Crews call formation wild when the look-through shows large, irregular clumps instead of a fine, even texture. Typical causes are high headbox consistency, a spike in long fiber, a poor jet-to-wire speed ratio or disturbed flow in the headbox. Wild formation brings uneven opacity, print mottle and weak spots, and grades with heavy print coverage reject it quickly.
Wild formation on the drive side again, check the slice profile before the printer sees mottle.
Also heard as
- cloudy formation
- flocky formation
- wild sheet
Related terms
Formation
How evenly fibers are spread through a paper sheet, judged by small-scale variation in mass.
Floc
Clump of entangled fibers in stock or in the finished sheet, the building block of poor formation.
Look-through
Visual check of formation made by holding a sheet up to a light and judging how even or cloudy it looks.
Mottle
Uneven, blotchy appearance in a print or coating, seen as cloudy patches of density or gloss.