Fines are pieces of fiber wall, ray cells and fibrils, usually defined as material passing a 200-mesh screen of about 75 micrometers. Mechanical pulp fines scatter light strongly and drive opacity, while chemical pulp fines from refining tend to bond and reduce scattering. Their retention on the wire also governs two-sidedness, because drainage pulls fines away from the wire side.
First-pass retention dropped and we lost fines, so opacity on the wire side is down.
Also heard as
- fine material
- fines fraction
Related terms
Light-scattering coefficient
Per-grammage measure of how strongly a paper redirects light, written s and given in square meters per kilogram.
Two-sidedness
Difference in properties between the two faces of a paper sheet, such as color, brightness, gloss or texture.
Wire side
Face of the sheet that lay against the forming wire while the sheet was formed.
Furnish
The recipe of pulps, fillers, dyes and chemicals that make up a paper grade's stock.
Same word, different worlds
Powder particles smaller than the specified size range, which cause buildup, spitting and poor flow.
Powder CoatingThe smallest particles in a powder, roughly under 10 microns, which fluidize, charge and recycle poorly.
Refractories & Furnace LiningsSmallest particle fraction of a refractory mix, which fills the gaps between coarse grains and forms the bond.
Asphalt PavingThe dust-sized part of the aggregate passing the No. 200 sieve, which stiffens the binder into a mastic.