PLA vs. ABS vs. PET-G

PLA, ABS, PET-G filaments are among the most popular printing material for printing on 3D printers. These are filaments that are easily available, have practical properties and a wide range of uses. But it is not true that each of these three filaments is suitable for all types of prints. PLA is one of the most well-known filaments, which is very popular with 3D printing users because it is easy to print with. But on the other hand, it is not one of the strongest materials.

ABS, on the other hand, is strong and durable, but then again, some people might be bothered by its smell when printing. PET-G is often used for prints that come into contact with food, but for beginners, printing with this filament could be problematic. So which filament is right for you? Let's look at them in more detail.

PLA - a favorite, but not as tough as he looks

Basic summary of PLA filament:

Name:      PLA (polylactic acid)

Advantages:

  • wide use
  • easy to print with
  • harmless composition
  • low deformation

Disadvantages:

  • not very strong and sturdy
  • gets wet easily
  • it cannot be smoothed with acetone
Main use:

      for prints where appearance is important and are not exposed to demanding conditions

What is it not suitable for:

  • it is not suitable for environments with high temperatures
  • not suitable for prints with mechanical stress

Press conditions:

  • nozzle: 175 - 200 °C
  • printing surface: 50 - 60 °C
  • PLA filament can be printed even without heating the bed
  • it is not necessary to cover the printer

Odor when printing:

      a slight odor reminiscent of vegetable oil frying

Post-processing:
  • easy
  • possibility of grinding, painting, cutting, melting
  • it is not possible to use acetone

Why will you enjoy printing with PLA?

If you already have some experience with 3D printing and remember your beginnings, you probably chose PLA as the filament you started with. Thanks to its features and ease of printing, it is highly recommended for beginners, who are just getting to know 3D printing. It has a low melting point, which is convenient for printing, but on the other hand, because of this, PLA prints cannot be used in places where high temperatures are expected (for example, the dashboard of a car in the summer months, etc.).

Among the main advantages is its price. This is a relatively affordable filament, which is available on the market in a wide range of colors (from classic basic colors to neon or even tri-colors). Some have a modified composition to make them more resistant to impact and mechanical wear. You can find them under the name PLA+. Thanks to their upgraded composition, you can also use them for parts that have a functional use. But compared to other filaments, their resistance is still lower. Other variants of PLA are created using different additives (for example, wood or metal). In addition to various colors, transparent and fluorescent colors are also available, as well as filaments that glow in the dark, for example in rainbow or green colors. Prints from PLA have a low probability of deformation, so you don't have to worry about printing larger models from this material.

Post-processing or additional modification of prints, is not too complicated for models made of PLA, because, as already written, PLA belongs to the softer materials. Sanding with sandpaper is most often used for additional finishing. And that's because it's easy and affordable. If you want to save time, you can also use an electronic sander for sanding. Other modification options include melting with, for example, a heat gun, cutting with a knife and, of course, painting. We devoted an entire article to the post-processing of PLA prints. Check it out here: How to adjust the surface of PLA filament prints.

Summary:

PLA did not gain its popularity by chance. Thanks to its properties, wide use and problem-free printing, it was and will be among the most frequently used filaments. Therefore, it should definitely not be missing in the equipment of every printer. But if you are going to make prints that will be exposed to temperature-demanding conditions (whether they are or are emergency) or should be flexible, you need to look for another filament that will meet the required properties.

   

ABS - a partner in discomfort that doesn't just throw it away

A basic summary of ABS filament:

Name:       ABS (Akrylonitrilbutadienstyren)
Advantages:
  • it is firm, tenacious
  • suitable even for demanding conditions
  • harmless to health
  • resistant to some chemicals, oils and greases
  • it can be smoothed with acetone
Disadvantages:
  • release of hazardous fumes
  • the necessity of a cover for the printer
  • more prone to twisting
Main use:

      for prints that are mechanically stressed or exposed to high temperatures

What is it not suitable for:

      not recommended for prints that come into contact with food

Press conditions:
Odor when printing:

      unpleasant smell

Post-processing:
  • using acetone
  • sandblasting
  • grinding

Why choose ABS for printing?

ABS filament is right behind PLA in terms of popularity. This material is used to make common accessories that you can probably find in your home. The main advantage you will appreciate with ABS is its resistance and toughness. Compared to PLA, it is therefore more suitable for prints that are mechanically stressed. You can also use it for models that will be in an external environment, because it can easily handle different weather and temperature conditions (only UV radiation does not work for it).

If you like to focus on post-processing your prints, you will be pleased to know that ABS prints can be easily smoothed with acetone. For this, you can use either a smoothing box that you assemble yourself, or a professional smoothing device. Other options for achieving a smooth surface of ABS prints are grinding and sandblasting. The time requirement may discourage you from grinding. Sandblasting is done using a sandblasting gun, either in professional devices used in industries, or manually in sandblasting boxes. If you are interested in more detailed information on the post-processing of ABS models, you can read about it in this article: Surface treatment of ABS / ASA using acetone and other techniques.

Thanks to additives and other modifications, different variants with specific properties have been created, for example ABS ESD has excellent insulating properties, so it will be ideal for printing parts used in electrical engineering. Another variant is ABS enriched with MMA, you can find it on the market under the abbreviation ABS-T. This filament is even stronger and more durable than its ABS predecessor. But it is also somewhat more demanding to print. Also worth mentioning is PC ABS, which is fire-resistant, so it found its use mainly in the industrial area.

The disadvantage of ABS filament is that it produces toxic fumes during printing. So it is necessary to use a cover for the 3D printer, which firstly prevents the spread of these vapors, and secondly ensures the maintenance of constant conditions during printing. ABS is very sensitive to temperature changes, so if the temperatures during printing were not constant, cracks or other deformation could occur in the prints. Even when using the printer cover, it is recommended to regularly ventilate the room.

Summary:

ABS has excellent properties that have proven themselves especially in demanding conditions. So, if you are going to print a model that will be mechanically stressed, its location will be in an external environment and it will be affected by chemical substances, you will definitely not make a mistake if you reach for ABS. But thanks to its strength, it will certainly not find its use in models where flexibility is desired. And because it is more demanding to print, during which you cannot avoid an unpleasant smell, for models that do not require specific properties, your choice may fall more on PLA.

PET-G - an acquaintance with whom you like to sit at the table

Basic summary of PET-G filament:

Name:      PET-G (Polyethylene terephthalate glycol)
Advantages:
  • watertight
  • impact resistant
  • flexible
  • chemically resistant
  • safe for food
  • tenacious, firm
Disadvantages:
  • not suitable for printing smaller parts
  • high adhesion to the substrate
  • worse for printing bridging and overhangs
Main use:

      for models that are in contact with food (eg: camping equipment) and for prints in an external environment

What is it not suitable for:
  • for printing bridges and overhangs
  • for printing detailed parts
Press conditions:
  • nozzle: 230 °C first layer, 240 °C other layers
  • printing surface: 85 °C first layer, 90 °C other layers
  • it is not necessary to cover the printer
Odor when printing:       odorless
Post-processing:
  • grinding, polishing
  • using epoxy resin
  • using a heat gun
  • it is not possible to use acetone

Why use PET-G for printing your models?

Even before you add the modified glycol to the PET-G filament, you will have the well-known substance PET, which is used to make products with which each of us is in daily contact - plastic bottles, or pet bottles, but also various other packaging products for foodstuffs. Thanks to its safety and ease of printing, PET-G has become a sought-after filament that even beginners can handle with ease. Another advantage is that it is among the cheaper filaments, it is relatively strong and, thanks to the good adhesion of the layers, it is also waterproof. It can easily handle more demanding conditions in an external environment. It will also come in handy for printing functional parts and outdoor applications. If you come across the label PET - G/CF, it is a filament supplemented with carbon (carbon) fiber. This admixture will provide a little more strength and durability.

Post-processing for PET-G offers various treatment options, but it will not work with acetone due to its chemical resistance. But for that, you can start sanding, polishing, spraying, processing with a hot air gun, but also with the use of other chemicals than the acetone just mentioned. You can read everything in the article: Tips for surface treatment of PET-G filament prints.

With PET-G, more often than with other filaments, you can encounter one problem - stringing (oozing, or "hairy print"), which is manifested by the formation of small fibers (hairs) on the model. This is often caused by setting the nozzle temperature too high, where a small amount of filament is still flowing from the nozzle, but the extruder is already moving on. Another disadvantage is that PET-G prints are slightly more prone to scratching, which could be detrimental for products that are supposed to have an aesthetic function as well.

Summary:

PET-G filament is an interesting alternative to PLA and ABS. It took durability and strength from ABS and its versatile use from PLA. But as mentioned, it won't be ideal for smaller, more detailed prints and for printing bridging and overhangs. The main advantage is that it is safe for food contact. However, it might bother you a bit when printing. Sometimes it will be necessary to search for more specific printer settings before you can achieve the perfect appearance of the prints.