Polymer Processing Suggestions-2022
Blue color indicates ‘MORE IMPORTANT’
Red color indicates ‘LESS IMPORTANT’
Molding, plastic compounding & thermoforming questions
1. What is polymer processing? Write the name of polymer processing techniques. Mention the
advantages of each of the techniques (5)
2. Why is compounding important in polymer processing? (2)
3. What is meant by mixing and compounding of polymeric materials? Explain the physical
process involved in mixing and compounding. 06
4. Define extrusion. With a simple sketch, show the different elements of a typical extruder
explaining the functions of each part.
06
5. Define extrusion. Sketch a single screw extruder and discuss working principle (2+5)
6. Compare between compression molding and injection molding. 04
7. What types of information can one get from the “pressure-temperature” diagram in the process
operation of injection molding? 03
8. What is co-extrusion? Differentiate between the single and multiple screw extruder. (4)
9. What do you mean by compounding? List the functions of protective additives in polymer
processing. 05
10. What is transfer molding? Explain the working principles of transfer mold with a simple
sketch.
04
11. Write down the essential stages of blow molding process. 03
12. What is compression molding? Write down some name of polymers which are suitable in
compression molding. (5)
13. Explain the working principle of compression molding (3)
14. Define the term “Breaker Plate”. Write down the functions of breaker plate in extrusion
molding. 03
15. Illustrate the film/sheet extrusion process.
03
16. What is extruder and extrusion? 04
17. Sketch a typical feed screw of an extruder and explain the functions of the different zones of a
feed screw.07
18. What parameters are important for compression molding? Which shape can be blow molded?
(4)
19. Define the term ‘Breathing’ (2)
20. State types of thermoforming. Mention which polymer are not suitable for processing in
thermoforming (1+3)
21. What is thermoforming? Explain the applications and advantages of injection molding (3)
22. Under what circumstances blow molding can be used instead of compression molding? What
are its advantages over the latter? (6)
Prepared by
Sohel Rana
23. Give examples and mention functions of the following additives (i) Fillers (ii) Plasticizers (iii)
antioxidants (iv) Lubricating and flow promoters and (v) Cross linking agents (vi) stabilizer
(6)
24. What are the causes and solution for the following problems during injection molding of
polymers? [process operation figure] (6)
i)
Weld line, ii) Flashes and iii) Short short (iv) Melt
25. Define the terms: i) Fillers; ii) Plasticizers; iii) Stabilizers; iv) Lubricating and Flow promoters;
and v) Cross-linking agents.
05
26. “Antioxidants are used to protect against the atmospheric oxidation” – Explain the
statement.02
27. Describe the components of injection molding technique.
04
28. Describe the injection molding window with suitable figure. 04
Thin Film Questions
1. Define polymer thin films? Why these films are so interesting in scientific applications-----2
2. How to classify the formation of polymer films from solution? Shortly describe the formation process
of: Free standing polymer films and diblock copolymer thin films-------4
3. How to produce polymer films by thermal spray processing. Note their special applications-----4
4. State the name of thin films deposition techniques. -------3
5. How to classify the formation of polymer films from solution? Shortly describe the films formation
process by spin coating. -----------5
6. State the name of thin films deposition techniques. Mention the basic principles of sputtering and PLD
techniques. -------------5
7. What is plasma polymerization? Mention the special characteristics and applications of films coming
from Plasma polymerization.
8. Define chemical and physical vapor deposition --------2
9. What are the steps involved in CVD? What conditions(parameters) for better output in CVD? -----5
Rubber Processing Questions
The term ‘Rubber’ belongs to Plastic or Elastomer? Explain. ---------3
Write down the recovery steps of natural rubber from its raw latex. -----------3
What are the functions of ‘Carbon Black’ in rubber processing? ------------3
Show the mechanism of sulfur vulcanized natural rubber. Which significant properties of rubber
products can change upon vulcanization? State the functions of ‘Activator’ and ‘Accelerant’ on
vulcanization. --6
5. Mention the roles of ‘Mastication’ for rubber processing. --------------2
6. Draw a sketch on coating of fabric with rubber using a calendaring process. --------3
1.
2.
3.
4.
Prepared by
Sohel Rana
7. Describe the shaping process of rubber products with suitable sketches. -------------9
8. Describe the production sequence of tire with suitable diagram. ----------------6
9. Describe the function of a tire. ---------------3
10. What is latex? Write down the recovery steps of natural rubber latex. ---------------3
11. Show the mechanism of radiation vulcanized natural rubber and SBR (6)
12. Mention the functions of: Accelerant, Activator and Carbon black in rubber processing. -------4.5
13. What are the functions of plasticizer in rubber? ----------------3
14. What is vulcanization? Give the mechanism of sulfur vulcanization of SBR. ------------------6
15. How to minimize the solid plastic waste from environment? --------------------3
16. How can you prepare plastic bottle using PET as the starting material? Explain in brief -----6
17. What do you know about latex? Write down the composition, preservation and coagulation
process of latex. ---5
18. Describe the principle of mastication. ------3
19. Explain role of different additives used in compounding in rubber processing. Why is two stage
mixing important in-rubber processing? ------------7
20. Why is carbon black used in rubber processing? -----------2
21. What is the role of calendaring? --------------3
22. What are the principal molding techniques for rubber processing? Why is carbon black used in
rubber processing? ---------------4
Grafting Questions:
1.
2.
3.
4.
5.
6.
What is grafting? What techniques can one follow to graft a polymer?
03
Define the term “living polymerization”. How it differs from conventional polymerization 03
What are the controlling factors of grafting? Explain effect of temperature on the grafting. 06
What practical advantages and disadvantages exist for the use of radiation in grafting? 02
Define the terms “ATRP” and “RAFT”. 02
Classify the radiation induced grafting methods and show the mechanism of three different
ways of grafting initiated by radiation techniques. 05
7. Show the radical formation mechanism of azo and peroxides compounds by heating
03
8. In case of photochemical grafting, show the mechanism of grafting materials with and without
sensitizer. 03
9. What are the controlling factors of grafting? Explain the effects of polymeric backbone and
monomer prior to grafting.
04
10. How to effects on the structures of cellulose and wool under UV light to graft onto a substrate.
Explain
05
11. What is Mercerization? Show the chemical structure of Mercerized cellulose. 03
12. What is photochemical grafting? Illustrate mechanism of photochemical grafting.
5.0
13. Outline the techniques of grafting and explain the controlling factors of grafting. 3+5
14. Mention industrial applications of grafting.
02
Prepared by
Sohel Rana
Radiation Questions
1. What do you mean by swelling of polymer in solvent? For a given polymer and solvent, the
equilibrium degree of swelling will be smaller when the degree of cross linking is higher. Why?
(4)
2. Gel point provides some vital information of a polymer network. How? (3)
3. What is Radiation Processing Technique (RPT)? What are the advantages of RPT over
conventional processing technology? (4)
4. Differentiate between UV and EB curing. (4)
5. Define the terms: i) Oligomers; ii) Swelling ratio; iii) Photo initiators; iv) Ultraviolet curing;
v) Electron beam curing; and vi) Gel content vii) Gel point (7)
6. What is biodegradability and stability of polymer. Why these two properties are essential for a
polymer? (3)
7. What is radiation curable coating? Explain advantages and disadvantages of it. What are the
common types of radiation used in radiation curing? (1+3+3)
8. What is radiation curable coating? What are the properties of coating materials? (5)
9. Define oligomers. State functions of oligomers in coating (5)
10. Mention industrial applications of radiation (3)
Polymer composite
1. What are polymer composites?
2. Classify the composite materials based on both matrix materials and reinforcing materials
structure (5)
3. Though Novolak and Resol are both phenol formaldehyde resin, Novolak resin can be stored
any length of time but not Resol, why? Discuss properties & applications of PF resin (4+2)
Fiber
1.
2.
3.
4.
5.
6.
7.
8.
What is meant by fiber? Describe the different types of textile fibers (5)
Define the following terms: (i) Denier (ii) Tenacity and (iii) Crimp (iv) Fiber (6)
Write the chemical structure of five polymer fibers coming from petrochemical sources. (2.5)
Show in detail the textile production cycle of fiber from polymer to apparel (4)
Shortly describe the textile fiber processing by a continuous path (4)
What is fiber spinning? What are the sources of synthetic fiber? (2+2)
Differentiate between dry and wet spinning process (6)
Name the technique(s) for spinning each of the following fiber: (i) Polyester (ii) Acrylic (iii)
Aramid (iv) Nylon (2)
9. Differentiate between filament yarn and staple yarn (2)
Prepared by
Sohel Rana