3D Product Materials & Finishing

Question 1

What is PLA filament and why is it commonly used for product prototyping?

Accepted Answer

Polylactic Acid, a biodegradable thermoplastic that is easy to print, low-warp, and available in many colors

Answer

PLA is a plant-derived thermoplastic that prints easily on unheated beds, produces little warping, and offers good detail — making it ideal for concept models and prototypes.

Question 2

What are the advantages of PETG filament over PLA for functional product prototypes?

Accepted Answer

PETG has better impact resistance, moisture resistance, and higher temperature tolerance than PLA

Answer

PETG combines PLA's ease of printing with better mechanical properties — higher impact and temperature resistance and food-safe characteristics for functional prototypes.

Question 3

What is 'Shore hardness' used to measure in product material selection?

Accepted Answer

The hardness and stiffness of rubber and flexible polymers

Answer

Shore hardness (A scale for soft rubbers, D scale for harder plastics) quantifies material firmness, used to spec flexible components like grips, gaskets, and seals.

Question 4

What is 'anisotropy' in 3D-printed parts and why does it matter?

Accepted Answer

The directional difference in mechanical properties — FDM parts are stronger along print layers than between them

Answer

FDM-printed parts are anisotropic because layer-to-layer bonding is weaker than in-plane strength, meaning part orientation relative to loads must be considered in design.

Question 5

What material property is described by 'tensile strength'?

Accepted Answer

The maximum stress a material can withstand when being pulled apart before it breaks

Answer

Tensile strength is the maximum pulling force per unit area a material can endure before fracturing — a key spec for structural product components.

3D Product Practice Test

3D Product Practice Test

3D Product Materials & Finishing