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What are the common materials used in 3D printing? - RP Space

What are the common materials used in 3D printing?

The materials used in 3D printing is one of the important considerations when 3D printing a certain object. This is because different material will have different material properties and the ease of 3D printing them will vary.

Therefore, understanding the commonly used material will help you decide the best material for your application.

In this article, we will be showing the common materials used in 3D printing, mainly in FDM (Fused Deposition Modelling) 3D printing technology.

 

1. PLA (PolyLactic Acid)

Cat Keychain/Phone Holder Printed with PLA

PLA is currently the most common material used for 3D printing. This is because PLA is a material that is very easy to 3D print with, and the chance of having a success print is very high with PLA.

 

Easy to Print and Works on All 3D Printers

PLA prints at a fairly low temperature (within the range of 190oC to 210oC) as compared to other 3D printing materials. This means that PLA can be used in all 3D printers because the hot-end (print head) of all 3D printers in the market will be able to withstand up to around 240oC.

As an example, certain materials such as polycarbonate, which requires around 290oC to 3D print it, would require a specific hot-end (print head) which is capable of printing higher temperatures.

Besides that, 3D printing with PLA do not require a heated build plate (print bed). A heated build plate (print bed) is basically the 3D printer is able to heat up its print bed to a certain temperature.

3D printers with heated build plate (print bed) is able to heat up the print bed to a certain temperature which prevents the printed plastic to shrink too much, which may cause warping or parts not sticking to the print bed. Since PLA do not shrink much when it cools down, it does not require a heated build plate.

This means that PLA can be used in all 3D printers because some 3D printer do not come with a heated build plate, which PLA has no problem printing on it. However, a heated build plate temperature of 50oC to 60oC would help although not necessary.

If you are new to 3D printing, be sure to grab a PLA filament as your first material. This is because it is easy to print and will work on all 3D printers. In fact, there are some 3D printers in the market which are specifically made to print PLA only.

 

“PLA is the most common material used for 3D printing because it is easy to print and will work on all FDM 3D printers”

 

2. ABS (Acrylonitrile Butadiene Styrene)

Lego 3D Printed with ABS
(Image by pixelpush design)

ABS is the material used to make Lego, and also one of the earliest materials used for 3d printing.

ABS is a good substitute for PLA if the printed part needs better toughness and temperature resistance. Also, the price of ABS filament is similar to PLA filament.

So, we mentioned that PLA is the most commonly used material in 3D printing. But ABS sounds like a better deal since it has better material properties than PLA and approximately the same cost. What’s the catch?

It is true that PLA is the most commonly used material in 3D printing. Despite the fact that ABS has better material properties, at approximately the same cost as PLA, it has two downsides which made it not as commonly used for 3D printing.

1. The toxic fumes that are emitted when 3D printing with ABS
2. Difficulty to print with ABS

 

Toxic Fumes

When printing with ABS, toxic fumes are emitted during the 3D printing process which can be easily identified from the terrible plastic smell when printing ABS. This toxic fumes are harmful to our health and you should avoid inhaling it.

There are studies showing that other 3D printing materials will emit a certain amount of harmful particles as well. However, there is no comprehensive answer at the moment to prove that.

But one thing for sure, those studies show that ABS emits way higher amount of the harmful particles as compared to other common 3D printing materials.

Therefore, make sure to print ABS in a well-ventilated room, to prevent inhaling the toxic fumes. However, it is also recommended to print other materials in well-ventilated room.

“Always 3D print ABS in a well-ventilated room.”

 

Difficult to Print

Another downside of printing with ABS is that, it is difficult to print with it.

ABS shrinks a lot after the material is extruded from the nozzle (tip of the print head). This causes some common issues such as warping and cracked layers, which reduces the chance of getting a success prints with ABS.

Warped Print
(Image by All3DP)
Print with Cracked Layers
(Image by Prusa3D)

In order to reduce warping, ABS cannot run away from a heated build plate (print bed), usually around 100oC. Making it not printable on 3D printers without heated bed.

Besides that, the ambient temperature needs to be around 50oC to make sure the layers do not shrink and crack. This indicates that the 3D printer requires an enclosure to keep the temperature around the print higher than room temperature.

This creates some challenge as most 3D printers do not come with an enclosure, which makes some people avoid printing with ABS as much as possible.

Nonetheless, ABS is still a great material for applications which require the additional impact and temperature resistance.

 

3. PETG (PolyEthylene Terephthalate Glycol)

PETG is a material which comes later than PLA and ABS, making it less popular.

PETG is a glycol-modified version of PET (PolyEthylene Terephthalate), where PET is commonly used to make plastic bottles.

PETG is a great material for 3D printing which has the properties close to ABS and ease of print of PLA.

This sounds like the best of both worlds, so this should be the best material for 3D printing isn’t it? Why is it not as popular as PLA?

 

Not That Easy

First of all, even though it is far easier to print with ABS (no issues with warping or cracked layers), it is still not as easy as PLA. One of the main challenge printing with PETG is stringing, which can make the prints quite ugly sometimes.

Stringing is basically thin strands of material on the print. As the print head moves around to print the object, some material may ooze out from the print head, forming all the strings. This effect is more obvious when printing with PETG.

Stringing on Print

Most of the time, parts which are 3D printed do not need to withstand great load, since they are mostly for home improvements or decorative. For these purpose, PLA is more than sufficient to achieve the objective. You will not have any problem with a book stand printed with PLA.

Therefore, there is really no need to go through the hassle to print with “slightly-harder-to-print” PETG when PLA can do most of the job.

Besides that, PETG is slightly harder to print without the heated build plate (print bed). However, there are people who manage to print PETG without heated build plate.

 

Overtake ABS? Maybe.

The reason why PLA and ABS is popular is because of their early entry into the 3D printing world. Therefore, PETG which joins the game later might need some time to climb up the rank.

The question is, will PETG eventually become more popular than ABS in the future? We are not sure, but we are seeing signs that PETG may one day, overtake ABS.

People use ABS instead of PLA not just for the additional toughness, but also the temperature resistance. In fact, temperature resistance may outweigh toughness when it comes to using ABS.

This is because PLA has a glass transition temperature (temperature which the material starts to become ductile – deform more under force) of approximately 60oC, which is quite achievable in cars parked under hot sun.

Although not all 3D printed parts may end up in the car which is parked under the hot sun, the parts may still deform under load when exposed to the hot sun especially if the heat surrounding it is enclosed and has nowhere to escape.

Therefore for outdoor applications, people tend to use ABS (glass transition temperature of 105oC) to get that extra margin of temperature resistance just to make sure the part will not deform even under the hot sun.

However, ABS is not anymore the only choice after PETG was introduced. PETG has a glass transition temperature of 80oC which is slightly higher than PLA but at the temperature range which is very difficult to achieve even under the hot sun.

This indicates that for applications solely to fit outdoor uses, PETG is a better candidate. This is because PETG does not emit toxic fumes, similar toughness as ABS, do not shrink as much as ABS, easier to print than ABS and can still withstand the outdoor temperatures.

You can check out this video by Maker’s Muse which demonstrate the effect of hot sun on PLA, ABS and PET prints.

Nonetheless, ABS is still suitable for applications which requires that additional temperature. It is pretty hard to directly compare the toughness of PETG and ABS since the layer lines formed during the 3D printing process makes the properties direction-dependent.

PETG filament is currently slightly more expensive than ABS filament. But once the demand for PETG eventually increase, the price will start to go down.

Looking to print parts which are slightly tougher and higher temperature resistance yet still easy to print? PETG is a good choice for this.

 

4. Nylon (Polyamide)

Hooks 3D Printed with Nylon
(Image by All3DP)

Nylon is a material which is very tough and partially flexible, which is very suitable for 3D printing functional parts.

Despite having good mechanical properties, nylon is hard to print. It is almost as hard to print as ABS as it warps quite a lot.

Besides that, Nylon prints at temperature around 250oC. This means that not all hot-end (print head) is able to print Nylon, limiting the popularity of Nylon.

 

Moisture Absorption

One of the main downside of Nylon is the hassle required to store the filament. Nylon is an extremely hygroscopic material, which means it tends to absorb moisture from the surrounding. For 3D printing filament, moisture in the filament will affect the quality of the printed part.

This is because the moisture tend will fill up the filament, which will turn into void as the moisture goes through the hot-end (print head) and evaporate. This eventually passes the voids onto the print, resulting in bad quality prints.

Parts Printed with Dry Filament (Left) and Wet Filament (Right)
(Image by MatterHackers)

Therefore, Nylon needs to be stored in an air-tight storage (best with desiccant to help remove the moisture from the air), or must be dried before using it to print parts (an easy way is to use a food dehydrator to dry the filament).

Anyway, Nylon is also slightly more expensive. Adding to the fact that it is hard to print (lower chance of printing successfully) and the additional costs required to keep the filament dry, people tend to shy away from it.

However, if your application requires parts with some serious toughness, and if you are willing to go through the hassle and learn how to make the best use out of Nylon, you will reap the benefit of the superior mechanical properties of using Nylon.

 

5. TPU (Thermoplastic PolyUrethane)

Mini Tyre 3D Printed with TPU
(Image by Tractus3D)

TPU is a type of flexible filament which is suitable for applications which requires some flexibility on the part such as a phone case.

TPU comes at a range of flexibility, measured by its shore hardness. The shore hardness for TPU is usually within the range of 60A to 90A (or up to 100A) where the higher the number, the less flexible it is.

 

Sometimes Too Flexible

Flexible filaments are quite difficult to print because it tends to buckle under compression. This means the path after the extruder gear (the gear which pushes the filament) needs to be well constrained. Else, the filament will start to bind up and roll to the side instead of the actual filament path.

Flexible Filament Buckles

With that in mind, printing with flexible filaments usually require the print speed to be slowed down quite a lot. This means that you can print faster with TPU which are less flexible (higher shore hardness), or you take your time to wait for a slower print using a more flexible (lower shore hardness) TPU.

At the current moment, the limitations of printing with flexible filaments lies mostly on the 3D printer itself, mainly on the filament path. In the future as the 3D printers get better and better, printing with flexible filaments will start to get easier and eventually making flexible filaments more popular.

If your part requires certain amount of flexibility, TPU is a great choice for such application.

 

 

Conclusion

There are many 3D printing materials available for different application. The 5 materials mentioned above are the common ones used in FDM (Fused Deposition Modelling) 3D printing technology.

PLA is currently the most commonly used material due to its ease of use and can be printed on all FDM 3D printers. ABS comes second because it is harder to print compared to PLA.

PETG is a close rival to ABS and may soon overtake ABS. Nylon and TPU are slightly more expensive and slightly harder to print, which makes them hard to gain popularity. Nonetheless, the superior material properties of Nylon and TPU make it suitable for wide range of functional parts.

Different materials are suited for different applications. Therefore, it is wise to study the materials and choose the best one for your application.

What materials do you like the most and why is it? Let us know in the comments below, we would love to hear from you.

 

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