1. What is the time required for complete coating to take place in the fluidized bed?
a) 2-3 sec
b) 5-10 sec
c) 1 sec
d) 20 sec
Explanation: It is optimum time, if more than that coating will be irregular and less than that incomplete coating will take place.
2. Which variety of plastic powders can be used for metal ware coating?
a) Polyvinyl
b) Polypropylene
c) Polyvinyl Chloride
d) All of the mentioned
Explanation: Any plastic material can be used.
3. What will happen if the metal ware is kept for long time for coating of polymer in the fluidized bed??
a) Better coating
b) Irregular thickness
c) Time is independent of time
d) None of the mentioned
Explanation: More time it stays more irregular the coating
4. What is the best method for application of plastic coating on the metal coating?
a) Fluidized bed
b) Spray
c) Electrostatic painting
d) Brush
Explanation: Best work possible with cheaper cost and less time required.
5. For coating using plastic in fluidized bed, thermoplastic powders are always used, true or false?
a) true
b) false
Explanation: If there is any irregular coating, thermoplastics can be remoulded.
6. What should be the temperature of the metal ware for best coating to occur?
a) Little more than the melting point of the polymer
b) Same as melting point temperature of the polymer
c) Very high temperature
d) None of the mentioned
Explanation: Little more energy for melting the plastic and still remaining hot.
7. Since the rate of deposition is proportional to the rate of heat transfer, thickness varies exponentially with film, true of false?
a) true
b) false
Explanation: Based on results provided by Gaynor.
8. According to Gaynor, how is the thickness of the film varies with time?
a) Exponentially
b) Linearly
c) Independent
d) Sinusoidally
Explanation: Based on research done by Gaynor, he concluded relation is exponential.
9. If the flow rate of coolants is increased in the fluidized bed, how will it effect the film formation?
a) Time duration of film formation will decreased
b) No effect
c) Time duration for film formation increases
d) None of the mentioned
Explanation: Duration for cooling will increase and hence for short duration for film formation.
10. What kind of driers are used for drying limestone, dolomite,coal, plastics?
a) Fluosolids dryers
b) Multi-stage dryers
c) Two-staged fluidized dryers
d) None of the mentioned
Explanation: Because it shows typical operating capabilities.