Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 7th Sem 2172302 Plastics Mold And Die Design Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?VII (NEW) EXAMINATION ? WINTER 2020
Subject Code:2172302 Date:19/01/2021
Subject Name:Plastics Mold & Die Design
Time:10:30 AM TO 12:30 PM Total Marks: 47
Instructions:
1. Attempt any THREE questions from Q.1 to Q.6 .
2. Q.7 is compulsory.
3. Make suitable assumptions wherever necessary.
4. Figures to the right indicate full marks.
MARKS
Q.1 (a) Define : Insert , Bolster , Guide pin
03
(b) Discuss the requirements of a gate
04
(c) Design a Hand Injection mould for the product shown in fig [a]
07
Q.2 (a) Calculate efficiency of round runner , trapezoidal runner and hexagonal
03
runner
(b) Differentiate between integer and insert type of mould
04
(c) Tick the correct one:
07
1. Material of Bolster is (a) MS (b) EN-24 (c) EN-8 (d) EN 48B (e) none
of these
2. Function of push back pin is [a] To eject the product. [b] to protect the
core/cavity while mould opening.[c] to protect the core/cavity while
mould closing [d] none of these.
3. Shaping operation removes metal in (a) Millimeters
(b) Cms Microns (d) None of these
4. For removal of metal burrs from the holes , the operation done is [a]
grinding [b] honing [c] reaming [d] polishing
5. Gate has a minimum cross sectional area due to : (a) To increase
pressure drop (b) to offer resistance so that impression fills
completely.(c) to decrease pressure drop (d) none of these.
6. Sleeve ejection is preferred for (a) short hollow products (b) tall hollow
products (c) solid tall products (d) solid short products.
7. Function of Ejector retainer plate is (a) to hold the ejector element (b) to
hold the ejector plate (c) to protect the ejector plate (d) none of these.
Q.3 (a) Draw a Pipe Die and explain its parts
03
(b) Calculate the shot capacity of the injection moulding machine if a product
04
of weight 15 gms is to be moulded in ABS and a 16 impression mould is
desired. Assume:
Bulk factor of PS = 1.9
Bulk factor of ABS = 1.8
Specific gravity of PS = 1.04
Specific gravity of ABS= 1.0
(c) Discuss Sleeve Ejection in Detail.
07
Q.4 (a) Discuss the importance of approach section in a Die
03
(b) Discuss about Design of Film Die.
04
(c) Discuss advantages, disadvantages and applications of Pin Gate;
07
Submarine Gate ; Overlap gate ; rectangular edge gate; tab gate ; ring
gate and diaphragm gate.
1
Q.5 (a) For the product shown in fig[b], discuss the gate that is most suitable.
03
Justify.
(b) What is the manufacturing process of Guide Pin.? Discuss
04
(c) A rectangular box molded in PP has dimensions of 185x125x40mm. Top
07
open, this box has wall thickness of 2mm throughout. If a 2 impression
mould is desired , do the feed system calculations
Q.6 (a) Rectangular Edge Gate cannot be used for PVC. Why?
03
(b) Calculate the shot capacity of injection machine for the product shown in
04
fig.[a].
Given Data : Bulk factor of PS = 1.4
Bulk factor of PP = 1.9
Specific gravity of PS= 1.04
Specific gravity of PP = 0.9
(c) Write the function of : Lathe ; Shaping machine ; Drilling machine ;
07
Grinding machine ; wire EDM ; milling machine ; honing machine.
Q.7
Draw a Monofilament die and discuss its parts
05
OR
Q.7
Fill in the blanks:
05
a. Material of ejector rod is ____________
b. For hollow products , ___________gate is used.
c. Rectangular edge gate cannot be used for __________materials.
d. ______________is the disadvantage of a pin gate.
2
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3
This post was last modified on 04 March 2021