PSE 201 Final Exam with all Correct & 100% Verified
Answers |Actual Complete Update |Already Graded A+
What are the major categories of chemical additives used for papermaking? ✔Correct
Answer-retention aids, sizing agents, fillers, strength agents, alum
What is so special about "alkaline papermaking?" ✔Correct Answer-It allows the use of
calcium carbonate as a filler.
What are the three broad goals of the stock prep area? ✔Correct Answer-Achieve desired
product properties, set/control sheet basis weight, increase sheet strength
How is the stock prep area set up? ✔Correct Answer-A collection of tile-lined tanks called
"chests." The dump chest contains the raw pulp. The mix (or blend) chest receives from the
dump chest and the furnish components and feeds the refiners. The machine chest receives the
refined stock and feeds the stuff box.
Why do we refine? ✔Correct Answer-It decreases yield loss at lower-cost grades
What physical changes occur to a papermaking fiber when it goes through refining? What
changes occur to the stock? ✔Correct Answer-They collapse into flat ribbons, fibrillate,
become more conformable, and can be shortened.
Where do fines come from? ✔Correct Answer-Refining
What things get better with refining? What things get worse? ✔Correct Answer-Tensile and
burst strength, formation, smoothness, and printability get better. Tear strength, freeness, yield,
opacity, bulk, and air porosity get worse.
What is the nature of the refining action? What type of equipment has been used to induce this
action into papermaking stock? ✔Correct Answer-It is a "rolling friction." Equipment that has
been used to induce this include the beater, Jordan, Claflin, and disk.
What is freeness? How is it measured? ✔Correct Answer-Describes how freely water drains
from a fiber slurry. It is measured by the CSF test.
What relative refining energy level is required for various grades? ✔Correct Answer-tissue <
linerboard base < multiwall bag < bleached board < fine papers < linerboard top < glassine
Why are some grades NOT refined? ✔Correct Answer-Market pulp is normally not refined
because the customer will do it themselves.
, What are the major goals of this area? ✔Correct Answer-To deliver the right amount of fiber
to the paper machine in order to meet basis weight specs, and to distribute that stock
uniformly.
What is the role of the basis weight valve? ✔Correct Answer-It sets the average basis weight
of the sheet by metering thick stock to the fan pump.
Why is the stuff box important? ✔Correct Answer-It dampens pulsations from the thick stock
pump that could cause sheet barring.
How is thick stock converted to thin stock? ✔Correct Answer-The fan pump dilutes thick stock
with white water from the fourdrinier
What is the deculator? ✔Correct Answer-It is a vacuum header that removes air after
centrifugal cleaning prior to the headbox.
What is the headbox screen used for? ✔Correct Answer-Pulses stock against a screen to stop
fiber flocs from getting through
What does the headbox manifold do? ✔Correct Answer-Deliver stock to the headbox with
absolute even fiber distribution across the machine width
Why is a headbox named that? ✔Correct Answer-It provides pressure, or "head"
What is the slice? ✔Correct Answer-The opening at the lip of the headbox where stock jets
out onto the wire
What are the major purposes of the headbox? ✔Correct Answer-To provide the pressure
necessary to deliver the correct amount of thin stock to the forming wire
What are the three major types of headboxes, and why we have to move to a different type as
the machine speeds increase. ✔Correct Answer-Atmospheric, air-padded, and hydraulic. We
need to use a different type as machine speed increases in order to maintain the rush/drag
ratio.
What is rush/drag ratio? ✔Correct Answer-The ratio of jet speed to wire speed, usually 1.0
plus or minus 5%
What are three major water removal zones/forces on a typical fourdrinier wet end? ✔Correct
Answer-Gravity, vacuum, press
What are the major types of wet end machines used for papermaking? ✔Correct Answer-
Fourdrinier, top-wire, gap former
Answers |Actual Complete Update |Already Graded A+
What are the major categories of chemical additives used for papermaking? ✔Correct
Answer-retention aids, sizing agents, fillers, strength agents, alum
What is so special about "alkaline papermaking?" ✔Correct Answer-It allows the use of
calcium carbonate as a filler.
What are the three broad goals of the stock prep area? ✔Correct Answer-Achieve desired
product properties, set/control sheet basis weight, increase sheet strength
How is the stock prep area set up? ✔Correct Answer-A collection of tile-lined tanks called
"chests." The dump chest contains the raw pulp. The mix (or blend) chest receives from the
dump chest and the furnish components and feeds the refiners. The machine chest receives the
refined stock and feeds the stuff box.
Why do we refine? ✔Correct Answer-It decreases yield loss at lower-cost grades
What physical changes occur to a papermaking fiber when it goes through refining? What
changes occur to the stock? ✔Correct Answer-They collapse into flat ribbons, fibrillate,
become more conformable, and can be shortened.
Where do fines come from? ✔Correct Answer-Refining
What things get better with refining? What things get worse? ✔Correct Answer-Tensile and
burst strength, formation, smoothness, and printability get better. Tear strength, freeness, yield,
opacity, bulk, and air porosity get worse.
What is the nature of the refining action? What type of equipment has been used to induce this
action into papermaking stock? ✔Correct Answer-It is a "rolling friction." Equipment that has
been used to induce this include the beater, Jordan, Claflin, and disk.
What is freeness? How is it measured? ✔Correct Answer-Describes how freely water drains
from a fiber slurry. It is measured by the CSF test.
What relative refining energy level is required for various grades? ✔Correct Answer-tissue <
linerboard base < multiwall bag < bleached board < fine papers < linerboard top < glassine
Why are some grades NOT refined? ✔Correct Answer-Market pulp is normally not refined
because the customer will do it themselves.
, What are the major goals of this area? ✔Correct Answer-To deliver the right amount of fiber
to the paper machine in order to meet basis weight specs, and to distribute that stock
uniformly.
What is the role of the basis weight valve? ✔Correct Answer-It sets the average basis weight
of the sheet by metering thick stock to the fan pump.
Why is the stuff box important? ✔Correct Answer-It dampens pulsations from the thick stock
pump that could cause sheet barring.
How is thick stock converted to thin stock? ✔Correct Answer-The fan pump dilutes thick stock
with white water from the fourdrinier
What is the deculator? ✔Correct Answer-It is a vacuum header that removes air after
centrifugal cleaning prior to the headbox.
What is the headbox screen used for? ✔Correct Answer-Pulses stock against a screen to stop
fiber flocs from getting through
What does the headbox manifold do? ✔Correct Answer-Deliver stock to the headbox with
absolute even fiber distribution across the machine width
Why is a headbox named that? ✔Correct Answer-It provides pressure, or "head"
What is the slice? ✔Correct Answer-The opening at the lip of the headbox where stock jets
out onto the wire
What are the major purposes of the headbox? ✔Correct Answer-To provide the pressure
necessary to deliver the correct amount of thin stock to the forming wire
What are the three major types of headboxes, and why we have to move to a different type as
the machine speeds increase. ✔Correct Answer-Atmospheric, air-padded, and hydraulic. We
need to use a different type as machine speed increases in order to maintain the rush/drag
ratio.
What is rush/drag ratio? ✔Correct Answer-The ratio of jet speed to wire speed, usually 1.0
plus or minus 5%
What are three major water removal zones/forces on a typical fourdrinier wet end? ✔Correct
Answer-Gravity, vacuum, press
What are the major types of wet end machines used for papermaking? ✔Correct Answer-
Fourdrinier, top-wire, gap former
