3D Printing

Posted on by Group E

What is 3D printing?

 

Additive manufacturing or 3D printing as it’s more commonly known is a process of making three dimensional solid objects from a digital file.  There are a few different fabrication processes being used in 3D printing, namely Stereolithography (SLA), Fused Deposition Modelling (FDM), Fused Filament Fabrication (FFF), Selective Laser Sintering (SLS), PolyJetting and a few others.  These processes all rely on layer-by-layer fabrication.

Originally invented in 1986 by Chuck Hull, 3D printing technology has shown significant growth over the last decade, and it has become increasingly common to see schools and universities now making this technology part of their curriculum.

 

How does 3D printing work?

 

There are a few different fabrication processes in 3D printing.  Although all of these processes will deliver the end result of a 3D printed object; some type of coding needs to be resident to instruct the printer on how to manufacture the object.

3D printing starts with the design of a digital file on your PC. These files normally have file extensions such as 3MF, STL, OBJ, PLY etc.  As most of us are aware, PC’s use a form of 1’s and 0’s called Binary Code to send text or instructions.  In order for a 3D printer to understand these instructions, it needs to be converted into a format that the 3D printer understands.  This converted format is called G-Code.

G-Code is a language that tells a machine or 3D printer how to move and where to deposit material during the fabrication process.  In short we can say that the G-Code creates a blueprint of the object being manufactured, outlining thousands of movements that the machine has to perform to complete the object.

 

The Fabrication Processes in 3D printing

 

As mentioned before there are a few different fabrication processes being used in 3D printing.  The following are the most commonly used ones:

  • Fused Deposition Modelling ( FDM ) / Fused Filament Fabrication (FFF)

FDM was invented by a man named S.Scott Crump.  The FDM technology was trademarked by a company call Stratasys in 1990.  This is why the same technology is often referred to as FFF by other 3D printer manufacturers.

This technology gets used in almost all desktop 3D printers today.  In this technology a thermoplastic, more commonly known as filament, are fed through a narrow tube, melted and then extruded out of a small nozzle into layers to build a 3D object/print.

The most common filaments used in the FDM/FFF fabrication processes are ABS and PLA.

The name thermoplastics are given to materials that become malleable when heated.  When heated this material can be shaped, after which the material quickly cools down and retains its shape.

PLA ( PolyLactic Acid ) is a biodegradable plastic which is made from renewable raw materials such as cornstarch or sugarcane.  PLA is commonly used for packaging material, plastic cups and plastic water bottles.   When printing, PLA gets heated to 190 – 220 degrees.  PLA is better suited for beginners as the product is less prone to warping or shrinking when cooling down.  Although PLA is easier to use, it is more prone to clog or jam.

ABS ( Acrylonitrile-Butadiene Styrene ) is an oil based plastic.  It’s a tough material, much stronger than PLA, used to create objects for everyday use.  Some products manufactured with ABS are electrical equipment, components for cars and even toys such as Lego Building Blocks.  When printing, ABS get heated to 230 – 250 degrees.  A heated bed is also required when printing with ABS, to ensure the printed object sticks to the build platform. When using ABS, it is recommended to do it in a well-ventilated environment, as it gives off a bad plastic smell.  Symptoms such as headaches have been reported by some users when ABS filament is used. Both PLA and ABS filament are available in a variety of colours.

What makes PLA preferable over ABS with Desktop 3D printer users is that PLA can be mixed with other materials.  There are a few PLA filaments available that are mixed with wood, bamboo, brass and copper. This enables users to make use of materials that have diverse characteristics and give sample objects a unique finish.

  • Stereolithograpy (SLA)

Invented in 1986, SLA is a very pricy form of Fabrication and is not used as often as FDM/FFF in today’s 3D market. The technology is also very different to FDM, as the SLA process uses lasers and resin that are photosensitive.  Objects in this technology are printed in a vat of resin.  During this printing process the lasers get used to cure/harden the resins layer by layer until an object is formed.

  • Selective Laser Sintering (SLS)

SLS was invented by Carl Deckard in the early 1980’s. The process involves particles of either plastic, glass or ceramics.  During the process a Laser gets used to expose the particles to a very high temperature which enables these particles to get fused together to form a 3D object.

This technology is mostly used by big companies and manufacturing organisation, although there are a few investors focusing on the development of machines using the SLS technology to be used safely in a home environment.

  • PolyJetting

This process was created by a company called Objet. This process use nozzles similar to inkjet nozzles to spray a photosensitive liquid onto a build platform.  Immediately after the liquid is sprayed onto the platform, a UV light gets projected onto the build plate, which in turn hardens the liquid to form a layer of the object.  This process gets repeated layer by layer to form a 3D print/object.

Other technologies such as Selective Laser Melting (SLM), Electronic Beam Melting (EBM) and Laminated Object Manufacturing (LOM) also exist, but are not commonly used.

 

Providers of 3D Printing

 

The three biggest International Companies leading the 3D printing industries are:

The 3D market in New Zealand is currently dominated by a US 3D printer manufacturer named Makerbot. These devices are imported by Ricoh NZ Ltd, who are also charged with local support for this product.

Concluding observations:

Overall, the market for 3D printing is showing signs of significant growth with multinational companies such as Hewlett-Packard taking 3D printing under its label. It’s widely anticipated that as applications of 3D printing technology grows and diversifies, coupled with the development of more affordable consumer level 3D printers this technology will become more and more integral to our lives. The recent developments in the areas of artificial limb and organ printing provide a perfect example of why 3D Printing technologies are poised to revolutionise processes in areas such as research and development, design and modelling as well as healthcare.

Author: Thilini Karunaratne

References:

  • 3dprinting.com
  • 3dprint.com
  • makerbot.com
  • stratasys.com
  • 3dprinthq.com

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