Breaks, wet end

1. Breaks may be due to one or more of the following:
— low wet web strength.
— low solids off couch.
— debris or slivers in stock.
— lumps.
— slime.
— water drops
— stock quality varying.
— stress/strain variations in web.
— wet-end chemistry varying.
— temperature or pressure variations.
— defective squirts.
— deckle problems.
— uneven basis weight profile; both MD or CD.
— poor felt conditioning.
— headbox control problems.
— condition of forming fabric.
2. Sheet take-off is varying at couch.
— check speed and motor load.
— check MD basis weight profile.
3. Breaks related to the solids content off the couch are influenced by:
— low freeness stock.
— low stock temperature.
— low couch vacuum.
— press felts too wet.
— varying stock ratios.
— consistency of thick stock varying.
— low wet web strength.
— first-pass retention varying.
— broke return not defibered completely.
4. Basis weight varying due to:
— variations in total head.
— varying stock temperature.
— basis weight control not functioning properly.
— problems with thick and/or thin stock systems.