Different Types of 3D Printers

3D printing can quite literally create a three-dimensional part without needing any other manufacturing process apart from the one it uses. Ever since 3D printing was first invented, there have been constant advancements in the system to achieve more accuracy and precision in the process while increasing the durability of the results.

Nowadays, 3D printers are not only limited to production or commercial applications as a lot of versions are designed for hobbyists for domestic purposes. Today, we will talk about all the different types of 3D printers available in India and try to understand the basic differences within them.

Before moving forward, let’s understand the basic principles of 3D printing.

What is 3D Printing?

3D printing (also known as additive manufacturing or rapid prototyping) is a technology that allows one to generate a physical, three-dimensional object from a software CAD model of the same. The process takes place by successively adding layers of material to generate the final physical product.

The technology itself is quite old as it was first introduced in the year 1980. But after years of design and development, the current generation 3D printers, as well as deposition material, is not accessible for everyone. This includes businessmen, commercial users, mass producers, and hobbyists too.

It allows a quick and effective method to test out a design without putting it through the production process. With an ideal 3D printer, you can quickly generate a prototype of your own design and check for weak spots and overall strength. This way, you can easily make the required changes in your CAD model before actually producing the final object.

Types of 3D Printers

While there has been a long time since the research and development of 3D printers has begun, only a handful of technologies have proved to be suitable for getting perfect results. The following types of 3D printers are very unique in terms of the working principle and the material used in them for printing.

Now that you are all caught up with 3D printing technology and a basic understanding of 3D printers, let’s start with different types of 3D printers that you will find in the industry.

Stereolithography (SLA)

This technology was the very first iteration and introduced way back in 1986. But, you will still find the same technology being used on a very large scale in the industry even today. Stereolithography works on the principle of selectively cured resins of photopolymers to create a solid object.

The SLA printers use various mirrors that operate on the X-axis and Y-axis which help to point the laser beam directly on the surface of the polymer to achieve its solidification.

Selective Laser Sintering (SLS)

This was the very first iteration and introduced way back in 1986. But, you will still find the same technology being used on a very large scale in the industry even today. Stereolithography works on the principle of selectively cured resins of photopolymers to create a solid object.

The SLA printers use various mirrors that operate on the X-axis and Y-axis which help to point the laser beam directly on the surface of the polymer to achieve its solidification.

Fused Deposition Modeling (FDM)

In this process, a special material extrusion press is used to create the 3D object. It is also called Fused Filament Fabrication (FFF) as it is simply depositing the materials on the workbench layer by layer until the 3D product is generated.

The material used for this type of 3D printing comes in solid form. But, while the printing is in action, it passes through a hot nozzle that partially melts the material to create a layer. As soon as it is deposited, it solidifies again to deliver a rigid integral structure.

Digital Light Process (DLP)

The working of the Digital Light Process 3D Printer is almost identical to that of the SLA. The only difference with these units is that this one takes help from a digital light projector that actually flashes the light evenly and for a shorter period to solidify one complete layer.

Apart from that, the light does the same job as seen in SLA 3D printing which is solidifying the photosensitive material. After the concurrent layers are solidified, a shape starts to form that is rigid and strong. Thus, the 3D object is developed.

Multi Jet Fusion (MJF)

Multi-jet fusion is a power-based 3D printing as the base material is provided in the form of fine powder rather than resins as seen previously. It also does not involve any lasers or light source for printing and works on basic thermal properties of the material to get the solidification.

The printing bed used or MJF is heated independently before the process. Once the right temperature is achieved, the agent is deposited upon the bed so that it melts selectively to form the required shape. MJF needs a detailing agent as well to achieve accuracy in complicated designs.

PolyJet or Material Jetting

This is a 3D printing technology that can be easily identified right by its name. Different types of photopolymer resins are deposited similarly to that of an inkjet printer. But instead of a single jet used for 2D printing, multi-jet fusion technology required multiple jets to generate a 3D object.

Multiple jets deposit hundreds of droplets of photosensitive material on the printing area that are quickly solidified by using an ultraviolet light source.  Once a single layer is complete, the platform displaces by one layer thickness so the next layer can be printed.

Direct Metal Laser Sintering (DMLS)

Unlike most 3D printers, a DMLS variant uses a metal powder instead of polymer or any form of plastic for the printing. While the component used for printing is changed, the overall process remains quite similar where a heat source is used to fuse metal particles one layer at a time.

As expected, the DMLS 3D printers are very heavy duty and only suitable for commercial and production purposes. They also come at a very high initial cost which is not ideal for domestic use.

Electron Beam Melting (EBM)

This is also a metal-based 3D printing technology that uses the same working principle as seen in the DMLS 3D printers. But, instead of using a laser or a dedicated heat source, a high energy beam of electrons is used to create a fusion between metal particles for each layer.

The electron beam manages to focus the energy on a very minuscule part of the deposition and the heat escalation is not an issue with electron beams. Thus, precise 3D printing results can be achieved with the EBM technology.

Selective laser melting (SLM)

While we are on the topic of metal-based 3D printing technologies, you should acknowledge yet another useful technique called selective laser melting. SLM can also generate high-quality metal prints by using a laser.

The overall operation takes place quite similar to DMLS technology until the deposition. But after that, a laser beam is used to completely melt the metal powder and form a homogenous structure. It has a limited application and used where structural integrity is of utmost importance.

Laminated object manufacturing (LOM)

This is one of the unique 3D printing technologies which only suits plastic or paper-based products due to it’s working principle. Laminated object manufacturing uses both heat and pressure to achieve the fusion between each layer of a print.

Instead of using a collection of residents, the material is fed directly to the workbench where a laser or blade is used to cut down the required layer. Once the layer is fixated on the bench, the platform moves to create space for the next layer and the process continues.

Binder Jetting (BJ) Technology

In binder jetting, a powder of sand or silica is generally preferred to attain maximum accuracy while printing a 3D object. The deposition method is similar to SLM and other 3D printing technologies. But instead of a laser or a heat source, a print head moves over the deposition and drops a special binder that binds the powder together.

As expected, the structural integrity of finished products is comparatively weaker in this case as it is dependent on the adhesion force between the binder and deposited power material. Also, a moving build platform is required to generate different layers in this case.

DROP ON DEMAND (DOD)

In contrast to most 3D printing technologies, drop-on-demand technology uses two different jets where one deposits the adhesive build material and the other deposits the support material. There is a predetermined path for both jets which is calculated automatically in reference to the 3D model.

As the deposition is not perfectly uniform in the case of DOD 3D printing, it also uses a fly cutter that is used to level the layer and make sure it’s completely flat before depositing the next layer. This grants a great surface finish to the printed objects.

Conclusion

By now, you must have acknowledged that there is a lot of variety in the 3D printing industry. While the basic principle of 3D printing remains the same, there are a lot of differences in multiple 3D printers. While some options are suitable for plastics based products, there are a few technologies that are more advanced and can also form stronger objects with metal as a base product.

Another factor that varies the most is the speed of printing which is different for all technologies mentioned here. generally, the structural integrity generated in slower methods is much more durable and long-lasting as compared to faster methods. But from a domestic or hobbyist’s point of view, even the most basic machine can deliver astounding results on plastic-based products.

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