Rubber Engineering & its Economics — Winter 2025

Define the given terms: (i) Supply (ii) Growth Development (iii) Inflation.

Outline the various functions of Rubber Engineer in the Rubber Industry.

What is the role of the Maintenance Department? Explain in detail.

State the primary purpose of the emergency brake mechanism on an Open Mixing Mill.

Briefly explain the phenomenon of "Band Formation" in rubber milling.

Discuss the significance of the various stages associated with the rubber mixing process on an open mill, from band formation to final sheet-off. What factors determine the end of the mixing cycle?

Discuss how the rotor design (e.g., tangential vs. intermeshing) influences the efficiency and quality of the rubber compound.

List any three ancillary equipment (e.g., cooling troughs, take-off units) used with a rubber extruder.

Distinguish between a Hot Feed Extruder and a Cold Feed Extruder based on raw material input and pre-heating requirements.

Outline the detailed procedure for preparing and setting up the compression mould (e.g., cleaning, applying release agent, loading the pre-form)

Define the following terms with respect to extrusion: L/D Ratio and Compression Ratio.

Draw a simple, neat cross-sectional sketch of a single-screw extruder and label the main components responsible for material conveyance and pressure generation.

Distinguish between the Compression Moulding and Transfer Moulding techniques when utilizing Hand Press.

Define the term "Nip Guard" in the context of an open mixing mill. What is its primary function?

Explain the working principle of the rupture disc (or pressure relief valve) installed on an extruder barrel or head.

Explain the role of the E-Stop (Emergency Stop) buttons and their placement on the press.

List of three different types of safety tripping devices commonly used on a two-roll mixing mill.

Distinguish between a guard and an interlock as safety features on an extruder, providing an example of each.1

Analyze the potential hazards related to mold misalignment and excessive pressure buildup during the initial trials and then propose three specific safety devices/procedures that an engineer must implement to mitigate these risks.

Define the following terms with respect to compression moulding: (i) Flash, (ii) Cavity, (iii) Cure Time.

List and briefly explain any four key advantages of the Compression Moulding process.

Analyze the critical process parameters of Rubber Injection Moulding: (i) Injection Pressure and (ii) Mould Temperature.

Define (i) Transfer Pot, (ii) Sprue Bush, and (iii) Cull in the context of transfer moulding.

Differentiate between compression moulding and transfer moulding based on (i) Perform preparation, (ii) Material-flow path, and (iii) Scrap/Cull formation.

Explain the importance of Temperature Control in the Rubber Injection Moulding process.