binder jetting

Question 1

Binder jetting

Answer 1

• A liquid bonding agent is selectively deposited to join powder
  materials.

Question 2

What is binder jetting similar too

Answer 2

jetting

Powder Bed

Question 3

advantages binder jet

Answer 3

Simple low cost systems compared to many other
AM techniques.
• Use starch & cellulose, or plaster (primarily
gypsum) powder materials.
• Binder solution is primarily water based.
• Colour Printer available.
• Fast process due to Jetting.
• Very little waste material.

Question 4

Disadvantages of binder jetting

Answer 4

• Limited Functional Parts
• Limited Strength
• Limited Materials (Starch, Plaster-Based
Materials)
• Poor Surface Finish
• Poor resolution
– Particle size distribution
– Wetting of the binder
• Multiple secondary processes

Question 5

Colour Binder Jetting why is it useful how fat is it

Answer 5

Example speed comparison:
– 1-2 hours for monochrome parts
– 4-6 hours in colou

comunicate ideas

Question 6

describe post process

Answer 6

Piston raised and the loose
powder is vacuumed to reveal
part.
• Parts in "green” state are very
fragile.
• De-powder the part then dry it
thoroughly.
• Resultant part is porous.
• Infiltration with liquid secondary
materials essential
Infiltration is the process of
applying a liquid resin to a
printed part to provide strength
and impart specific properties.
• Infiltration systems are selected
for their ability to:
– fill porosities
– Improve mechanical properties
– Ensure suitable thermal properties
– ease of use
• Common Infiltrants include:
– Elastomer, Erethane, Wax and
Cyanoacrylate

Question 7

Example applications

Answer 7

Plaster Casting Moulds

Question 8

how would a metal part be made

Answer 8

• In-process binding of metal powders with polymer based binder.
• Post processing requires the parts must be furnace sintered to
remove binder.
• Infiltration with a low melting point metal.

Question 9

Aerosol jet

Answer 9

• Atomised jet of
material sprayed
onto a substrate

Print variety of
materials like ink jet
printing

Question 10

aerosol vs inkjet

Answer 10

Inkjet
nozzle clogs
low density inks
random directionallity

Aerosol jet 
Clog resistant nozzle
High density droplets
Continuous stream
Tightly focused

Question 11

Describe which two process categories binder jetting is most similar to.

Answer 11

Process similar to Powder Bed Fusion except that Binder Jetting
selectively deposits a binder material which bonds powder rather than
melting by laser
• Process similar to Jetting techniques except binder jetting uses inkjet
heads to deposit only part of the final material

Question 12

What are the advantages and disadvantages of the binder jetting process?

Answer 12

Advantages:
• Simple low cost systems compared to many other AM techniques.
• Use starch & cellulose, or plaster (primarily gypsum) powder materials.
• Binder solution is primarily water based.
• Colour Printer available.
• Fast process due to Jetting.
• Very little waste material (unused powder can be recycled)
Disadvantages:
• Limited Functional Parts
• Limited Strength
• Limited Materials (Starch, Plaster-Based Materials)
• Poor Surface Finish
• Poor resolution
• Particle size distribution
• Wetting of the binder
• Multiple secondary processes

Question 13

ebam exam question describe it

Answer 13

• In the EBAM process, an electron beam is used to create melt pool on the
work part.
• A vacuum environment is required in the EBAM
• Metal wire is fed into the melt pool.
• Sciaky Inc. EBAM machine can produce parts 5.8m (l) x 1.2m (w) x 1.2m
(h) and 2.4m in diameter.

Question 14

Describe why additive manufacturing of ceramics is often difficult.

Answer 14

Sintering of ceramics often needs very high temperatures [1 mark] and if a binder
is used the final part after burning away the binder will be very porous [1 mark].