Back to the product list

Web Stabilizers and Pocket Ventilation

RunPro Solution

Web stabilizers, pocket ventilation and machine geometry modifications eliminate runnability problems efficiently and are often required to ensure fluent paper making process in the press and dryer sections. These maintenance free solutions have a huge impact on drying and energy costs. 

 

Especially in high-speed paper machines, the first single-felted groups are very sensitive to run. Still very wet, the web stretches and breaks easily. Moving surfaces, like cylinders, rolls and drying fabrics, cause air flows and pressure differences, especially in the nips, reducing dryer section runnability. This can lead to sheet fluttering, breaks, complicated tail threading and paper quality problems, such as edge flipping or wrinkles. Without high-vacuum support, the wet web tends to follow the upper cylinder, resulting in breaks and paper defects.

Traditional runnability control with increased draw not only reduces sheet strength and quality but easily causes breaks in the dryer section, finishing processes and later in printing presses, too. A high draw difference means additional raw material costs, as more chemical pulp is required to improve sheet strength.

Reducing the draw provides the potential to increase machine speed and optimize furnish. The RunPro EasyOne web stabilizer optimizes the web release with a special high-vacuum system during the critical sheet release between the upper cylinder and the vacuum roll. It prevents the web from following the upper cylinder, resulting in fewer breaks and defects.

When designing RunPro EasyOne, traditional air nozzles and mechanical seals across the machine have been replaced by pivoting high-release, non-contact nozzles. In critical opening nips, the nozzles bend and do not break the fabric if a paper jam occurs. Air is blown with high speed through the high-release nozzles against the fabric’s running direction. Thanks to the combination of the geometry, the construction of the stabilizer and the dynamic forces created by the air flows, a negative pressure is created in the opening nip towards the release point. This negative pressure ensures that the web sticks to the felt and not to the cylinder surface. The special and patented design is very robust. Possible paper jams and wear part consumption are significantly reduced.

Press Section

Single Felted Section

Double Felted Section

Related Solutions