from printing houses, due to uneven tension profiles, increase costs and lose production. iRoll creates new options to improve web runnability and thus reduce production costs. It also provides mills with excellent end products. There are four iRoll applications available: reel drum, tension measuring roll, winding drum and the Portable iRoll service.
iRoll for reeling and winding
iRoll measures roll profiles automatically, online, directly at the winder or reel nip. The nip profile correlates directly with the diameter and hardness profile of the paper roll, clearly showing the peaks and valleys. When thousands of paper layers are reeled on top of each other, the thickness variations are accumulated and make relatively large variations in the parent roll diameter and hardness profile.
Using iRoll with actuators such as calender zone controls, basis weight or coat weight profilers allows closed loop control of roll profiles. This enables an immediate response to profile-related quality variations and runnability problems, and reduces recovery time after grade changes.
When used as a condition monitoring tool for reeling nip mechanics and controls, iRoll detects wear and enables correctly-timed corrective maintenance actions.
iRoll for measuring and controlling web tension profiles
iRoll monitors the full-width tension profile continuously, online, and without any separate scanning devices. This helps detect uneven tension profiles at an early stage, long before they would be revealed at the printing press. The iRoll tension measuring roll also allows closed loop control. There are multiple concepts for controlling tension profiles and improving runnability. The actuators include press section steamboxes, drying section moisturizers or calender profiling.
Portable iRoll for process analyses and maintenance services
The Portable iRoll service allows paper and board makers to analyze profiles online, and to do it quickly and cost efficiently without investments.
Portable iRoll for detecting reeling problems online
The portable iRoll service also measures reeling nip load profiles online. It immediately shows reeling defects and variations in parent roll quality derived from the paper thickness profile, for example. iRoll detects force peaks, discontinuities and skewed nip profiles during parent roll build-up. With this information paper makers can
- fine-tune reeling parameters and troubleshoot profile-related reeling problems that originate in earlier process stages
- make bump tests to find responses with calender zone controls, dry weight, etc., and to optimize paper web properties
- detect wear in reeling nip mechanics and controls
For nip load measuring purposes, the portable iRoll can be located on the reel, rereeler, calender wind-up, winder, or wherever precise information on the wind-up process is needed.
Portable iRoll for detecting tension profile problems online
Runnability problems such as slack edges, wrinkles and web shifting are typically caused by uneven tension profiles. Portable iRoll makes full-width, online tension profile measurements before the sizer, reel, calender, coating station or winder, and makes it possible to response test different actuators with bump tests and optimize paper web properties. Tension profiles can be affected by dryer section moisturizers, infra dryers, steam boxes or calenders.
