ENGM 445 Final Questions with
complete solution
Which two of the following are purposes of finishing operations such as
grinding used for parts made of the new ceramics?
apply a surface coating
electroplate the surface
improve surface finish
increase dimensional accuracy - correct answer improve surface finish
increase dimensional accuracy
A roving is a collection of twisted continuous strands, whereas a yarn is an
untwisted collection of filaments. T o F - correct answer False
Of the open mold processes for polymer matrix composites, hand lay-up is the
least labor-intensive. T o F - correct answer False
In the hand lay-up process, a dry layer of fiber reinforcement is placed onto
the mold and impregnated by liquid uncured resin using a manual rolling
technique; the process is repeated for successive layers. T o F - correct
answer True
Automated tape-laying (ATL) machines dispense a prepreg tape onto an open
mold by following a programmed series of back-and-forth passes across the
mold surface until the parallel rows of tape complete each layer. T o F -
correct answer True
,The principal process parameters in curing (cross-linking) of the thermosets
used in fiber-reinforced polymer composites are time, temperature, and
pressure. T o F - correct answer True
Resin transfer molding is a closed-mold process in which a preform mat is
placed in the mold and a thermosetting resin is transferred into the cavity
under moderate pressure to impregnate the preform. T o F - correct answer
True
Although thermoplastic fiber-reinforced plastics can be injection molded,
thermosetting FRPs cannot be injection molded because of the risk of
premature cross-linking in the injection chamber. T o F - correct answer False
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. T o F - correct answer True
The term prepreg stands for which one of the following? - correct answer pre-
impregnated fibers
An advantage of using an open mold versus a closed mold is which one of the
following? - correct answer the mold costs much less than if two matching
molds were used
Which two of the following products are not made by hand lay-up open-mold
operations?
Boat hulls
Fishing Polls
Larger Container tanks
Swimming pools
, Tennis Rackets - correct answer Fishing Polls
Tennis Rackets
In the spray-up method, liquid resin is applied on an open mold and chopped
fibers are then sprayed onto the resin to build successive FRP laminations. T
o F - correct answer False
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? -
correct answer Autoclave
A molding operation that uses sheet-molding compound is a form of which
one of the following? - correct answer compression molding
Filament winding involves the use of which one of the following fiber
reinforcements? - correct answer continuous filaments
The special tooling in filament winding that determines the shape of the
filament-wound part is called which one of the following? - correct answer
mandrel
The most important rubber product is which one of the following? - correct
answer pneumatic tires
The name of the natural rubber sheets that have been dried in smokehouses
is which one of the following? - correct answer ribbed smoked sheet
Of the following additives in rubber, which one would rank as the single most
important? - correct answer carbon black
complete solution
Which two of the following are purposes of finishing operations such as
grinding used for parts made of the new ceramics?
apply a surface coating
electroplate the surface
improve surface finish
increase dimensional accuracy - correct answer improve surface finish
increase dimensional accuracy
A roving is a collection of twisted continuous strands, whereas a yarn is an
untwisted collection of filaments. T o F - correct answer False
Of the open mold processes for polymer matrix composites, hand lay-up is the
least labor-intensive. T o F - correct answer False
In the hand lay-up process, a dry layer of fiber reinforcement is placed onto
the mold and impregnated by liquid uncured resin using a manual rolling
technique; the process is repeated for successive layers. T o F - correct
answer True
Automated tape-laying (ATL) machines dispense a prepreg tape onto an open
mold by following a programmed series of back-and-forth passes across the
mold surface until the parallel rows of tape complete each layer. T o F -
correct answer True
,The principal process parameters in curing (cross-linking) of the thermosets
used in fiber-reinforced polymer composites are time, temperature, and
pressure. T o F - correct answer True
Resin transfer molding is a closed-mold process in which a preform mat is
placed in the mold and a thermosetting resin is transferred into the cavity
under moderate pressure to impregnate the preform. T o F - correct answer
True
Although thermoplastic fiber-reinforced plastics can be injection molded,
thermosetting FRPs cannot be injection molded because of the risk of
premature cross-linking in the injection chamber. T o F - correct answer False
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. T o F - correct answer True
The term prepreg stands for which one of the following? - correct answer pre-
impregnated fibers
An advantage of using an open mold versus a closed mold is which one of the
following? - correct answer the mold costs much less than if two matching
molds were used
Which two of the following products are not made by hand lay-up open-mold
operations?
Boat hulls
Fishing Polls
Larger Container tanks
Swimming pools
, Tennis Rackets - correct answer Fishing Polls
Tennis Rackets
In the spray-up method, liquid resin is applied on an open mold and chopped
fibers are then sprayed onto the resin to build successive FRP laminations. T
o F - correct answer False
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? -
correct answer Autoclave
A molding operation that uses sheet-molding compound is a form of which
one of the following? - correct answer compression molding
Filament winding involves the use of which one of the following fiber
reinforcements? - correct answer continuous filaments
The special tooling in filament winding that determines the shape of the
filament-wound part is called which one of the following? - correct answer
mandrel
The most important rubber product is which one of the following? - correct
answer pneumatic tires
The name of the natural rubber sheets that have been dried in smokehouses
is which one of the following? - correct answer ribbed smoked sheet
Of the following additives in rubber, which one would rank as the single most
important? - correct answer carbon black
