The 7 Categories of Additive Manufacturing

 Before we go into more detail, what exactly is additive manufacturing? Additive manufacturing is the industrial name for 3D printing, a process controlled by a computer that creates 3D objects by depositing materials, layer by layer. As its name suggests, it is adding material to create an object.

The benefits of AM are extensive. It allows businesses to reduce waste, produce parts faster and help lower costs. By creating an object in a layer system, there is very little waste produced and the process runs based on a digital design from a CAD model. 

1. VAT Photopolymerisation

Recognised as the most visually appealing AM method, it uses photopolymerisation to produce a 3D object. This is the process of exposing liquid polymers to Ultraviolet (UV) light in order to turn liquid into solids. Then, a 3D printer uses digital light processing technology, to project the image into a vat of liquid polymers one layer at a time. Draining the photopolymer resin and exposing it to UV light is repeated until the object is complete, with the vat drained revealing the 3D object. 

2. Powder Bed Fusion

The powder bed fusion method uses either a laser or electron beam to melt and fuse material powder together. The process works by first applying a thin .1mm layer of material onto a build platform then using a laser, the powder is fused into place. This method of AM is relatively slow as it works in .1mm layers and can sometimes use more energy than other methods. 

3. Material Jetting

This method is similar to that of a 2D inkjet printer. In this process, liquid materials such as wax, photopolymers and polymers are dropped down onto a work surface. Then a UV light cures the final object. This type of AM allows for full-colour and multicolor prints. 

4. Binder Jetting

One of the more popular methods of AM as it is extremely cost effective and can readily optimise new technologies. This process requires two materials; a powder base material and a binder, which is usually in liquid form. A print head moves horizontally along the x and y axis, depositing alternating layers of the build material and the bind material. 

5. Material Extrusion

Known as the most affordable method of additive manufacturing, this method can commonly be found in homes or office settings. The printer would run you up a few hundred pounds and is easily accessible being sold on sites like Amazon. In this process, material is deposited through a nozzle, where it is heated and built layer by layer. The nozzle can only move horizontally and the build platform moves up and down after each new layer.

6. Sheet Lamination

Sheet lamination is a process that can refer to ultrasonic additive manufacturing (UAM) and laminated object manufacturing (LOM). Both processes are similar in that they use sheets or ribbons of metal which are bound together using ultrasonic welding.

7. Directed Energy Deposition

This process can also be referred to as laser-engineered net shaping or 3D laser cladding. However, the process is different to the rest as it is most commonly used to repair or add material to existing objects. The printing process uses material extrusion, however the nozzle can move freely along four or five axes