What Is 3D Printing, and How Does It Work?


What Is 3D Printing, and How Does It Work?

Key Points

  • 3D printing is a manufacturing technique that creates 3D objects layer-by-layer, offering the potential to produce detailed products faster and cheaper than traditional methods.
  • There are various techniques used in 3D printing, including fused deposition modeling (FDM), powder bed fusion (PBF), stereolithography (SLA), and digital light processing (DLP).
  • Currently, 3D printing is primarily used for rapid prototyping, but it has the potential to be used in various industries, including consumer goods, healthcare, and aerospace.

When it was first developed, 3D printing seemed like something out of a Sci-Fi movie. In reality, the actual process isn’t too complicated, even though the results can be fascinating. What was once seen as a bit of a novelty has soon become popular, with a vast amount of applications and potential uses. But what is 3D printing, and how does it work? We’ve answered these questions in this article.

What Is 3D Printing?

At a very basic level, 3D printing is similar to traditional printing methods, except it’s used to create 3D objects rather than print ink onto paper. That’s a fairly vague description, however, so let’s take a closer look.

3D printing is also described as additive manufacturing because the product is built slowly from many printed layers (hence “additive”). You can think of this as creating several layers of a cake, and then stacking them up to create the finished product. Initially, it was mostly intended for rapid prototyping but has creating end products is on the horizon. The main benefit is the ability to create complicated products quicker and cheaper than traditional methods. We’re not quite there yet in many respects, as 3D printing tends to still be too slow for mass production purposes. However, its applications in product design are already apparent.

How Does 3D Printing Work?

fdm vs. resin 3d printing
Different techniques are used depending on the product specifications and applications.

There are many different kinds of 3D printing, but the general steps involved in each remain the same. These are:

  • Producing the 3D model using CAD (computer-aided engineering) software.
  • Converting the CAD model into STL (standard tessellation language) format. The model is also sliced into layers so that the 3D printer knows how to deposit the materials to create each layer with precision.
  • Transferring the STL file to the computer in charge of the 3D printer and giving details such as the orientation and desired size.
  • Setting up the 3D printer to be used.
  • Starting the printing and monitoring the process as it goes.
  • Removing the object from the printer once it’s finished.
  • Carrying out any required post-processing tasks, i.e. washing support materials off the object, or brushing off any excess materials, i.e. powders used to create the product.

We can use various CAD programs to produce models, but they perform similarly. The major difference is in how 3D printers work to create the layers. The techniques used are described in this table, along with their applications.

Techniques Used

Powder bed fusion (PBF)Thermal energy is applied to the powder to fuse specific areas. PBF includes selective laser melting (SLM) and electron beam melting (ELM).Primarily metals, but occasionally polymers, plastics, and composites. High-precision manufacturing.
Selective laser sintering (SLS)Similar to PBF, but uses lasers to sinter the powders without melting.Mostly polymers, but sometimes metals. Lower precision manufacturing.
Digital light processing (DLP)A micromirror is used to reflect UV light onto photosensitive resin, pixel-by-pixel, to solidify it and create layers.Used for high-resolution objects with smooth surfaces, i.e. prototyping, jewelry, consumer products, and dental devices.
Stereolithography (SLA)Photosensitive resin is still used, but the printer platform lowers into the liquid, and the UV laser hardens sections. Must be cured in post-processing.Similar to DLP.
Binder jettingA binding agent is deposited onto the powder bed, which solidifies the material. Excess powder is brushed in post-processing and curing may occur.Automotive industries, aerospace, construction, prototyping, and consumer products.
Material jettingPrint heads deposit layers of liquid material, similar to traditional printing. Layers are cured as they’re created, and the supports removed after.Prototyping, medical industries, and construction.
Fused deposition modeling (FDM)Thermoplastic filament is melted and then deposited. Supports are removed in post-processing.Affordable prototypes, tools, manufacturing and engineering.
Sheet laminationIn laminated object manufacturing (LOM), thin sheets of material are fed to the printer, which cuts them precisely. These are then bound using an adhesive., and excess material is removed. In ultrasonic additive manufacturing (UAM), layers of metal foil are bonded using ultrasonic vibrations, then trimmed.LOM is used for large prototypes, and UAM is used for producing strong metal components, i.e. for aircraft and vehicles.
Direct energy deposition (DED)Wire or powder is melted and then deposited.Aircraft components.

How Will 3D Printing Be Used in the Future?

Currently, 3D printing is mostly being used to create quick and cheap prototypes, rather than end products. However, the technology is progressing rapidly and being tested all around the world, so we’ll likely see it being used in more and more industries in the near future. Developments like printed food, shoes, and medicines, as well as tissue and even whole organs, may seem unrealistic, but they’re very possible. The main issue stopping these products from hitting the shelves already is that the printing time is currently too slow to achieve this on a mass scale.

Wrapping Up

In summary, 3D printing is an extremely exciting manufacturing technique that is set to disrupt virtually all industries. By recreating a 3D model layer-by-layer, 3D printing has the potential to produce accurately detailed products quicker and cheaper than traditional manufacturing methods. 3D printing works via different techniques to deposit the materials onto the printing platform. These include fused deposition modeling (FDM), powder bed fusion (PBF), stereolithography (SLA), and digital light processing (DLP). While 3D printing is currently mostly being used in product testing, as printing times improve and shorten, vast amounts of products will be able to be created. Everything from consumer goods and healthcare products to vehicle parts, materials for aircraft and even organs and tissue. If it can be imagined as a product, there’s a good chance we’ll one day see it being produced by a 3D printer.

Frequently Asked Questions

What is 3D printing?

3D printing is also called additive manufacturing and is used to create 3D objects by constructing them from single layers. It does this by taking a 3D model of the object and various manufacturing techniques to construct it from physical materials.

What techniques are used in 3D printing?

Many techniques are used to construct the layers of the final product. Common techniques include powder bed fusion (PBF), selective laser sintering (SLS), digital light processing (DLP), stereolithography (SLA), fused deposition modeling (FDM), and directed energy deposition (DED).

What materials can 3D printing make use of?

3D printing can use lots of kinds of materials, including plastics, polymers, metals, resins, and composite materials. The choice depends on the product requirements and specs.

What can 3D printing be used for?

3D printing can be used to create virtually any product, but the printing time tends to be significantly long. Therefore, it’s mostly being used to create prototypes currently, but could potentially be used to create aircraft and vehicle components, housing materials, medical devices and consumer goods, and even organs for transplants.

What is post-processing?

Some 3D printing methods require some additional processing stages after the product has been constructed. These can include curing (or hardening), which is usually used with techniques that utilize photosensitive resins, removing support structures (i.e. by washing away water-soluble supports or physically removing them), or painting or decorating the finished product.

What are the benefits of 3D printing?

3D printing is relatively accessible and can produce consistently excellent products better than other methods. It’s also extremely useful for product testing and design, since prototypes can be produced easily and cheaply. 3D printers can also switch between source materials easier than traditional methods.

What are the disadvantages of 3D printing?

3D printers can potentially produce inaccurate results if their component parts aren’t working properly or the 3D model is suboptimal. The strength of the product can also be adversely affected by the layer-by-layer construction process, and the requirement of post-processing can slow down the whole development process, as well as introduce additional overheads.

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