Multiple Choice Question Design

Softwood from coniferous trees, used in building frames, typically sawn into standard sizes.

Predefined sizes and shapes of timber, such as strips, boards, and planks.

Hard, corrosion-resistant materials, used for high-temperature applications and in tools.

High compressive strength, low tensile strength, low ductility, and brittle, excellent electrical/thermal insulators.

Often made by molding then fired in high-temperature furnaces to create the material.

Usually not cost-effective due to high melting temperatures required.

A type of polymer that forms strong cross-links between chains, making it rigid, hard, and unable to be reshaped after molding. It does not soften when heated but instead chars or burns.

A type of polymer that can be repeatedly melted and remolded. It softens when heated and hardens when cooled.

High strength, stiff, and brittle; excellent temperature, chemical, and electrical resistance.

Good strength and stiffness; brittle; good temperature, chemical, and electrical resistance. Lower cost.

Stiff, hard, strong, resistant to some chemicals and stains.

Hard, high strength; flexible, tough; low thermal conductivity.

Higher tensile strength; elastic; resistant to abrasion and swelling.

Thermoplastics can be repeatedly melted and remolded, while thermosetting polymers cannot. Thermosets have permanent cross-links, while thermoplastics do not.

A thermoplastic polymer is recommended for a microwave bowl because it can be heated repeatedly and will not release harmful chemicals.

A process for creating polymer parts using a machine that melts polymer granules to their molten state. The molten polymer is then forced under pressure into a mold to take the desired shape.

Small, solid pellets of polymer material used as raw material in injection molding.

Heating polymer granules to a liquid state. This is a crucial step in injection molding.

A mold cavity into which the molten polymer is injected and cools into the desired form.

A component in the injection molding machine that pushes the polymer granules and melts them.

Part of the machine that contains the polymer granules waiting to be fed into the process.

Components in the mould that remove the finished part from the mould.

Process of cooling the injected part in the mold to ensure the final shape of the part.

Injection moulding allows for quick production cycles making thousands of parts per hour.

Despite the high cost of equipment, injection molding is relatively cost-effective due to the high rate of production of parts.

The machine uses components such as an Archimedian screw, feed hopper, ejector pins, mold, guide bars, heaters, moving mold, hydraulic ram, and hydraulic motor.