A paper coating defect caused by excessively high solid content or high
viscosity of coating solution or poor adjustment of doctor.
Alum Spot
Paper sheet having small undissolved alum crystals.
Backing Roll Mark
A paper coating defect caused by the building up of coating in areas along
the machine direction where low spots occur in the coating back-up roll.
Blackened Paper
A defect in paper caused by crushing in the calender such that fibers
are pressed so closely that number of light reflecting surfaces decreases so
much that paper becomes transparent.
Blade Cut
A blade scratch that cuts deeply into or through the web.
Blade Scratch
A very fine, hair like indentation in a coated surface that runs in the
machine direction, caused by a particle of varied origin becoming lodged
behind the blade during coating.
Blistering (Coated Paper)
Caused when water vapours can not escape fast enough through coating layers
in the coating dryer section of the heat-set press.
Burst
The defect in paper characterized by rapture in the web not extended to
edges. It is caused by too high web tension between a hard and soft section of
the reel during winding and results in a machine direction shearing force that
exceeds the strength of paper.
Calender Cut
A mark or cut occurring in the paper sheet as a result of wrinkles in the
web while being calendered.
Calender Mark
Paper defects caused by faulty calender roll surfaces or extraneous matter
which has entered the nips and stick to its surface.
Cloudy Paper
Paper with unevenness in look-through.
Cockling
When the surface of the paper has wave like appearance.
Contraries
Presence of any foreign substance such as sand, dirt etc.
Crack
1. A defect in coated paper, caused by the separation of
the coating layer on the formation of fissures in the
surface of the coating due to printing or other
converting process.
2. Crack at fold: Fissures in the crease when any paper
is folded along a fold line. May be due to separation of
coating or separation of fibers. More prevalent when the
paper has been over-dried. In boards it may occur along
score-folds even though the scoring has been done to
minimize cracking at the fold. The term is also applied
when coatings crack without fiber failure during a
folding operation.
Cracked Edge
A paper web and fourdrinier wire defect occurring as small breaks on the
edges, with very little migration towards the center.
Crazing
Defects in paper coating, appearing as short, random, intersecting cracks
in the coating surface.
Crease
1. Deformation remaining from a fold over.
2. Cross direction wrinkles( Washboard): Fold over of a
web in the cross machine direction, giving a crease
running in the machine direction.
3. Blade crease: A crease essentially in the machine
direction devoid of coating in the creased area.
4. Calender Crease: Usually a sharp crease caused by
passage through the Calender of a crease or of a fold
generated at the Calender; often cut through when it is
preferable to call it a Calender out.
5. Smoothed crease: A flattened-out crease running mainly
in the machine direction. Can occur at the wet press
section, dryer (dryer wrinkles), size press, winder or
sheeter.
Crush
A rippled paper surface defect that is caused by the use of too high
pressure and/ or too high moisture in the press section.
Damp Streaks
Streaks caused by uneven pressing or drying during paper
manufacturing.
Dead Spots
Paper sheet having any dull areas in an otherwise highly glossy surface.
Drag Spots
Irregular streaks or long thin lumpy areas on the paper's surface.
Edge Cut
Edge tears fold over during the winding operation. It may be caused by dull
slitter that nicks the edge after which the stress of winding will cause the
tear to open or the reel is bumped on the edge.
Fish Eye
A paper defect appearing as glazed, translucent spot caused by slime, fiber bundles, and/or improperly prepared chemical additives in the stock.
Fuzz
Fibrous projections on the surface of a sheet of paper,
caused by excessive suction, insufficient beating or lack
of surface sizing. Lint appears in much the same manner
but is not attached to the surface.
Lint
Lint originates from loosely bonded surface fibers. This is also called fuzz
or fluff also. Lint can cause fiber build up in the printed image areas when the
lint mixes with ink.
Missing Coating (Coated Paper)
Coating is missing at spots or in machine direction due to some problem at
coater.
Paper Dust
Cut or Broken fibers, fines, fillers depositing on paper during cutting or
slitting.
Pin Holes
Imperfections in paper which appear as minute holes upon looking through the sheet. They originate from foreign particles, which are pressed through the sheet.
Piping
Defect in reels, consisting of ridges running around the circumference, due to moisture take-up by the surface layers or uneven binding or hard and soft spots.
Poor Joint
1. The joint tape is not properly placed and therefore sticks to the paper
underneath.
2. The two webs are not put in line with each other and therefore
paper protrude at the end of the reel.
3. The joint tape is not covered by the paper or the backing. The tape
stick to other paper layer and may cause a break.
Poor Slitter Cut
Caused by dull or chipped off slitter. The cut appear irregular or rough.
It gives the reel end a wavy or shaggy appearance.
Roping
Paper defect appearing as a machine direction wrinkle in the sheet.
Longitudinal wrinkles in a coated paper.
Shiners
Transparent spots in a sheet of paper caused by squeezing partly cooked
fiber bundles and splinters during calendering.
Slime Holes
A hole in paper, characterized by brownish translucent material around the edges. Caused by a lump of slime which has formed in stock system from the growth
microorganisms, then becoming detached and flowing onto the paper machine wire with the fiber to form a non-fibrous area.
Slivers
Small splinters of wood in a sheet of paper.
Snailing
Streaks or snake like marks on the surface of a sheet.
Spongy Papers
Paper that is too compressible or ink absorbent for its intended purpose.
Table Rolls Mark
Basis weight variations of web caused by waves on the wire created by table
rolls.
Tacky Speckles
Types of contaminants found in de-inked pulp caused by plastic adhesive
-like particles originating from heat seal coating, backing adhesive etc.
Trash in Roll
Any foreign material such as loose piece of paper, dust, dirt etc. caught
up or blown in to a roll of paper during manufacturing or rewinding.
Trim in Roll
A paper roll defect caused by the rewinder slitter trim shaving
inadvertently being wound up in the roll.
Uneven Caliper or Thickness (Not due to basis weight variation)
Variation in thickness on spot or in cross direction. May be caused by
defective or improper crowning of press/calender rolls.
Uneven Winding
A random edge formed at the end of a paper roll during rewinding caused by
the lateral movement of the sheet and/or core.
Wild Formation
Paper sheet with uneven, random distribution of fibers, yielding a mottled
appearance on look-through.
