WET END CHEMISTRY

What type of materials are antifoams?
1. Silicones and high molecular weight alcohols
2. viscous polymers
3. non-viscous polymers
4. carbohydrates
What will happen if too much antifoam is added to the system?
1. It will create foam
2. It will stop foam permanently
3. You cannot overdose with antifoam
4. It will make the finished sheet too slippery
Which of the following is a functional aid?
1. Dye
2. Bacteriacide
3. Antifoam
4. Retention aid
Which of the following is a Process aid?
1. Retention aid
2. Wet strength resin
3. Dye
4. Pigment
Which of the following does NOT have a duel function
1. Dialdehyde starch
2. Alum
3. Cationic starch
4. Kymene
Wet strength resins are based on the chemistry of which element?
1. Nitrogen
2. Oxygen
3. Carbon
4. Phosphorous
Why is water a liquid and not a gas?
1. Because of hydrogen bonding
2. Because it is too heavy
3. Because of the ionisation of the hydroxyl group
4. Because of the pH
Fibres have a negative charge above pH 7 because of ......
1. the ionisation of the carboxyl groups on some extractive molecules
2. the -OH groups on the cellulose
3. the -OH groups on the hemicellulose
4. lignin
What type of bond does Alkyl Ketene Dimer (AKD) form with cellulose?
1. Covalent
2. Ionic
3. Hydrogen
4. No bond
What do cationic starch and PAAE have in common
1. They can both act as a retention aid
2. They both provide wet strength
3. They both have a negative charge
4. They are both polymers of glucose
Why do we use reverse sizing?
1. Where there is hard water
2. When we are also using a dye
3. Where there is limited access to the pipework
4. To make the sheet more absorbant
Which pigment has the highest refractive index?
1. TiO2
2. CaCO3
3. Kaolin
4. Limestone
What is the Tyndal effect?
1. Where we can see a light beam passing through a colloidal suspension
2. Colloidal particles not being able to settle at the bottom of a container
3. When small particles come together to form flocs
4. The reflection from very shiney surfaces
What is Brownian motion?
1. where colloidal particles cannot settle
2. where colloidal particles agglomerate
3. where air sticks to particles and sticks them together
4. An illness
Keesom forces are
1. permanent dipoles
2. induced dipoles
3. oscillating dipoles
4. part of the Stern Layer
Which of the following best describes zeta potential
1. the potential difference between the potential at the surface and the potential at the border of the solvent bubble
2. the potential difference between the potential at the Stern layer and the potential at the border of the solvent bubble
3. the potential difference between the potential at the surface and the potential at the Stern layer
4. The potential at the surface of the particle
Which polymer type would be used to promore patch flocculation
1. Short and highly charged
2. Long and highly charged
3. Short with a low charge density
4. Long with a low charge density
Why do we use retention aid systems that include microparticles such as silica or bentonite?
1. To increase drainage rates
2. To decrease drainage rates
3. To improve formation
4. To increase retention
How does coagulation happen?
1. Charge neutralisation reduces the size of the solvent bubble allowing particles to get close
2. Positive and negative ions attract each other
3. It is caused by polymer entanglement
4. Gravity
What is the function of Poly DADMAC
1. to reduce the zeta potential
2. to act as a bridge between the fibre and the additives
3. to increase the charge on fibres
4. to neutralise alum

WET END CHEMISTRY

Quiz