manufacturing: Plastics and PM
In plastics injection molding, which of the following statements is the correct definition of a sink?
A depression on the surface of the molded part causes by shrinkage upon solidification
Which of the following process would be applicable to produce hulls for small boats
Blow molding, rotational molding, vacuum termoforming
filament winding involves the use of which one of the following fiber reinforcements?
Continuous filaments
A hot-runner three-plate mold offers which of the following advantages when compared to a cold-runner, two plate mold
Gating is usually a the base of the part to reduce part lines, Automatic separation of parts from runners
Which of the following is the most common polymer type in fiber-reinforced polymer composites
Thermosets
In ceramic, properties improvement comes from
strong bonds between complex oxide particles, loss of moisture,
The termal tempering of glass is
takes relatively short time, hot glass is cooled quickly, it is better with lower thermal conductivity, it is better with higher coefficient of thermal expansion
Which of the following processes are generally limited to thermoplastic polymers
thermoforming and blow molding
Injection molding is not suitable for processes thermosets becasue of their short solidifaction time
true
Use of a parison is associated with which plastic shaping processes?
blow molding
The term encapsulation refers to which of the following plastics shaping processes?
casting
A molding operation that uses sheet-molding compound is a form of which of the following
compression molding
Which of the following forming processes does not apply to thermoset polymers
extrusion
True/false: In rotational molding, centrifugal force is used to force the polymer melt against the surfaces of the mold cavity where solidification occurs
false
True/false: Thermosets are injection molded in cool molds
false
Density within the compacted powder metal parts vary due to
friction between particles and the particles and the mold
which of the following is not a property of polymers
high strength to weight ratios compared to metals
isostatic pressing resolves which of the following problems
homogenous density distribution
Injection molding is similar to which of the following metal forming processes
hot chamber die casting
Green mold
moisture is contained in the mold
A female mold with a smooth surface will produce a good finish on which surfaces of the laminated product in the hand lay-up method
outside surface
In hot isostatic pressing, the mold is most typically made of which of the following
sheet metal