This set of Composite Materials Multiple Choice Questions & Answers (MCQs) focuses on “Other Manufacturing Process”.
1. Which process works by placing a resin film under the dry fiber preform in the initial stage?
a) Compression molding
b) Pultrusion
c) Resin film infusion
d) Filament winding
View Answer
Explanation: In the Resin film infusion process, a resin film which is pre-catalysed is placed under the dry fiber preform where the liquid resin flows through the preform and becomes matrix on curing. The process begins by placing the resin film over the mold surface and then placing the dry fiber preform on top of the resin film.
2. Resin film infusion can be carried out by using the bag-molding technique.
a) True
b) False
View Answer
Explanation: The assembly of the dry fiber preform and resin film is placed inside an autoclave after covering it with a vacuum bag. The vacuum bag helps in the removal of the entrapped air from the preform.
3. What forces the liquid resin to infiltrate the preform in the Resin film infusion process?
a) Applied pressure
b) Temperature raise
c) Increase in viscosity
d) Vacuum
View Answer
Explanation: The resin viscosity decreases and the resin starts to flow through the dry fiber preform, as the temperature is increased in the autoclave. But this does not ensure the proper infiltration of the liquid resin into the preform. Therefore, Pressure is exerted to force the liquid resin to infiltrate the preform and wet out the fibers.
4. High fibre volumes can be accurately achieved with low void contents in the Resin film infusion process.
a) True
b) False
View Answer
Explanation: The resin infuses into the dry fiber preform evenly, without leaving voids or dry areas. Other advantages of Resin film infusion include less expensive molds, uniform resin distribution, short fabrication time and good safety.
5. Which process uses pressure to compress the resin-impregnated foam in between the reinforcements?
a) Compression molding
b) Bag molding
c) Tube rolling
d) Elastic reservoir molding
View Answer
Explanation: Elastic reservoir molding is a process in which a sandwich of dry fiber reinforcements and liquid resin-impregnated foam are pressed with a molding pressure of 520 kPa-1030 kPa. The resin flows out and wets the face layers when the foam is compressed. A sandwich of low-density core and fibre-reinforced skins is formed on curing.
6. What is used for the storing of the liquid catalysed resin in Elastic reservoir molding?
a) Polyurethane
b) Polyester
c) Polypropylene
d) Polyvinyl chloride
View Answer
Explanation: Flexible Polyurethane foam placed at the center of the sandwich acts an elastic reservoir for storing the catalysed liquid resin. This foam is compressed by exerting pressure for the liquid resin to flow out and infiltrate into the dry fiber reinforcement.
7. Low-cost tooling is an advantage of the Elastic reservoir process.
a) True
b) False
View Answer
Explanation: Elastic reservoir molding process has several advantages. It includes better control of properties, low-cost tooling and a better stiffness–weight ratio.
8. Elastic reservoir molding is widely used in molding complex parts.
a) True
b) False
View Answer
Explanation: Elastic reservoir molding is generally limited to molding thin panels of simple geometry. Some of its applications are radar reflecting surfaces, luggage carriers, roof panels and automotive body panels.
9. Which process is used to produce long and thick-walled continuous tubing?
a) Vacuum bag molding
b) Tube rolling
c) Filament winding
d) Pultrusion
View Answer
Explanation: Tube rolling is a composite manufacturing process for producing finite-length rods and tubes. This method is often used to fabricate circular tubes for bicycle frames or space trusses.
10. Precut lengths of a prepreg are rolled onto a removable mandrel in a tube rolling process.
a) True
b) False
View Answer
Explanation: The uncured prepreg tube is wrapped with a sleeve and cured at higher temperatures in an air-circulating oven. As the outer wrap shrinks and tightens on the rolled prepreg, the entrapped air between the layers is forced out through the ends. After curing occurs, the mandrel is removed and a hollow tube is formed.
Sanfoundry Global Education & Learning Series – Composite Materials.
To practice all areas of Composite Materials, here is complete set of 1000+ Multiple Choice Questions and Answers.
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