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Paper machine wet end1.1.Machine directionWith the help of TAPIO measurements MD basis weight variations caused by wires, other dewatering elements like foils, screens, fan pump, consistency control, headbox pressure variations, pressure pulses etc. can be detected, and the cause of the variations can be found out. With the help of PROMA and TAPIO BW control tuning is easy to audit. 1.2.Cross direction In CD the wire itself, basis weight CD control, high-pressure showers, headbox recirculation flow, manifold tubing and other reasons can cause CD variations. CD variations can be either periodical or thin/heavy edges or other nonperiodic variations. With the help of TAPIO profile measurements the variations and their causes can be detected. The on line quality control systems can not measure the first few centimeters of the paper web, but the edges do often cause breaks anyhow. 1.3.Actions When the causes of the variations are found, the actions can be taken to correct the faults. In the case of the wet end typical actions are wire comparisons, control (CD/MD) tuning, shower oscillating mechanism improvement or repair, return flow valve adjustment, foil angle adjustment etc. Due to the fact that all major machine builders and most major paper companies have the TAPIO PMA TAPIO measurements has become a de facto standard measurement in industry. Now this situation is in the process to get the final confirmation since TAPPI is currently working on to make TAPIO style basis weight measurements as an official TAPPI standard. 
Customer had problems with sheet edges. They had an average 5 breaks per day each lasting 20 minutes. By using the TAPIO PMA tehy found the source of the problem. The reason for these breaks was then corrected, resulting in increased production. The incremental revenue was estimated at $15,000 US per day, over $5 million per year.
*Case by Mr. Jari Mäkinen UPM-Kymmene, Jämsänkoski Mill.1.4.Benefits When the basis weight variations are minimized there will be fewer breaks. The production will be increased. More production - more invoicing! When the product is more even the basis weight and moisture can be kept closer the tolerance limits, and material savings can be achieved. Even very small percentual savings mean high cumulative savings and fast payback for the TAPIO Analyzer. Press part2.1.Machine directionPress section water removal variations caused by press felts or out of balance or corrugated press rolls can be detected by measuring the optical properties of paper by TAPIO Analyzer. With TAPIO Analyzing software each roll and felt causing variation can be easily identified. 2.2.Cross direction Various problems can be analyzed such as incorrect crown of the roll for the pressure/felt combination used, doctor blade may be leaking, felt cleaning is not functioning correctly (wet streaks) or the felt itself is not even in CD. These and other the faults and causes can be found out by the help of TAPIO profile measurements and analysis. Also zone-controlled rolls plugged felts and suction rolls causing hole marking can be readily detected. 2.3.Actions Roll grinding, felt selection, felt cleaning equipment service, doctor blade changes etc. are the usual actions. Also optimization of the CD-controls (zone-controlled rolls or other) is often valuable. 2.4.Benefits More even quality, better printability, higher dry matter content out of the press section, less breaks are the usual benefits. Higher dry matter content makes energy savings possible. If the press section is the production bottleneck then major savings by increased production can be achieved. Paper machine wet end & Press part >> Size press & Coating head >> Calenders & Paper Formation >> Quality control & On-Line vs. TAPIO measurements |
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