Solved Important Questions

SOLVED QUESTIONS

1. State the purpose of the following in plastics (1) Plastizers (2) Fillers and (3) Stabilizer.

Refer chapter 5.1.3 in Page 5.3.

2. Discuss the properties of plastic materials and give their limitations. 

Refer chapter 5.1.4 in Page 5.4.

3. What are the types of plastics?

Refer chapter 5.2 in Page 5.5.

4. Write the difference between thermoplastics and thermosetting plastics.

Refer chapter 5.2.3 in 5.9.

5. What are the types of moulding of thermoplastics?

Refer chapter 5.3 in Page 5.10.

6. Explain the principle of injection moulding process.

Refer chapter 5.4.1 in Page 5.10.

7. Describe briefly the plunger type injection moulding process for producing plastics components. 

Refer chapter 5.4.1.1 in Page 5.11.

8. Why is screw injection moulding machine better than a ram type injection moulding machine? 

Refer chapter 5.4.1.2 in Page 5.12.

9. Explain the application of injection moulding.

Refer Page 5.13.

10. Discuss any two of the defects that can occur in plastic injection moulding.

5.4.1.3 in Page 5.13.

11. Explain the various steps required to manufacture a plastic bottle using blow moulding process with neat sketches.

Refer chapter 5.4.2 in Page 5.18.

12. Explain the injection blow moulding process.

Refer chapter 5.4.3 in Page 5.19.

13. Explain briefly with neat sketches two commercially used methods of blow moulding for blowing of plastics bottles and mention their specific advantages.

Refer chapter 5.3.4 in Page 5.21.

14. What is rotational moulding? State its advantages and limitations.

Refer chapter 5.4.6 in Page 5.22.

15. Explain the calendering process.

Refer chapter 5.4.5 in Page 5.24.

16. Briefly explain the following with sketches:

1) Calendering

Refer chapter 5.4.8 in Page 5.25.

2) Blow moulding.

Refer chapter 5.4.2 in Page 5.18.

17. Explain the extrusion process.

Refer chapter 5.3.9 in Page 5.26.

18. Explain with neat diagrams the thermoforming process. State its advantages over other processes.

Refer chapter 5.3.10 in Page-5.27.

19. Explain how plastic sheets are manufactured by thermo forming method.

Refer chapter 5.3.10 in Page 5.27.

20. Describe any two types of thermoforming process.

Refer Pages 5.27 & 5.28.

21. Describe the working principle of film blowing and thermoforming.

Refer chapter 5.3.7 in Page 5.24 for film blowing and chapter 5.3.10 in Page 5.27 for thermoforming.

22. Why is the thermoforming a valuable method for the plastic manufacturer? Explain the process with neat sketch.

Refer chapter 5.3.10 in Page 5.27.

23. Sketch and explain the principle of vacuum forming process for plastics.

Refer chapter 5.3.10 in Page 5.27.

24. Discuss the processing of thermosetting plastics.

Refer chapter 5.4 in Page 5.30.

25. Describe the compression moulding process.

Refer chapter 5.4.1 in Page 5.30.

26. Describe the following plastic processing methods with neat sketches (i) Compression moulding (ii) Blow moulding.

Refer chapter 5.4.1in Page 5.30 for compression moulding and chapter 5.3.2 in Page 5.18 for blow moulding.

27. Explain positive, semi positive and flash type compression moulding.

Refer Page 5.31.

28. What is transfer moulding? Discuss it advantages and limitations.

Refer chapter 5.4.2 in Page 5.32.

29. What is laminating? Explain the high pressure method of laminating.

Refer chapter 5.6 in Page 5.34.

30. Explain the various moulding process for reinforced plastics.

Refer Page 5.35.

31. Enumerate various methods of bonding thermoplastics. 

Refer chapter 5.7 in Page 5.36.

32. Describe any one method of bonding thermoplastics.

Refer chapter 5.7.1.2 in Page 5.38.

33. Explain briefly the following methods of bonding of thermoplastics:

(i) Fusion bonding

Refer chapter 5.7.2 in Page 5.40.

(ii) Vibration welding

Refer chapter 5.7.2.3 in Page 5.43.

(iii) Solvent bonding

Refer chapter 5.7.1.1 in Page 5.38.

(iv) Induction welding.

Refer chapter 5.7.2.4 in Page 5.44.