Gas Content

Entrained and dissolved gas can influence stock flow stability, sheet formation, and retention of fines and chemicals within the approach flow system and headbox. When gas levels become excessive or unstable, the resulting hydraulic disturbances may contribute to poor formation, basis weight variation, and inconsistent performance on other important quality metrics.

Gas can produce bubbles in the forming zone, causing thin areas, pinholes, and weak spots. Lighter basis weight grades are particularly sensitive to these effects because there is little opportunity to mask sheet non-uniformities. Holes and weak spots originating at the headbox may lead to downstream problems such as sheet breaks on the machine or in converting lines, higher reject rates in quality control, or even customer complaints.

Gas can affect the distribution and retention of fines, short fibers, and wet-end additives. Because these components play an important role in sheet strength, surface properties, and print performance, changes in their retention may contribute to variability in sheet quality と overuse of chemical additives.