Introduction to 3D printing

3D printing (or additive manufacturing) refers to the process of making a three-dimensional object from a digital file. It is called additive manufacturing because in the 3d printing process, layers of material are added to one another until the final object is created. The final object is built up of many but thin layers.

Have a look at this video from Mashable that gives an introduction to 3D printing.

3D printing in 3 steps

3D printing has a few steps to follow before you are holding a 3D object in your hand:
First you need a file that tells the 3D printer what you want to print
Then you need to send this file to a 3D printer
Lastly the 3D printer prints the object you asked for
**Step 1: Getting a file ready to print in 3D**
If you want to print something that already exists in the real world, and is small enough to print, then you can use a 3D scanner to scan the object so you can import it into a 3D modelling program. A 3D scanner makes a 3D digital copy of an object. 3D scanners vary from simple scanners for use at home to industrial scanners that can create very detailed scans of big objects.

If you want to print something new, then you need to design it in a 3D modelling program. Sometimes people scan an existing object using 2 3D scanner and then make changes to it to create something new for printing.

**Step 2: Sending the file to a 3D printer**
There are many types of printers available today, and range from simple desktop printers for hobbyists all the way through to large industrial printers that can print large objects of a very high quality.

Most printers fall into one of three categories:
Desktop
Professional
Industrial or Manufacturing
**Step 3: Printing your 3D file**
Although all 3D printers use additive manufacturing (ie. they all add layers of material to build up the 3D object), they might use different technology to do so. These technologies differ in how the layers are built.

3D printing technologies

In 2010, the American Society for Testing and Materials (ASTM) group “ASTM F42 – Additive Manufacturing”, developed a set of standards that classify the Additive Manufacturing processes into 7 categories:

The two most common types of 3D printing involve either:

melting a material to create the individual layers, or
hardening a soft resin by heating it with a UV light or laser to create the layers of the 3D print.

Vat Photopolymerisation

In this category of 3D printing, a container of resin is hardened by a UV light source, layer by layer. For each layer, the laser beam heats a cross-section of the 3D object in the liquid resin. The ultraviolet laser cures and solidifies the pattern traced on the resin and joins it to the layer below. After each layer is hardened, the 3D printer moves the platform that the 3D model is supported on by a small amount so a new layer can be printed.

The most common used technology in this category of 3D printing is Stereolithography (SLA). Another is Continuous Liquid Interface Production (CLIP).

Material Jetting

3D printing in this category is carried out much like traditional printing but is carried out in three dimensions. A nozzle builds up the 3D model layer by layer by depositing a material onto a base and then curing it with UV light.

The Stratasys Objet 500 Connex 3D printers that use this technology. You can read more about them here.

Binder Jetting

Binder jetting uses two materials that are deposited into the build chamber - a powdered base material and a liquid binder. The 3D printer spreads the powdered base material in a layer, then the printer will apply a liquid binder through a jet nozzle to the powder. This binds the powder into a solid. After the printer has built up all its layers, the ‘unglued’ powdered base material can be cleaned off.

MaterialExtrusion

The most common type of 3D printing in this category is called Fused Deposition Modelling (FDM). This term and its abbreviation (FDM) are trademarked by Stratasys Inc. Other companies that use this technology use the term fused filament fabrication (FFF).

The FDM technology uses a plastic (or metal) filament that is fed from a coil to an extrusion nozzle. The nozzle is heated to melt the material and can be moved in both horizontal and vertical directions by software that controls the printer. The molten plastic hardens as it is printed and the 3D model is built up layer by layer like the rest of the technologies.

One of the benefits of FDM printing is that different filaments can be used to create a model with different colours and properties. You can read more about the Stratasys 3D printers that use FDM technology here.

Power Bed Fusion

While similar to Binder Jetting, Powder Bed Fusion hardens a powder into a solid. Where it is different is that it doesn’t use a binder liquid, but simply hardens the base material using a high power laser. The software that drives the 3D printer tells the laser which parts of the powdered material need to be hardened. Again, the model is built up layer by layer by moving the support bed down after each layer is cured.

Like binder jetting, unused powder can be cleaned away after the model is completed and then reused in another 3D model.

The most common used technology in this category of 3D printing is Selective Laser Sintering (SLS).

Sheet Lamination

In Sheet Lamination, layers of a base material are welded together and then milled into shape. The sheets can be metal, paper or plastic.

Directed Energy Deposition

Stratasys

Thinking of using 3D printing in your business?

Stratasys is a leading provider of 3D printing solutions that will make your business more efficient, cost-effective and creative. They have a range of professional 3D printers to meet any need. You can visit their website here.

To get a better idea of which 3D printers in their range could help you, choose a link below:

DemaPlasTech are agents for Stratasys 3D printers in South Africa

Whether you are looking to purchase a new Stratasys 3D printer or need support and maintenance for your existing printer, get in touch and we will see how we can help.