Question 1

The joints made by an electromagnetic forming process are much stronger than the parent material.

Accepted Answer

Electromagnetic forming is a process that uses electromagnetic forces to shape metal. The process can be used to create joints that are stronger than the parent material because the electromagnetic forces can be used to create a stronger bond between the two pieces of metal.

Question 2

What is the minimum pressure required in a compression molding process?&#10;A)0.5 mpa&#10;B)1 mpa&#10;C)1.5 mpa&#10;D)2 mpa

Accepted Answer

The minimum pressure required in a compression molding process is 0.5 mpa. This is because the pressure must be high enough to overcome the resistance of the material to flow into the mold, but not so high that it causes the material to flash out of the mold.

Question 3

What is the minimum curing time required in a compression molding process?&#10;A)0.4 minutes&#10;B)0.5 minutes&#10;C)0.6 minutes&#10;D)0.7 minutes

Accepted Answer

The minimum curing time required in a compression molding process is typically 0.5 minutes. This time can vary based on the specific material and process conditions, but 0.5 minutes is a standard minimum for ensuring proper curing in a general context.

Question 4

What is the maximum pressure required in a transfer molding process?&#10;A)80 mpa&#10;B)90 mpa&#10;C)100 mpa&#10;D)120 mpa

Accepted Answer

The maximum pressure required in a transfer molding process is typically around 100 MPa.

Question 5

Thermosetting materials are the polymeric materials which get soften on heating with or without pressure.

Accepted Answer

Thermosetting materials do not soften on heating; instead, they undergo a chemical reaction that sets their shape permanently.

Question 6

Polyurethanes plastics can be made in flexible foams even after belonging to thermosetting polymers.

Accepted Answer

Polyurethanes are versatile materials that can be engineered to be either flexible or rigid, making them suitable for a wide range of applications, including flexible foams, despite being thermosetting polymers which typically do not melt upon heating.

Question 7

Thermosetting plastics like epoxies can be used for filament wound rocket motor casings in missiles by combining with glass fibers.

Accepted Answer

Thermosetting plastics, such as epoxies, when combined with reinforcing materials like glass fibers, can be used to create strong, durable composites suitable for high-stress applications including filament wound rocket motor casings in missiles.

Question 8

Mechanical properties of any plastics are mainly dependent on the temperature, force and time of load applied.

Accepted Answer

The mechanical properties of plastics, such as strength, flexibility, and durability, are significantly influenced by the temperature, the magnitude and duration of the force applied, and the time over which the load is applied. These factors affect how the plastic material behaves under different conditions.

Question 9

Where does the granular molding material get loaded into?&#10;A)barrel&#10;B)hopper&#10;C)pellets&#10;D)split

Accepted Answer

The granular molding material is loaded into the hopper. The hopper is a large container used in industrial processes to hold and dispense bulk material like granular molding material before it is fed into a machine, such as an injection molding machine.

Question 10

There is a varied pressure provided in the solidification unit of injection molding process.

Accepted Answer

In the injection molding process, pressure is applied during the injection and packing phases, but once the material enters the solidification unit (mold cavity), the pressure is generally held constant to ensure uniform filling and cooling, rather than varied.

Question 11

Which of the following is not an application of blow molding process?&#10;A)toy bodies&#10;B)door liners&#10;C)bottles&#10;D)pipes

Accepted Answer

The answer of Which of the following is not an...

Question 12

The heater in the vacuum forming process is heated up to 90&#176;C.

Accepted Answer

The answer of The heater in the vacuum forming process...

Question 13

The initial cost in blow molding is low.

Accepted Answer

The answer of The initial cost in blow molding is...

Deck 12: Polymer Processing Techniques