GC 3460 FINAL STUDY GUIDE
Brightness - Answers :enhanced by bleaching fibers and adding fluorescing pigments to
the pulp
Opacity - Answers :amount of light that is transmitted through the paper. Layering of the
cellulose fibers determines how transparent paper will be.
Smoothness - Answers :evenness or lack of contour of paper surface. This depends on
the degree of fiber refining, extent of wet pressing, extent of calendaring, use of
coatings, and desired finish
Coating - Answers :paper finishing operation in which surface of paper is covered with a
substance to impart a desired finish or texture of particular coating to improve
printability. Affects ink absorption and ink holdout. Enhances whiteness, opacity, and
gloss of paper
Paper making proces - Answers :Step 1: Felling
Step 2: Debarking
Step 3: Chipping
Step 4: Pulping
Step 5: Mixing
Step 6: Forming the Web
Step 7: Pressing
Step 8: Drying
Step 1: Felling - Answers :Tree is cut down and delimbed and transported/ whole tree is
chipped on site
Step 2: Debarking - Answers :Bark is stripped w/o damaging wood
Step 3: Chipping - Answers :logs are chipped into pieces size of quarter
Step 4: Pulping - Answers :Reduces wood to loose fibers in water
Step 5: Mixing - Answers :Pulp goes into mixer where materials are added to improve
quality (Fillers, Sizing, Dyes)
Step 6: Forming the Web - Answers :Liquid pulp poured onto wire where fibers are
caught, and water is drained (or vacuumed) away.
- Headbox- pulp is fed through headbox through slice (99% water)
- Slice
- Single wire
- Twin wire
, Step 7: Pressing - Answers :Belts move web between press rolls, remove more water
and compresses paper
- Felts- Pressure used to squeeze water from web (65%)
Step 8: Drying - Answers :Damp web is moved through drier in between hot cylinders
and felt covered belts that absorb water
- Driers- Control moisture content. Moist paper have greater fiber-to-fiber bonds
- Surface Sizing- Treated with thin film to strengthen the surface
- Calendaring- web passes through calendar stacks. Increases smoothness, gloss.
Decreases caliper, opacity
- Coatings- Increases ink holdout, smoothness, gloss, brightness.
Coated - Answers :Colored ink pigment sits on top of sheet (ink holdout/ retained ink
gloss) lower strength (less fibers)
- Matte
- Dull
- Gloss
Uncoated - Answers :Can be smooth or textured, glare free for reading, stronger and
more opaque
- Calendared (smooth finish)
- Textured (linen, vellum, laid) - embossing
- Machine Finish (little to no calendaring or treatments)
Pigment - Answers :solid
Vehicle - Answers :(liquid component)
- Resins: (makes pigments stick to substrate) Resins are solids that must be dissolved
by a liquid solvent so it can flow through ink train
- Solvents: Resins are solids that must be dissolved by a liquid solvent without
attacking pigment. Must evaporate at acceptable rate (volatility). Must be compatible
with printing plate and provide flow and adhesion
- Additives:
1. Driers- Manganese (dries ink- through drier) and Cobalt (sets ink- top drier) speed up
oxidation process
2. Plasticizers- added to synthetic resin to produce/promote plasticity and flexibility and
reduce brittleness (impart gloss, adhesion, and protected against cold temps/brittleness)
3. Waxes- applied to polish/protect (pros: improve rub resistance, reduce COF, improve
resistance to water) (cons: excessive wax can crystalize making ink trap difficult,
reduces gloss, and increases drying time)
4. Anti-skinning agents
5. Wetting agents (liquid inks)
6. Stiffening agents (paste inks)
7. Tack reducers
Brightness - Answers :enhanced by bleaching fibers and adding fluorescing pigments to
the pulp
Opacity - Answers :amount of light that is transmitted through the paper. Layering of the
cellulose fibers determines how transparent paper will be.
Smoothness - Answers :evenness or lack of contour of paper surface. This depends on
the degree of fiber refining, extent of wet pressing, extent of calendaring, use of
coatings, and desired finish
Coating - Answers :paper finishing operation in which surface of paper is covered with a
substance to impart a desired finish or texture of particular coating to improve
printability. Affects ink absorption and ink holdout. Enhances whiteness, opacity, and
gloss of paper
Paper making proces - Answers :Step 1: Felling
Step 2: Debarking
Step 3: Chipping
Step 4: Pulping
Step 5: Mixing
Step 6: Forming the Web
Step 7: Pressing
Step 8: Drying
Step 1: Felling - Answers :Tree is cut down and delimbed and transported/ whole tree is
chipped on site
Step 2: Debarking - Answers :Bark is stripped w/o damaging wood
Step 3: Chipping - Answers :logs are chipped into pieces size of quarter
Step 4: Pulping - Answers :Reduces wood to loose fibers in water
Step 5: Mixing - Answers :Pulp goes into mixer where materials are added to improve
quality (Fillers, Sizing, Dyes)
Step 6: Forming the Web - Answers :Liquid pulp poured onto wire where fibers are
caught, and water is drained (or vacuumed) away.
- Headbox- pulp is fed through headbox through slice (99% water)
- Slice
- Single wire
- Twin wire
, Step 7: Pressing - Answers :Belts move web between press rolls, remove more water
and compresses paper
- Felts- Pressure used to squeeze water from web (65%)
Step 8: Drying - Answers :Damp web is moved through drier in between hot cylinders
and felt covered belts that absorb water
- Driers- Control moisture content. Moist paper have greater fiber-to-fiber bonds
- Surface Sizing- Treated with thin film to strengthen the surface
- Calendaring- web passes through calendar stacks. Increases smoothness, gloss.
Decreases caliper, opacity
- Coatings- Increases ink holdout, smoothness, gloss, brightness.
Coated - Answers :Colored ink pigment sits on top of sheet (ink holdout/ retained ink
gloss) lower strength (less fibers)
- Matte
- Dull
- Gloss
Uncoated - Answers :Can be smooth or textured, glare free for reading, stronger and
more opaque
- Calendared (smooth finish)
- Textured (linen, vellum, laid) - embossing
- Machine Finish (little to no calendaring or treatments)
Pigment - Answers :solid
Vehicle - Answers :(liquid component)
- Resins: (makes pigments stick to substrate) Resins are solids that must be dissolved
by a liquid solvent so it can flow through ink train
- Solvents: Resins are solids that must be dissolved by a liquid solvent without
attacking pigment. Must evaporate at acceptable rate (volatility). Must be compatible
with printing plate and provide flow and adhesion
- Additives:
1. Driers- Manganese (dries ink- through drier) and Cobalt (sets ink- top drier) speed up
oxidation process
2. Plasticizers- added to synthetic resin to produce/promote plasticity and flexibility and
reduce brittleness (impart gloss, adhesion, and protected against cold temps/brittleness)
3. Waxes- applied to polish/protect (pros: improve rub resistance, reduce COF, improve
resistance to water) (cons: excessive wax can crystalize making ink trap difficult,
reduces gloss, and increases drying time)
4. Anti-skinning agents
5. Wetting agents (liquid inks)
6. Stiffening agents (paste inks)
7. Tack reducers
