PETG vs Nylon

by | Feb 21, 2021

Both PETG and Nylon are considered high-performance 3D printing filaments. Each one also comes with unique challenges. They are some of the best go-to materials if you need a 3D printed part to be durable and wear-resistant.

Choosing between PETG and Nylon depends on your specific application. Do you need the part to be flexible or chemically resistant? Do you have budget limitations?

In this article, we’re breaking down all the factors of difference between Nylon and PETG.

Application Comparison

Both of them are polymers that are highly valued for their mechanical properties. These plastics are ubiquitous in commercial products and valuable in several industrial, scientific, and medical scenarios.

PETG is a glycol-enhanced version of Polyethylene Terephthalate (PET). As an FDA-compliant material for food storage, People always use PETG material for single-use and reusable water bottles and food containers. It is also perfect for medical tools and accessories, as PETG can withstand sterilization temperatures via autoclaving.

Nylon is the mainstream term for Polyamides (PA) and is currently one of the world’s most commercially valuable polymers. Nylon fibers are used practically everywhere – from clothes to tires, parachutes, and toothbrushes. With excellent heat stability, molded Nylon can use for internal car components or oven-safe food containers.

Properties Comparison

Making a wise choice between Nylon and PETG requires that we break both materials down into their benefits and drawbacks. They are both excellent materials, after all. However, there are certain areas where PETG is better than Nylon and vice-versa.

Here are some of the primary material properties comparison between PETG and Nylon.

1. Strength

It is best to assess the strength of a material in terms of tensile strength. It defines the maximum load that a material can support before breaking apart or deforming irreversibly. Based on this metric alone, PETG holds a slight advantage at 50 MPa versus Nylon, ranging from 40 to 45 MPa.

Take note that there are high-strength versions of both Nylon and PETG, modified for increased tensile strength. Thus, it is still possible for a high-strength Nylon filament to be stronger than standard PETG.

About the materials used in FDM 3d printing, most of them are standard types.

2. Durability

The durability of a material is determined by how long it lasts when exposed to certain conditions. It is tough to quantify because the material can reveal in different environments, depending on your application.

Generally speaking, Nylon is one of the most durable 3D printing materials. With its semi-crystalline structure, Nylon can withstand harsh conditions and repeated stress without breaking apart.

While PETG is also known as a durable material, it still does not compare to the toughness of Nylon. It can also withstand outdoor conditions but is not as resilient against mechanical stress.

3. Flexibility

The most reliable measure of flexibility of a material is its flexural or bend modulus. It is a measure of how much force a material can withstand in a bending test before breaking.

The flexural modulus of PETG is about 300,000 psi. However, Nylon still beats it handily at 450,000 psi. It is hardly surprising considering how the malleability of Nylon has made it possible to create fabrics entirely out of Nylon fibers. This flexibility also gives Nylon superior impact strength.

4. Hygroscopicity

Hygroscopicity is an indicator of how quickly a material absorbs moisture from its environment. 3D printing filaments as excess humidity can cause several quality and performance issues.

While all 3D printing filaments are naturally hygroscopic, Nylon has gained a reputation for being one of the most sensitive to hygroscopicity. Nylon absorbs moisture extremely fast. When left in the open for 48 hours, Nylon can absorb enough water to lead to a ruined print.

PETG is also hygroscopic but is nowhere near as sensitive to moisture as Nylon. In any case, it is always good practice to store your filaments in airtight bags with some desiccant. Are drying your filament in an oven or a dedicated filament dryer before printing is also a good idea.

5. Odor

Neither Nylon nor PETG produces an unpleasant smell during printing. Even if the odor is not an issue, we still suggest printing in a room with good ventilation. 3D printing naturally releases plastic microparticles that can accumulate in your respiratory over time.

Despite the lack of odor, Nylon can release caprolactam when heated. Claims of caprolactam being carcinogenic have been disproven, but exposure to it can still cause headaches and irritation.

6. Ease of Use

PETG holds a clear advantage over Nylon because Nylon is highly prone to warping.

You’ll likely have to bring out all your bed adhesion tools when working with Nylon – a heated bed, adhesives, and a print bed enclosure. You may even have to resort to printing with a brim or raft.

7. Resistance

The resistance to chemicals relies mainly on its chemical composition and molecular structure. PETG and Nylon are distinct from each other in this regard because they react differently to a range of chemical agents.

Nylon is generally resistant to alcohol and solvents. PETG is also resistant to alcohol but also resists reactions with acids, bases, and water. Neither holds the advantage in this category. Instead, it is only a matter of using the proper material for any application.

8. Safet

Whether you’re printing with PETG or Nylon, the usual safety measures should put in place. Wear breathing protection, make sure to have good ventilation, and don’t touch any moving or hot parts.

As mentioned, Nylon tends to produce caprolactam fumes that can be irritating after acute exposure. Although claims of caprolactam being carcinogenic have been disproven, venting the fumes is good practice regardless.

3D Printing Comparison

3D printing performance is an important parameter when choosing between the filaments. Aside from ease of use, other factors need to be considered. These include the level of detail that a filament can produce and how easily the finished print can be post-processed.

1. Printing Temperature

The printing temperature for PETG is anywhere between 220 to 250 °C. PETG does not require a heated print bed as it is not prone to warping. However, it still benefits from a print bed heated to 50 to 75 °C.

Nylon prints at slightly higher temperatures, It’s about2 40 to 260 °C. This temperature can be problematic for extruders with PTFE liners, as PTFE starts to break down at 250 °C. You will almost certainly need to get an all-metal hot end to print with Nylon.

A heated bed set at 60 to 80 °C is necessary when printing with Nylon. The heated bed is non-negotiable because of how heavily Nylon warps.

2. Bed Adhesion

Whether you’re printing with a heated bed or not, the best bed adhesive for PETG is either a glue stick or blue painters’ tape. This opinion is relatively fool-proof, and you should have minimal bed adhesion issues.

Nylon is an entirely different matter. Even with a heated bed, Nylon also requires an adhesive to prevent warping. The cheapest option is to use any PVA-based glue. Some users have reported great success with a Gasoline build surface, a unique fiberglass surface coated with an epoxy resin.

3. Support

While there is no specific material support best used for either Nylon or PETG, HIPS is a good option for both. HIPS prints at the range of 220 to 240 °C, which is close enough to both PETG and Nylon’s printing temperature.

The only downside of using HIPS is that you will need a limonene solvent stock for support removal. On the upside, limonene is quite common and provides an effortless way to remove support structures.

You can also choose not to use unique support material instead of printing the supports with Nylon or PETG. Support removal can be quite tedious with this method and may damage your final print if you’re not careful.

4. Warping

There is a massive difference in warping behavior between the two filaments. Warping is not an issue with PETG. This problem is partly the reason for the boost in popularity of PETG as a worthwhile alternative to ABS.

On the other hand, warping is one of the significant drawbacks of printing with Nylon. It makes Nylon a very challenging material to work with. Nylon is not the type of filament that we would recommend to beginners.

5. Accuracy

Due to the high shrinkage and proneness to warping, Nylon does not have a good performance in dimensional accuracy. Shrinkage is a natural result of the material cooling down rapidly.

Retaining accurate dimensions and fine details is a lot easier with PETG. Not only does PETG not warp, but it has no problems with being cooled down quickly. It makes it easier to print outstanding details.

6. Finish

Both PETG and Nylon do not benefit from any solvent-based finishing processes. The only option to make them smooth is to via sanding and polishing. Surface finish is a little more challenging with Nylon, given how abrasion-resistant and malleable the material is.

Heat treatment is another viable post-processing option. It involves using a heat gun to partially melt any imperfections on the surface of the finished print. This method can work with either PETG or Nylon, although it’s also easy to ruin a part with the improper technique.

In terms of the 3D printing experience, PETG is undoubtedly the more forgiving and beginner-friendly option. The heavy warping problem of Nylon makes it a very challenging material to work with, although the output quality is usually worth the trouble.

Price Comparison

Nylon is more expensive than PETG. The price of PETG is not a massive departure from that of PLA or ABS. Some brands offer 1-kilogram spools of PETG at about $20, with some premium brands reaching up to $30. such as Glass Fiber and carbon fiber reinforced PETG filament.

Standard Nylon filament is already quite expensive – about $30 to $60 for a 1-kilogram spool. As with PETG, there are also unique Nylon blends that promise better performance and enhanced mechanical properties. The most expensive of these can cost up to $80 per spool.

Summary

PETG is more friendly for beginners because it is easy to print, low warping, and inexpensive.

Printing with Nylon is more challenging but will also yield a more heavy-duty product. Nylon is suitable for parts that need durable, heat-resistant, and abrasion-resistant.

With both filaments having merits and demerits, picking the best one depends on the application and experience.