PLA vs. ABS: Differences and Comparisons
Learn all about these two materials that are commonly used in 3D printing applications.
PLA (Polylactic Acid) and ABS (Acrylonitrile Butadiene Styrene) are both used for a wide variety of industrial and consumer applications. PLA is more brittle than ABS and tends to degrade when exposed to UV light. However, it is easier to print and does not warp as easily as ABS. PLA is ideal for quick and easy prototypes, whereas ABS is better suited for functional applications. PLA and ABS are both relatively inexpensive.
This article will compare PLA vs. ABS in terms of their relative advantages, disadvantages, and properties.
PLA Definition and Comparison to ABS
PLA (Polylactic Acid) is a semicrystalline thermoplastic polyester. It is derived from renewable sources and is therefore classified as a bioplastic. PLA is typically manufactured from plant starch. This origin ultimately yields the two key monomers used in PLA synthesis—lactic acid and lactide. Each monomer can be used to produce PLA using a number of different processes.
Low-molecular-weight PLA was first produced in 1932. In 1952, DuPont further developed the process and created high-molecular-weight PLA. PLA is easy to print. It is biodegradable and therefore more environmentally friendly than ABS. Far less energy is also required to produce PLA. Figure 1 below shows a cup made from PLA:
To learn more, see our guide on What is PLA.
Polylactic acid (PLA) printed cup.
Image Credit: Shutterstock.com/photokup
What Are the Advantages of PLA Compared to ABS?
Listed below are two key advantages of PLA vs. ABS:
- PLA is much easier to print than ABS. PLA can be printed at lower temperatures and does not warp as readily.
- Under the right conditions, i.e., those present in an industrial composting facility, PLA will break down into non-toxic by-products.
What Are the Disadvantages of PLA Compared to ABS?
Listed below are two key disadvantages of PLA vs. ABS:
- PLA cannot withstand impact loads very well and will crack more easily than ABS.
- PLA cannot withstand prolonged exposure to UV light.
ABS Definition and Comparison to PLA
Acrylonitrile Butadiene Styrene (ABS) was first patented in 1948 and commercialized in 1954 by the Borg-Warner Corporation. It is an amorphous thermoplastic polymer where the molecular structure is disordered. ABS is commonly manufactured via the polymerization of styrene and acrylonitrile. ABS is a tougher plastic than PLA. It can be used for applications that require significant strength and impact resistance. For more information, see our guide on what is ABS.
Figure 2 below shows plastic wire made from ABS:
ABS plastic wire.
Image Credit: Shutterstock.com/Alexander Tolstykh
What Are the Advantages of ABS Compared to PLA?
Listed below are two key advantages of ABS vs. PLA:
- ABS has a higher glass transition temperature than PLA.
- ABS is generally tougher than PLA. It can withstand impact loads and has better abrasion resistance.
What Are the Disadvantages of ABS Compared to PLA?
Listed below are three key disadvantages of ABS vs. PLA:
- ABS is difficult to 3D print. The increased temperature differential between ambient and the print means that the part cools rapidly, thereby introducing warping.
- ABS releases VOCs (Volatile Organic Compounds) and UPFs (Ultrafine Particles) during printing. Both can cause eye and respiratory tract irritation as well as nausea and headaches during excessive exposure.
- ABS-printed parts need a heated and properly ventilated build volume to print correctly.
| Attribute | PLA | ABS |
|---|---|---|
Attribute Used for high-temperature applications | PLA No | ABS Yes |
Attribute UV Resistant | PLA No | ABS Yes |
Attribute Brittle | PLA Yes | ABS No |
Attribute Biodegradable | PLA Yes | ABS No |
Attribute Produces dangerous fumes during 3D printing | PLA No | ABS Yes |
Attribute Made using renewable raw materials | PLA Yes | ABS No |
Attribute Glass transition temperature | PLA 60°C | ABS 105°C |
Attribute Low-cost | PLA Yes | ABS Yes |
Attribute Tensile strength | PLA 65 MPa | ABS 40 MPa |
Attribute Impact Strength (Notched Izod, J/m) | PLA 96.1 | ABS 200 - 215 |
Attribute Abrasion Resistant | PLA No | ABS Yes |
PLA is more brittle than ABS but has higher tensile strength. ABS is better suited to applications that require impact resistance and overall toughness. PLA is better suited to parts that focus on form instead of function, for example, a visual prototype.
PLA vs. ABS: Applications Comparison
PLA is not widely used for typical consumer and industrial applications. It is mostly used for 3D printing in hobbyist applications or prototyping but has found some applications in the biomedical industry. ABS, on the other hand, is used as an engineering plastic across almost every industry. It is preferred for applications requiring toughness and impact resistance.
PLA vs. ABS: Part Accuracy Comparison
PLA is a very easy material to 3D print and it produces parts that are dimensionally stable. ABS, on the other hand, tends to warp easily during printing.
PLA vs. ABS: Speed Comparison
Both PLA and ABS can print at rates from 45 to 60 mm/s.
PLA vs. ABS: Surface Comparison
3D-printed PLA and ABS have the common FDM (Fused Deposition Modeling) surface finish with visible layer lines. However, ABS can be vapor smoothed with solvents like acetone while PLA must be hand sanded for optimal surface finish. The vapor smoothing process melts the surface, giving it a smooth and homogeneous finish.
PLA vs. ABS: Heat Resistance Comparison
PLA has poor heat resistance when compared to ABS. PLA will begin to soften at 60 °C whereas ABS does not begin to soften until 105 °C.
PLA vs. ABS: Biodegradability Comparison
PLA is a bioplastic and biodegradable under the correct conditions. Unfortunately, these conditions are only present in industrial composting facilities. The required conditions include high temperatures and exposure to specific microbial environments. PLA can take up to 80 years to fully decompose in nature. ABS, on the other hand, is not biodegradable and can take hundreds of years to fully decompose.
PLA vs. ABS: Toxicity Comparison
PLA is generally recognized as safe and non-toxic after printing. During printing, PLA releases VOCs (Volatile Organic Compounds). As such, it is not recommended to print PLA in an unventilated area. However, these VOCs are low in concentration and ventilation is just an added precaution. ABS contains no known carcinogens and has no adverse health effects once printed. However, ABS also releases dangerous VOCs and nanoparticles (UPFs) during printing, far more than is the case with PLA. As such, it is advised to cover printers with a hood and to utilize a ventilation duct.
PLA vs. ABS: Cost Comparison
PLA and ABS are among the lowest-cost materials used in 3D printing. Both can be purchased for around $20 per 1 kg spool. ABS can be slightly more expensive than PLA, but the difference is usually insignificant.
What Are the Mutual Alternatives to PLA and ABS?
Despite the benefits of using PLA and ABS, an alternative material can achieve similar results:
- PETG: PETG (Polyethylene Terephthalate Glycol) provides a good middle ground between ABS and PLA. It prints as easily as PLA, but has mechanical properties as good as those of ABS, without its challenges of excessive warping and toxic fumes.
What Are the Similarities Between PLA and ABS?
Listed below are two of the similarities between PLA and ABS:
- PLA and ABS are the lowest-cost 3D-printable plastics. A 1 kg filament spool of either plastic costs approximately $20.
- PLA and ABS both print optimally at the same speed of around 40 to 60 mm/s.
What Are the Other Comparisons for PLA Besides ABS?
Listed below are the comparisons for PLA besides ABS:
- PLA vs. PLA+: PLA+ is an enhanced version of PLA. Like PLA, PLA+ is also easy to print, exhibits minimal shrinkage after printing, and is great for proof-of-concept prototypes. For more information, see our guide on the PLA vs. PLA+.
What Are the Other Comparisons for ABS Besides PLA?
Listed below are the comparisons for ABS besides PLA:
- ABS vs. PC: Polycarbonate (PC) is the strongest available 3D-printable plastic. It has improved properties when compared to ABS, such as higher ultimate tensile strength and higher temperature resistance. Like ABS, PC tends to warp easily and must be printed at temperatures approaching 300 °C.
Summary
This article contrasted PLA and ABS, both of which are commonly used 3D printing materials. To learn more about which plastic is better and how Xometry can assist material selection, contact a Xometry representative.
Xometry provides a wide range of manufacturing capabilities, including 3D printing and value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.
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