3D Printing (Powder)

Question 1

3D Printing / Powder

Answer 1

Category - Binder Jetting

• ink jet printing heads move across a powdered material in a scanning pattern, distributing a liquid inorganic binder and ink to “glue” the powder particles in the shape of each layer.

Question 2

3D Printing / Photopolymer

Answer 2

Category - Material Jetting

• Ink jet printing heads eject micro droplets of molten plastic or wax material onto a stationary platform is which is cured by UV light (polymer phase change inkjet or jetted photopolymer technology)

Question 3

3D printing (powder bed) - principle/method

Answer 3

• ink jet printing heads move across a powdered material in a scanning pattern ejecting droplets of an adhesive bonding material into the required cross section shape.
• Lowering the platform with the powder bed by the slice thickness after each new layer is formed at the surface.
• The unbonded powder remains loose and acts as support structure for overhanging or fragile features.
• Post process e.g. heat treatment to strengthen the part by solidification.

Question 4

3D printing (powder bed) process characteristics.

Answer 4

• Layer thickness 0.1mm
• Vertical Build Speed 5-28mm/he
• Prototype often porous with slightly grainy surface.
• May lack strength; sinter or infiltrate with glue to make stronger.
• Parts can be sanded, drilled and tapped
• accuracy 300x450 or 600x540dpi

Question 5

3D Printing (powderbed) Materials?

Answer 5

• Plastic or starch based powders (ABS, PA, PC)

Question 6

3D printing (powder bed) applications?

Answer 6

• Concept Models
• Parts for limited Functional testing
• Colour Models for FEA and other engineering related applications.
• Architectural and landscape models.
• Colour industrial design models especially consumer goods and packaging.
• Castings

Question 7

3D printing (Powder bed) Advantages?

Answer 7

• Good Range of Materials (Metal, Polymer and ceramics)
• Two material method allows for a number of different binder powder combinations and various mechanical properties.
• Quick processing time.
• No support structure required.
• Realistic, multi coloured models, complex geometries with intricate, small and detailed features.
• Good for secondary operations (parts can be sanded, drilled, tapped and painted and electroplated)
• Office Friendly (quiet, safe, odourfree easy to use)

Question 8

3D printing (powder bed) Limitations?

Answer 8

• Accuracy and surface finish fair.
• Fragile prototypes - may require strengthening.
• Post processing is often required to strengthen the part (enhance mechanical and structural properties)
• Overall process time is extended by binder to set and the part fully solidifies while in the machine.