What is 3D Printing?

Have you guys ever wondered to create your own 3D designs into reality? If yes, then it is the time to do so.
With the fast growing 3D technology, it has become possible to create 3D designs into real 3D objects. So, let us see how we can get from an idea to our first 3D print. You will need a 3D printable design to begin with and then you can either buy a 3D printer or use an online service to get your idea materialized. To 3D print something, first you need a 3D model – the mathematical representation of any three-dimensional surface of an object. These are created using computer-aided design (CAD) tools such as AUTODESK 123D Design, Blender, SketchUp, etc.
So, now let us begin with understanding the 3D printing!

3D Printing is an additive manufacturing process that creates a physical object from a digital design. There are different 3D printing technologies and materials but all are based on the same principle: a digital model is turned into a solid three-dimensional physical object by adding material layer by layer.

How does 3D printing work?
Every 3D print starts as a digital 3D design file like a blueprint for a physical object. Trying to print without a design file is like trying to print a document on a sheet of paper without a text file. This design file is sliced into thin layers which is then sent to the 3D printer.
From here on, the printing process varies by technology starting from desktop printers that melt a plastic material and lay it down onto a print platform to large industrial machines that use a laser to selectively melt metal powder at high temperatures. The printing can take hours to complete depending on the size, and the printed objects are often post-processed to reach the desired finish.

How do the different 3D printing technologies work?
All 3D printing technologies create physical objects from digital designs layer by layer, but each using its own proprietary method. The most common 3D printing technologies are discussed below:

1. Fused Deposition Modeling (FDM)
   The FDM printing process starts with a string of solid material called the filament which in turn is guided from a reel attached to the 3D printer to a heated nozzle inside of the 3D printer that melts the material. Once in a melted state the material can be made through predetermined path created by the software on the computer. As the material is made as a layer of the object on this path, it instantly cools down and solidifies – providing the foundation for the next layer of material until the entire object is manufactured.
   FDM is a great choice for quick and low-cost prototyping and can be used for a wide variety of applications. More recent innovations in FDM 3D printing include the ability to manufacture functional end products with embedded electronics and mechanical parts such as drones.
2. Stereolithography and Digital Light Processing (SLA & DLP)
   These technologies create 3D printed objects from a liquid (photopolymer) resin by using a light source to solidify the liquid material.
   To create a 3D printed object, a build platform is submerged into a translucent tank filled with liquid resin. Once the build platform is submerged, a light located inside the machine maps each layer of the object through the bottom of the tank thus solidifying the material. After the layer has been mapped and solidified by the light source, the platform lifts up and lets a new layer of resin flow beneath the object once again. This process is repeated layer by layer until the desired object has been completed.
   SLA & DLP 3D printers produce highly accurate parts with smooth surface finishes and are commonly used for highly detailed sculptures, jewelry molds, and prototypes.
3. Selective Laser Sintering (SLS)
   Selective Laser Sintering (SLS) uses a laser to melt and solidify layers of powdered material into finished objects.
   These printers have two beds that are called the pistons. When the printing process begins, a laser maps the first layer of the object in the powder which selectively melts or sinters the material. Once a layer has been solidified, the print bed moves down slightly as the other bed containing the powder moves up and a roller spreads a new layer of powder atop the object. This process is repeated, and the laser melts successive layers one by one until the desired object has been completed.
   SLS is widely used for producing functional prototypes and parts as well as some end products.
4. Material Jetting (PolyJet and MultiJet Modeling)
   Material Jetting (Stratasys PolyJet and 3D Systems MultiJet Modeling) technologies are similar to inkjet printing but instead of jetting drops of ink onto paper these 3D printers jet layers of liquid photopolymer onto a build tray and cure them instantly using UV light.
   The build process begins when the printer jets the liquid material onto the build tray. These jets are followed by UV light, which instantly cures the tiny droplets of liquid photopolymer. As the process is repeated, these thin layers accumulate on the build tray to create a precise object.
   These are the most precise 3D printing technologies today, printing with up to 16-micron (that’s thinner than a human hair) layers.
5. Binder Jetting
   The binder jetting technology is similar to SLS in the way that the printer uses thin layers of powdered material to build up an object but instead of using a laser that sinters the layer together, these printers use a binding agent extruded from a nozzle to bind the powder together.
   The process starts with a nozzle spreading the binding agent across the first layer of the object and binding the powder together. Once the first layer has been fused with the binding agent, the printing bed moves down slightly and a thin layer of new powder is spread atop the object. This process repeats until the desired object has been fully formed. After it is removed from the print bed, the object is cleaned from excess powder and coated with an adhesive glue to give it strength and to make it resistant to discoloration.
   It is relatively affordable compared to SLS as the printing process requires less energy, but the printed objects are less strong. The ability to print in full color has made sandstone popular for architectural models and lifelike sculptures.

The Advantages of 3D Printing :

• Create complex designs
• Customize each and every item
• No need of tools and moulds
• Speed and ease of prototyping
• Less waste

The Limitations of 3D Printing :

• Higher cost of large production runs
• Less material choices, colors and finishes
• Limited strength and endurance
• Lower precision

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