Injection Molding Technology — Winter 2024

Explain the basic working principle of an injection moulding machine.

Explain the function and significance of the clamping unit in an injection

mExopulladiinn gi.n m daecthaiinl et.h e basic principles of the reciprocating screw machine in injection moulding.

Briefly explain what a thermocouple is and its role in the injection moulding machine.

Differentiate between a standard nozzle and a needle-type nozzle.

Explain the various screw types used in injection moulding machines and how they influence screw plasticization and output.

Describe the constructional features of the clamping unit in an injection moulding machine. Compare toggle clamp and hydraulic clamp mechanisms, discussing their advantages and limitations.

What is a bimetallic barrel and why is it used in injection moulding?

Explain the importance of a grooved barrel in an injection moulding machine.

What factors determine the tonnage of the clamping unit in an injection moulding machine?

What is the function of the hopper in an injection moulding machine?

Define the PVT (Pressure-Volume-Temperature) diagram in the context of injection moulding.

Compare hydraulic clamping with toggle clamping in terms of their working mechanism.

Mention two advantages and two disadvantages of the injection moulding process.

What are the key process variables that influence the quality of parts produced in injection moulding?

Discuss in detail the machine startup and shutdown procedures in an injection moulding machine,

What are the typical materials used in injection moulding of thermosets?

List two design considerations for parts made with thermoset injection moulding.

What are some common troubleshooting techniques for defects encountered in thermoset injection moulding?

What are the main causes of short shots in injection moulding?

What are flow marks, and how can they be prevented in injection moulding?

Explain the common faults such as crazing, discoloration, and silver streaks in injection moulding. What are their causes, and how can these defects be corrected?

What is the purpose of a conveyor in an injection moulding setup?

Describe how a hopper loader operates and its importance in injection moulding.

List out the types of process variables that affect the injection cycle and explain them in detail.