Various types of 3D printing technologies are used for rapid prototyping or small batch production of plastic and metal parts. It has advantage of quick turnaround time and special tooling is not required to develop prototypes. In this article we will discuss various types of 3D printing technologies and their applications. We suggest you also read this article on various types of metal 3D printers
Types of 3D Printing Technology
Following types of additive manufacturing technologies are widely used to manufacture plastic and metal parts quickly. Each of these 3D printing technologies has their own advantages, limitations and applications.
- Fusion Deposition Modelling (FDM)
- Stereolithographic (SLA)
- Digital Light Processing (DLP)
- Selective Laser Sintering (SLS)
- Material Jetting
- Polyjet Printing
- Multijet Printing
- Direct Metal Laser Sintering (DMLS)
- Electron Beam Melting (EBM)
- Selective Laser Melting
Fusion Deposition Modelling (FDM)
In FDM 3D printing technology, heated thermoplastic material comes out through a nozzle layer by layer to manufacture 3D printed plastic parts. After each layer is extruded, the build platform moves down to make space for the next layer. Therefore printing layer thickness depends on the nozzle diameter, smaller the layer thickness more smoother will be the part finish.
ABS, ASA, Nylon, PC, PC+ABS, PLA equivalent FDM materials are available in multiple colors. Material selection for FDM 3D printing is done according to the required application. Click this link to know the difference between FDM printing materials: ABS vs PLA vs Nylon.
Advantages of FDM 3D Printing
FDM 3D printing process has the following advantages.
- Affordable low cost desktop FDM 3D printers are available in the market.
- Cheapest available 3D printing technology.
- Complex geometries can be manufactured
- Multiple Features and components can be combined into one part.
- Undercuts, interior features, attachment fittings can be incorporated into 3D printed parts.
Disadvantages of FDM 3D Printing
FDM 3D printing process has the following limitations.
- Rough surface finish.
- FDM 3D printed parts are porous.
- Critical features can not be manufactured.
SLA additive Manufacturing Process utilizes liquid photo-polymer resin material to manufacture 3D printed parts. In this light source is used to solidify the liquid material layer by layer.
To manufacture 3D printed parts, the build platform is submerged into a translucent tank filled with liquid resin. Afterwards a light source inside the 3D Printer is used to solidify material layer by layer. As one layer gets solidified, the platform lifts up to create the next layer. This process is repeated layer by layer until the part is finished.
SLA 3D printing is used to manufacture highly detailed sculptures, jewelry molds and it’s prototypes.
Advantages of SLA 3D Printing
SLA 3D printing technology has the following advantages.
- Highly accurate parts.
- Smooth surface finish.
- Low cost SLA desktop 3D printers are available.
Disadvantages of SLA 3D Printing
SLA 3D printing process has the following disadvantages.
- Not recommended for manufacturing large parts.
- Manufacturing process is a bit messy.
- High material cost.
- High 3D printer cost compared to FDM 3D printer.
Digital Light Processing (DLP)
Similar to SLA, DLP 3D printer also works on vat polymerization technology. It utilizes a digital light projector screen to cure the liquid polymer.
When compared to SLA 3d printing, DLP projector screen cures the complete layer of the liquid material instead of curing point to point.
Advantages of DLP 3D Printer
- Faster than SLA 3D printing.
- Good resolution parts can be manufactured.
- Clear parts can be 3D printed using clear resin.
Disadvantages of DLP 3D Printers
- Part Cleaning process is messy
- High machine and unit part manufacturing cost.
- Limited Commercial grade materials are available for 3D Printing.
Selective Laser Sintering (SLS)
SLS 3D printing utilizes a laser beam to sinter the powdered plastic material to manufacture solid parts. For 3D printing, powder is preheated up to a temperature just below the powder melting point. Laser scans the cross section of the 3D cad model and heats the powder at its melting point. As a result powder fuses together to make a solid geometry. Afterwards the build platform is moved downward layer by layer to create a solid geometry.
During sls 3d printing process unfused powder works as support structure for the part. Nylon (PA11 & PA12) materials are widely used for SLS 3D printing.
Advantages of Selective Laser Sintering
SLS 3D printing has the following advantages:
- Dedicated support structure is not required.
- Complex geometries can be 3D printed.
- Good surface finish,
- SLS Nylon is a good alternative to injection molded plastic.
Disadvantages of Selective Laser Sintering
SLS 3D printing has the following limitations:
- Material is porous and brittle.
- Similar to SLA, SLS 3D printing process is messy.
- Manufactured parts are prone to warpage
- High post processing time.
Polyjet 3D Printing
In Polyjet type of 3D printing technology UV light is used to solidify photopolymer material. During 3D printing liquid polymer is sprayed from a multi nozzle print head that is instantly solidified by a UV-light. Once a layer is cured, the platform is moved downward in z-direction and polymer is sprayed. In this way a 3D printed part is manufactured layer by layer.
Advantages of PolyJet 3D Printing
- Smooth Part Finish.
- High accuracy upto 0.016 mm can be achieved.
- Thin walls and complex geometries can be manufactured.
- Multicolor and multi-material 3D printing is possible.
Disadvantages of PolyJet 3D Printing
- Costly and time consuming process.
- Printer and material need to be protected from light.
- Water jets are used to remove supports. This makes the process messy.
Direct Metal Laser Sintering (DMLS)
In Direct metal laser sintering (DMLS) additive manufacturing process fine laser beam is used to weld and fuse metal powder and manufacture metal parts. Resolution of 3D printed metal parts depends on the powdered metal particle size, laser beam and bed movement.
Compared to selective laser melting, DMLS does not melt metal particles. It heats metal particles so that their surface gets welded with each other.
Advantages of Direct Metal Laser Sintering
- Metal parts can be 3D printed.
- Variety of metals can be 3D Printed.
Disadvantages of Direct Metal Laser Sintering
- High Cost
- Smaller Build Area
- Porous parts.
Selective Laser Melting
Selective laser melting (SLM) is a type of 3D printing technology that utilizes a laser to melt metal powder instead of welding it. SLM 3D printed metal parts are equivalent to the parts manufactured using traditional manufacturing processes.
Advantages of Selective Laser Melting (SLM)
- Various types of metal can be 3D printed.
- Complex shapes and internal features can be manufactured.
- Manufactured parts have properties similar to parts manufactured with traditional manufacturing processes.
Disadvantages of Selective Laser Melting (SLM)
- High Cost.
- Rough surface finish.
- Post processing operations are required.
Electron Beam Melting
Electron beam melting (EBM) process utilizes a high power electron beam to melt metal powder layer by layer to manufacture solid metal parts by fusing melted metal layers.
EBM additive manufacturing process is done in a vacuum chamber to prevent contamination and oxidation of the metal powder. It is widely used to manufacture low weight aerospace, medical and defense components.
Advantages of Electron Beam Melting
- Faster printing speed.
- High quality metal parts equivalent to casting can be 3D printed.
- Less support structure.
- Less residual stress in printed parts.
Disadvantages of Electron Beam Melting
- Lower Accuracy.
- High Cost Compared to SLM and DMLS.
- Limited Material options.
We will keep adding more updates on various types of 3D printing technology. Please add your suggestions, comments or questions on various types of 3D printing technology in the comment box.