Nowadays 3D printing is almost used as a synonym for all the different Additive Manufacturing processes that are used. However, there are many processes which vary in printing method, those processes differ in the material and machine they use. Learn about the different AM technologies in this blogpost.
3D printing and AM technologies become more and more adopted as a production technology for prototypes and small series. The benefit is that you can fully tailor your product to its application and develop multiple variations of a prototype in a small timeframe. However, what is available and what are the characteristics of each AM technology?
Vat polymerisation is an AM technology which applies liquid photopolymer resin layer by layer. Ultraviolet light is used to cure the resin and constrict the model. When the object is created the build platform moves downwards after each layer. Due to the liquid material instead of other 3D printing materials like powder, there is not structural support in the build phase. The support is given by the unbound material which do not attach to the liquid material.
Material jetting has a technique similar to a standard ink jet printer. The material is jetted onto a stage. It uses either a Drop on Demand (DOD) or continuous approach. It gets solid and the model is built layer by layer. The material lands from a pipe which moves horizontally over the platform. There is variety in the complexity of the machines around and in their ways of controlling the deposition of material. The layers deposed get hardened by making use of ultraviolet light.
In binder jetting two elements are used: a binder and a powder based material. The material which builds the object is in powder form while the binder is in liquid form. There is a printhead which moves horizontally along the x and y axes of the used machine and sets varying layers of the binding material and the building material. The object being printed gets lowered on its build platform after each new layer is set. Because of the method of binding, the characteristics of the material are not always very suitable for structural parts. Also, even though the quite good speed of printing, additional post processing can add a lot of time to the total process.
Fuse deposition modelling (FDM) is a widespread Material Extrusion process. Material is pulled through a pipe, where it gets heated up and after it is built up layer by layer. The pipe itself can move from left to right and there is a platform which moves up and down after each new layer is set. This technique is commonly used in many domestic environments, for people who have 3D printing as a hobby or who like to keep things rather inexpensive. The process has many factors influencing the quality of the final model.
Power Bed Fusion
The Powder Bed Fusion process involves these commonly used printing techniques: Selective laser sintering (SLS), Direct metal laser sintering (DMLS), Selective heat sintering (SHS), Selective laser melting (SLM) and Electron beam melting (EBM). Powder bed fusion (PBF) methods either make use of an electron beam or a laser to melt and then fuse material powder together.
Sheet lamination processes list laminated object manufacturing (LOM) and ultrasonic additive manufacturing (UAM). UAM uses ribbons or sheets of metal. Ultrasonic welding is used to bound them together. It requires removal of the unbound metal and additional cnc machining. This is often needed during the welding process. LOM has a kind of similar layer by layer approach, however, it uses paper instead of metal and adhesive instead of welding. In the LOM process a cross hatching method is used during the printing process as it allows for easy removal after building has finished. The laminated objects are often used for visual and aesthetic models but are not suitable products for structural use.
Directed Energy Deposition
Directed Energy Deposition (DED) is a more complex printing process which is widely used to repair or add extra material to existing parts. A typical DED machine has a pipe mounted on a multi axis arm. It deposits melted material onto the wished for surface, where the material then solidifies. The process of directed energy deposition can be compared to material extrusion (ME), however in DED the pipe can move in multiple directions (in contrary to ME) and the nozzle is not fixed to a specific axis point. The material is melted upon deposition by either an electron beam or a laser. It can be deposited from any angle because of four and five axis machines. Direct energy deposition is used with a variety of materials like ceramics, polymers and metal. It is mostly used with a metal material.
At Luxexcel we use our unique, patented Printoptical © Technology. Our 3D printing process differs from before mentioned AM technologies, as we use a photopolymer that is solidified with UV light. Our process guarantees high detail, optical properties (total refraction, surface roughness, scattering) and high shape conformity.
If you want to learn more about our 3D printing service for optics, download our free Ebook.