answers already passed 2025/2026
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