lecture 4- Filaments for Material Extrusion

Question 1

What is the feed system for ME printers

Answer 1

Torque and a pinch system to feed and retract the filaments at precise amounts.

Question 2

List common filament failures

Answer 2

Entanglement-loss of tension on reel
Jamming or slipping-shit quality filament from supplier
Degradation-Basically damage to reel

Question 3

Breifly describe the filament manufacture process

Answer 3

Screw extruder forces the plastic through a die where it is cooled and wound

Question 4

Filament selection process

Answer 4

Think about the Printer being used 
-operating temperature
-Diameter of nozzle
-Stiffness of material
Think of application 
-Strength
Flexibility
Post process
Enviroment

Question 5

Most common material used in ME?

And 2nd most common

Answer 5

PLA
-Made from starch
-Can print without heated bed
-Good stifness/poor heat 
ABS
From oil
Heated bed needed
Good strength parts
Curling and warping

Question 6

Filiment selection Considerations

Answer 6

Filament selection will require consideration of .
• Machine limitations / requirements
• Process limitations / requirements,
• Application requirements

Question 7

What is blending?

Answer 7

Blending materials to give a wide range of properties such as

• warp
• melt temp
• Flexibility
• Glass temp

Question 8

Filament materials

Answer 8

PEEK 
High performance (expensive)

PPSU- Medical field for sterilisation

Fibre reienforced-Carbon/Glass/Kevlar peices

Support structure-Sacrificial material