Printing with PETG: The Good and The Bad

PETG: An Overview of the Pros and Cons

PETG, or Polyethylene Terephthalate Glycol-modified, is quickly gaining traction over notable competitors such as ABS and PLA. While PLA and ABS are still widely prevalent and available products in the 3D printing filament market, PETG has seen its popularity grow, particularly with 3D printing professionals.

There are a few reasons why 3D printing professionals, in particular, are beginning to gravitate toward PETG as their primary 3D printing filament:

• Durability: PETG is even more durable than ABS, which used to be the more durable alternative to PLA. PETG features a Vicat softening temperature of 85 degrees Celsius and a heat deflection temperature of 70 degrees Celsius. Additionally, PETG is nearly 30 times denser than PLA, at 31.27 grams per centimeters cubed.
• Printability: PETG is also preferred regarding its printability. The filament is noted for its solid adherence to the printer bed and its lack of warping or odor. PETG also requires a lower printing bed temperature, between 60 and 80 degrees Celsius, than ABS and has a comparable printing temperature range to PLA at 230 to 250 degrees Celsius.
• Notable Features: Several other peripheral features related to the PETG have contributed to its rise in popularity. For one, PETG as a material is notably easy to sanitize. PETG is also water-resistant, making it the superior filament for any water-holding objects to PLA, which is not water-resistant.

With this being said, PETG is also not without its flaws. Let’s take a look at some of the drawbacks to using PETG as opposed to other 3D printing filaments:

• Physical Issues: Although PETG is notably more durable than most other popular 3D printing filaments, there have been several issues with the final 3D-printed product of a PETG print. PETG has been critiqued for being susceptible to scratching, perhaps due to its glossy and smooth finish, and deformed parts due to print speed sensitivities.
• Price: PETG is also one of the pricier filament options on the market. At roughly $39 per kilogram, PETG is the priciest filament among the three filaments listed in this article (PETG, PLA, and ABS).

Now, let’s take a brief look at the history behind PETG and its rise in popularity in the 3D printing industry.

PETG is Quickly Outdoing the Competition

PETG is actually a copolymerization of the homopolymer PET, which is commonly used to form water bottles and food containers. Initially created in 1941, PET is now one of the most popular plastics in its own right, accounting for over 18% of global plastic production. However, when it comes to 3D printing, PET on its own is not a competitor.

So, some properties of PET were modified to create a filament that could be used in 3D printing. In this case, the ethylene glycol in the PET was replaced with cyclohexanedimethanol, or CHDM. This modification interferes with the crystallization process of PET and, as a result, lowers its melting temperature, making it the perfect polymer for 3D printing.

Now, PETG is one of the most popular 3D printing filament products on the market. However, this does not necessarily mean that it is the best product for your 3D printing needs. Let’s take a look at all of the advantages and disadvantages of using PETG.

Should I Use PETG for My 3D Printing Project?

PETG is undoubtedly one of the premier 3D printing filament products on the market. Still, it is essential to examine all facets of the product before ultimately deciding whether or not the product is right for you. In this case, let’s take a closer look at PETG’s pros and cons through its printability, durability, notable features, and price.

Printability

First, let’s take a look at the pros associated with PETG’s printability:

• Adheres to Printer Bed: Largely due to the impressive density of PETG, its layers adhere quite well to the printer bed, allowing for a very reliable print if done correctly.
• No Odor: Unlike other filament products, like ABS, which emit an odor while being printed, PETG emits no smell whatsoever.

Now, let’s study the cons associated with PETG’s printability:

• Sensitive to Print Speed: Unfortunately, to get a reliable print with PETG, you have to be sure you have adjusted all your settings as precisely as possible. PETG is highly susceptible to print speed: a fast print will lead to lousy layer adhesion and extruder skipping, while a slow print will lead to deformed parts, stringing, and oozing.
• Requires Precision: Apart from its print speed, PETG also requires several other precise settings to ensure it is processing effectively. If you are using a dual extruder printer, there are soluble supporting filaments, PVA or HIPS. But, if you are using a single extruder printer, you must leave a 0.1mm gap between each support.

Durability

The pros concerning PETG’s durability include:

• Greater Density: As mentioned earlier, PETG is 30 times denser than PLA, at 31.27 grams per centimeters cubed, making it one of the most durable filaments on the market.
• Solid Layer Adhesion: In addition to its favorable printer bed adhesion, PETG also produces solid layer adhesion when all settings are adjusted accordingly.

Now, let’s take a look at the cons associated with PETG’s durability.

• Susceptible to Scratching: While many admire PETG for its smooth, glossy finish, this quality does leave PETG more susceptible to scratching than other popular filaments.

Notable Features

The most helpful and convenient features of PETG are:

• Easy to Sanitize: One of the critical features in PETG’s rise in popularity; this is why most face shields are made of PET material.
• Does Not Require Fans: Unlike most other filament products, PETG does not require cooling fans to operate.
• Water Resistant: Finally, PETG is also resistant to water, making it the perfect material for a water bottle or container.

The only downside to PETG’s features is that it requires a heating plate to operate.

Price

At roughly $35 to $40 per spool, PETG is more expensive than other popular filament products like PLA. However, there is not much of a discrepancy here. PLA is generally priced around $30 to $35 per spool, so if you are enamored by any of the advantages to using PETG listed above, this minimal discrepancy in price should not assuage you from choosing PETG.

Final Thoughts

Ultimately, PETG is the right filament choice for you if you have experience working with 3D printers and are looking for a more durable and accurate filament to support your 3D projects. And with the price only going down, it’s definitely worth giving a try.