3D Printing – A beginner’s guide to the most commonly used materials
With the introduction of 3D printing, many industries have been completely transformed. Production is faster than ever, complexity of design is no longer an issue and models and prototypes can be made at the push of a button but with so many printing materials available, you might not know where to start.
This guide will take you through a huge selection of the filaments available on the market. Find out the properties of each material, both good and bad, to find the most suitable filament for your project. Whether you need the strongest 3D printer filament, the cheapest one or the most durable, you’ll find everything you need to know in our complete and comprehensive guide.
Acrylonitrile Butadiene Styrene is a petroleum based, spaghetti-like filament. Although it is non biodegradable, it is one of the most popular and commonly used 3D printing filaments (don’t worry, it can be recycled). It was one of the first plastics used for 3D printing, likely because it is easy to print, low cost and extremely durable, allowing it to be used for a range of applications and purposes.
As previously mentioned, ABS is highly durable and tough. It is non-toxic, retains colour well and results in a smooth finish. It is water and chemical resistant but can be degraded by UV radiation therefore, it is not generally suitable for outdoor applications. As the UV degrades the filament, it loses its colour and becomes brittle.
It is able to withstand high impact and high temperatures before deformation begins (around 220 degrees celsius). The temperature at which this occurs is known as a material’s glass transition temperature. Because ABS is so resistant to high temperatures, the extrusion temperature must also be very high. This however, does not come without its issues.
At such a high temperature, ABS releases unpleasant and potentially harmful fumes therefore efficient ventilation is a must. This is providing that the ventilation process does not cool the print too rapidly resulting in warping. Warping occurs when the plastic contracts during the cooling process and thus separates from the print bed, ruining the print. To counteract warping and ensure adherence to the bed, when using ABS, a heated bed should be used. For taller prints with many layers it may be useful to enclose the printer, in order to keep the temperature as high as possible during the printing process and ensure layers do not separate.
Another method of promoting bed adhesion is to use brims and rafts. A brim is a printed outline of your object, attached to the bottom edges of it, helping to secure it to the printer bed and prevent warping. Similarly a raft can be used. A raft is a printed platform positioned below your object. This also helps with bed adhesion and warping but can also be used to stabilise objects during the process. After completion, both brims and rafts can be easily removed to leave the desired 3D print.
Due to its non-toxic and durable nature, ABS is perfect for use in things such as children’s toys. It is smooth, easy to shape and can be dyed bright colours. One of the most common examples of ABS use is in the creation of Lego bricks.
PLA, short for Polylactic Acid, is quickly becoming the most widely used 3D printing filament. Much like ABS it is inexpensive, strong , easy to print and has a wide variety of applications.
This is where the similarities end however.
It has a rougher texture than ABS, it can be sanded and painted however it is hard to glue together. Due to a low extrusion temperature however, repairs can be made easily be remoulding or welding.
PLA is a much more environmentally friendly option; derived from crops such as corn and sugarcane, it is renewable and biodegradable. This becomes apparent during the print process as rather than unpleasant fumes being released, PLA gives off a sweet aroma, not unlike popcorn. As a biodegradable material, it is decomposed by bacteria over time thereby avoiding pollution. This will take a long time giving PLA filaments a very good shelf life nonetheless.
For extrusion PLA does not require high temperatures, with a glass transition temperature of only 60 degrees celsius (depending on the manufacturer and the chemical formulation), so there is no need to use a heated print bed. At such a low temperature PLA is prone to oozing. Oozing causes stringy bits of plastic to be left behind on the model. This occurs when filament leaks out of the nozzle whilst it is moving to a different location and is dominant when printing PLA due to the ease of flow. In order to counteract this, a cooling fan should be used. This will quickly cool the plastic to a temperature below its glass transition temperature (the point at which it deforms).
Water saturated PLA has a higher extrusion temperature and is more difficult to print, which could result in defects of the finished product. This highlights the importance of storing filaments properly after use.
As previously mentioned, the formulation of PLA may differ dependent on the manufacturer. Chemicals and additives can be added to make it more heat resistant and less brittle than in its simplest form.
One of the most common uses of PLA is in medical sutures. As it is a biodegradable substance, the sutures are broken down into lactic acid by the body’s bacteria. It is also commonly used in food packaging, although it is important to note that not all PLA filaments are food safe! This will depend on any additives added by the manufacturer. Finally, PLA can be found in many hygiene products from sanitary products to disposable items used in hospitals i.e. aprons, bed sheets etc.
This is a filament rarely used alone. Polyvinyl Alcohol has an interesting feature in that it completely dissolves when in contact with warm water. Due to this it is usually used as a support structure for objects with complex structures, likely to warp without support. For example, a structure may have many thin and delicate lines; the PVA would be printed in between these lines to produce a dense structure. When submerged in warm water the PVA will dissolve leaving only the desired print behind.
It is a biodegradable material therefore friendly to the environment but can be difficult to source and expensive to use. It has an extrusion temperature of around 200 degrees celsius; if heated above this it will release unpleasant fumes so this should be avoided where possible.
After use, it is extremely important to store PVA in an air-tight, moisture-free container. It is highly susceptible to water and therefore attracts moisture from the air. This is known as being hygroscopic. When disposing of PVA, care should be taken as PVA saturated water can cause drain blockages.
Used predominantly as a support structure material, PVA is used for anything with complex, geometric shapes. Most commonly used with PLA in dual extrusion, but can be used with other filaments. PVA is a very soft material could also be used in making models and quick prototypes of products. Although the properties of PVA lends itself well to this application, its expensive nature and somewhat difficult sourcing may restrict its use for this purpose.
Polyamide, or Nylon as it is widely known, is a tough yet semi-flexible material used in 3D printing.The thinner the layer, the more flexible it is. It has high impact and abrasion resistance making it an extremely durable material to use.
With extrusion temperatures between 220 – 250 degrees celsius (depending on the chemical composition), it can be prone to warping. Once again this is due to difficulty adhering to the print bed. As with ABS rafts and brims can help with this and a heated print bed is an absolute necessity. You may also want to enclose the printer to maintain a relatively high air temperature ensuring layers further away from the print bed do not separate.
Unlike ABS, even at high temperatures, Nylon does not have an odour and is non-toxic. It is relatively hygroscopic, readily absorbing moisture from the surrounding air, so should be stored in an air-tight environment after use.
Nylon as a 3D printing filament is generally used for mechanical and engineering purposes. This may be in the creation of high performance machine parts and tools. With its high abrasion resistance, parts made of Nylon are less likely to wear out, even with continued use.
Another filament often used for structural support during printing, HIPS’ full name is High Impact Polystyrene. A variation of this is High Density Polyethylene (HDPE); both filaments have the same properties and behave in the same way.
HIPS/HDPE is often used to support complex structures made of ABS as it holds many of the same qualities, making it the ideal partner for dual extrusion. It is low cost and has high impact, water and heat resistance. It has a glass transition temperature of around 230 degrees celsius meaning that a heat bed and a heat chamber is required during printing. Above this temperature unpleasant fumes will be released so it is important to ensure effective ventilation is present.
After printing in order to dissolve the HIPS/HDPE and free the desired structure, it must be submerged in d-limonene rather than water.
Structural support, as mentioned prior, is one of the uses of HIPS/HDPE as a 3D printing filament. Another common application of HIPS/HDPE is in the production of pipes and fittings, many producers of recyclable packaging also make use of it due to it’s high impact resistance, offering protection to packaged objects.
Again PET is a filament that comes in many variations. PET in its simplest form is Polyethylene Terephthalate but, can also be seen as PETT (marketed as T-glase) or as PETG (the glycol modified version of PET).
It is an easy to print material, giving a smooth and glossy overall finish. The finished result has a glass-like quality which can be maintained even if dyed. It is water resistant and has a good impact resistance despite being only semi-rigid.
Although, it has a somewhat high extrusion temperature of 230 degrees celsius, it is not prone to warping, as many other materials are at these temperatures. This is because it cools efficiently. It also does not release any unpleasant odours, even at high temperatures. A heated print bed can help with adhesion of the print but is not essential, as it is with ABS. Adherence can be greatly improved by reducing the speed at which the part is printed.
One of the main issues with PET is stringing and blobs at the beginning/end of segments. A way to combat this may be to play with the retraction settings on your printer to try and minimise the amount of leakage from the nozzle, when moving to new print areas. Many people have also found ‘coasting’ to be helpful. This stops the flow of plastic filament before the section is finished, allowing the last area to be filled in by the remaining filament in the nozzle (with the help of gravity of course). The nozzle can then be moved to a different area without leaks occurring.
PET is very frequently used in the production of water bottles and plastic bottles for soft drinks. It is ideal for this use as it is lightweight, has impressive moisture barrier properties and can be widely recycled. Very thin layers of PET have also been used to coat other materials to make them less porous.
Flexible filaments such as TPE (Thermoplastic Elastomers) and TPU (Thermoplastic Polyurethane) stretch and bend, as you would expect from the name. They are able to stretch as they are composed of a blend of hard plastic and rubber. The degree of flexibility depends on the amount of rubber within the blend.
As these filaments are able to stretch and bend, they have a very high impact resistance and good vibration dampening. They also have a long shelf life, not broken down with prolonged use or exposure.
The area in which this type of filament falls short is in its ease of print. TPE and TPU are notoriously difficult to print suffering from stringing, blobs and poor bridging. Stringing and blobs can often be counteracted or at least minimised, by adjusting the speed, retraction and coasting settings on the printer. Bridging on the other hand, cannot be combatted so easily. As the filaments bend, when trying to print bridged areas of an object, the filament often bends and breaks before the bridge can be completed. Many printers may also require modifications to print TPE/TPU to prevent blockages.
The ability to bend around an object and absorb high impact means that these filaments are perfect for making protective cases for items such as mobile phones and tablets. It is also commonly used in sportswear. Adidas for example use TPU pellets in cushioning technology used in their footwear.
A great alternative to ABS, Acrylic Styrene Acrylonitrile also has a high temperature and impact resistance, making it strong and durable. Unlike ABS it is not degraded by UV radiation due to a different type of rubber used in the formulation.
It does however, have many of the same drawback of ABS. Releasing unpleasant and potentially dangerous fumes at high temperatures, due to the presence of styrene, ventilation is required. A heated bed is also required during printing to ensure adherence and to avoid warping, unfortunately ASA is prone to overheating which can result in print quality issues, as well as the aforementioned dangerous fumes. Reducing the temperature slightly when printing taller layers can help with this issue. It is also an expensive filament to purchase so can increase the unit cost of prints significantly.
As ASA is not degraded by UV radiation, it is highly suitable for outdoor use. It will maintain its strength, durability and colour even with prolonged exposure. This makes it perfect to make things such as sunglasses or outdoor toys or storage solutions.
Polycarbonate is a strong, durable filament that has a very high heat and impact resistance. It has a moderately high glass transition temperature of 150 degrees celsius; it will bend but does not break. It must be printed at extremely high temperatures however, as the layers will begin to separate if it is too cool.
As with many of the high printing temperature filaments, it is likely to suffer from warping and oozing unless a heated print bed is used. It is also extremely hygroscopic, attracting lots of moisture from the air. Effective storage in a moisture-free environment is therefore, very important to maintain the shelf life of PC filaments.
It’s properties mean that Polycarbonate is well suited to tough environments and engineering applications. It has been known to be used in safety glasses, riot shields and even in bullet proof glass.
One of the more temperamental 3D printing filaments, Polypropylene is a semi-flexible, lightweight material, giving a smooth finish. The flexible nature of PP means that it has good fatigue resistance, not wearing out easily.
Very difficult to print, it has a range of issues. First of all it has a high extrusion temperature meaning that adherence to the print bed is very difficult and thus a heated bed is required. An enclosure is also recommended in order to maintain a high surrounding air temperature. It is also one of the more expensive filaments available and warps heavily on cooling .
Although seemingly rife with issues, it is the perfect material to make items that will undergo heavy use due to its high fatigue resistance. The type of items usually made from PP are things such as dog leads, watch straps and storage containers.
For high precision printing, Polyoxymethylene is usually a good choice. Often donned the engineering plastic, it is strong and rigid and resistant to wear. This is partly thanks to its low friction coefficient allowing moving parts to slide past each other, reducing wear.
It is prone to warping which can be an issue if precise interlocking or moving parts are required. Again, with the addition of a heated print bed, adherence can be ensured and warping reduced to negligible amounts.
As the engineering plastic, it has many applications within that sector from machine parts to tools. Nevertheless, there are more well recognised applications, for example, zips. Highly precise to ensure sections interlock properly with low friction so that the parts are able to move freely past each other makes POM the perfect choice.
Polymethyl Methacrylate, more commonly known as acrylic, is a shatter resistant, rigid and lightweight filament often used as an alternative to glass. As you may have guessed, PMMA has high levels of clarity when printed correctly.
Clarity is increased when flow is consistent, a high nozzle temperature must be used to ensure this consistent flow and prevent warping. Once again an enclosed print chamber will help with this, regulating the rate at which the print cools.
Acrylic is used in a wide range of areas and applications but the clarity and shatter-proof qualities of it make it perfect for use in replacement windows. It is also used in toys and items designed for children. The shatter resistant aspect of it means that items are less likely to break in a way that could be dangerous.
ABS and PLA are diverse filaments that can be used in a wide range of applications. This makes them the perfect base filaments to mix with other fibres or chemicals in order to add new properties. For the most part, the blends behave in a very similar way to ABS or PLA (dependent on the base) but certain additions can potentially change their properties.
Tiny fibres of carbon fibre are added to Nylon or ABS in order to increase the strength and stiffness. It is extremely light so decreases the overall weight of the print, as well as improving stability. It can also prevent shrinkage during cooling thus, removing the problem of warping.
The tiny fibres can be abrasive to the printer nozzle so, switching to a more durable nozzle is advised. Furthermore, clogs and oozing can be an issue when using Carbon Fibre filaments. Reducing the speed of the print will aid in removing clogs and will also ensure that the filament does not break mid-print. It can be very brittle when printing so sharp corners and sudden movements are not advised.
Commonly used in items that are required to be lightweight and stiff, yet also able to withstand significant impact. These may be items such as Jigs, fixtures and end use parts.
Most wood filament blends contain around 30% wood but this changes depending on the manufacturer. Wood or sometimes cork, is added as a very fine dust which means that is not as abrasive to printer nozzles as the carbon fibre blend is.
It has a pleasant aromatic smell during printing and gives a real wood finish, although this may need to be brought out by finishing techniques such as sanding. The colour of the finish can also be adjusted by varying the temperature at which it is printed. Higher temperatures create a darker wood finish.
As the filament contains real wood particles, these can block the nozzle and cause oozing. The nozzle is unable to maintain suction when moving to new print areas, due to the particles, therefore some leakage is to be expected. As with PET, coasting can be helpful in avoiding this.
Wood filaments are generally used for decorative purposes so the applications are almost endless. Items such as phone cases made from wood filament are widely available.
Employing the same premise, fine metal powder is blended into a base material to produce metal filaments. This can be done with a variety of metals from copper to bronze to stainless steel. Naturally this increases the weight of the blend meaning prints are very heavy. This added weight means that metal filaments have significant bridging limitations.
As would be expected this kind of filament is highly abrasive to the nozzle so printers may require adjustments to be compatible with metal filaments. They can also be brittle and expensive, more so with more precious metals and percentage of metal in the composition. As with the wood filament, finishing such as sanding and polishing, is required to bring out the metallic aesthetic.
Again, metal filaments can be used in many ways and are often used for decorative purposes. It is frequently used in printing sculptures and figurines.
Conductive filaments contain conductive carbon particles giving this filament the ability to conduct electricity.
This property means that low voltage circuits can be printed for use in items such as LEDs or homemade gaming controllers.
Glow in the Dark
Phosphorescent materials are added to PLA or ABS which absorb photons (tiny light particles). After effectively charging in the light, when objects are left in the dark, the photons are released allowing it to glow in the dark.
This is generally used for decorative purposes in items such as action figures and decorations.
Powdered iron is added to the base filament allowing the filament to become ferromagnetic. Ferromagnetic means that the item itself is not magnetic but will stick to other magnetic items.
The most obvious application for this is in the creation of fridge ornaments.
Colour changing filaments can be created using different additions to the base dependent on the colour change desired. The colour then changes based on temperature so layers closer to a heated print bed will be one colour, whilst those further away will be another.
This style of filament is mainly used for decorative purposes such as ornaments and vases etc.
Stone or other earth based materials are blended with the base to produce filaments that result in a faux pottery finish. Many manufacturers even make clay or ceramic filaments that are able to be fired in a kiln and glazed after printing, just like real pottery.
Clay and ceramic filaments are great for making any kind of item you would usually find in a pottery shop, i.e. plates, vases mugs etc.
By now you should know everything you need to know about the most popular kinds of 3D printer filaments available and how each filament type is best used. Hopefully, our guide has given you some insight into the best filament type to use for your next 3D printing project. For more information on compatible printers do not hesitate to get in touch!