EDUCATION

The 3D Printing Process: How does it Work?

Formlabs Form 3 SLA 3D Printer
Above: Formlabs Form 3 runs on Low Force Stereolithography (LFS) ™ Technology/Image Credit: Formlabs

3D Printing encompasses various different technologies like the Fused Deposition Modelling, Stereolithography, Digital Light Processing, Selective Laser Sintering, etc. but the basic principle of manufacturing parts through a layer by layer process remains the same. For explanation purpose we showcase the working of an SLA 3D Printing process.

Step 1: CAD Model

The first basic requirement of any 3D printing process is a CAD Model. It is the 3D design for the product you want to print. This model can be developed from various softwares (Catia, Fusion360, Solidworks, Creo, etc.) but the final output has to be in a machine readable format, mainly STEP, STL & OBJ but a few other formats are also used. 

Step 2: Slicing

The designed model is now to be loaded into slicing software. The slicing software or Slicer, literally slices the 3D model into multiple layers depending on the specifications you provide. These slices (also called as layers) are then deposited one above the other during the actual printing process. The slicer converts the design into co-ordinates which the printer understands and the material is deposited as per the co-ordinates.

The output of this slicer is in the form of a text file with a file extension being ‘.gcode’.

Step 3: Setting up the Machine

The part can be printed through various 3D printing technologies and depending on the final application of the part, the appropriate technology & material is chosen and machine is set up. FDM printers use filaments like PLA, ABS, PC, PET-G, etc. while SLA & DLP printers use resins with usage-based properties (tough, flexible, dental etc.) & SLS uses powdered material (mostly Nylon).

Step 4: 3D Printing

The next step is to simply 3D print the model. The gcode file is loaded into the printer and the printing starts. The printer will print the object as per the print parameters set in the slicer. These settings can be modified for every single print. The printing time depends on different factors and can vary from minutes to hours to even days.

How 3D Printing Works?

3D printing is a type of additive manufacturing technology where a 3D object is created by laying down layers of materials. The working of 3D printers is similar to that of inkjet printers. However, unlike inkjet printers, 3D printers do not use ink but rather use different types of materials. These materials may include polymers, metals, ceramics, composites, concrete, bioinks, etc. The material is deposited in layers to create a physical object.

Below is the basic process and the step-by-step explanation of how a 3D printer works.

Above: The working of SLA 3D printer

1. Laser Source: First and foremost, a laser source emits a laser beam. This laser beam helps to solidify the liquid material to form the final three-dimensional object.

2. The Elevator: The main function of this elevator is to help lay the layers. This elevator moves up and down thereby raising and lowering the platform in order to help lay the layers of object

3. Vat: The vat is a vessel like structure which contains or stores the liquid material.

4. Layered Parts: This is the actual 3D printed object that is created when the material is deposited one-by-one or in layers on top of each other

5. Material: The material (called resin in case of SLA and DLP printers) is the substance which is used to create an object. There may be different forms of resins used such as tough resin, dental resin, flexible resin, etc. Other printers like FDM & SLS use different materials. Today, a lot of different materials are used in 3D printing. Some of the materials used in 3D printing include gold, silver, ceramics, biomaterials and food.

Step 5: Post Processing

Post-processing of FDM 3D printed parts
Above: Post-processing of FDM 3D printed parts with Sanding/Image Credit: MakerBot

This is the final step in the 3D printing process. Once the printer stops, the print has to be removed from the bed. This process varies as per the type of technology used. In a standard FDM printer it can be easily removed with a scrapper (it is advisable to wear gloves during this step). Even after the removal of the print the part has to undergo some amount of post-processing. The amount depends on the complexity of the model and printing technology used. The most common post processing techniques include removal of support structures, cleaning off the excess resin material on the surface of the part, brushing off the excess powder in case of sintering technologies, extra smoothening with the help of sand paper polishing or sand blasting, etc.


About Manufactur3D Magazine: Manufactur3D is an online magazine on 3D printing. which publishes the latest 3D printing news, insights and analysis from all around the world. Visit our 3D Printing Education page to read more such informative articles. To stay up-to-date about the latest happenings in the 3D printing world, like us on Facebook or follow us on LinkedIn.