UPTU Previous Question Papers B Tech 6th Semester Polymer Processing-2 2006-07

UPTU Previous Question Papers B Tech

6th Semester Polymer Processing-2 2006-07

 

Note : (1) Attempt all questions.

(2) All questions carry equal marks.

1. Attempt any four parts of the following :

(a) What is the basic concept of for forming a plastic product by Injection Moulding Process ?

Why this is considered one of the most important moulding processes?

(b) Draw a neat diagram of Two Stage Screw Plasticizing Injection Moulding Machine and discuss its advantages over Plunger type machine.

(c) Describe the Jet Process for injection moulding of Thermoset Plastics with the help of a diagram.

(d) Define the following terms :

(i) Daylight

(ii) Injection Rate

(iii) Injection Pressure

(iv) Injection Capacity

(v) Plasticizing Rate.

(e) What are the special features of an Injection Screw? Explain with a diagram.

(f)  Discuss the causes and corrective measures for the following Injection Moulding faults :

(i) Short Shots

(ii) Sink Marks

(iii) Voids

(iv) Poor Weld Lines

(v) Flash.

 

2. Attempt any four parts of the following:

(a) Draw a neat diagram of cross-sectional views through screw channel at different stages of transfer of plastic material along the screw and explain it.

(b) What are various types of Clamping Devices used in Injection Moulding Machine? Give advantages and disadvantages of each.

(c) What do you understand by the Clamping Tonnage of an Injection Moulding Machine?

What size of general purpose polystyrene article can be moulded on a 350 ton hydraulic clamp machine having 2.5 inch reciprocating screw?

(d) Describe the process of Gas Assist Injection Moulding Machine and give its advantages.

(e) What is the criteria for efficient conveyance of plastic material in the screw channel? Discuss with the help of equation.

(f)  What are the differences between a hydraulic and electric drive used for Injection Moulding Machine?

 

3. Attempt any two parts of the following :

(a) Discuss the basic characteristic properties required in a material for Thermoforming. Give names of materials which fulfill these. Describe the principal of Thermoforming Process and define the Specific Processing Temperatures used.

(b) Name the process used for moulding Polyurethane and give its principle. Describe the production of an article with the help of a diagram. What are the other materials that can be processed by this technique?

(c) Describe any two of the following thermoforming processes with the help of neat diagram of each step:

(i) Drape Forming

(ii) Reverse Draw Thermoforming

(iii) Pressure Forming

 

4. Attempt any two parts of the following :

(a) What do you understand by Blow Moulding Process? What are various methods for forming an article by this technique? Discuss any one with figure giving advantages and disadvantages of it.

(b) What is the importance of Parison Programming and Die Shaping in Blow Moulding Process? Discuss the methods used for this.

(c) Describe any two of the following in brief:

(i) Casting of Epoxy Resin

(ii) Air Entrance in Blow Moulding

(iii) Blister packaging.

 

5. Attempt any two parts of the following :

(a) Describe the basic principle of Calendering Process. What are its advantages over other process? Discuss various steps involved and draw various Calender Designs used commonly.

(b) What type of articles are manufactured by Rotational Moulding? Explain various stages involved in the process with the help of a diagram. What are the specific features of mould used in the process ?

(c) Why only PET is used for Stretch Blow Moulding? Discuss the process and its utility in the industry.

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