By Mitch
September 19th, 2023
FDM (Fused Deposition Modelling) 3D printing is probably the most widely used and well known 3D printing medium among experts and hobbyists alike. Have a look at our other article, “What is FDM 3D Printing” for more insight into how the process works and when to use it.
In this article though, we’re going to look at the various different types of filament materials that can be used in FDM 3D printing and provide a comparison between them. You may think that there is only one or two types of filaments that could be used but there are far more than that and they all have their own specific characteristics and working parameters.
The most commonly used among home users and hobbyists in FDM 3D printing is probably PLA and then possibly ABS, PETG and the flexible filaments that we’re going to look at. A lot of the filaments in our list however are for more specialist use and in some cases will only have one valuable use.
Let’s then take a look at just some of the filament types that are in use today. As a note, it’s worth mentioning at this point that there are also variants within some of the different types and it’s worth looking out for those when comparing within the same type.
PLA (Polylactic Acid)
PLA is the go-to material for most users due to its ease-of-use, dimensional accuracy and wide availability. Most beginners in 3D printing use PLA for these exact same reasons and the range of colors and different types within the PLA genre is mind blowing.
Standard PLA is the most common but you can also find PLA+, silk, matt, rainbow, glow-in -the-dark and even colour changing PLA to name but a few. There are also variants of PLA where a particular additive has been included which changes the consistency and performance of standard PLA. We’ll be looking at those later on.
PLA Has a low melting point so to become workable for 3D printing, you need a nozzle temperature of between 190-220ºC and a hot bed temperature of around 50-60ºC.
As a note, the working temperature or melting point of a filament can also be referred to as the Glass Transition Temperature (GTT) and is the point at which the temperature causes the molecular structure of the material to alter. In other words, the melting point.
Pros
Easy to work with | Low printing temperatures and easy to cut and sand in post processing |
Rigid and relatively strong | Can withstand a certain degree of impact |
Good dimensional accuracy | Good quality PLA will be +/- 0.02mm or better |
Long shelf life | If stored correctly, PLA will last as long as you need it |
Cons
Low heat resistance | The low working temperature has a disadvantage when it comes to heat exposure when printed |
Blockages occur regularly | The low melting point again plays a part at slow printing speeds |
Requires cooling fans | Somewhere between a pro and con for this as most printers have fans anyway |
Filament can get brittle and break | If not stored correctly, the filament will harden and break. Vacuum storage is suggested and use of a filament dryer |
Not suitable for outdoor use | PLA is vulnerable to water and UV light so won’t react well to being outdoors |
ABS (Acrylonitrile Butadiene Styrene)
ABS is a material which great for printing tough and durable parts that can also withstand high temperatures. The typical GTT of ABS is 230-260ºC for the nozzle and 80-130ºC for the print bed. You can immediately see therefore that the working parameters for ABS are much higher than for PLA.
The use of ABS is fairly widespread throughout manufacturing industries and very widely used in toy production. In fact, probably the most famous name in toys, Lego, uses ABS for all of its bricks and imagine how many billions of those there are in the world.
ABS can also be used for machine parts and electrical housings as well as in everyday items such as office printers, vacuum cleaners, kitchen utensils and even musical instruments.
Pros
Good impact and wear resistance | ABS can withstand high impact which makes it ideal for use in machinery and toys |
Less oozing and stringing gives models smoother finish | Higher working temperatures give less potential for blockage at low print speeds |
Can be used outside | Strength and water resistance make it durable under harsh weather conditions and UV light |
Good heat and chemical resistance | Can withstand higher temperatures and is resistant to some chemicals which make ABS a good material for machinery |
Cons
Heavy warping can occur | Ambient cooling can affect the shape of the 3D print as layers are added |
Needs heated bed or heated chamber | Needs heated bed or heated chamber |
Produces a pungent odour while printing | The high temperature and inherent chemicals in ABS can smell unpleasant when printing |
TPE (Thermoplastic Elastomer) and TPU (Thermoplastic Polyurethane)
These are both types of flexible filaments that are known are known for their elasticity allowing them to easily stretch and bend. They’ve been grouped together as they have very similar properties and working parameters.
These working parameters however do make flexible filaments a bit tricky to print with as you need to get the bed adhesion just right to allow it to stick but then come off the print bed undamaged.
These filaments are ideal for making flexible parts in machinery, such as grommets and gear belts but also lend themselves well to toys and similar items. Going back to our friend, Lego, they use flexible materials such as these for making the tyres on vehicles etc. More recently, you may have seen flexible filaments used to print full sized, wearable shoes as well as prototypes for production line trainers.
Pros
Flexible and soft | Ideal for making durable but flexible items |
Excellent vibration dampening | Suitable therefore for use in machinery where vibration can be an issue |
Long shelf life | Like PLA, if stored correctly they will last as long as they’re needed |
Good impact resistance | The rubber-like consistency allows for absorption and cushioning of Impact |
Cons
Difficult to print | Not the easiest material due to the adhesion issues and temperature ranges |
Poor bridging characteristics | Not ideal for printing anything where supports are needed or bridging is required |
Possibility of nozzle clogs and other issues | The viscosity of flexible filaments makes them stick to the parts of am FDM printer so can causes clogs and blockages |
May not work well on Bowden extruders | This alludes back to the clogging issue so a direct drive extrusion system may be better |
PETG (Polyethylene Terephthalate Glycol)
PETG filaments are known for their ease of use, smooth surface finish, and water resistance. These are probably the most commonly used of the plastic materials found throughout the world as they are used for things such as water and soft drink bottles as well as some food containers.
Although PETG is regularly used in the food industry, it is not ratified as being “food safe” in all territories of the world so caution should be taken if printing food related items. Storage of unused filament will also be a factor in this case due to the possibility of food contamination.
Pros
Smooth surface finish | If printed correctly, PETG will have a nice look to any object |
Adheres well to the bed with negligible warping | Under the right conditions, printing should produce good results |
Mostly odourless while printing | Ideal both for the comfort of the user and the final printed object if used for food etc. |
Strong but also some flexibility | If printed with a high infill percentage then PETG objects will be very strong and solid. Thinner walls and less infill will give more flexibility |
Cons
Poor bridging characteristics | Supports would be needed in most areas |
Can produce thin hairs on the surface from stringing | This is a common factor and therefore needs a fair degree of post processing |
Not easy to work with | The working parameters in terms of heat, adhesion and stringing make PETG an unpopular choice for the casual user |
Nylon
Nylon is a tough and semi-flexible material that offers high impact and abrasion resistance. It is an ideal choice for printing durable parts for machinery and electrical components. It’s also resistant to oils and some other chemicals, lending itself well to printing electrical and control panel housings.
Nylon as a product is well-known in the manufacture of clothing, where it’s added to give cotton a reinforcing stretchiness. The material is also commonly used for things such as pulley wheels or even the wheels that move the axis on your 3D printer. It can also be used for making some toys, lending itself well to 3D printing.
The downside of nylon in this regard is it’s water absorption which also makes it unsuitable for use outdoors.
Pros
Tough and partially flexible | Has a hard finish but also some flexibility which is ideal for certain moving parts |
High impact resistance | It’s strength allows for it to be used in high wear situations |
No unpleasant odour while printing | Good for the working environment |
Good abrasion resistance | As mentioned, it can be used to make wheels which will take wear when used |
Cons
Prone to Warping | The slower printing speeds needed leave the object prone to ambient temperature changes which can lead to warping |
Air-tight storage required to prevent water absorption | Vacuum packing is the best option but mistakes happen so a filament dryer is an option |
Improperly dried filaments can cause printing defects | Moisture can cause “popping” while printing and lead to uneven layers and under extrusion |
Not suitable for moist and humid environments | The moisture factor again |
ASA (Acrylic Styrene Acrylonitrile)
ASA is a common alternative to ABS and is great for outdoor applications due to its high UV, temperature and impact resistance.
The material is lighter than ABS due to the Styrene content as you’ll see noted in one of the later listed filaments. This makes it suitable for things such as model aircraft and drones, small hand tools and outdoor covers for switches and electrical panels.
Pros
Strong UV resistance | Won’t fade or become distorted by UV rays |
High impact and wear resistance | Great for outdoor and regular use items such as the safety equipment already mentioned |
High glass transition temperature (GTT) | This is basically the melting point of the material |
Cons
Requires higher extruder temperatures | The GTT is higher so will need a printer capable of the raised temperatures |
Requires ventilation due to potentially dangerous fumes | A clear and ventilated working environment is essential |
Polycarbonate
Polycarbonate is known for its strength and durability. It has very high heat and impact resistance making it an ideal choice for tough environments.
This is a similar type of filament to the Carbon Fibre Filled filament that we’ll look at briefly later. The difference being that the carbon and other polymers are mixed to become a copolymer, not to be confused with a mixed polymer. This makes the resultant material much stronger than an additive based filament as the carbon element runs through the entire molecular structure.
Pros
Impact resistant | Able to withstand direct impact due to its tight structure and flexibility |
High heat resistance | Ideally suitable for machinery parts or in other environments where high temperatures prevail |
Naturally transparent | Although colour additives can be included to increase the opacity |
Bendable without breaking | Very strong under stress testing so can be easily re-shaped and formed to fit around static objects |
Cons
Requires very high print temperatures | Due to its high heat resistance the GTT is of course much higher. This may define 3D printer choice |
Prone to warping | The flexibility can be a downside if exposed to heat for greatly extended periods |
High risk of leakage and nozzle clogging while printing | The slow print speeds and high temperatures required can cause issues |
Absorbs moisture from the air which can cause print defects | Vacuum storage is essential and a dry printing environment is recommended |
Polypropylene
Polypropylene is great for high-cycle, low strength applications due to its fatigue resistance, semi-flexible and lightweight characteristics.
You’ll find polypropylene used in the manufacture of plastic furniture as may be used in a garden, low-friction gears in machinery and vehicles and also plastic bottles and containers.
We’ve mentioned that PETG is used in making bottles but Polypropylene is reserved for chemicals such as bleach as well as cleaning and first-aid specific liquids.
Pros
Good impact and fatigue resistance | Flexible enough to withstand impact and ideal for use as a container for chemicals |
Good heat and chemical resistance | Resistant to external heat and UV light. Will resists chemicals so again, good for containers |
Smooth surface finish | If printed correctly, polypropylene will have a smooth appearance and feel |
Cons
Heavy warping | Due to the flexibility aspect, warping is unfortunately inevitable |
Low strength | Can be easily cut or torn even using scissors |
Difficult to adhere to bed and other adhesives | Due to the good chemical resistance, its hard to get good bed adhesion |
HIPS (High Impact Polystyrene)
HIPS is a lightweight material most commonly used as a dissolvable support structure for ABS models.
If you imagine Polystyrene or styrene as its also known, then you’ll know that this will evaporate when exposed to heat. This makes it a useful material for creating aluminium objects where the model is crafted in styrene, placed in sand and then the molten aluminium is poured into to replace it.
HIPS also evaporates but not when heated. The application of d-Limonene is used to completely dissolve the printed HIPS leaving just the ABS model behind.
Pros
Impact and water resistant | HIPS is strong despite its dissolvability |
Lightweight | Very lightweight which makes sense with the Polystyrene element involved |
Dissolvable by d-Limonene | An easily obtainable liquid which works well at dissolving HIPS |
Cons
Heated bed or chamber required | This is common in most FDM printers but the heated chamber may make things more difficult |
High printing temperature | Again, a specialist 3D printer may be needed to cope with the high working temperature |
Ventilation required | HIPS can give off toxic fumes so a ventilated workspace is a must |
PVA (Polyvinyl Alcohol)
You may be more familiar with PVA as being a glue used to stick things like cardboard and paper but PVA is also known for its ability to be dissolved in water. That’s what makes it ideal for glue as it washes off easily if spilt.
In FDM 3D printing, PVA is often used as a support material for complex prints where it may be more difficult to remove those supports in post processing. If combined with a stronger material for the main body of the print, the supports can then easily be removed just by using water.
Pros
Good to use for complex supports | Makes it easier to remove supports in post processing |
Water soluble | No harsh chemicals are needed |
No additional equipment required | All you need is water and a suitable vessel |
Cons
Moisture sensitive | Best to keep dry and vacuum, stored. A low humidity working environment is also recommended |
Greater chances of clogging if the nozzle is left hot when not extruding | HIPS will continue to extrude on its own if still heated so this can lead to severe clogging |
Other Additive Based Filaments
As we mentioned at the start of this article, there are variations on a theme withing different types of filament. Aside from the different finishes of PLA for instance, there are some filaments that use PLA or ABS as the base material to include certain additives. These additives will change and enhance the base material making them more adaptable to a wider range of uses.
There are many of these additive based filaments but we’ve picked out three that are most commonly used.
Carbon Fibre Filled
Carbon fibre filaments contain short fibres that are infused into a PLA or ABS base material to help increase strength and rigidity. This makes them a strong but lightweight alternative to using metals.
Wood Filled
Wood filaments combine a PLA base material with cork, wood dust, or other derivatives giving the models a real wooden look and feel. Some wood filled filaments can also give off the actual aroma of the wood itself which is pleasant but dissipates over time. Don’t however confuse wood filled filaments with “wood effect” filaments as these will only give a similar look to real wood.
Metal Filled
Metal filled filaments are made in a similar way to carbon fibre filaments by mixing a fine metal powder into a base material, providing a unique metallic finish. They also have increased strength but added weight which may not be suitable in all applications.
Conclusion
As you can see from this list, there are many different types of filament that can be used in the field of FDM 3D printing. This list however isn’t exhaustive so there are other variants and specialist filament types that haven’t been mentioned. Hopefully though this will give you a good idea of which filament to use for your project and how each one performs both while being printed and as a final 3D printed object.
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