The water stored in the void volume of a press felt affects the sheet quality and the machine runnability in several ways:
an uneven felt moisture profile means an uneven sheet moisture profile
poor sheet dryness due to insufficient hydraulic pressure in the nip
sheet crushing or torn felts due to excessive hydraulic pressure
trim lifting, sheet stealing and edge drop-offs are often due to local moisture variations
press bouncing and other vibrations, for example barring
fines and fillers being flushed out of the sheet
Feltest products to measure press felt moisture profiles:
Feltest PresScan – the alternative, no-nonsense felt moisture meter.
Feltest Aequo – still under development, but this revolutionary new felt moisture profile meter will be introduced in a few months. Leave your email here if you want to be informed!