PSE 322 ACTUAL EXAM QUESTIONS WITH SOLUTIONS
2025 GRADED A+
✔✔What type of consistency sensing equipment has no moving parts? - ✔✔Microwave
✔✔What type of printing employs plastic binder that is heated to its melting point during
printing? - ✔✔Xerography
✔✔Which of the following types of pulp is susceptible to alkaline darkening if exposed to
high pH? - ✔✔High yield pulp (e.g. ONP)
✔✔In a DAF unit, why does the dissolved air become transformed into small bubbles
when it enters a flotation unit? - ✔✔Decreased pressure
✔✔The washing unit operation is especially effective for removal of what kind of printing
ink? - ✔✔Flexo
✔✔What is a "collector chemical" used for? - ✔✔Flotation deinking
✔✔What makes kraft fibers more variable in properties, less porous in the mesopore
range (2 to 50 nm), and more in need of dry-strength agent usage? - ✔✔Recycling of
the fibers
✔✔Kraft fibers tend to become stiffened each time that they are dried in the
manufacture of paper. How does this affect their ability to form inter-fiber bonds? -
✔✔Recycled kraft fibers generally have lower inter-fiber bonding ability.
✔✔What does a rotating consistency transmitter sense in order to be able to estimate
the consistency of a pulp suspension? - ✔✔Torque required to turn rotating blades
✔✔What process control issue can be solved by increased deinking efforts, increased
bleaching, and adding more fluorescent whitener? - ✔✔Low brightness of paper
✔✔Which of the following process control problems is usually easiest to solve? -
✔✔Data outside of control limits but very steady
✔✔Why is peroxide bleach often added when pulping old newspaper pulp? - ✔✔It
contains lignin that can be bleached.
✔✔What type of printing employs hydrophobic oily ink? - ✔✔Offset lithography
✔✔What kinds of ink can be effectively separated from water using dissolved air
flotation? - ✔✔Offset lithographic
,✔✔What part of the process usually is regarded as the first opportunity to add deinking
chemicals, e.g. surfactants and NaOH, during a deinking operation at a paper mill? -
✔✔At pulper
✔✔What is it called when a deinking additive helps flakes of xerographic toner to form
particles large enough to be filtered effectively with a screen? - ✔✔Agglomerative
deinking
✔✔In which of the following ways does the addition of NaOH affect typical papermaking
fibers? - ✔✔It swells them.
✔✔The high conformability of refined, wet kraft pulp fibers can be attributed to what? -
✔✔Delamination within fiber cell walls
✔✔Which of the following is the result of a titration with highly charged polymer, where
the endpoint corresponds to approximately zero zeta potential? - ✔✔Charge demand
✔✔Why do papermakers usually want to refine pulp to a constant freeness? -
✔✔Freeness is correlated with paper strength development.
✔✔Which of the following is the average electrical potential at a hydrodynamic slip
plane adjacent to a surface? - ✔✔Zeta potential
✔✔What unit operation is effective for contaminant removal only if the particles are
large enough and also different in density from the water? - ✔✔Hydrocyclone
✔✔Why are industrial screening operations often ineffective for the separation of
stickies? - ✔✔The stickies get extruded through the slots.
✔✔What type of binder is used in flexographic printing? - ✔✔Water-dispersible
✔✔The contaminants having the largest particle size can be best removed from
recovered paper stock by means of what operation? - ✔✔Screening
✔✔What tends to catalyze the decomposition of hydrogen peroxide in papermaking
systems? - ✔✔Transition metal ions, e.g. Mn2+
✔✔Which of the following reactions can represent saponification? - ✔✔ROOH + NaOH
--> ROO- + Na+ + H2O
,✔✔What type of surfactant has the highest ratio of water-loving to water-hating
character? - ✔✔HIGH HLB
✔✔If the online testing of the cationic demand of thin stock is being measured, which of
the following variables would it make sense to adjust based on that information? -
✔✔Flow of a high-charge cationic polymer
✔✔Why isn't a "hockey stick" type of consistency probe completely defeated by
changes in the flow rate of furnish in a stock line? - ✔✔Cleverly designed bending of the
tip
✔✔What parameter can be measured if a paper mill needs a way to determine the ratio
between softwood and hardwood fibers in a certain stock stream? - ✔✔Fiber length
✔✔What are two requirements for a particle of ink to be effectively removed from water
by flotation deinking? - ✔✔Small size and hydrophobic
✔✔What term means the maximum temperature that a surfactant solution remains clear
when it is gradually heated? - ✔✔Cloud point
✔✔What type of fibers often are easier to dry, form bulkier sheets, and achieve
somewhat higher opacity? - ✔✔Recycled kraft fibers
✔✔What is often controlled just before refining the pulp to achieve more uniform
results? - ✔✔Consistency
✔✔Which of the following represents a favorable dosage of a high-charge cationic
additive to a typical paper machine system? - ✔✔Neutralization of most of the dissolved
and colloidal anionic substances and leaving a net negative charge on the fiber surfaces
✔✔What type of ink most readily enters the water phase during deinking? -
✔✔Flexographic
✔✔If barium sulfate scale is forming on the slots of a pressure screen, which of the
following steps is likely to be helpful to minimize this? - ✔✔Replace alum with PAC.
✔✔Spraying a dilute solution of cationic polymer on the forming fabric can accomplish
what? - ✔✔Prevent buildup of tacky deposits on the fabric
✔✔How would the ignition factor (0.86) be determined for kaolin clay (hydrous form)? -
✔✔(mass after 900 C incineration) / (starting dry mass)
, ✔✔What type of felt-cleaning formulation is effective for solubilization calcium
carbonate? - ✔✔Acidic
✔✔Why is it important to treat every incoming stream of liquid or suspension to a paper
machine with biocide? - ✔✔Minimize inoculation of the system.
✔✔Why is there often not a strong correlation between such indicators of slime
problems such as web breaks, slime holes, slime monitor readings, plate counts, ATP
tests results, etc.? - ✔✔The tests are sensitive to different parts of a diverse population
of slime organisms, some of which are attached, planktonic, filamentous, etc.
✔✔Compared to most other common minerals, talc particles have which combination of
attributes? - ✔✔Soft and hydrophobic
✔✔What is the maximum concentration of individually dissolved surfactant molecules in
a aqueous solution? - ✔✔CMC
✔✔What is a micelle? - ✔✔Cluster of surface active molecules in a liquid
✔✔When do surfactants tend to have their biggest negative effects on paper's wet-web
strength? - ✔✔Above the critical micelle concentration (CMC)
✔✔Enzymes will break down what kinds of materials in paper mills? - ✔✔Starch, esters,
proteins
✔✔What can be achieved by the aging of wood chips? - ✔✔Reduced pitch deposit
problems
✔✔How does downtime due to web breaks affect the paper mill's bottom line? -
✔✔Reduction in revenue due to less product made during the period
✔✔What type of additive helps to minimize problems with wood pitch and stickies, often
helping to retain such materials harmlessly in the paper product? - ✔✔Talc
✔✔What type of slime bacteria is detected by "plate-count" tests, using growth medium
in Petri dishes? - ✔✔Suspended in water
✔✔Considering tacky materials such as wood resins, what will all the following tend to
do (increasing temperature; decreasing molecular mass; decreasing purity)? - ✔✔More
liquid-like character
✔✔What is the name of a type of bacteria that grows as a chain, often in response to
various stresses on the bacterial survival? - ✔✔Filamentous
2025 GRADED A+
✔✔What type of consistency sensing equipment has no moving parts? - ✔✔Microwave
✔✔What type of printing employs plastic binder that is heated to its melting point during
printing? - ✔✔Xerography
✔✔Which of the following types of pulp is susceptible to alkaline darkening if exposed to
high pH? - ✔✔High yield pulp (e.g. ONP)
✔✔In a DAF unit, why does the dissolved air become transformed into small bubbles
when it enters a flotation unit? - ✔✔Decreased pressure
✔✔The washing unit operation is especially effective for removal of what kind of printing
ink? - ✔✔Flexo
✔✔What is a "collector chemical" used for? - ✔✔Flotation deinking
✔✔What makes kraft fibers more variable in properties, less porous in the mesopore
range (2 to 50 nm), and more in need of dry-strength agent usage? - ✔✔Recycling of
the fibers
✔✔Kraft fibers tend to become stiffened each time that they are dried in the
manufacture of paper. How does this affect their ability to form inter-fiber bonds? -
✔✔Recycled kraft fibers generally have lower inter-fiber bonding ability.
✔✔What does a rotating consistency transmitter sense in order to be able to estimate
the consistency of a pulp suspension? - ✔✔Torque required to turn rotating blades
✔✔What process control issue can be solved by increased deinking efforts, increased
bleaching, and adding more fluorescent whitener? - ✔✔Low brightness of paper
✔✔Which of the following process control problems is usually easiest to solve? -
✔✔Data outside of control limits but very steady
✔✔Why is peroxide bleach often added when pulping old newspaper pulp? - ✔✔It
contains lignin that can be bleached.
✔✔What type of printing employs hydrophobic oily ink? - ✔✔Offset lithography
✔✔What kinds of ink can be effectively separated from water using dissolved air
flotation? - ✔✔Offset lithographic
,✔✔What part of the process usually is regarded as the first opportunity to add deinking
chemicals, e.g. surfactants and NaOH, during a deinking operation at a paper mill? -
✔✔At pulper
✔✔What is it called when a deinking additive helps flakes of xerographic toner to form
particles large enough to be filtered effectively with a screen? - ✔✔Agglomerative
deinking
✔✔In which of the following ways does the addition of NaOH affect typical papermaking
fibers? - ✔✔It swells them.
✔✔The high conformability of refined, wet kraft pulp fibers can be attributed to what? -
✔✔Delamination within fiber cell walls
✔✔Which of the following is the result of a titration with highly charged polymer, where
the endpoint corresponds to approximately zero zeta potential? - ✔✔Charge demand
✔✔Why do papermakers usually want to refine pulp to a constant freeness? -
✔✔Freeness is correlated with paper strength development.
✔✔Which of the following is the average electrical potential at a hydrodynamic slip
plane adjacent to a surface? - ✔✔Zeta potential
✔✔What unit operation is effective for contaminant removal only if the particles are
large enough and also different in density from the water? - ✔✔Hydrocyclone
✔✔Why are industrial screening operations often ineffective for the separation of
stickies? - ✔✔The stickies get extruded through the slots.
✔✔What type of binder is used in flexographic printing? - ✔✔Water-dispersible
✔✔The contaminants having the largest particle size can be best removed from
recovered paper stock by means of what operation? - ✔✔Screening
✔✔What tends to catalyze the decomposition of hydrogen peroxide in papermaking
systems? - ✔✔Transition metal ions, e.g. Mn2+
✔✔Which of the following reactions can represent saponification? - ✔✔ROOH + NaOH
--> ROO- + Na+ + H2O
,✔✔What type of surfactant has the highest ratio of water-loving to water-hating
character? - ✔✔HIGH HLB
✔✔If the online testing of the cationic demand of thin stock is being measured, which of
the following variables would it make sense to adjust based on that information? -
✔✔Flow of a high-charge cationic polymer
✔✔Why isn't a "hockey stick" type of consistency probe completely defeated by
changes in the flow rate of furnish in a stock line? - ✔✔Cleverly designed bending of the
tip
✔✔What parameter can be measured if a paper mill needs a way to determine the ratio
between softwood and hardwood fibers in a certain stock stream? - ✔✔Fiber length
✔✔What are two requirements for a particle of ink to be effectively removed from water
by flotation deinking? - ✔✔Small size and hydrophobic
✔✔What term means the maximum temperature that a surfactant solution remains clear
when it is gradually heated? - ✔✔Cloud point
✔✔What type of fibers often are easier to dry, form bulkier sheets, and achieve
somewhat higher opacity? - ✔✔Recycled kraft fibers
✔✔What is often controlled just before refining the pulp to achieve more uniform
results? - ✔✔Consistency
✔✔Which of the following represents a favorable dosage of a high-charge cationic
additive to a typical paper machine system? - ✔✔Neutralization of most of the dissolved
and colloidal anionic substances and leaving a net negative charge on the fiber surfaces
✔✔What type of ink most readily enters the water phase during deinking? -
✔✔Flexographic
✔✔If barium sulfate scale is forming on the slots of a pressure screen, which of the
following steps is likely to be helpful to minimize this? - ✔✔Replace alum with PAC.
✔✔Spraying a dilute solution of cationic polymer on the forming fabric can accomplish
what? - ✔✔Prevent buildup of tacky deposits on the fabric
✔✔How would the ignition factor (0.86) be determined for kaolin clay (hydrous form)? -
✔✔(mass after 900 C incineration) / (starting dry mass)
, ✔✔What type of felt-cleaning formulation is effective for solubilization calcium
carbonate? - ✔✔Acidic
✔✔Why is it important to treat every incoming stream of liquid or suspension to a paper
machine with biocide? - ✔✔Minimize inoculation of the system.
✔✔Why is there often not a strong correlation between such indicators of slime
problems such as web breaks, slime holes, slime monitor readings, plate counts, ATP
tests results, etc.? - ✔✔The tests are sensitive to different parts of a diverse population
of slime organisms, some of which are attached, planktonic, filamentous, etc.
✔✔Compared to most other common minerals, talc particles have which combination of
attributes? - ✔✔Soft and hydrophobic
✔✔What is the maximum concentration of individually dissolved surfactant molecules in
a aqueous solution? - ✔✔CMC
✔✔What is a micelle? - ✔✔Cluster of surface active molecules in a liquid
✔✔When do surfactants tend to have their biggest negative effects on paper's wet-web
strength? - ✔✔Above the critical micelle concentration (CMC)
✔✔Enzymes will break down what kinds of materials in paper mills? - ✔✔Starch, esters,
proteins
✔✔What can be achieved by the aging of wood chips? - ✔✔Reduced pitch deposit
problems
✔✔How does downtime due to web breaks affect the paper mill's bottom line? -
✔✔Reduction in revenue due to less product made during the period
✔✔What type of additive helps to minimize problems with wood pitch and stickies, often
helping to retain such materials harmlessly in the paper product? - ✔✔Talc
✔✔What type of slime bacteria is detected by "plate-count" tests, using growth medium
in Petri dishes? - ✔✔Suspended in water
✔✔Considering tacky materials such as wood resins, what will all the following tend to
do (increasing temperature; decreasing molecular mass; decreasing purity)? - ✔✔More
liquid-like character
✔✔What is the name of a type of bacteria that grows as a chain, often in response to
various stresses on the bacterial survival? - ✔✔Filamentous
