3D-printing was discovered more than 30 years ago by the original founder of 3D-systems. This first 3D-printer was named stereolithography apparatus and used a laser to cure a light reactive resin. During the years after the discovery, other companies like EnvisionTEC came up with new methods of curing the light reactive resin, by projector, instead of a laser. The last years, companies like Wanhao and Anycubic made resin based 3D-printing accessible for everyone by the introduction of cheaper LCD based 3D-printers.
During these past years, many companies came up with their own 3D-printing technique and named it differently, although it is based on one of the three techniques listed below. Picture source: Formlabs website.
Laser SLA is based on the original invention, used by companies as 3D-systems, Formlabs, UnionTech and Peopoly Moai. The laser is used to selectively cure the resin, by scanning the surface. The resin cures and becomes a hard plastic at the spots where the laser ‘hits’ the resin.
DLP-SLA is a technique which uses a projector to selectively cure the resin. It is generally a faster printing technique compared to Laser SLA, due to the fact that the projector can expose the whole layer at once, where a laser has to scan to cure the resin. A few single LED’s are in the center of the DLP projector. The light from these LED’s is guided to a DMD chip, which creates the actual curing pattern. This 3D-printing technique is used by companies like EnvitionTEC, Sprintray, Atum3D, Rapidshape, Miicraft and Kudo3D
One of the latest developments in resin 3D-printing is MSLA, also called LCD based 3D-printing. This technique uses an affordable LCD screen to create the mask, eliminating expensive DMD chips that are used in DLP techniques. This technique works by an array of LED’s illuminating on the LCD. The LCD is used as a mask, which creates the curing pattern. The liquid resin turns into a rigid plastic on the spots where the light ‘hits’ the resin. Companies like Wanhao, Anycubic, Sparkmaker, Kudo3D, Creality, XYZprinting, Phrozen, and many more.
How do SLA, DLP and LCD 3D-printers compare?
There are many differences between the three main resin based 3D-printing techniques. The table below shows the generic differences.
|Laser SLA||DLP SLA||MSLA|
One of the main drawbacks of Laser SLA techniques is its price for the machines and consumables. This also applies to DLP 3D-printers. DLP printers have another technical disadvantage to keep in mind, the (affordable) DMD chips are usually 1920*1080 pixels, which limits the quality of printing when upscaling the build area. LCD based printing is a lot cheaper compared to the other techniques. These machines are more affordable and also consumables like FEP foil for your resin tray is cheaper.
What most users don’t realize is that the LCD display is also count as a consumable, which should be replaced from time to time. The build area is dependant on each machine and technically it is easier to create a bigger build area, by placing a bigger LCD in the machine.
Are all resins compatible with the different printing techniques?
Not all resins are compatible with the different printing techniques. It is important to read the resin manufacturers datasheets to understand if it is compatible with your 3D-printer. Laser based 3D-printers have a very powerful laser, which would need a slower curing resin to get a stable printing process. While LCD based 3D-printers have a low power LED light source, which works very well with fast curing resins. DLP 3D-printers can be configured in many different ways, making it impossible to predict curing behaviour of the resin without testing.
The Liqcreate resins are developed to work with most techniques. Liqcreate Strong-X, Clear Impact, Deep Blue, Stone Coal Black and Hazard Glow are developed to print on Laser- and DLP based machines, while still working on LCD 3D-printers when exposure times are increased. While the Liqcreate Premium line is developed to print fast on low-power DLP and LCD printers. Read more about the resins here: