Selecting 3D Printer Filament - Kitronik University – Kitronik Ltd

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This Kitronik University course explains the differences between various types of extrusion style 3D printer filament.

What is Extrusion Style 3D Printer Filament: A 3D printer behaves like a 2D printer in the same way that you instruct the 2D printer to print a 2D drawing on paper. You use word processing software and the printer replicates the writing by 'printing' out a pattern as instructed by the software using liquid ink. Laser printers use a laser to etch the toner onto the page, so that is still a process of 2D printing. Instead, the 3D printer 'prints' a 3D object in successive layers using the 'filament' from a design drawn in CAD software. The Robox 3D Printer is an excellent example of a 3D printer with dual nozzles that can accept different types of plastic. Fused Deposition Modeling (FDM). Also known as 'extrusion' 3D Printing. This process creates models by heating and extruding a plastic material, usually a filament or pellets. Each extruded layer fuses to the layer beneath it, gradually building up a shape. Extrusion style printers work by building up thin layers of heated plastic material. This process is known a ‘Fused Filament Fabrication’. The plastic material is supplied on reels and is known as ‘filament’. The filaments looks a bit like wire (without the metal core) and are available in different diameters depending upon the requirement of the 3D printer for which they have been produced. The plastics used to create the filaments are thermoplastics, which are plastic materials that can be formed into a new shape when heated above a ‘glass transition temperature’ (the point at which the plastic becomes soft and can be reshaped). The two most popular filaments used in 3D printing are ABS and PLA. There are also special filaments with unique features including colour-changing ThermoChrome, wood effect Woody Beech Effect PLA, support material including HIPs and high quality ColorFabb_XT filaments. Not all thermoplastics are suitable to create filaments for 3D printer. This is because for a material to be used in 3D printing it has to achieve the right balance of:

A suitable glass transition temperature.
The right viscosity when heated (not too liquid).
Good bonding between filament layers.
Low levels of shrinkage during cooling.
Suitable mechanical and visual characteristics of the final 3D printed object.

What is ABS 3D printing filament?

ABS stands for Acrylonitrile Butadiene Styrene (ABS is a petroleum derived product). It is a commonly used thermoplastic material and is very popular for 3D printing. ABS has a glass transition temperature (the temperature at which the material becomes soft) of around 105°C. A typical nozzle temperature for ABS would be in the range of 210°C to 240°C.

A 3D printed FM Radio case using ABS filament

Advantages of ABS:

Strong and quite flexible which makes it a good choice for parts that have a ‘mechanical’ function. Parts are often suitable for post print re-work and machining.
Good surface quality.
Nice to touch and feel.
Good chemical resistance.
Excellent extrusion characteristics.

Disadvantages of ABS:

Warping. This is the main issue with ABS. When ABS cools it has a tendency to shrink. This can lead to warping and the material lifting from the print be. For this reason it is essential to use a 3D printer that has a heated bed when printing with ABS, as this reduces the rate at which the ABS cools and keeps any warping to a minimum.
Smell during the print process. Some people seem to hardly notice this, but to other people it can be more obvious.
Derived from Petroleum which is a non-renewable source.

What is PLA 3D printing filament?

PLA stands for Polylactic Acid and it is derived from renewable sources such as corn starch. It is a commonly used biodegradable thermoplastic material and is very popular for 3D printing. It is often considered a ‘greener’ alternative to ABS. PLA has a glass transition temperature of around 60°C to 65°C. A typical nozzle temperature for ABS would be in the range of 180°C to 210°C.

A 3D printed bowl using PLA filament

Advantages of PLA:

Biodegradable and derived from a renewable source.
More rigid than ABS filament.
Excellent print layer bonding.
Low odour during the print process.
Low warping and can achieve sharp corners and fine detailed prints.
Glossy feel to prints.

Disadvantages of PLA:

Low glass transition temperature can cause parts to deform in hot environments.
3D printed parts can be brittle and break when over flexed so less suitable to mechanical applications than ABS.

What is ThermoChrome PLA 3D Printing Filament?

ThermoChrome Purple-Pink PLA 3D Printer Filament for 3D printers has a unique colour-changing feature - when the material is cold it is deep purple, but as it warms it changes colour to light pink perfect for printing wearable items such as necklaces and wrist straps and bath thermometers.

A 3D printed cup holder showing the colour change when warm (left) and at room temperature (right)

Advantages of ThermoChrome:

Changes colour when heated above room temperature.
PLA filament - Has all of the related advantages of PLA filament:
Biodegradable and derived from a renewable source.
More rigid than ABS filament.
Excellent print layer bonding.
Low odour during the print process.
Low warping and can achieve sharp corners and fine detailed prints.
Glossy feel to prints.

Disadvantages of ThermoChrome:

Only changes the hue of the specified colour once heated.
Does not change into multiple colours when heated.
Does not change colour at a lower temperature.

What is Woody Beech Effect PLA 3D Printing Filament?

Woody Beech Effect PLA filament has a unique foam structure and mimics real wood. A foam structure is activated during the printing process which mimics some of the properties of wood (without the need for additional maintenance). You often cannot tell a part has been 3D printed due to the foaming agent which conceals the laminate layers. Woody Beech Effect PLA is light weight with a density of just 0.8 g/cm the material is 35-40% lighter than ordinary PLA and is perfect for printing wooden structures. For example: dolls houses including the contents, garden ornaments, chess sets and pen pots.

A Stereo Amplifier 3D printed case using Woody Beech PLA filament with a plywood face

Advantages of Woody Beech Effect PLA:

Mimics some of the properties of wood without the need for additional maintenance.
Contains no actual wood so the wood powder doesn't cause any problems with the 3D Printers' extruder.
Unique foam structure that is 35-40% lighter than ordinary PLA 3D Printing filament.
PLA filament - Environmentally friendly with all of the related benefits of PLA 3D Printing filament.

Disadvantages of Woody Beech Effect PLA:

Contains no actual wood - Looks more like cardboard when looking really close at the prints (<1m).

What is HIPs (High Impact Polystyrene) 3D Printing Filament?

HIPS stands for High Impact Polystyrene and is a unique high quality material that is as strong and stiff as ABS, but is much easier to print as it is less likely to shrink or warp. HIPS is a natural colour (off-white), dissolvable filament that is frequently used as support material for 3D prints because it can be used as a great support material and is easily removable when using Limonene as a solvent. The material is unique as you can sand, glue, prime or paint your prints. HIPS is ideal for printing in conjunction with ABS because the mechanical properties of the two materials are very similar as they are printed at similar temperatures. The primary difference between HIPS and ABS is that you can use HIPS as a support material for ABS 3D prints. You can use Limonene as a solvent to remove the HIPS. The removal of the HIPS support material leaves a nice, clean finish. Advantages of HIPs:

Like water soluble PVA HIPs can be used to print support material / structures.
HIPs can be dissolved in a chemical called Limonene.
As strong and stiff as ABS.
Less warping of print, so possibly more detail and better visual quality to prints.

Disadvantages of HIPs:

Sometimes reacts with ABS when used as a support material due to similar chemical properties.

What is ColorFabb_XT 3D Printing Filament?

ColorFabb's Amphora XT-Copolyester is a low-odour, styrene-free choice that is uniquely suited for 3D printing applications. It is the only 3D printing filament that has been designed specifically for 3D printing and 3D printers. With Amphora, you can create items that are more functional, durable, efficient and attractive. Now you can fulfil your vision with 3D creations that exhibit the superior aesthetics and toughness they deserve. ColorFabb_XT 3D Printer Filament has the unique stability of ABS and the environmental footprint of PLA. ColorFabb has the benefits of both ABS and PLA including the rigidity of ABS and the renewable benefits of PLA. The Clear ColorFabb_XT unlike PLA, is completely transparent. So if your 3D print project requires some transparency then you should give ColorFabb_XT a try, it is the most transparent filament as you can get!

A 3D printed Dinosaur using ColorFabb_XT filament

Advantages of ColorFabb_XT:

Clear ColorFabb_XT is highly transparent - The most transparent 3D Printing filament you can get.
Very strong prints - Able to withstand knocks and sudden impacts.
Low odour.
Styrene free formulation.

Disadvantages of ColorFabb_XT:

Expensive per gram when compared to more traditional 3D Printing filaments such as PLA or ABS.

What other 3D printer filaments options are there and what are their characteristics?

What is Water soluble PVA (Polyvinyl Acetate) 3D Printing Filament?

Used to print ‘support’ material (structures) in 3D printers that can support more than one filament.
The support material would sit under sharp overhangs and around free hanging components that otherwise sit in free space and would be impossible to print.
The PVA is then washed away on water to leave the remaining structure.