The Basics of 3D Printing: Part 3


by Matt Weir




One thing that I’ve learned in my short time in the 3D printing world is, there is a plethora of 3D printing technologies, and most of them are confusingly named, and provide little insight to infer what each type actually does, or differentiate itself from one type to the next. While there are a number of different types, some are definitely used more than others, and I will only be covering the most common/ and most used processes. For example, here at U-Dimensions we use SLA, SLS, and relatively new type of printing called Polyjet to print our products.


Stereolithography (SLA)

SLA is the oldest of 3D printing technologies, going back to 1983, yet still remains one of the most popular forms of printing. SLA exposes a later of photosensitive liquid resin to a UV-layer beam, so that the resin hardens and becomes solid. Objects are printed with an overhanging printer arm, and the object is printed from the bottom up, with each layer forming on top of the proceeding one. The object must be rinsed with a solvent after printing is completed. SLA has become increasingly popular in jewelry due to its smooth surfaces and ability to include detail.


Selective Laser Sintering (SLS)

Similar to SLA, SLS however, uses powdered material to build area instead of resin. A laser is used to selectively sinter a layer of granules, which binds the material together to create a solid structure. This process is widely used for product development and rapid prototyping, being able to use materials such as nylon, glass, and ceramics to metals. These are massive professional grade printers to say the least.



Similar to Inkjet printing, Polyjet jets layers of curable liquid photopolymer onto a build tray. The printers jets instantly UV-cures these time droplets of liquid polymer, with the capability of create one or several precise 3D models or parts. Polyjet is said to be able to create smother and more detailed products than other printer currently on the market, as well as achieve a wider variety of colors than the current plastic printers.



Currently only Mcor is producing these kinds of printers, however we really like the products we are able to create from them. This printer type is able to print in 3D full color in CYMK, on all surfaces. By using paper rather than resin or powder, it offers a more environmentally friendly printing alternative.


Digital Light Processing (DLP)

DLP is similar to SLA, but uses a special projector to melt the resin, rather than a laser. IT sues a micro-mirror grid, laid out on a semiconductor chip, in which tiny mirrors tilt back and forth, creating light and dark pixels. These printers are generally reserved for professional environments or avid tinkerers keen on making their own printers.


Fused Deposition Modeling (FDM)

This is the most common type of method used for desktop 3D printing. It uses molten plastic, which is deposit from a tower, building the object layer by layer. The object is built from the bottom up, and the product will most likely require support structures. It is a cost effective way to produce product development and prototyping.


Tweet us @u_dimensions with any other questions you have and we will do our best to answer them!