PSE 322 FINAL EXAM QUESTIONS & ANSWERS
ASA properties - Answers :sizing additive
reacts really fast
liquid at room temp
AKD properties - Answers :less reactive
waxy solid at room temp
Starch properties - Answers :low cost
good H-bonding
makes paper stiff
microscopic parts
What is the first thing you have to do to starch before using it? - Answers :cook it
(helps utilize its best strength performance)
How long does it take to fully cook starch? - Answers :20 minutes
If ____ isn't cooked it acts like a ____ - Answers :starch
filler
Two ways to cook starch - Answers :batch cooking
jet/continuous cooking
What happens if cooked starch sits? - Answers :Subject to retrogradation
(will crystallize)
Why does amylopectin resists retrogradation? - Answers :it's branched
What two things do we want wed end starch to have? - Answers :higher molecular mass
cationic charge
Basic ways to increase dry strength - Answers :increase refining
use strength agent
Tissue tear properties - Answers :very weak paper
few fibers break
low refining
Tracing tear properties - Answers :well bonded paper
many fibers break
highly refined
RBA is based on what? (two things) - Answers :Tensile strength
# of fibers broken
, Consequences of refining (4 things) - Answers :interfiber bonding
slower drainage
denser, thinner paper
decreased tear strength
RBA Equation - Answers :(s_unbonded - s_bonded)/s_unbonded
RBA can be found by what optical criteria? - Answers :Scattering coefficient
Less light scattering = (increase/decrease) RBA - Answers :increase
What term in the page equation can explain strength increase from the addition of
cationic starch? - Answers :the interfacial shear strength (tau)
Ideal spot for bonding agents? - Answers :Before fan pump in thickstock
Two limitation on cationic starch - Answers :space
fiber surface
What two things does paper strength depend on? - Answers :1.) strength of individual
fiber
2.) strength of bonds between them
Amylose properties - Answers :vulnerable to retrogradation
linear
Amylopectin properties - Answers :branched
dense
does not retrograde
Relative wet strength aka "percent _____ over ______" - Answers :wet
dry
What kind of wet strength does money need? - Answers :high, permanent
What kind of wet strength does tissue need? - Answers :moderate
What kind of wet strength does paper towels need? - Answers :temporary
What kind of wet strength does copy paper need? - Answers :none
Temporary wet strength agents
Have _____
Create _____ bonds - Answers :aldehydes
covalent
ASA properties - Answers :sizing additive
reacts really fast
liquid at room temp
AKD properties - Answers :less reactive
waxy solid at room temp
Starch properties - Answers :low cost
good H-bonding
makes paper stiff
microscopic parts
What is the first thing you have to do to starch before using it? - Answers :cook it
(helps utilize its best strength performance)
How long does it take to fully cook starch? - Answers :20 minutes
If ____ isn't cooked it acts like a ____ - Answers :starch
filler
Two ways to cook starch - Answers :batch cooking
jet/continuous cooking
What happens if cooked starch sits? - Answers :Subject to retrogradation
(will crystallize)
Why does amylopectin resists retrogradation? - Answers :it's branched
What two things do we want wed end starch to have? - Answers :higher molecular mass
cationic charge
Basic ways to increase dry strength - Answers :increase refining
use strength agent
Tissue tear properties - Answers :very weak paper
few fibers break
low refining
Tracing tear properties - Answers :well bonded paper
many fibers break
highly refined
RBA is based on what? (two things) - Answers :Tensile strength
# of fibers broken
, Consequences of refining (4 things) - Answers :interfiber bonding
slower drainage
denser, thinner paper
decreased tear strength
RBA Equation - Answers :(s_unbonded - s_bonded)/s_unbonded
RBA can be found by what optical criteria? - Answers :Scattering coefficient
Less light scattering = (increase/decrease) RBA - Answers :increase
What term in the page equation can explain strength increase from the addition of
cationic starch? - Answers :the interfacial shear strength (tau)
Ideal spot for bonding agents? - Answers :Before fan pump in thickstock
Two limitation on cationic starch - Answers :space
fiber surface
What two things does paper strength depend on? - Answers :1.) strength of individual
fiber
2.) strength of bonds between them
Amylose properties - Answers :vulnerable to retrogradation
linear
Amylopectin properties - Answers :branched
dense
does not retrograde
Relative wet strength aka "percent _____ over ______" - Answers :wet
dry
What kind of wet strength does money need? - Answers :high, permanent
What kind of wet strength does tissue need? - Answers :moderate
What kind of wet strength does paper towels need? - Answers :temporary
What kind of wet strength does copy paper need? - Answers :none
Temporary wet strength agents
Have _____
Create _____ bonds - Answers :aldehydes
covalent
