What Is 3D Printing?
What is 3D printing? 3D printing, also referred to as Additive Manufacturing, is the creation of a product or component from a CAD (Computer-Aided Design) or digital CAD model. 3D printing covers a range of materials and methods in which products are created via the digital control of a printer. The typical method used to create parts is by continuous layer deposition.
3D printing is an additive process because the material is continually added from scratch to give the final result. Many other manufacturing processes are known as subtractive, such as machining, milling, drilling etc. because the material is continuously taken away.
2019 saw great development in 3D printing, improving repeatability, reliability and the range of materials available for use. As a result, additive manufacturing is now seen as a feasible process to be used for manufacturing in a production environment.
An additional technique used for additive manufacturing is the creation of parts from scanning others. A method like this allows a precise and quick replication of current products or slight modification if required.
How Does 3D Printing Work?
As mentioned above, 3D printing (additive manufacturing) works on the principle of building layers to create a part. The geometry of the part is generally input via a CAD model or by scanning a part. Due to the digital control and the principles of the method, there tend to be fewer mistakes from additive manufacturing compared to other manufacturing methods. Fortunately, most 3D printing programs analyse the CAD models or inputs for errors and proposes amendments – helping reduce errors.
Once the model is refined and finalised, the software breaks it down into many thin layers producing a file type that is compatible with the printer and instructs it to print layer by layer.
Astonishingly, the average layer thickness during the process if 100 um (250 DPI – Dots Per Inch is the other frequent measurement unit). Some 3D printers can even print at a thickness of 16 um!
Although the resolution of 3D printing is small and accurate for the majority of uses, obtaining a greater dimensional accuracy the model is printed slightly bigger than required and then the material is removed using a subtractive process.
The most common method of 3D printing is FDM (Fused Deposition Modelling), which utilises a thermoplastic as the material. The material is initially melted and deposited through a heated nozzle in layers to give the final product.
What Materials Can Be Used for 3D Printing?
FDM is the most popular method of additive manufacturing, and the process uses a thermoplastic such as acrylonitrile butadiene styrene (ABS). However, this is not the only material available for use in 3D printing.
Due to recent rapid development, it is now possible to print using ceramics and metals. The expansion into the use of different materials has made 3D printing even more feasible for more industries and applications.
There is currently research and testing being undertaken to further technology to allow the use of different materials in the same model. This type of technology would allow the integration of different materials in a model which again would open 3D printing to even more industries!
Differences Between CNC and 3D Printing
Both CNC (Computer Numerical Control) and 3D printing work from the same input, which is a CAD model. However, they are very different manufacturing processes.
CNC starts with a block of material and removes part of the material to give the desired shape. 3D printing begins with no material and adds to it to produce the desired shape. From these descriptions, it shows that CNC is a subtractive process. As part of the subtractive process, there is a lot of waster material left after the product has been created. In additive manufacturing, there is minimal waste material at the end due to adding material from the starting position and not removing it. The only waste material is material that requires removal after the product has been made to obtain the desired finish.
However, CNC provides some benefits which can not be accomplished with 3D printing, such as great dimensional accuracy, variety of compatible materials and reliability. The benefits highlighted are key reasons why CNC is used as an industrial manufacturing process for production.
What Are the Advantages of 3D Printing?
- – 3D printing can produce complex shapes, which would not be possible by hand. The most complex geometries include hollow structures that contain internal truss members to provide structural stability.
- – Ability to cut weight from components
- – Can reduce costs of manufacture
- – Quick prototyping
- – Minimal waste making it environmentally friendly
What Are the Disadvantages of 3D Printing?
- – To obtain greater dimensional accuracy, models are required to be printed slightly oversize and then have material removed using a subtractive process.
- – Current limitations to the variety of material that can be used.
- – Curved surfaces in products tend to have a stepped surface finish due to the nature of depositing layer upon layer.
- – Restricted size of products
- – Part structure can be an issue due to the build up of layer, potentially
Where Has 3D Printing Been Used?
The process has been used across a wide range of industries due to its versatility. These industries include transport, food, health and education.
Transportation Industry
The transportation industry has used additive manufacturing to produce models, which have the benefit of allowing them to be assessed and scrutinised. However, some companies have taken this a step further. Koenigsegg’s One 1 has actual parts that have been 3D printed.
Additionally, within the transportation industry, Airbus manufactured the A350 XWB included over 1000 parts that had been 3D printed!
Health Sector
Within the health sector, additive manufacturing has been used for a range of different scenarios and surgeries. They amazingly range from a kidney transplant, facial rebuild to joint replacements.
Education Sector
3D printing has been used throughout the education sector to help capture the imagination and interest of children. The ability to do this stems from the speed of being able to produce models and prototypes. Imagine how much more interested we would have been in lessons if we had 3D printing, and model prototypes made to help us understand topics better!
Summary
3D printing, additive manufacturing, was a concept that was developed as early as the 1940’s however, progress over the last 20 years has allowed commercialised and consistent use of the method to create products. There are many benefits to the process, however, there are still some core developments required to further the process and make it as common as other subtractive manufacturing processes.
Large organisations have realised the benefits that additive manufacturing can bring o their industry and have hence started implementing it.
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