When it comes to 3D printing, there are several filaments that people use, but it’s steadily growing to users opting in for either PLA or PETG. This had me wondering, is PETG actually stronger than PLA? I set out to do some research to find out this answer and share it with you guys.
PETG is actually stronger than PLA in terms of tensile strength. PETG is also more durable, impact resistant & flexible than PLA so it’s a great option to add to your 3D printing materials. The heat-resistance and UV-resistance of PETG outdoes PLA so it is better for outdoor use in terms of strength.
Keep reading for some more details about the strength differences between PLA and PETG, as well as other differences.
How Strong is PLA?
There are plenty of filaments that are used in 3D printing. While selecting a filament for 3D printing, users consider a lot of things such as its strength, heat resistance, impact resistance, etc.
When you check what other users pick for their 3D printing filament, you get to know that PLA is the most commonly used filament.
The main reason behind this is because of its strength, but also because it is so easy to handle and print with.
Unlike ABS, PLA doesn’t experience warping so easily and doesn’t require extra steps to print well, just a good temperature, good first layer and even flow rate.
When looking at the strength of PLA, we are looking at a tensile strength of 7,250, which is easily strong enough to hold a TV from a wall mount without bending, warping, or breaking.
For comparison, ABS has a tensile strength of 4,700 and as tested by Airwolf 3D https://airwolf3d.com/2017/07/24/strongest-3d-printer-filament/ a 285 lbs 3D printed hook instantly broke ABS, while PLA survived.
Do keep in mind though, PLA has a fairly low heat-resistance so it isn’t advised to use PLA in warmer climates if the goal is functional use.
It can also degrade under UV light from the sun, but this is usually in the color pigments. Over a long period of time, it could end up losing strength.
PLA is a widely available and cheap thermoplastic which is probably one of the stiffest 3D printing filament out there, but it does mean its more prone to cracking and snapping.
How Strong is PETG?
PETG is a relatively new filament which has been gaining popularity in the 3D printing field for a number of reasons, one of them being strength.
When looking at the tensile strength of PETG, there are mixed numbers but generally, we are looking at a range between 4,100 – 8500 psi. This would depend on a few factors, from testing accuracy to the quality of the PETG, but generally its quite high, in the 7000s.
Flexural yield psi of PETG:
PETG is the choice of many 3D printer users who want to make something very tough, especially for functional use or outdoor use.. If you want to print something that needs better flexibility and strength than using PETG may be your best bet.
It is a filament material that requires relatively more heat than PLA to melt. It can also bear bending because of its flexibility which means that your print will not be damaged just by a little pressure or impact.
PETG is better in terms of durability and tensile strength. PETG provides you with the opportunity to use it in all types of extreme environments because it is specially designed to provide strength and impact resistance.
The upgrades of PETG are fully protected allowing them to resist oil, grease, and UV lights efficiently.
It doesn’t shrink much which allows you to print complex components as well as the components to endure stress such as springs, tools, and hooks to carry weight.
Is PETG Stronger Than PLA?
PETG is indeed stronger than PLA in many ways, which has been thoroughly tested by many. Although PLA is widely used, when talking about the stronger filament, PETG goes above and beyond, mainly due to its flexibility, durability, and heat-resistance.
It has the ability to bear the heat or temperature to the extent at which the PLA may start warping. One thing that you should know is that PETG is a hard filament and requires more time to melt as compared to PLA filament.
PETG can cause problems of stringing or oozing and you will have to calibrate the settings of your 3D printer to fight that problem.
PLA is a lot easier to print with and you are likely to get a smooth finish with it.
Although PETG is harder to print with, it has an amazing ability to stick to the bed, as well as preventing detatching from the print bed like many people experience. For this reason, PETG requires less pressure when extruding the first layer.
There is a type of filament that comes in-between these two which is widely known as PLA+. It is an upgraded form of PLA filament and has all the positive features of the common PLA.
They usually operate at the same temperature but the main difference is that PLA+ is stronger, more durable, and has more capability to stick to the bed. But we can only say that PLA+ is better than PLA, not than the PETG filament.
PLA Vs PETG – The Main Differences
Safety of PLA & PETG
PLA is a safer filament then PETG. The main reason behind this fact is that it is produced from organic sources and it will convert into lactic acid which cannot bring any harm to the person.
It will offer a pleasant and relaxing smell while printing which makes it superior from ABS or Nylon in this regard.
PETG is safer than many other filaments such as Nylon or ABS but not then the PLA. It has been reported to have weird smells, but that does depend on what temperature you use and which brand you purchase.
Taking a deep look will bring the results that both these filaments are safe and can be used without any threat.
Ease of Printing for PLA & PETG
PLA is considered as the filament for beginners because of its ease of printing. When it comes to comparing PLA and PETG on convenience, PLA usually wins.
If you don’t have 3D printing experience, and you run into many problems with print quality or just getting successful prints, I would stick with PLA, otherwise, PETG is a great filament to get acquainted with.
Many users have said that PETG is similar to the durability of ABS, while having the ease of printing of PLA, so it doesn’t have too much of a difference in terms of ease of printing.
Settings do need to be dialed in properly, especially retraction settings, so keep this in mind when printing PETG.
Shrinkage During Cooling for PLA & PETG
Both PETG and PLA will show a bit of shrinkage while cooled. This shrinkage rate is much less as compared to other filaments. The shrinkage rate of these filaments when cooled ranges between 0.20-0.25%.
The shrinkage of PLA is almost neglible, while PETG does show some visible shrinkage, but not as much as ABS.
Comparing other filaments, ABS shrink almost 0.7% to 0.8% while Nylon may shrink up to 1.5%.
In terms of creating dimensionally accurate objects,
PLA & PETG Food Safety
Both PLA and PETG are considered food safe and their prints are widely used to store food products.
PLA is food safe because it is produced through the extract of sugarcane and corn which makes it an organic filament and completely safe for the food.
3D printing objects are usually designed for single-use products and probably shouldn’t be used twice due to the nature of the layers and gaps in the 3D printed objects.
You can use a food-safe epoxy to improve the food-safe performance of objects.
PETG has great resistance to heat, UV light, different types of solvent which help it to be a safe filament for food. PETG is experimented and is proved to be a food-safe for outdoor applications as well. PLA is safer than the PETG if we do a strict comparison.
You don’t want to be using filament with color additives when looking for food-safe filament, which is more common with PETG plastic. Pure PLA isn’t a usual filament that people purchase.