What is Additive Manufacturing?

Advantages of AM

• Save money on short-run manufacturing

• Possibility of market-testing

• Get your prototype faster and cheaper

• Rapid design changes

• Minimize waste

• Direct Production: CAD to Build

• No tooling or molding

• Otherwise impossible, complex geometric shapes and designs

• Possibility for weight reduction

• Product customization

Additive manufacturing (AM) is a production process which builds a component from the ground up, fused together one fine layer at a time. Unlike traditional forms of manufacturing, this newer process is not subtractive—in which material is removed—nor does it require molding or casting.  Conventional production is like sculpting marble—remove the material to reveal the intended object. AM creates layer by layer and is transformative—making a liquid or powder into solid part, for example. Depending on the machine, additive technologies can produce components from a variety of materials—plastic, metal, ceramic.

AM is more energy efficient and environmentally friendly than conventional production methods.  With traditional manufacturing, material is removed and wasted.  With AM, waste is minimal because parts are made layer by layer.

At Primary, we use five types of additive manufacturing: CLIP, DLP, MJF, FDM, and LPBF. To learn more about each of these processes, read more in the sections below!

Advances in 3D Printing

AM is also known as “Direct Manufacturing” because the part is produced directly from a CAD drawing. But most know AM by its colloquial name—3D printing. However, many manufacturers who implement additive technology hesitate to call their production process 3D printing because those words carry a sort of amateur connotation. It elicits an image of a hobbyist printing from their garage with low quality finishes. 

But production-level 3D printing—or as we call it additive manufacturing—has come a long way in the last several years.  Gone are the days of poor resolution and visible layers.  Advanced additive technologies create products which have production-grade finishes and engineering-grade properties.

Not only can AM now create high-quality products, but more importantly, it enables the creation of complex designs and impossible geometries which before were otherwise unobtainable from traditional processes.  This ability has been one of the driving forces of innovation in the last several years. 

Engineers in a variety of industries have been reimagining parts and designs using additive technology.  Aerospace, automotive, and medical companies have been some of the first to implement these newer production processes. 

Seven Categories of Additive Manufacturing

There are seven types of additive manufacturing.  Each of these categories have subtypes of processes and various companies have developed new technologies and machines for each process.

Types of Additive Manufacturing

1. Material Extrusion

2. Vat Photopolymerization

3. Powder Bed Fusion

4. Material Jetting

5. Binder Jetting

6. Direct Energy Deposition

7. Sheet Lamination

#1 Material Extrusion (FDM or FFF)

Attributes

• Fast and inexpensive

• Great for prototyping and modeling

• Low-resolution surface finish

• Complex Shapes and Designs

• Most common technology

• Heat extrusion based

• Uses thermoplastics

Material extrusion is the most common form of additive manufacturing.  Though there are production-level extrusion machines, most amateur and at-home 3D printers are extrusion-based.  These machines build the part one layer at a time by melting the thermoplastic filament with a headed extruder as the material is deposited onto the build platform.  This type of additive production is fast and inexpensive—perfect for prototyping and modeling. 

At Primary, we use production-level FDM machines built by Ultimaker to produce prototypes, models, and toys.

#2 Vat Photopolymerization (DLP, CLIP)

Vat photopolymerization uses light to cure liquid resin into a solid object one layer at a time.  This process has several technological iterations such as Continuous Liquid Interface Production (CLIP), Stereolithography (SLA), and Digital Light Processing (DLP).  These methods require designs with supports built in to hold the part onto the platform and a post-processes cleaning and curing method.  Parts manufactured using this manufacturing technique are accurate and have high-quality surface finishes. 

At Primary, we use Carbons DLS machines and 3D System’s Figure 4 machines which both use Continuous DLP.

Attributes

• High-resolution surface finish

• Accurate

• Otherwise impossible geometries

• Requires post-process support cleaning and curing

• Photopolymers cured with light

• Uses Liquid-Resins

#3 Powder Bed Fusion (MJF, LPBF, SLS)

Powder Bed Fusion use lasers or heat to fuse metal or plastic powder layer by layer. 

At Primary, we use two versions of powder bed fusion.

Multi Jet Fusion (MFJ) uses Inkjet technology to distribute the fusing material onto a thin layer of plastic powder and then uses infrared to activate the fusion process.

Laser Powder Bed Fusion (LPBF) uses inert gas, metallic powder, and a laser to melt layers into a solid metal part.

Attributes

• Low-resolution finish unless post-processed

• Parts can have an internal porosity

• Fusion with lasers or heat

• Uses powder materials (plastic or metal)

#4 Material Jetting

Attributes

• High-resolution surface finish

• Accurate

• High Cost

• Dissolvable supports

• Uses Inkjet Technology

• Photopolymers cured with light

• Can use multiple materials/colors

Material jetting is another process which uses photopolymers and light (or heat curing).  Unlike vat photopolymerization, however, this method uses an ink jetting process (similar to MJF) to distribute the material onto the print bed.  This manufacturing process also needs supports, however, because multiple materials can be used, the supports are often built with a dissolvable material. This is not a service we provide at Primary.

#5  Binder Jetting

Attributes

• Low-quality mechanical properties

• Binding powder with adhesive

• Requires post-processing

• Uses Inkjet Technology

• Uses ceramic or metals

Binder jetting is a process which deposits a thin layer of powder onto a build area followed by a layer of liquid adhesive.  This method binds the ceramic or metal material together to create a solid product. This process uses ink jetting similar to that of a 2D printer.  Binder jetting is another process which requires post-processing.  While this process is great for models, it’s not ideal for functional prototypes—whether metal or ceramic, the mechanical properties are not as strong as other manufacturing methods. This is not a service we provide at Primary.

#6  Direct Energy Disposition

Attributes

• Uses a laser or electric arc

• Metal or wire

• Add material/repair parts

Direct energy deposition is a process which melts metal powder or wire with a laser or electric arc.  This method is best for adding material to an already existing part.  Because this process isn’t ideal for producing parts from scratch, this is not a service we provide at Primary.

#7  Sheet Lamination

Attributes

• Process of layering sheets

• Uses paper/adhesive or metal/welding

Sheet lamination is a process that binds sheet material to form an object.  The LOM method uses paper and adhesive while UAM is an ultrasonic metal welding process.  Because plastic parts and rapid prototyping are our specialties, sheet lamination is not a service we provide.