More crepe wrinkles in reels occur today due to larger diameter reels,
more calendering for a smoother finish, fillers causing increased pap
er density, and recycled furnish giving a lower coefficient of frictio
n. Reel density analysis and J-line testing determine the quality of t
he parent reel and identify the location of small crepe wrinkles in th
e paper. The Reel Density Monitor displays the density profile of the
critical primary to secondary arm transfer and often shows a consisten
t density decrease at the point of primary arm release. This paper com
pares the wound-in density profile with the nip load between the reel
and the reel drum and shows the effect of the nip load on the density
profile. Examples from two paper machines describe how this can diagno
se reel building problems and optimize the parameters that control ree
l building.