1
PSE322 Questions and Correct Answers
Question: What type of costs related to the manufacture of paper does
not change when the amount of product being made per unit time in a
paper mill changes?
Answer: Fixed Costs
Question: Which of the following is NOT classified as an extractive
component of wood?
Phenolpropane
a.Phenolpropane
b.Rosin
c.Triglyceride fat
d.Pinene
Answer: Phenolpropane
Question: What is the name of the hollow space in the middle of a
hardwood fiber or in a softwood tracheid?
Answer: Lumen
Question: Before bleaching, kraft-pulped fibers have what color?
Answer: Brown
Question: Which of the following is true regarding the S2 sublayer
within wood fibers often used for paper pulp?
a.Microfibril angle at right angles to the fiber axis
b.The most important layer, by mass
c.Highest concentration of lignin
d.Adjacent to the middle lamella
Answer: b.The most important layer, by mass
Pretest - Stuvia US
,2
Question: What often becomes ribbon-like in the course of pulping,
refining, and formation into paper?
a.Parenchyma cells
b.Precipitated hemicellulose
c.Cellulosic fines
d.Fibers
Answer: d.Fibers
Question: Which two unit operations in the paper machine system
typically involve the highest level of hydrodynamic shear stress?
a.Flow distributor and rectifier rolls
b.Fan pulp and pressure screen
c.Headbox slice and hydrofoils
d.Dynamic drainage jar and sheet mold
Answer: b.Fan pulp and pressure screen
Question: Accepts from which bank of hydrocyclones goes forward to
the next unit operation (pressure screen)?
Answer: Primary
Question: What helps to prevent formation of a fiber mat within the
pressure screen system?
a.Bubbles of air
b.Action of the rotor
c.Wiper blades
d.Mechanical vibrations
Answer: b.Action of the rotor
Pretest - Stuvia US
,3
Question: What usually provides the vacuum for a typical low-vacuum
box on a Fourdrinier paper machine?
a.A vacuum pump
b.The weight of water flowing down a tube to a seal tank
c.Evaporation induced by convective currents of air
d.A fan that accelerates air and water from the box
Answer: b.The weight of water flowing down a tube to a seal tank
Question: What happens to the capillary vacuum effect (negative
pressure) within the meniscus at a crossing between adjacent fibers in
paper during the evaporative drying process?
a. The negative pressure is reduced in the course of drying because of
steadily increasing temperature.
b. The capillary forces remain constant, since they depend only on the
nature of the fluid and the air, as long as the contact angle with the fiber
surface is zero.
c. The attractive force due to the meniscus becomes stronger as the
distance between the fibers decreases because of evaporation.
d. The capillary forces become repulsive, allowing the paper to expand
and achieve the bulk that is desired in such grades as paper towels.
Answer: c. The attractive force due to the meniscus becomes stronger as
the distance between the fibers decreases because of evaporation.
Question: Where does the main suction take place as the forming fabric
passes over a hydrofoil?
a. At the leading edge due to a doctoring effect, in which water is being
removed from the bottom side of the forming fabric on a Fourdrinier
paper machine
b. On the trailing 2/3 of the surface, where the forming fabric may have
to change its path slightly, with the help of vacuum, to maintain contact
with the foil surface
Pretest - Stuvia US
, 4
c. On the leading edge, where the foil is pressing most strongly against
the hydrofoil surface, leading to a maximization of the venturi effect
d. At the trailing edge, where there is an abrupt break-off of the suction
action, often leading to "stock jump", which is especially apparent under
stroboscopic illumination
Answer: b. On the trailing 2/3 of the surface, where the forming fabric
may have to change its path slightly, with the help of vacuum, to
maintain contact with the foil surface
Question: What location associated with a steam-heated dryer can
typically has the highest temperature?
a. Within condensate at the inner surface of the can
b. Within the steel shell itself, due to its heat capacity
c. In the paper, due to its contact with multiple dryer cans
d. On the outer surface, due to the flow of heat outwards
Answer: b. Within the steel shell itself, due to its heat capacity
Question: What is usually used at the wet end to cut the edge of the
wet web to achieve the desired width of paper at the reel of the paper
machine?
a. Laser cutters
b. Slitter knives
c. Trim squirts
d. Doctor blades
Answer: c. Trim squirts
Question: Which is an accurate description of hydrogen bonds within
liquid water?
a. Connecting and disconnecting in femtoseconds
b. Stronger than covalent bonds
c. Same as ice, but with occasional defects
Pretest - Stuvia US
PSE322 Questions and Correct Answers
Question: What type of costs related to the manufacture of paper does
not change when the amount of product being made per unit time in a
paper mill changes?
Answer: Fixed Costs
Question: Which of the following is NOT classified as an extractive
component of wood?
Phenolpropane
a.Phenolpropane
b.Rosin
c.Triglyceride fat
d.Pinene
Answer: Phenolpropane
Question: What is the name of the hollow space in the middle of a
hardwood fiber or in a softwood tracheid?
Answer: Lumen
Question: Before bleaching, kraft-pulped fibers have what color?
Answer: Brown
Question: Which of the following is true regarding the S2 sublayer
within wood fibers often used for paper pulp?
a.Microfibril angle at right angles to the fiber axis
b.The most important layer, by mass
c.Highest concentration of lignin
d.Adjacent to the middle lamella
Answer: b.The most important layer, by mass
Pretest - Stuvia US
,2
Question: What often becomes ribbon-like in the course of pulping,
refining, and formation into paper?
a.Parenchyma cells
b.Precipitated hemicellulose
c.Cellulosic fines
d.Fibers
Answer: d.Fibers
Question: Which two unit operations in the paper machine system
typically involve the highest level of hydrodynamic shear stress?
a.Flow distributor and rectifier rolls
b.Fan pulp and pressure screen
c.Headbox slice and hydrofoils
d.Dynamic drainage jar and sheet mold
Answer: b.Fan pulp and pressure screen
Question: Accepts from which bank of hydrocyclones goes forward to
the next unit operation (pressure screen)?
Answer: Primary
Question: What helps to prevent formation of a fiber mat within the
pressure screen system?
a.Bubbles of air
b.Action of the rotor
c.Wiper blades
d.Mechanical vibrations
Answer: b.Action of the rotor
Pretest - Stuvia US
,3
Question: What usually provides the vacuum for a typical low-vacuum
box on a Fourdrinier paper machine?
a.A vacuum pump
b.The weight of water flowing down a tube to a seal tank
c.Evaporation induced by convective currents of air
d.A fan that accelerates air and water from the box
Answer: b.The weight of water flowing down a tube to a seal tank
Question: What happens to the capillary vacuum effect (negative
pressure) within the meniscus at a crossing between adjacent fibers in
paper during the evaporative drying process?
a. The negative pressure is reduced in the course of drying because of
steadily increasing temperature.
b. The capillary forces remain constant, since they depend only on the
nature of the fluid and the air, as long as the contact angle with the fiber
surface is zero.
c. The attractive force due to the meniscus becomes stronger as the
distance between the fibers decreases because of evaporation.
d. The capillary forces become repulsive, allowing the paper to expand
and achieve the bulk that is desired in such grades as paper towels.
Answer: c. The attractive force due to the meniscus becomes stronger as
the distance between the fibers decreases because of evaporation.
Question: Where does the main suction take place as the forming fabric
passes over a hydrofoil?
a. At the leading edge due to a doctoring effect, in which water is being
removed from the bottom side of the forming fabric on a Fourdrinier
paper machine
b. On the trailing 2/3 of the surface, where the forming fabric may have
to change its path slightly, with the help of vacuum, to maintain contact
with the foil surface
Pretest - Stuvia US
, 4
c. On the leading edge, where the foil is pressing most strongly against
the hydrofoil surface, leading to a maximization of the venturi effect
d. At the trailing edge, where there is an abrupt break-off of the suction
action, often leading to "stock jump", which is especially apparent under
stroboscopic illumination
Answer: b. On the trailing 2/3 of the surface, where the forming fabric
may have to change its path slightly, with the help of vacuum, to
maintain contact with the foil surface
Question: What location associated with a steam-heated dryer can
typically has the highest temperature?
a. Within condensate at the inner surface of the can
b. Within the steel shell itself, due to its heat capacity
c. In the paper, due to its contact with multiple dryer cans
d. On the outer surface, due to the flow of heat outwards
Answer: b. Within the steel shell itself, due to its heat capacity
Question: What is usually used at the wet end to cut the edge of the
wet web to achieve the desired width of paper at the reel of the paper
machine?
a. Laser cutters
b. Slitter knives
c. Trim squirts
d. Doctor blades
Answer: c. Trim squirts
Question: Which is an accurate description of hydrogen bonds within
liquid water?
a. Connecting and disconnecting in femtoseconds
b. Stronger than covalent bonds
c. Same as ice, but with occasional defects
Pretest - Stuvia US
