Deck 11: Processing of Polymer Matrix Composites and Rubber

Question 1

A polymer matrix composite is a composite material consisting of a polymer embedded with a reinforcing phase such as fibers or powders:

Answer 1

True

Question 2

Which one of the following is the most common polymer type in fiber-reinforced polymer composites:

A)elastomers
B)thermoplastics
C)thermosets

Answer 2

thermosets

Question 3

Most rubber products can be described as which of the following (three best answers):

A)elastomer reinforced with carbon black
B)fiber-reinforced composite
C)particle-reinforced composite
D)polymer matrix composite
E)pure elastomer
F)pure polymer

Answer 3

elastomer reinforced with carbon black
particle-reinforced composite
polymer matrix composite

Question 4

The difference between a roving and a yarn is that a roving consists of untwisted filaments whereas a yarn consists of twisted filaments:

Question 5

The advantage of using an open mold is which one of the following:

A)higher production rates are possible
B)smoother surfaces are achieved on both sides of the molding
C)the interior of the mold is accessible
D)the mold costs much less than if two matching molds were used

Question 6

Of the three open mold processes for polymer matrix composites described in the text, hand lay-up is the least labor-intensive:

Question 7

A positive open mold with a smooth surface will produce a good finish on which surface of the laminated product in the hand lay-up method:

A)inside surface
B)outside surface

Question 8

Which of the following products are not typically made by hand lay-up open mold operations (two best answers):

A)boat hulls
B)fishing poles
C)large container tanks
D)swimming pools
E)tennis rackets

Question 9

An apparatus that provides control over both temperature and pressure and is used to cure polymer matrix composites is called which one of the following:

A)autoclave
B)curing furnace
C)curing oven
D)pressure cooker

Question 10

A molding operation that uses sheet-molding compound is a form of which one of the following:

A)compression molding
B)contact molding
C)injection molding
D)open mold processing
E)pultrusion
F)transfer molding

Question 11

Filament winding involves the use of which one of the following fiber reinforcements:

A)continuous filaments
B)fabrics
C)mats
D)prepregs
E)short fibers
F)woven rovings

Question 12

The special tooling in filament winding that determines the shape of the filament-wound part is called which one of the following:

A)collet
B)core
C)fixture
D)mandrel
E)mold
F)pattern

Question 13

Pultrusion is most similar to which one of the following plastic shaping processes:

A)blow-molding
B)extrusion
C)injection molding
D)thermoforming

Question 14

Pulforming is similar to pultrusion but is capable of producing a semicircular contour with altered cross sections at one or more locations along the length of the part:

Question 15

Water jet cutting is one of several ways of cutting or trimming uncured or cured FRPs; in the case of cured FRPs, the process is noted for its reduction of dust and noise:

Question 16

The most important rubber product is which one of the following:

A)footwear
B)conveyor belts
C)pneumatic tires
D)tennis balls

Question 17

The chemical name of the ingredient recovered from the latex of the rubber tree is which one of the following:

A)polybutadiene
B)polyisobutylene
C)polyisoprene
D)polystyrene

Question 18

Of the following rubber additives, which one would rank as the single most important:

A)antioxidants
B)carbon black
C)clays and other hydrous aluminum silicates
D)plasticizers and softening oils
E)reclaimed rubber

Question 19

Which one of the following molding processes is the most important in the production of products made of conventional rubber:

A)compression molding
B)injection molding
C)thermoforming
D)transfer molding

Question 20

Which of the following ingredients do not contribute to the vulcanizing process (two correct answers):

A)calcium carbonate
B)carbon black
C)stearic acid
D)sulfur
E)zinc oxide

Question 21

How many minutes are required to cure (vulcanize) a modern passenger car tire:

A)5
B)15
C)25
D)45

Question 22

When is the tread pattern imprinted onto the circumference of the tire:

A)during preforming
B)while building the carcass
C)during molding
D)during curing

Question 23

Which of the following are not normally used in the processing of thermoplastic elastomers (two correct answers):

A)blow molding
B)compression molding
C)extrusion
D)injection molding
E)vulcanization