3D Product Materials and Finishing

Question 1

What is the difference between thermoplastics and thermosets in product manufacturing?

Accepted Answer

Thermoplastics soften and reshape when heated repeatedly; thermosets cure permanently and cannot be remelted

Answer

Thermoplastics are always rigid; thermosets are always flexible

Answer

Thermoplastics are used only in 3D printing; thermosets are used in injection molding

Answer

Thermoplastics are bio-based; thermosets are petroleum-based

Question 2

What is 'Shore hardness' and what product property does it measure?

Accepted Answer

A scale measuring the hardness or resistance to indentation of rubber, elastomer, and plastic materials

Answer

A color calibration standard for surface finishes

Answer

A measure of a material's tensile strength

Answer

An electrical conductivity rating for polymers

Question 3

What is 'overmolding' in plastic product manufacturing?

Accepted Answer

Molding a second material over a rigid substrate to add soft-touch grip, sealing, or color accents

Answer

Creating a mold from an existing product for reproduction

Answer

Coating a metal part with a plastic sleeve

Answer

A defect where plastic flashes over the parting line

Question 4

What is 'anodizing' and to which base material is it applied?

Accepted Answer

An electrochemical process that grows a hard, corrosion-resistant oxide layer on aluminum surfaces

Answer

A painting technique for plastic parts

Answer

A chrome plating process for steel

Answer

A powder coating process for zinc die castings

Question 5

What is 'surface roughness' (Ra) in manufacturing, and why does it matter for product design?

Accepted Answer

The average deviation of surface peaks and valleys from the mean line, affecting feel, friction, and coating adhesion

Answer

The color variation on painted surfaces

Answer

The warpage of a flat surface during cooling

Answer

The thickness uniformity of an injection molded wall

Question 6

What is polycarbonate (PC) known for in consumer product applications?

Accepted Answer

Very high impact resistance and optical transparency, used in safety lenses, phone cases, and headlight lenses

Answer

Extreme chemical resistance and low friction for bearings

Answer

Biodegradability and renewable sourcing

Answer

Very high-temperature resistance above 300°C