In this article, we will analyze the similarities and differences between PLA and ABS from performance to printing requirements, and hope to help you better understand the use.
ABS and PLA are commonly used3D printingplastic materials, but for customers who are new to 3D printing, they don't know how to pick the right material for them. This article will analyze the similarities and differences between PLA and ABS from performance to printing requirements, hoping to help you better understand the use.
I. Characteristics and performance of PLA and ABS
When it comes to the characteristics of PLA and ABS, the first thing to consider is what they are made of. Although they are both thermoplastics, there are differences between them. PLA is known to be made from organic sources such as corn or sugar cane, while ABS, like most standard plastics, is made from petroleum. More specifically, PLA is made from fermented plant starches from sources such as corn, cassava, maize, sugar cane or sugar beet pulp, where the sugars are converted to lactic acid, which is then polymerized into polylactic acid. In contrast, ABS is composed of three monomers: acrylonitrile, butadiene and styrene. Acrylonitrile is a synthetic (man-made) monomer derived from propylene and ammonia, butadiene is a petroleum hydrocarbon, and styrene is made by dehydrogenating ethylbenzene (chemically removing hydrogen). These materials have an impact on the "sustainability" of the environment.
△ As shown above (image credit: Fictiv), there are differences in appearance and performance between parts 3D printed with PLA and ABS.
PLA is often touted as a more environmentally friendly material because it is biodegradable. However, it is important to note that it is only truly biodegradable under the right conditions, and many cities do not have the right tools to properly degrade the material. This means that while it is possible, the only way to be truly "environmentally friendly" in practice is through industrial composting. ABS, on the other hand, is considered to be an unsustainable or non-environmentally friendly material. As mentioned earlier, it is made from petroleum, as are most plastics, which means that it is not processed in a sustainable manner. However, one advantage is that ABS is recyclable and many people don't realize how limited the biodegradability of PLA is, so some beginners may be more certain that PLA will be disposed of properly without generating more waste.
Difference #1: ABS has better heat resistance, better mechanical properties
Beyond their material roots, ABS and PLA have another different property - heat resistance. ABS has some heat resistance and a high glass transition temperature, while PLA can melt at much lower temperatures and is therefore not considered heat resistant. This, of course, affects the application of the material and will be described in more detail later.
If you are looking for a tougher material with better mechanical properties, I recommend ABS, which is more impact resistant, more durable and lighter than PLA, in addition to being heat resistant and having higher heat distortion. However, both materials have similar tensile strengths (ABS is slightly lower), and ABS is generally better suited for more industrial applications, primarily because of its improved ductility and ability not to break, as well as its higher flexural strength and higher elongation before break. Because of these multiple properties, ABS can even be used for end-use applications, which is one of the reasons it is so popular in industries such as injection molding.
△ Characteristics of PLA and ABS
It is worth noting that PLA is stronger and harder than ABS. However, it cannot be used in environments involving higher temperatures because it has a very low melting point and will lose these properties above 50 degrees Celsius. However, even though ABS is significantly more heat resistant than PLA, because both are thermoplastics, both degrade over time under UV light and high temperatures.
Difference #2: PLA is Easier to Print
Now that we've covered the properties of PLA versus ABS, the next step is to discuss the 3D printing process itself. First, the preparation for printing will be different for the two thermoplastics due to their different glass transition temperatures. This is due to the need to consider the temperature range over which the thermodynamic transformation of the substance occurs. In the case of PLA, the glass transition temperature range is between 60 - 100oC, while ABS is between 105 - 200oC. This determines the parameters set in the slicer and the time needed to heat the 3D printer and reach the desired temperature.
Also, the variables of the manufacturing process, including the print platform and print head, must be set correctly. ABS requires a higher print bed temperature, around 80 - 110oC, while PLA is typically 60oC. In terms of extruders, PLA also requires lower temperatures, specifically around 180 - 230°C, while ABS requires 210 - 250°C.
In terms of ease of use, ABS is known to be more complex to print than PLA. The printing problems encountered are also related to the temperature and properties of each material. PLA melts at a lower temperature than ABS, so there is less thermal variation in the curing of the layers when the 3D printing process of the part is complete. However, because ABS requires a higher temperature to melt, a more abrupt change occurs when cooling the part. This thermal shrinkage can lead to part distortion. One of the most common problems is warpage, where the end of the part shrinks, detaches from the pallet and deforms. To avoid this, it is critical to control the temperature and printing environment when printing with ABS, and use adhesives if necessary.
△ ABS is prone to warpage, which is a problem related to the shrinkage of the material under sudden changes in temperature
Both materials print at roughly the same speed and there is no need to readjust the speed parameters in the slicer for different materials. PLA usually prints at 60 mm/sec, with some users using even higher speeds. ABS, on the other hand, is usually in the 40-60 mm/s range, making it difficult to reach higher speeds.
Another point to keep in mind during the manufacturing process is the waste emissions generated during the manufacturing process, as almost all thermoplastic filaments produce noxious odors and gases during the printing process. When the material is heated, it releases substances containing particles that are harmful to health. In the case of PLA, since it comes from a natural plant source, it does not emit a strong odor and therefore is not a concern. However, ABS emits toxic fumes and unpleasant odors, and I strongly recommend using a closed print enclosure and air filter when working with ABS to prevent fumes from being released into the work space. Even so, continuous ventilation is recommended during the printing process to ensure that the fumes do not reach our lungs. This is related to the presence of styrene in ABS, a material that is toxic to humans when inhaled.
Luke Taylor, Polymaker's marketing manager, explains, "PLA is a weaker material, but the advantage is that it's easy to use and easy to print. Users don't need a heated bed, they don't need high temperatures, and it has very low shrinkage, whereas ABS has very high shrinkage. In general, we see that the better the mechanical properties, the more difficult it is to use. Although we can also add things to PLA to make it stronger without changing the printability. "
△ Figures 3D printed with Polymaker's PLA filament (photo credit: Polymaker)
Difference 3: Post-processing
Most post-processing techniques are available for both thermoplastics. While there are some obvious differences, such as the finish of the printed part, PLA parts tend to have a brighter surface, while ABS tends to have a more matte finish. Both materials can also be painted for decoration after printing. ABS is generally easier to post-process than PLA. First, while both can be sanded, the process is easier due to the durability of ABS. PLA is also more difficult to sand because it is less heat resistant and melts more easily.
Meanwhile, ABS is not only easier to post-treat using these basic methods, but if you want a really shiny finish, parts made from ABS can be smoothed with acetone vapor. Acetone is a colorless liquid that is commonly used as a solvent for plastics. While it cannot be used with PLA, those who have ABS parts can use acetone for faster post-treatment and glossy finishes. A similar process can still be done with PLA. THF or tetrahydrofuran can be used for hand polishing if you wish to vapor smooth parts made from PLA filaments.
△ These finished parts have a glossy finish due to acetone smoothing (photo credit: zortrax)
Difference 4: PLA has a lower price
Mohou.com currently quotes PLA at $0.65 a gram and domestic ABS at $1.99 a gram, making ABS relatively more expensive than PLA. However, the price is also want to performance, or see what characteristics of the material you want to choose.
Second, the application of PLA and ABS
PLA is the most used material in FDM 3D printing and is mainly used in the creator environment. This is mainly due to its ease of printing, as well as its fragile, delicate and sensitive to sunlight and heat properties. For this reason, it is often used extensively by novice users or for creating decorative parts and toys.
ABS, on the other hand, is a more industrial material with advanced properties that make it more difficult to print, but the quality of the parts is better. For this reason, it is often used in the development of prototypes, gears or tools. In short, it is often implemented in situations where parts may be subjected to physical stress and where high mechanical and thermal resistance is required. Therefore, before starting the additive manufacturing process, evaluate the differences between the two materials to make parts according to their use.
ΔPLA is typically used for more manufacturer applications, decorative elements and toys. ABS can be used for applications that require higher mechanical and thermal resistance.
