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Although PLA and ABS are still the most common filaments used in 3D printing today, alternative materials are becoming increasingly popular. One of these alternative options, PETG, has become popular because of its exceptional durability, good adhesion, and resistance to degradation by water and other chemicals. If you’re wondering what exactly PETG is and how to work with it, you’ve come to the right place.
What is PETG?
PETG is a variation of the very popular polyethylene terephthalate (PET). PET is one of the most common plastics in the world today and is used in food containers, water bottles, and even clothing fiber. Due to its high mechanical strength, its resistance to extreme temperatures and its ability to restrict moisture, it and its various variants are useful in the food industry, as a thermal insulation material or as a precursor for engineering resins.
The addition of glycol during the polymerization process results in the formation of a “glycol-modified” PET or PETG. The addition of glycol results in plastic that is more durable, less brittle, clearer, and easier to use. PETG is widely used for outdoor signage because of its excellent printability and lamination properties. Other uses for PETG include medical and food containers, electronic devices, credit or gift cards, store fittings, and prostheses.
Why use PETG?
As mentioned earlier, PETG offers durability and impact resistance that is even superior to PET. Working with PETG is also easier than PET, as PET easily becomes cloudy and brittle when overheated. The added glycol in PETG removes this limitation by preventing the material from crystallizing and thus becoming fragile. Its temperature-resistant properties also make PETG an excellent material for containers for medical applications, as PETG can be sterilized or autoclaved without it breaking.
PETG has shown good chemical resistance, be it to acidic or alkaline substances. It also retains the excellent moisture blocking property of PET, making it a good choice for containers for water or other beverages. It is also suitable for containers, which are easier to grip due to their softer and pliable nature.
In terms of how easy it is to 3D print, PETG’s temperature resistance and excellent layer adhesion have made it less prone to warping and shrinkage. It has been described that PETG filaments have a combination of the best properties of PLA and ABS: They are stronger and more temperature-resistant, yet easy to process.
As a thermoplastic, one of the most interesting properties of PETG is that it is 100% recyclable. It can be shaped and reshaped over and over again by heating without the material deteriorating. This means that waste material (e.g. backing) and printing errors can be converted into new prints and this process can be repeated indefinitely.
Due to its properties, we recommend the use of PETG filaments for printed products that may be exposed to sudden or prolonged loads, such as: B. Protective components and mechanical parts. PETG filaments are also a good material when printing parts that are supposed to come into contact with food material, e.g. B. Cups and food containers.
How do you work with PETG filaments?
The first thing to do when working with PETG filament is to ensure that the printer model you are using has extruder temperatures of 220 to 245 ° C. The bed temperature must also be kept at 70 to 75 ° C or a little higher in the first shifts.
We achieved the best results with blue painter’s tape for adhesion to the print bed. With or without heating, this type of adhesion results in a fairly smooth floor finish. If you want a glossy, glass-like finish, you’ll need to use a heated borosilicate glass print bed. For a heated glass bed, we recommend a temperature of 50 to 60 ° C. A thin layer of non-perfumed hairspray also improves adhesion. BuildTak print surfaces are also very suitable for the adhesion of PETG prints.
If you want your print to be exceptionally durable, we recommend fanless printing. If the molten PETG comes into contact with the previous layer at a high temperature, this leads to very strong layer adhesion. The disadvantage of this strategy is that it may tend to be stringed, resulting in a print that is less detailed or may need further processing. To fix this, we recommend printing without a fan for the first two layers and with a fan (100%) for all subsequent layers.
The high printing temperature of PETG makes working with it susceptible to clothing, especially if the extruder nozzle is placed too close to the bed. We recommend leaving a gap of approx. 0.2 mm between the nozzle and the print bed so that the melted plastic has more space to deposit. If this setting does not work for you, we recommend moving the nozzle away from the bed in small steps until there is no longer any visible covering.
If strings are still appearing, you may need to slow down the print speed. We recommend a setting of approx. 55 mm / s or even only 15 mm / s.
Another thing to note is that PETG filaments are hygroscopic, which means they are actively absorbing moisture from their surroundings. PETG plastic must be packed in an airtight container, e.g. A vacuum-sealed bag with a couple of desiccant packs. Printing with wet PETG filament results in a product that is significantly weaker than expected.
What are the limitations of PETG?
The main drawbacks to using PETG are finding the “sweet spot” for your printer’s settings to produce a print that is both permanent and detailed. Certain settings are required to get the best results with PETG printing. PETG isn’t as easy to work with as PLA, which means you’ll likely need to experiment for a while before you get good results. Once you get the settings that work, printing with PETG should be a breeze.
PETG is a very poor choice of material for support structures, precisely because of its excellent adhesion. Removing support structures made with PETG can be very difficult, but not impossible.
The resulting PETG print, while permanent, can be weakened by UV light. If you are printing a product that is designed to be exposed to constant outdoor exposure, you can expect its strength to decrease over time. PETG products are also more easily scratched than those made from PET.
What are the best brands of PETG filament?
PETG is an easy-to-make material and has developed a large market for 3D printing. Manufacturers have responded with a variety of PETG filament products, the best of which are featured here.
MatterHackers’ PETG filament line of products is one of the most popular today. It is available in different colors, e.g. B. White, Green and Blue. Your PETG filaments are sold in 3.00 mm size and 1 kg spools. MatterHackers PETG filament has performed exceptionally well in terms of both strength and appearance, making its product one of the first choices if you are looking for a good PETG product in the market.
HATCHBOX is another well-known product made from 3D printing filaments and its PETG product certainly doesn’t disappoint. Your PETG filaments are also available in different colors. They currently offer 1.75mm filaments in 1kg spools.
ColorFabb’s XT series is the line of PETG filament products. They are characterized by long-lasting products that are temperature-resistant and have low odor emissions during printing. The prints made from the XT filaments offer a reasonable balance between mechanical strength and visual appeal. They come in a variety of colors (including transparent) and are sold in sizes 1.75mm and 3.00mm. ColorFabb offers 0.75 kg spools for its PETG filaments.
Taulman 3D also has its own line of PETG filaments, marketed under the N-Vent line as Eastman Amphora 3D Polymer AM1800. Their N-Vent products are available in 1.75mm and 3mm sizes and in 1 pound spools. There is also a wide variety of colors available for the N-Vent line of PETG filaments.
The PETG filaments sold by PRILINE are probably some of the cheapest on the market, which makes them good budget options. They are sold in 1kg spools that are 1.75mm in size and come in a variety of colors. Although less expensive, PRILINE products still deliver the standard thicknesses of PETG material.
|material||Glycol modified polyethylene terephthalate (PETG)|
|Applications||– Suitable for high-strength, impact-resistant applications
– Can be sterilized, so it is suitable for food and beverage containers
|Recommended printing temperature||220 to 245 ° C.|
|Recommended bed temperature||70 to 75 ° C; 50 to 60 ° C for glass print bed|
|Bed liability||– Blue painter’s tape (recommended) for heated and unheated bed
– Glass heated bed with a touch of hairspray
– BuildTak printing surface
|speed||Slow printing speed of 55 mm / s or less; can be as low as 15 mm / s|
|cooling||No fan for the first two layers, then fan with 100% setting for all subsequent layers|
More and more 3D printing users have started to see the benefits of working with PETG filaments. Although they can be difficult to work with at the beginning, as they are less forgiving than PLA when it comes to printer settings, this “sweet spot” is well worth the effort for prints that look great and have excellent mechanical strength.
Prints made with PETG are sturdy but have just the right amount of compliance, which makes them extremely durable. The strength of PETG doesn’t stop there: it has excellent layer adhesion, has a lower chance of warping or shrinking, and is 100% recyclable. If you want to go beyond PLA and ABS, we recommend taking PETG for a spin.
Warning; 3D printers should never be left unattended. They can pose a fire hazard.