Complete these exercises at your leasure and mail me with your score. Good Luck!
Why are coatings applied to certain grades of paper and board?
To improve barrier properties or smoothness
To improve whiteness or uniformity
To improve uniformity or barrier properties
To improve whiteness or smoothness
What happened to make the use of calcium carbonate in coating formulations a possibility?
The development PCC
The development of neutral sizing systems
The change from phosphor bronze wires to fabric wires
The development of neutral rosin systems
What is the difference between European and American clay deposits?
The USA has two main deposit areas and Europe has many
The USA has primary and secondary deposits and Europe only has primary
The USA has primary and secondary deposits and Europe only has secondary
The USA has two main deposit areas and Europe has only one
What are the three main components of a sheet that may influence coating application?
Smoothness porosity and absorbency
Smoothness porosity and size
Fibre, filler and porosity
Fibre, filler and size
What was the first type of size to be used in papermaking?
Rosin
Rosin/alum
Gelatine
Alkyl Ketene Dimer
What three words describe the general mechanism for sizing?
Retention, spreading, orientation,
Retention orientation, curing
Spreading, orientation, curing
Spreading, orienting, crosslinking
Which of the following is not a type of calcium carbonate?
PCC
Granite
Marble
Whiting
In the early 1990’s the quantities of starch used in the UK paper and board industries started to decline. Why?
There was a switch from starch to latex
Less coated materials were being produced
Less paper and board was being produced
There was a switch to different types of starch
The purpose of a pigment is to enhance the printability of the coated surface. It does this by providing absorbency, smoothness, and what other two properties?
Gloss and brightness
Brightness and opacity
Smoothness and gloss
Strength and smoothness
What is the definition of refractive index?
The angle at which light is refracted when it moves from an air medium to a solid medium
The angle at which light is refracted when it moves from a solid medium to an air medium
The ratio of the speed of light in air, to the speed of light in a solid
The ratio of the speed of light in a solid , to the speed of light in air
Which type of particle will give the better gloss?
Smooth
Rough
Large
Small
Which of the pigments has the highest refractive index?
Anatase
Rutile
Clay
PCC
Other than price, what is the main disadvantage of calcined clays?
Availability
Colour
Particle size distribution
Rheology
Ideally coating pigments should be very insoluble, but there is one used which does have a much higher degree of solubility than the others. Which is it?
Gypsum
PCC
Satin white
Talc
Which dispersant works satisfactorily initially, but starts to deteriorate after two or three days?
Polyacrylate
Polyphosphate
Polyacetate
Polynitrate
Which of the following is NOT a natural binder?
Casein
CMC
Soy Polymer
Starch
Which type of starch has branched chains?
Amylopectin
Amylose
Amylase
Xylem
Styrene is most commonly reacted with which other monomer to produce a latex for use in paper and board coatings?
Acrylate
Butadiene
Ethylene
Vinyl acetate
What stabilises the latex particles in suspension?
Lipids
Particle size
Sodium hydroxide
Surfactants
As the styrene ratio decreases in an SB latex, what effect will this have on the dry pick strength?
The dry pick strength will decrease
The dry pick strength will increase
The dry pick strength will increase then decrease
The dry pick strength will decrease then increase
As the styrene ratio decreases in an SB latex, what effect will this have on the stiffness?
The stiffness will decrease
The stiffness will increase
The stiffness will increase then decrease
The stiffness will decrease then increase
Coatings consist of pigments, binders and other additives. Additives usually represent what proportion of the mix?
About 5%
About 10%
About 15%
About 20%
Coatings consist of pigments, binders and other additives. Which one of the following would be considered an additive?
SB latex
Cationic Starch
Casein
Polyvinyl alcohol
Biological attack on coating mixes can lead to various problems including bad odour, mix instability, poor runnability and which one of the following?