DLP (Digital Light Processing) is a similar process to stereolithography in that it is a 3D printing process that works with photopolymers. The major difference is the light source. DLP uses a more conventional light source, such as an arc lamp with a liquid crystal display panel, which is applied to the entire surface of the vat of photopolymer resin in a single pass, generally making it faster than SL. Also like SL, DLP produces highly accurate parts with excellent resolution, but its similarities also include the same requirements for support structures and post-curing. However, one advantage of DLP over SL is that only a shallow vat of resin is required to facilitate the process, which generally results in less waste and lower running costs.
In this process, once the 3D model is sent to the printer, a vat of liquid polymer is exposed to light from a DLP projector under safelight conditions. The DLP projector displays the image of the 3D model onto the liquid polymer. The exposed liquid polymer hardens and the build plate moves down and the liquid polymer is once more exposed to light. The process is repeated until the 3D model is complete and the vat is drained of liquid, revealing the solidified model. DLP 3D printing is faster and can print objects with a higher resolution.
Because of the nature of the SL process, it requires support structures for some parts, specifically those with overhangs or undercuts. These structures need to be manually removed. In terms of other post processing steps, many objects 3D printed using SL need to be cleaned and cured. Curing involves subjecting the part to intense light in an oven-like machine to fully harden the resin.
Master copies for vacuum casting and other low volume prototyping techniques
Patterns for investment casting
Functional testing prototypes
Low volume/ limited edition products especially for complex geometries
Visual prototypes for photo shoots and market testing
- Dental/ jewelry/ art and other sectors which require high detailing and finish
Minimum Wall thickness: 0.8 mm
Minimum details size: 2 mm (for text/ hole diameters etc)
Layer thickness: 0.05 mm – 0.1 mm
Max dimensions: 650 x 650 x 450 mm
Standard Accuracy: ± 0.2% (with lower limit on ± 0.2 mm). Dimensions tend to change with exposure to direct sunlight or another UV source
Lead Time: Minimum 2 working days for despatch
Surface finish: Smooth, with tiny visible layers
Basic: Support Removal, Curing, Smoothing
Add on: Primer, Coating/ Painting