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33 Cards in this Set
- Front
- Back
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What is the definition of 3D printing?
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A layer-by-layer approach to selectively bind and adhere layers of powder to form a solid object
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How is 3DP different from SLS?
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SLS uses a laser to bond the powder thermally, whereas 3DP bonds chemically, consequently, SLS uses alot more energy (about 10000 times more)
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How is 3DP different from jetting?
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In jetting all of the material is deposited via the print head, in 3DP only the binder is. As a result, 3DP doesn't require support structures, where Jetting does.
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What are the process steps for 3DP?
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1. Import STL file
2. Fill feedbox with powder 3. Start building 4. Layer of powder spread over build platform/last layer 5. Print binder solution 6. Remaining powder supports next layer 7. Build platform is lowered, feeder platform is raised 8. Repeat steps 4-7 for each layer 9. Remove part from remaining powder 10. Post-process |
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Where was 3DP invented?
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MIT
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How are droplets generated in 3DP?
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Thermal or piezo-electric nozzles
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How long does a droplet take to seperate fully from the nozzle
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1mm or 50 microseconds
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What are the pros and cons of building colour parts?
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Communicate ideas to customer more easily, but takes 3-4 times longer to build
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What are the advantages of using 3DP for Geometric/Design prototyping?
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Doesn't take long
Colour is available Low cost compared to other techniques |
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What is the build speed range of monochrome 3DP?
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21-51mm per hour
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What is the layer thickness range of 3DP?
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75-250 microns
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What is the build speed range of colour 3DP?
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8-16mm per hour
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What are the advantages of using plaster rather than starch and cellulose powder in 3DP?
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Higher detail, 4-5 times stronger, reduced need for infiltration
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What are the advantages of using starch and cellulose powder rather than plaster in 3DP?
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Cheaper, faster. Suitable for sacrificial mold casting
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What post-processing steps are taken with 3DP?
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Piston raises part out of powder. Excess powder vacuumed off. Part is dried. Part is infiltrated with secondary liquids
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What common infiltration liquids are availabe in 3DP?
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Elastomer
Urethrane Sicomet 9000 Zr10 Wax |
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What are the application method, properties, and possible use of elastomer infiltrated parts?
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Dipping the part or painting it. Rubber like properties. For use with thin walled parts
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What are the application method, properties, and possible use of urethrane infiltrated parts?
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Static mixing machine. Look and feel of plastic. Marketing models.
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What are the properties of wax infiltrated parts? Why use it?
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Higher strength and better surface finish, because its cheap.
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What are the application method and properties Sicomet 9000 infiltrated parts?
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Poured onto part. Cyanoacrylate, improved durability and strength.
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What are the application method and properties of Zr 10 infiltrated parts?
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Applied directly. Cyanoacrylate, improved durability and strength.
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How can 3DP models be used for casting?
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Plaster models can be used to create molds for non-ferrous metals, such as zinc, aluminium and copper. Ferrous metals react with the sulphur in gypsum so can't be used with plaster models. It is important that all powder is removed and the part is dried in an oven before casting.
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What advantages are there to using post-process infiltration?
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Wide range of material properties without having to change primary material.
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Describe Zp140
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A powder option for 3DP, produces monochrome parts. Can be cured with tap water, making it more environmentally friendly. Halves the hardening time of parts. Provides the fastest, cheapest, whitest parts available.
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What powders are available in 3DP?
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High performance composite
Snap-fit Elastomeric Investment casting Direct casting |
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Describe the high performance composite powder
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Produces strong, high definition parts with a good surface finish. Best choice when producing colour parts. Can be used to produce thin-walled parts. Made of a heavily engineered plaster.
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Describe the Snap-fit
composite powder |
A more porous, plaster based material, allows more absorbtion of the Z-snap epoxy infiltrant. Used to create plastic-like parts.
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Describe the Elastomeric
composite powder |
Used to create rubber-like parts, comprised of Cellulose with speciality fibres and additives
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Describe the Investment casting powder
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Maximises absorbtion while minimising residue, used to create investment cast patterns. Comprised of Cellulose with speciality fibres and additives
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Describe the direct casting powder
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Used for casting molds for non-ferrous models. Comprised of foundry sand, plaster and additives. Provides a heat-resistant part with a good surface finish
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What are the relative strenghts of 3DP?
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High speed
Versatile material choice Simple Reliable Minimal wastage Colour |
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What are the relative weaknesses of 3DP?
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Generally weaker than SLS
Low surface finish quality Post processing is common |
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What areas of application are suitable to 3DP?
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Concept models
Direct CAD to casting of metal parts Direct metal parts Structural ceramics Functionally gradient materials |
