1. What does PHB stand for?
a) Polyhydrobutyl
b) Polyhydroxybutyrate
c) Polyhydroxybutene
d) Polyhydroxybutane
Discussion
Explanation: PHB stands for Polyhydroxybutyrate. It is a polyester, popular as a food grade packaging material for snacks, dry products and etc. It is a biodegradable semi-crystalline thermoplastic material produced via fermentation of renewable carbs.
2. CEN headquarters are located in __________
a) Brussels
b) London
c) New York
d) Rome
Discussion
Explanation: CEN (European Committee for Standardisation) headquarters are located in Brussels, Belgium. It is responsible for the preparation of certain standards on compostability, in order to increase sustainability.
3. Arrange the following in correct order of WVTR.
a) EVOH > PET > HDPE > Al
b) Al > EVOH > HDPE > PET
c) PET > EVOH > HDPE > Al
d) EVOH > HDPE > PET > Al
Discussion
Explanation: The correct order of decreasing Water Vapour Transmission Rate is Ethylene Vinyl Alcohol > Polyethylene Terephthalate > High Density Polyethylene > Aluminium. Hence, amongst the given films, Aluminium is the best water vapour barrier.
4. The term OTR related to packaging films stands for ________
a) Overall Thermal Resistance
b) Outer Tear Resistance
c) Oxygen Transmission Rate
d) Odour Transfer Rate
Discussion
Explanation: The term OTR related to packaging films stands for oxygen transmission rate. It is the rate by which oxygen permeates through a plastic film. The plastic films having a greater oxygen transmission rate are a poor barrier against gases, especially oxygen.
5. The term WVTR related to packaging films stands for ________
a) Water vapour transmission rate
b) Water vapour transient rate
c) Water vapour transfer rate
d) Water to vapour total ratio
Discussion
Explanation: The term WVTR related to packaging films stands for Water vapour transmission rate. It is the rate by which water vapour/moisture permeates through a plastic film. The plastic films having a greater water vapour transmission rate is a poor barrier against water vapour or moisture.
6. WVTR is expressed as _________
a) gm2/hr
b) g/m224hr
c) g/m2hr
d) g/cm224hr
Discussion
Explanation: WVTR – Water vapour transmission rate is expressed as gm2/24hr. WVTR is the quantity of water vapour in gram that will permeate from one side of a film of an area 1m2 to other in 24 hours.
7. Arrange the following in correct order of OTR
a) EVOH > PET > LDPE > HDPE
b) PET > EVOH > LDPE > HDPE
c) LDPE > HDPE > EVOH > PET
d) LDPE > HDPE > PET > EVOH
Discussion
Explanation: The correct order of decreasing Oxygen Transmission Rate is Low Density Polyethylene > High Density Polyethylene > Polyethylene Terephthalate > Ethylene Vinyl Alcohol. Hence, amongst the given films, Ethylene Vinyl Alcohol is the best oxygen barrier.
8. Permeability is calculated using ________ and _________
a) diffusion, solubility
b) permeance, solubility
c) diffusion, permeance
d) transmittivity, solubility
Discussion
Explanation: Permeability is calculated using Diffusion and Solubility. Permeability is the product of diffusion and solubility. When a gas/vapour passes through the plastic film, it solubilizes first and then diffuses through the film.
9. Permeability is calculated by the formula P=D/S.
a) True
b) False
Discussion
Explanation: Permeability is the multiplication of diffusion coefficient and solubility coefficient. P=D*S. P,D,S stands for Permeability coefficient, Diffusivity Coefficient and Solubility Coefficient respectively. It is because, vapour/gas solubilizes and then diffuses through the film to reach it’s other side.
10. What is the unit of coefficient of Diffusion coefficient?
a) m2/s
b) cm2/s
c) m/s
d) m2s
Discussion
Explanation: The unit of coefficient of Diffusion coefficient is m2/s. Diffusion coefficient is a measure of how fast a permeate moves through the plastic polymer. It depends on degree of crystallinity of polymer.