Printing has come a long way from the earlier days of woodblock printing to offset printing to screen printing, inkjet printing laser printing. Now we are in the era of Additive manufacturing, which we commonly know as 3D printing or digital printing. Additive manufacturing is an appropriate name for modern 3D printing technology. This is because the printer essentially adding layer upon layer of material till you get the final product. Initially, in this era of additive manufacturing, only plastic was viable for the 3D objects. However, nowadays plastic, metal, and concrete can be 3D printed.
To do this, we use 3D modeling computer software like Computer-Aided Design (CAD), machine equipment, and layering material. Once you make the 3D design in the CAD, you then send the material for printing. The device then adds layers of the set material. This is where the additive in the age of additive manufacturing comes from. Digital manufacturing technology includes layered manufacturing and additive fabrication, 3D printing, Direct Digital Manufacturing (DDM), and Rapid Prototyping (RP).
The application of 3D printing is expanding. Therefore the printing technology is not confined to white paper like in the olden days.
However, in recent times you can use 3D printing / Additive manufacturing to fabricate end-use products for aircraft, medical implants, automobiles, dental restorations, and even fashion products.
History of Additive Manufacturing / 3D printing
The concept of additive manufacturing / 3D printing was first described by Raymond F. Jones in his story, “Tools of the Trade,” which was published in November of 1950. It was an issue of Astounding Science Fiction magazine. 3D printing was referred to as “molecular spray” in his story. Additive manufacturing has been around since the early 1950s when it was considered something only suitable for the production of functional or aesthetic prototypes, which was known as rapid prototyping then.
Only in the 2000s did additive manufacturing become popular. Later in the years around 2019 the precision, repeatability, and material range of printing have become so good that they are considered a viable industrial production technology. Here we officially enter the era of additive manufacturing.
It is also able to create hollow parts with internal truss structures that help in reducing weight and saves up some extra material as well. Recently deposition modeling (FDM) is the most common 3D printing process in use.
When you add all of these facts into consideration, it is easy to understand why additive manufacturing is high on the supply chain.
General principles of Additive Manufacturing
There are mainly three general principles of Additive manufacturing or 3D modeling.
Modeling
With the help of computer-aided design (CAD), one can create 3D printable models. Besides, that one can also use a 3D scanner, or a plain digital camera and photogrammetry software. However, using CAD is the best way to have minimum errors.
Printing
The file of the model that we will print will be an STL file which must be examined before printing so that there are no errors or as few as possible. Most of the time CAD applications produce errors in the output modeled STL file like holes, self-intersections, noise shells, faces normal and manifold errors. Using the repair function in a step in STL generation fixes such problems to minimize the errors.
“Slicer” then processes the checked error-less file . Slicer converts the model into a series of thin layers and produces a G-code file for the printer. Now. you can print model using 3D printing client software. One drawback of 3D printers is the time it takes to print. Because it is not simple, printing can take anywhere from several hours to several days depending on the complexity of the model, size, and method used.
Finishing
Although people try to minimize as much error as possible but still creating a thicker layer first and then later removing the material using a higher-resolution subtractive process is efficient and more precise. Some printable polymers can make the finished surface smooth using chemical vapor processes that are based on acetone and similar solvents. You can even remove Even aluminum and steel with GMAW 3D printing. It allows for substrate surface modifications for such hard objects as well.