Guestblog by Joris Peels, 3D printing strategy consultant
In a previous article I go over some of the most confusing terms and definitions in 3D printing. I also detail some of the major technologies in 3D Printing such as SLA, SLS, FDM & DMLS. In this post I will discuss other 3D printing technologies DLP, EBM & Mcor. I hope that with this series of posts I will be able to help people find their way in 3D printing.
Digital Light Processing is a technology whereby a digital micro mirror creates and image. This is used in office projectors and also by Envisiontec to 3D print. Colloquially the term DLP is used in 3D printing to refer to the technology. A projector hardens a 3D model in a bath of resin. This technology reliably produces accurate batches of small parts. It is ideal for such applications as 3D printed digital hearing aid shells and dental parts. Both some of the largest consumer applications of the technology. DLP can also be used as a lost wax casting material in making jewelry. Often DLP competes with SLA for customers. For large parts SLA is generally better. The form factor of the DLP machines is however more compact. Often when customers actually implement Additive Manufacturing in a high throughput consumer application seemingly prosaic things such as the size of the machine play a large part in technology choice. For example if one company wants to produce very large batches of hearing aid shells with one single machine and material they will probably choose SLA. On the other hand if they wish to be more flexible and offer many different skin tones then DLP will be chosen because this lets them have more machines & materials. More machines also means more redundancy and flexibility to start builds at different times. If they wish to produce their hearing aid shells in a semi-office or office environment then the smaller form factor also plays a significant role in companies preferring DLP over SLA.
EBM or Electron Beam Melting is a technology whereby an electron beam melts powdered metal in a vacuum. EBM is considered a competitor to DMLS and is defined as also being a powder bed fusion technology. Historically EBM, developed by Arcam, has produced rougher parts with higher densities than DMLS. If you are considering making metal parts its best to evaluate all the metal vendors using the exact parts you need to make. Often machine, vendor and technology choice are very dependent on the vendor or geometry of the part. EBM is used by GE’s Avio Aero unit to make turbine blades for military aircraft. Tens of thousands of individualized titanium hip cups are made using Arcam EBM as well. As with DMLS adopting metal 3D printing technology will be a step change more difficult than plastic and there is a lot of post finishing required.
LOM (Laminated Object Manufacturing) is officially called sheet lamination. Initially this was done by applying rolls or sheets of paper onto of each other and then using lasers to cut them into the correct shape. The lasers turned out to be a very bad idea. LOM machines often caught fire and this lead to the technology gaining a bad reputation. Irish company Mcor reinvented it by using blades instead of lasers. Without the fires and with full color 3D printing of paper objects Mcor is used by educators, designers and engineers. The paper parts are actually much tougher and resilient than people expect. Mcor 3D printers are used in education to make educational models, used in surgical planning and 3D printing GIS maps. Mcor is the cheapest 3D printing technology by far in terms of individual part cost.