ABS VS PLA, How to Choose the Suitable One

ABS and PLA are the most popular 3D printing plastic materials. Do you know the differences in performance and printing requirements between PLA and ABS?

Characteristics and Performance, ABS VS PLA

The raw material decides the properties of PLA and ABS. There are differences between them, even though they both are thermoplastics.

PLA is from organic sources like corn or sugar cane, while ABS, like most standard plastics, is from petroleum. More specifically, PLA is from fermented plant starches in corn, tapioca, corn, sugar cane, or beet pulp. The sugars are converted into lactic acid and then polymerized into polylactic acid.

By contrast, ABS contains three monomers: acrylonitrile, butadiene, and styrene. Acrylonitrile is an artifact monomer derived from propylene and ammonia. Butadiene is a petroleum hydrocarbon, and styrene is from the dehydrogenation of ethylbenzene. These materials are harmful to the environment.

PLA is hailed as a more environmentally friendly material because of its biodegradability. However, it’s important to note that it only biodegrades under the right conditions, and many cities don’t have the proper tools to degrade it, which means that only industrial composting is environmentally friendly. On the other hand, ABS is considered an unsustainable or non-environmentally-friendly material. However, one advantage is that ABS is recyclable. Many people don’t realize the limited biodegradability of PLA, so some beginners may be more sure that PLA will be disposed of properly without generating more waste.

The Differences between ABS and PLA

ABS is better in heat resistance and mechanical performance.

Except for the sources of the material, ABS and PLA are different in heat resistance. ABS is more heat resistant and has a higher glass transition temperature. PLA melts at much lower temperatures and is not heat resistant, which would affect the use of the material.

If you want a more rigid material with better mechanical properties, you can choose ABS. In addition to heat resistance and higher heat distortion, it is more impact-resistant, durable, and lighter than PLA. However, the two have similar tensile strengths (ABS is slightly lower). ABS is generally more suitable for more industrial applications mainly due to the improved flexibility and ability to not break, as well as higher flexural strength and elongation before the break. Because of these properties, ABS can even be used in terminal products, which is one of the reasons it is widely used in industries such as injection molding.

PLA is more solid and stiffer than ABS. However, because of the low melting point, it loses these properties above 50℃. So, it is not suitable in higher-temperature environments. Although ABS has significantly higher heat resistance than PLA, both are still thermoplastics and will degrade with time passing under UV light and high temperatures.

PLA is Easier for 3D Printing Than ABS

Because of the diverse glass transition temperatures of the two thermoplastics, the preparation work for 3D printing is different. You have to consider the temperature range of the material’s thermodynamic transformation. For PLA, the glass transition temperature ranges from 60 – 100°C, while for ABS, it is 105 – 200°C. It determines the parameters set in the slicer and how long it takes to heat the 3D printer to the desired temperature.

They have similar settings for variables in the manufacturing process, including the print platform and print head. ABS requires a higher lathe temperature, around 80-110°C, while PLA is typically 60°C. Regarding extruders, PLA also requires lower temperatures, around 180-230°C, while ABS requires 210-250°C.

ABS is known to be more complex than PLA in terms of its use. Printing problems are also related to the temperature and properties of each material. The melting temperature of PLA is lower than that of ABS, so the thermal variation of curing of the layers is lower after the completion of printing. However, because of the higher melting temperature of ABS, there will be more abrupt changes in parts cooling. This thermal shrinkage can cause a buckle. One of the most common problems is warping, where the ends of the part shrink, come off the pallet, and deform. It is critical to control the temperature and printing environment to avoid it when printing with ABS and use adhesives if necessary.

The printing speed for these two materials is similar. You do not have to readjust the speed parameters in the slicer for different materials. PLA typically prints at 60mm/sec. And some users even use higher speeds. On the other hand, ABS is usually about 40-60 mm/s, and it is difficult to reach higher rates.

Post-Processing

Although there are some noticeable differences, most post-processing techniques are available for both thermoplastics. PLA parts have a brighter finish, while ABS tends to have a matte finish. Both materials support painting after printing. ABS is generally easier to post-process than PLA. Both of them support sanding. The process is simple due to the durability of ABS. PLA is difficult for sanding because it has a lower heat resistance and would melt easily.

ABS is not only easier to post-process with these basic methods. You can smooth ABS-made parts with acetone vapor, a colorless liquid commonly used as a solvent for plastics to get a shiny surface. If you wish to steam smooth items from PLA filament, THF can be used for hand polishing.

Application of PLA and ABS

PLA is the most used material in FDM 3D printing, mainly in creative designs. It is a result of its ease of printing, brittle, fragile, and sensitive nature to sunlight and heat. For this reason, it is widely used by beginners or for decorative parts and toys.

ABS is a more industrialized material with advanced properties. Although it is more difficult for 3D printing, the quality of the parts is better. It is often for prototypes, gears, or tools. In short, it is for products subject to physical stress and high mechanical and thermal resistance. So, before starting the additive manufacturing process, evaluate the differences between the two materials to make parts according to their purpose.

WKproto offers excellent 3D printing with ABS and PLA. Contact us if you need a 3D printing service with ABS or PLA material.