Out of so many available filaments, PLA and PETG are the most used filaments for 3d printing. Due to their favorable properties, easy processing, and advantages, both filaments are highly demanded in various industries. Both filaments are from the polyester group and have some basic similarities yet different features. So, before opting for any of the two, you must understand them and choose according to your needs.
So, here we go! To make it easier to understand PETG vs. PLA, I will discuss their basic features, similarities, differences, and processing methods in a broader way. You will also know their applications, advantages, and limitations.
What is PLA Filament
PLA or Poly Lactic Acid filament is a thermoplastic popularly used to print various objects in different industries. It is a biodegradable and environment-friendly plastic. PLA goes through a process of condensation of polymerized lactic acid.
What is PETG Filament
PETG stands for Poly Ethylene Terephthalate Glycol. It is also a thermoplastic and a co-polyester. The glycol-modified plastic has a clear and crystal visualization. It is easy to print and process by FDM technology. It has high rigidity and ABS-like mechanical properties.
It can withstand harsh outdoor climates and has great resistance to many chemicals. PETG filament comes in various product names by different manufacturers. Moreover, it is available in different brands and unique blends. Due to this, it has enhanced specific material properties.
PETG filament can endure moisture and high temperatures. Professionals prefer it over PLA because of its print stability and no shrinkage. It has good electrical properties.
PET And PETG- Difference
PET stands for Polyethylene Terephthalate. PETG is a copolymerized thermoplastic of PET resin. There is an addition of Glycol in PET to enhance its quality and properties. Glycol helps to prevent corrosion in the object. It also enhances the crystallization property and makes it transparent.
PETG is easier to print than PET filaments. On the other side, PET is a soft material that can break due to pressure. Scratch marks are easily visible on such prints. Thus PETG is preferred over PET for printing objects.
History Of PLA and PETG
Wallace Carothers invented PLA in the 1920s. It was too expensive commercially for general use. In 1989, PLA was made from vegetable starches like corn by Dr. Patrick R. Gruber and his wife, Sally. They produced it by heating corn and polymers on a stove. It helped to decrease the price of PLA manufacturing.
PET stands for Polyethylene Terephthalate. PETG is a copolymerized thermoplastic of PET resin. Due to the copolymerization process, PETG has high rigidity and low melting temperatures. You can process them through injection molding, filaments, and sheet extrusion.
Properties Of PLA vs. PETG
In the petg vs. pla, both filaments melt during the printing process and harden after cooling. However, this does not affect their qualities due to their physical and mechanical properties.
- Temperature Resistance- It has low heat printing temperatures and cannot endure extreme heat. So, they are not good for outdoor equipment.
- PLA has a common filament density of about 1.24 g/cm³.
- The Vicat softening temperature and heat deflection temperature of this filament is around 54-55 ºC.
- Semirigid- This filament is neither too rigid nor too flexible. It has better physical properties than PLA. Due to its semi-rigidity, you can 3d print different kinds of objects.
- Impact Resistance- It has good impact resistance. It does not break easily.
- Thermal Characteristics- It has a better thermal resistance capability and contributes to less warping.
- Odorless- It does not produce a foul smell while 3d printing.
- Filament Density- PETG has a higher density filament compared to PLA variants. It is around 1.27 g/cm³.
- It has good electrical properties.
Advantages of PLA vs. PETG
- Low Cost- It is cheaper and more easily available filament in the market. You will get them at slightly cheaper rates than PETG.
- Strength- It is a strong filament and has semi-flexibility, making it easier to print.
- Smooth Finishing- PLA is better for making aesthetic-purpose objects because of its better smooth surface, accuracy, and end-product finishing.
- A wide range of colors is available in PLA. It offers many variations and matching colors than PETG.
- Easily Blend With Other Filaments- You can recreate different textures and objects by blending PLA with other filaments. Many filament-blending options are available for PLA.
- Recycle- PLA is a biodegradable filament. You can recycle it.
Here are some of the advantages that you will get by using PETG filament-
- Surface Finish- If you choose PETG filament for 3d printing, you will get the printed objects’ glossy and smooth surface finish.
- Adhesion- It has better adhesion than PLA if you are using a heated print bed.
- Smell- It does not produce a bad smell during printing. It is odorless.
- Chemical resistance- PETG filament has good resistance capability against chemicals, making it safer for various applications.
- You will get crystal clear prints and transparent objects from PETG filaments. They are also available in various colors, but you will find more transparent filaments in PETG. Their blended forms also provide unique prints.
- It has more supporting materials available that you can use to make complex and intricate objects in your 3d printer. But it will not give you as smooth finishing as PLA.
- Recycle- PETG is also a biodegradable material. It can be recycled and converted into new filament.
- Better than ABS- Not just PLA, but it is also a better choice than ABS for many reasons. PETG is less prone to warping than ABS while printing. Moreover, ABS requires much higher printing bed temperatures (100 ºC) than PETG (60–80 ºC). You will get less smoke and fumes while processing PETG in respect to ABS.
How To Process PLA
There is no exact printing temperature available for PLA. The printing temperature for PLA should be around 190-220 °C, but it is better to keep printing in different temperatures for future reference. The printing temperatures can also vary if you are using a blended form. In both cases, the printing temperature would be lower than PETG.
To process PLA in your 3d printer, you do not require a heated bed. The bed temperature should be around 60°C. You can print it in the open case. But for PETG, you will need one. It is easier to print PLA filaments.
But if your machine has an in-built print bed, you can use it because it will help PLA stick more and cause fewer warpage issues. Do not print them in very cool temperatures because it will harm the nozzles and cause blockages. You will need supports for printing complex designs in PLA.
How To Process PETG
The printing temperature should be around 230-250 °C for printing PETG. If you are mixing the filament with another, the temperature would be different. For PETG, you will need a heated print bed at a temperature between 70 to 90 °C. It is better to spread some PVA glue on the bed before starting the process. Otherwise, the hard stuck filament can damage the bed.
Use lower nozzle temperatures for printing to avoid stringing of the filaments. Make sure that the nozzle gap is slightly bigger. Otherwise, it will affect the bed adhesion. While printing the filament, you will have to use supports for better prints. There should be more distance between the model and support during the process.
It is easier to do post-processing PLA than PETG printed parts. You can paint the PLA-printed layers with acrylic paint. But it is not possible with PETG because firstly, you will need to apply a plastic primer.
Though it is hard to stick PLA parts with the help of glue, you can achieve it by using glue for polystyrene. But you cannot do it with PETG printed parts.
Adhesion of PLA vs. PETG
Printing any filament and getting perfect prints is largely based upon the perfect adhesion. The same goes for PLA and PETG. Before starting the process, the printing bed or hotbed must be of good quality and properly fixed at accurate levels.
In the case of PLA, first layer adhesion must be proper because it is the base of the entire print. Printing bed temperatures for PLA may vary because of different manufacturers. So, you need to monitor it to save from shrinkage and warping during the process.
In the case of PETG, you require a heated print bed at a high temperature for better adhesion. The hot end temperature should be between 220 and 250 °C. Otherwise, the filament will not stick properly and will result in stringing and warping prints.
In both cases, if the filament is not sticking, it is because of low temperatures. If you exceed temperatures more than the limit, it will melt the filaments and result in an elephant’s foot syndrome. Thus, always use the trial and error method to find perfect temperatures.
Disadvantages of PLA vs. PETG
- Heat Resistance- It has a low heat resistance and cannot withstand too much heat during printing. The PLA objects can not withstand the harsh outdoor temperature and can break.
- Moisture- PLA is not good in containing moisture for longer periods. It will start decaying if left in moisture or water.
3. Warping- It is more prone to warping during the printing process.
4. Limited Applications- Its properties can only print things for aesthetic purposes or light objects. It is not suitable for printing mechanical components or heavy industry items.
5. Food safety- Though popularly used for food packaging, it is not completely safe. During the making of wrappers or food containers, tiny holes or gaps exist between the printed layers. Moisture enters gradually and damages the food if it is left for longer durations.
6. Filament Leakage- If you print in different segments and change the extruder’s path, hot PLA might get a leak and string formation. Spilled hot PLA filament can sabotage your entire print.
Just like PLA filament, PETG has its limitations. It is better to know the shortcomings before investing in PETG printing.
- Softer Surface – It has a softer surface than PLA-printed objects during printing. Thus, it is prone to wear.
- Stringing- It does not have many warping issues, but it is prone to stringing while 3d printing. It can produce thin hairs or fine lines on the surface during poor adhesion.
Things To Consider While Printing-PETG vs. PLA
One of the most important things to consider while switching the filaments during printing is correct nozzle temperatures. For instance, if you are feeding PLA filament after printing PETG material, keep the nozzle temperature according to PETG filament and let the remaining filaments discharge.
Keep feeding PLA till it starts to come out from the extruder. Now, you need to adjust the nozzle temperature according to PLA. If you keep changing these filaments in lower temperatures, inside PETG material will clog.
Apart from this, there are several other important things that you should know before opting between these two. Here is a list-
- Bed Temperature: For gaining better prints, you should keep the bed temperature between 45-60 °C. It does not require a heated bed for better adhesion. It is optional. You can easily print it in the open printing chambers.
- Extrusion- For printing PLA filaments, you should keep the extruder temperature between 190-220 °C. There is no need for any special hot-end while printing.
- Cooling- It is best to use a cooling fan to decrease the excess heat of the printed parts while printing.
- For increasing the durability of PLA objects, it is better to paint them to save them from external weather.
- Bed Temperature: For gaining better prints, you should keep the bed temperature between 75-90 °C. It is good to have a heated bed for better adhesion to avoid warping and stringing during layer printing. You can use both enclosed as well as open printing chambers.
- Extrusion- For printing PETG filaments, you should keep the extruder temperature between 230-250 °C. Below this temperature will not give you the exact results.
- There is no need for any special hot-end while printing. However, use a cooling fan to decrease the excess heat of the printed parts while printing.
- 4. It is better to print on a good printing surface under a properly calibrated retraction setting to avoid any deformity of larger prints.
Applications- PETG vs PLA
Prototypes- PLA is best for beginners as well as for printing the initial stages of models. It is mostly used for printing prototypes and models. If something goes wrong, you can easily correct it in the model.
Fixtures- It is also known for making quick fixtures for small machines and equipment.
Food Packaging- It is used for making food packaging items. It does not spoil packed food or beverages. The properties like biodegradability, odorless, and heat resistance make it an ideal filament to make food containers, wrappers, bottles, and packaging objects.
Medical Equipment- It is also used for printing many medical devices, equipment, and medical implants. These are biodegradable and easy to print.
Fashion Industry- PLA is also popular for making cosmetics like lipsticks, perfume bottles, nail polish, cream tubes, and many more fashion items.
Toys- Another thing on the list is toys. You can print big to desktop toys with this filament. It is easier to mold and create unique designs. They are biodegradable. You can recycle and reuse them many times.
Wearable Objects- You can transform PLA into fabric too. It has flexibility in printed apparel, making it comfortable to wear. Such fabrics can be used to make a wide range of clothes and other essentials like belts, caps, slippers, footwear, and many more items one can think of.
Industrial Use- It is also used for printing different components used in automobile and electronic industries.
Water Bottles- Its water resistance property makes water bottles, containers, and jars.
Face Shields- During the coronavirus pandemic, it has emerged as one of the most used filaments. It is used to make face masks and face shields. You can sanitize the equipment easily.
Industrial Components- PETG is popularly used for making professional and industrial objects. It prints hardware parts, mechanical components for machinery, objects related to electricity, and transparent parts.
PLA is the first choice for 3d printing beginners because it is easy to print and process. On the other hand, PETG has risen as a better alternative nowadays. Both have their benefits and cons. In the markets or online, you will get PLA filament in two sizes- 1.75 mm diameter and 2.85 mm diameter. The same is with the PETG filaments.
If you are looking for strength, toughness, and high quality, we recommend using PETG filaments. You should go for PLA for more finished, accurate looks and aesthetic beauty.