stereolithography - wikipedia, the free encyclopedia

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An SLA produced part

StereolithographyFrom Wikipedia, the free encyclopedia

Stereolithography (SLA), also known as optical

fabrication, photo-solidification, solid free-form

fabrication and solid imaging, is an additive manufacturing3D printing technology used for producing models,

prototypes, patterns, and production parts.

Contents

1 History2 Technology

3 Advantages and disadvantages

4 See also5 References

5.1 Notes5.2 Bibliography

6 External links

History

The term stereolithography was coined in 1986 by Charles (Chuck) W. Hull,

[1]

who patented it asa method and apparatus for making solid objects by successively "printing" thin layers of the

ultraviolet curable material one on top of the other. Hull's patent described a concentrated beam of

ultraviolet light focused onto the surface of a vat filled with liquid photopolymer. The light beam

draws the object onto the surface of the liquid layer by layer, and using polymerization or cross-

linking to create a solid, a complex process which requires automation. In 1986, Hull founded the

first company to generalize and commercialize this procedure, 3D Systems Inc,[2][3][4] which is

currently based in Rock Hill, SC. More recently, attempts have been made to construct mathematical

models of the stereolithography process and design algorithms to determine whether a proposed

object may be constructed by the process.[5]

Technology

Stereolithography is an additive manufacturing process which employs a vat of liquid ultraviolet

curable photopolymer "resin" and an ultraviolet laser to build parts' layers one at a time. For each

layer, the laser beam traces a cross-section of the part pattern on the surface of the liquid resin.

Exposure to the ultraviolet laser light cures and solidifies the pattern traced on the resin and joins it to

the layer below.

After the pattern has been traced, the SLA's elevator platform descends by a distance equal to the

thickness of a single layer, typically 0.05 mm to 0.15 mm (0.002" to 0.006"). Then, a resin-filledblade sweeps across the cross section of the part, re-coating it with fresh material. On this new liquid

surface, the subsequent layer pattern is traced, joining the previous layer. A complete 3-D part is

Stereolithography - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Stereolithography

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Stereolithography apparatus

formed by this process. After being built, parts are immersed

in a chemical bath in order to be cleaned of excess resin and

are subsequently cured in an ultraviolet oven.

Stereolithography requires the use of supporting structures

which serve to attach the part to the elevator platform,

prevent deflection due to gravity and hold the cross sectionsin place so that they resist lateral pressure from the re-coater

blade. Supports are generated automatically during the

preparation of 3D Computer Aided Design models for use on

the stereolithography machine, although they may be

manipulated manually. Supports must be removed from the

finished product manually, unlike in other, less costly, rapid

prototyping technologies.

Advantages and disadvantages

One of the advantages of stereolithography is its speed; functional parts can be manufactured as

shortly as within a day. The length of time it takes to produce one particular part depends on the size

and complexity of the project and can last from a few hours to more than a day. Most

stereolithography machines can produce parts with a maximum size of approximately 505060 cm

(20"20"24") and some, such as the Mammoth stereolithography machine (which has a build

platform of 2107080 cm),[6] are capable of producing single parts of more than 2 m in length.

Prototypes made by stereolithography are strong enough to be machined and can be used as master

patterns for injection molding, thermoforming, blow molding, and various metal casting processes.

Although stereolithography can produce a wide variety of shapes, it is often expensive; the cost of

photo-curable resin ranges from $80 to $210 per liter, and the cost of stereolithography machinesranges from $100,000 to more than $500,000.

See also

Stereolithography (medicine)

References

Notes

^ U.S. Patent 4,575,330 (Apparatus for Production of Three-Dimensional Objects byStereolithography)

1.

^ (http://www.3dsystems.com/company/index.asp) 3D Systems Inc Company Info2.^ Stereolithography (http://www.photopolymer.com/stereolithography.htm)3.^ What is Stereolithography? (http://production3dprinters.com/sla/stereolithography)4.^ B. Asberg, G. Blanco, P. Bose, J. Garcia-Lopez, M. Overmars, G. Toussaint, G. Wilfong and B. Zhu,

"Feasibility of design in stereolithography,"Algorithmica, Special Issue on Computational Geometry inManufacturing, Vol. 19, No. 1/2, Sept/Oct, 1997, pp. 6183.

5.

^ Mammoth stereolithography: Technical specifications (http://www.materialise.com/mammoth-specifications) . materialise.com

6.

Bibliography


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http://www.3dsystems.com/company/index.asp)http://www.photopolymer.com/stereolithography.htm)http://production3dprinters.com/sla/stereolithography)http://www.materialise.com/mammothhttp://en.wikipedia.org/wiki/Stereolithographyhttp://en.wikipedia.org/wiki/Stereolithographyhttp://www.materialise.com/mammothhttp://production3dprinters.com/sla/stereolithography)http://www.photopolymer.com/stereolithography.htm)http://www.3dsystems.com/company/index.asp)


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Kalpakjian, Serope and Steven R. Schmid.Manufacturing Engineering and Technology 5thedition. Ch. 20 (pp. 586587 Pearson Prentice Hall. Upper Saddle River NJ, 2006.

External links

Graphical Display of the Stereolithography Process (http://www.laserproto.com

/ServicesProcess.aspx?PageID=5) : A resource page maintained by Laser Prototypes(Europe) Ltd

Castle Island's Worldwide Guide to Rapid Prototyping (http://home.att.net/~castleisland/) ,with comprehensive information on rapid prototyping, rapid tooling, stereolithography andsolid freeform fabrication technology products and services. Complete rapid prototyping

service bureau listingsHow Stereolithography (3-D Layering) Works (http://computer.howstuffworks.com/stereolith.htm/printable) from HowStuffWorks.com

Manufacturing Engineering Centre (MEC), Cardiff University, UK (http://www.mec.cf.ac.uk/services/?view=sla&style=default)

Rapid Prototyping and Stereolithography animation (http://www.protocam.com/html/video.html) Animation demonstrates stereolithography and the actions of an SLmachineAbout 3D Systems, Company History (http://www.3dsystems.com/company/index.asp)

Retrieved from "http://en.wikipedia.org/w/index.php?title=Stereolithography&oldid=486285639"

Categories: American inventions Laser applications Solid freeform fabrication

This page was last modified on 8 April 2012 at 17:28.Text is available under the Creative Commons Attribution-ShareAlike License; additional

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