CENTRAL INSTITUTE OF PLASTICS ENGINEERING & TECHNOLOGY
Question Bank
COURSE : DPT
SEMESTER : IV
SUBJECT : Plastics Product and Mould Design
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1) Feed system is
(a) Flow path from Runner to impression (b) Nothing but moulding and safe
(c) Melt flow path which connects nozzle with the impression (d) None of the above
2) Register Ring is used for
(a) Ejecting the moulding (b) Matching core and cavity (c) Aligning plates together
(d) Locating mould with machine
3) Material used for making core / cavity for long productions
(a) Mild steel (b) P20 steel (c) EN18 steel (d) Cast iron
4) Shot weight is referred as
(a) Weight of the mould (b) Weight of the machine (c) Weight of the moulding
(d) Weight of the moulding and feed system
5) Eye bolt is used for
(a) Clamping plates together (b) Clamping mould with the machine
(c) Lifting the mould to the machine (d) None of the above
6) Runner efficiency is referred as
(a) The ratio between cross sectional area and periphery of the runner
(b) The ratio between the length and width of the runner
(c) The output of the runner (d) None of the above
7) Mould venting is nothing but the
(a) Provision for escape of air and gas from the mould cavity (b) Heating of the mould
(c) Provision for allowing air to enter into the mould cavity (d) None of the above
8) Draft is given in the plastics product
(a) For easy flow of plastics materials (b) To reduce the melt pressure drop
(c) For easy ejection of the product from the core (d) For easy machining of the product
9) SQC means ________________
10) Oil is used as a heating / cooling media for the material of
(a) PE (b) PVC (c) PS (d) PC
11) Expand the following plastic material
(a) PEEK
(b) PBT
12) MFI stands for ___________________
13) An angular piece of material used to support the bosses and strengthen the wall is called
(a) RIB (b) HUB (c) Gussets (d) Web
14) The shrinkage occurring after a part has been removed from the mould is called
(a) Differential shrinkage (b) Volumetric shrinkage (c) Post moulding shrinkage
(d) Anisotropic shrinkage
15) The distance between two machine platens of injection moulding machine in fully opened position is called
(a) Shut height of the mould (b) Maximum daylight of the machine
(c) Ejection stroke (d) Maximum mould thickness
16) The rounded inside corner of a plastic product is called
(a) Radii (b) Fillet (c) Taper (d) Bosses
Contd.., P/2
Page No. 2
17) A mark on a molded piece made by the meeting of two fronts is
(a) Meld line (b) Weld line (c) Knit line (d) Flow line
18) The main sprue will be removed from
(a) Ejector pin (b) Sprue puller (c) Dowel pin (d) Push back pin
19) In what type of mould pinpoint gate is used
(a) Two plate mould (b) Stripper plate mould (c) Three plate mould (d) Split mould
20) The material preferred for integral hinge is
(a) Polystyrene (b) Polyvinyl Chloride (c) Polyamide (d) Polypropylene
21) The final closing of split cavities will be done by
(a) Finger CAM (b) Spring (c) Locking heel (d) Dogleg CAM
22) The automatic degating is possible by using the
(a) Sprue gate (b) Edge gate (c) Film gate (d) Submarine gate
23) What type of thread is used in caps for tooth paste tubes?
(a) Square thread (b) Acme thread (c) Buttress thread (d) Bottle thread
24) The only part feature to which shrinkage allowance is not applied to is an
(a) Angle (b) Linear Dimensions (c) Height (d) Fillet
25) The general shape of Dog-leg Cam is
(a) Square (b) Rectangle (c) Circle (d) Hexagon
26) The allowance flash thickness in compression moulding is
(a) 0.5 mm (b) 0.25 mm (c) 1.0 mm (d) 1.25 mm
27) PET material is used for stretch blow moulding due to its ability to be free blown at temperature
(a) 96ºC (b) 28ºC (c) 156ºC (d) 220ºC
28) The hot hollow tubed plastics in blow mould is called as
(a) Tube (b) Preform (c) Parison (d) All of these
29) PET preform is manufactured by _____________ process
(a) Injection (b) Blow (c) Compression (d) Extrusion
30) For what type of material, positive type compression mould is used?
(a) High bulky material (b) Low bulky material (c) All plastics material
(d) For the materials which has filler as small fibers
31) The ratio of the volume of the loose plastic powder to the volume of the moulding is called
(a) L/D Ratio (b) Compression ratio (c) Bulk factor (d) Blow ratio
32) What is the alternate name of phenol formaldehyde?
(a) Epoxy (b) Bakelite (c) SMC (d) BMC
33) Rotational moulding machine consists of _______
(a) Rotating spindle (b) Oven (c) Cooling chamber (d) All of these
34) In rotational moulding, the raw material used as
(a) Powder (b) Granules (c) Sheet (d) Liquid
35) GD & T stands for __________
36) Expand FRTP _________
37) The circular form of the leftover material is the base of the well in transfer moulding is called ____
(a) Chamber (b) Box (c) Cull (d) Sprue
Contd.., P/3
Page No. 3
38) _______________ is an indentation or projection on a molded part.
(a) Rib (b) Undercut (c) Hinge (d) None of these
39) Amorphous plastics shrink _____________ crystalline plastics
(a) More than (b) Less than (c) Same as (d) None of these
40) The fit used for mould Guide pillar and Guide bush is
(a) H8 g6 (b) H7 g9 (c) H7 g6 (d) H7 g8
41) A pin used to mould a hole in the molded part is
(a) Core pin (b) Dowel pin (c) Ejector pin (d) None of these
42) Which of the method is recommended for delayed opening in split cavities
(a) Dogleg Cam (b) Finger Cam (c) Angle lift (d) Hydraulic
43) What mould material generally prefer for the Rotational mould?
(a) Aluminum (b) Lead (c) Mild steel (d) Electro formed nickel
44) The best preferred runner type is ____________
(a) Half round (b) Full round (c) Trapezoidal (d) Modified Trapezoidal
45) Clamping force in Blow mould is calculated as
(a) 1.25 x projected area x Blow pressure (b) 1.25 x Blow ratio x cavity area
(c) Average blow pressure x cavity area (d) 1/2 x Blow pressure x cavity area
46) Thin-gauge thermoforming is primarily the manufactured of
(a) Disposable cups & trays (b) Vehicle door (c) Dash panels (d) Refrigerator liners
47) Sheet thickness less than __________ mm is usually referred as Thin-gauge
(a) 1.5 mm (b) 2.0 mm (c) 2.5 mm (d) 3 mm
48) The mould materials for thermoforming ___________
(a) Plaster of Paris (b) Wooden mould (c) Aluminum mould (d) All of these
49) Die Swell = Cross section of the extrudate divided by ______________
(a) Die Diameter (b) Die length (c) Die cross section (d) None of the above
50) Coat Hanger Die is used for producing ____________ products.
(a) Rod (b) Pipe (c) Sheet (d) Wire
51) ___________________ mould is used to manufacture large deep draw parts.
(a) Flash type (b) Landed positive type (c) Semi positive type (d) Fully positive type.
52) Basic factors of Product Designs are
(a) Function (b) Aesthetics (c) Shape (d) All of these
53) The textile bobbin is an example of __________ undercut product.
(a) Internal (b) External (c) Local (d) None of these
54) Generally the heights of the bosses are ___________ times of its diameter.
(a) 2 (b) 3 (c) 4 (d) 1
55) The angle of locking heel must be __________ than the angle of finger cam in a split injection mould.
(a) Greater (b) Lesser (d) equal to (d) None of these
56) We take _______ watts/kg of steel specifically for calculation of heat for compression mould.
(a) 5 to10 (b) 10 to15 (c) 15 to 20 (d) 20 to 30
57) ___________ in compression moulding helps in evacuation of air.
(a) Cooling (b) Venting (c) Breathing (d) None of the above
58) Plunger transfer mould will develop ____________ frictional force than the pot type transfer mould.
(a) More (b) Less (c) Same (d) None of the above
Contd.., P/4
Page No. 4
59) The small gate cross section is desired so that ___________
(a) Gate freezes soon (b) Easy degating (c) Small witness mark on impression
(d) All of these
60) Brass Inserts are used in plastic part to take ____________
(a) Wear and tear (b) to aid in assembly work (c) to transmit electric current (d) All of these
61) The main advantage of Air ejection is _________________
(a) Ejector grid is not required (b) Operated at any half of the mould.
(c) Useful for double ejection (d) All of these
62) The factors that influence Thermoset moulding are _______________
(a) Temperature (b) Pressure (c) Cure Time (d) All of these
63) In ______________ mould, two injection moulds are operated in the same moulding machine.
(a) Three pale (b) Hot Runner (c) Unscrewing (d) Stack
64) What are the assembly methods for plastic parts?
(a) By Screw (b) Welds (c) Snap latches (d) All of these
65) Stripping of threaded undercuts is permissible with maximum strain of ________ percent.
(a) 10 (b) 8 (c) 15 (d) 21
66) Cooling time is proportional to the ________ of the heaviest part wall thickness or the power of
______ for the largest runner diameter.
67) Assembly of mould on the machine for the indirect clamping consists of ________ & ________
68) Standard Two plate mould consists of ______ daylight.
69) Three plate mould with stripper plate ejection consists of _______ daylights.
70) The SPI “A” Grade mould finishes are completed with __________
71) The SPI “B” Grade mould finishes are completed with __________
72) R I M Stands for ________________
73) B M C Stands for _______________
74) S M C Stands for _______________
75) R T M Stands for _______________
76) S R I M Stands for _______________
77) Expand BIS ______________________
78) Expand ISO ______________________
79) Expand EDM _____________________
80) _______________ is abbreviated as LCPs.
81) _______________ is abbreviated as Tg.
82) ______________ is abbreviated as SPI
83) ___________ is abbreviated as LFW
84) Draw down ratio = die gap divided by ______________ x blow ratio
85) ___________ is abbreviated as L/D ratio
86) Film thickness is expressed in terms of __________
87) _________________ is abbreviated as B.T.U
88) ______________ is abbreviated as IML
Contd.., P/5
Page No. 5
89) _____________ is abbreviated as FRP
90) The ratio of the volume of the first flight of an extruder screw (at the feed end) to the volume of the last flight
(at the metering end) is _______________ .
91) 'O' Ring is used to prevent ________________ of the coolant in the mould.
92) The included angle of the sprue bush is ______________.
93) Shot weight = ____________________ plus weight of the feed system.
94) Clamping force = _________________ x Effective Injection Pressure.
95) Ejection system is provided generally in the ___________ side of the mould.
96) ____________ is used to give alignment of the mould with the Injection moulding machine.
97) Split cavity mould is suitable for _________________ components.
98) The part of the mould which gives the outer shape of the moulding is ______________
99) ______________ is the channel for connecting the runner with impression.
100) The best preferred runner type is _________________
101) _______________ is used to bring ejector assembly to its original position.
102) ___________ is provided in moulded parts for easy removal of components.
103) Combination of compression & Injection moulding is known as _______________
104) Generally, the compression moulds are heated by _______________
105) _________________ decides the size of the loading chamber in compression moulding.
106) The period required to harden thermosetting materials is called ______________
107) ______________are used to permit displacement of excess plastic materials in blow moulding.
108) Parison is used in _________________ moulding process.
109) The allowable flash thickness is ____________ mm in compression moulding process.
110) Parison diameter is controlled by ____________ & ______________
111) _____________ material is suitable for blow mould construction.
112) In compression moulding, evacuation of air is done by ______________
113) Blow ratio = Part maximum diameter divided by ________________
114) Stretch blow moulding process involves _______________ molecular orientation.
115) An angular piece of material used to support the bosses and strengthen the wall is called _________
116) Bakelite is the commercial name of _____________________
117) Coat hanger Die is used for producing _________________ products.
118) The Extrusion Pipe die channel is made up of two sections namely _________ and ________section.
119) In order to eliminate sink marks, the wall thickness should be _____________
120) ______ is caused by volumetric change in the polymer as it cools from molten condition to solid state.
121) In split cavity moulds the finger cam angle is ________ to _________.
122) __________ are standard component part used to seal ends of drilled flow way holes.
123) A maximum of ________ % regrind can be blended with virgin material.
124) Commonly used plastic Gear materials are ___________ & ______________
125) ____________ is defined as the geometry and topology of a feature.
126) Register ring is used for aligning two halves of the mould. (Say True or False)
127) Diaphragm gate used for hollow / cylindrical mouldings. (Say True or False)
128) Venting is provided in the mould to prevent flash in the parting surface. (Say True or False)
129) Bubbler cooling system is adapted generally in cavity part of the mould. (Say True or False)
Contd.., P/6
Page No. 6
130) Automatic degating is possible in direct sprue gate. (Say True or False)
131) Push back pin is used to push the moulding from the core. (Say True or False)
132) The stripper plate is used for ejecting the product from the mould. (Say True or False)
133) In compression mould material to be compressed through feed system. (Say True or False)
134) In blow moulds core is necessary part. (Say True or False)
135) Rapid prototyping is an addition process. (Say True or False)
136) The blow ratio in extrusion moulding process is usually 1.5 to 3.0 - (Say True or False)
137) In thermosetting moulds normally cartridge heaters are used. (Say True or False)
138) Blow mould is provided with pinch off at the bottom to squeeze and weld parison. (Say True or False)
139) Flash is desirable in transfer mould design. (Say True or False)
140) Bulk factor of plastics materials is not useful in compression mould design. (Say True or False)
141) The term 'Cull' is associated in transfer moulding process. (Say True or False)
142) In compression moulding process, flash is required on moulding. (Say True or False)
143) The die used for coating of wire and cable is cross head / offset die. (Say True or False)
144) Preform is used for making Extruded bottles. (Say True or False)
145) Wire coating die is used in gas injection mould. (Say True or False)
146) In gas injection mould atmospheric air is filled. (Say True or False)
147) The best shape for a rotational moulded part is ball. (Say True or False)
148) Bosses help in assembling of the plastic parts. (Say True or False)
149) When the cycle time is reduced the production rate is increased. (Say True or False)
150) Ribs are given to provide strength to the component. (Say True or False)
151) Plastic product should be uniform wall thickness to avoid sink mark and warpage. (Say True or False)
152) Vertical flash occurs in open flash type of compression mould. (Say True or False)
153) Undercut is an indentation or projection on a moulded part. (Say True or False)
154) Fillet Radius is used to prevent stress concentration. (Say True or False)
155) Flash is caused by volumetric change in the polymer as it cools from molten condition to solid state.
(Say True or False)
156) Big containers (Sintex tank) are manufactured by Rotational Moulding process. (Say True or False)
157) Neck sizes for stretch blow bottles are standardized. (Say True or False)
158) Thicker walls increase material consumption, lengthen cycle time. (Say True or False)
159) Polycarbonate has high MFI. (Say True or False)
160) Raised letters on the moulded plastic part are depressed letters on the mould. (Say True or False)
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