Vat Polymerization

Process description

Vat polymerization was the first additive manufacturing developed in 1986 by Charles hull. it starts with a print plate being lowered to the top of a vat filled with a photoreactive resin. a light source is then used to cure the first layer direct on the build plate. the build plate is then raised so the next layer can be cured directly onto the last. this is repeated until the part is complete. the part then must be put through a washing process, and then a final cure with a strong light.

Strengths & Weaknesses

The benefits of Vat Polymerization :

• fine detail: since detail is limited by screen resolution this allows for extremally fine details, and an excellent surface finish
• clear parts: the fine detail, and material used allows for vp printing to create more clear parts then other processes

The drawbacks of Vat Polymerization:

• Toxic materials: Most materials that VP printers use are generally extremally toxic, and should be handled with care. protective equipment should be worn, And vp printing should always be done with proper ventilation to protect against toxic fumes.
• weaker material properties: resins tend to be brittle and not very tough
• post processing: VP parts need to be cleaned of wet resin, and recured
• Resin degradation: resins tend to degrade in color and strength over time. especially if exposed to the elements

	Low	High
volume X/Y/Z (mm)	96/54/127	380/380/250
resolution (mm)	.05	.003
layer height (um)	15	25
price ($)	450	500,000

Technologies

There are a number of specific technologies that can vastly change to capabilities of a printer.

• Digital Light Processing: uses a projection of the layer to cure the entire thing at the same time. this makes it very fast but with the trade off of decreasing accuracy.
• Stereolithography: uses a light beam to cure a layer one line at a time, this makes it accurate, but slower