How is PLA different from ABS material?

  • What are the main differences when using ABS over PLA and vice versa?


    I think this is too broad for a good exhaustive answer unless restricted to just ABS and PLA...

    I'm voting to close this as too broad. Asking generically about filament types is opening the answer to too many possible filaments, and any answer would become incomplete over time as more filament types are created.

    @1337joe: I disagree. While it is true that many filament types exist, it would be good to have a canonical post which addresses general characteristics and differences of ABS & PLA for general purpose printing.

    @Paul Yes, if it's restricted to ABS and PLA FDM printing. If it's open to "different filaments" then I'd suggest closing it.

    @CJK I'm editing it to limit the answers to just ABS and PLA, the two most popular FDM filaments. I would otherwise vote to close this question as too broad, as this information would take a book if you included a comparison between all filament types. If you disagree, go ahead and roll it back.

  • Kevin Morse

    Kevin Morse Correct answer

    6 years ago

    Paraphrasing this site. Feel free to add suggestions in the form of comments and I will try to incorporate them.



    Summary




    • ABS: Stronger, machinable, more flexible, and more temperature
      resistant than PLA. Typically printed on a heated bed. Warping is a common problem when printing ABS.

    • PLA: Wider range of filaments available, easier and in some cases faster to print. Not as strong as ABS and the fact that its biodegradable could be seen as both a benefit and a drawback.



    Material Properties:




    • ABS: Strong plastic with mild flexibility. Naturally beige in color. Can be filled and sanded. Higher temperature. Easy to recycle.

    • PLA: Not as strong as ABS but more rigid. Naturally transparent. More difficult to fill and sand. Can sag in hot temperatures. Sourced from organic matter so it can be broken down in commercial compost facilities.



    Part Accuracy:




    • ABS: Part warping is a significant issue. Sharp corners will often be rounded.

    • PLA: Less heat required contributes to less warping. Becomes more liquid at common extruder temperatures so finer details can be printed.



    Safety and Handling:




    • ABS: Strong burning/melting plastic smell is present when printing ABS. Health concerns have been raised regarding airborne ultrafine particles generated while printing with ABS (ref). ABS will absorb moisture causing popping when the moisture enters the hot end. This leads to discontinuities in the print job.

    • PLA: Doesn't smell as strongly when printing due to its organic nature. Moisture can also be absorbed into PLA and can irreversibly damage it.


    Is a heated bed *required* for ABS? Our printer supports ABS but doesn't have a heated bed (but I've only used PLA)

    Yes. I don't think it's possible without.

    Here's the printer we have: https://printm3d.com It claims to print both ABS and PLA and doesn't have a heated bed.

    So after researching I have found some reports of people printing ABS without heated bed. I think common practice is still to use a heated bed but I will revise my answer.

    PLA becomes soft at around 50C, ABS at around 100. So if you print something that might sit under the sun in a hot sunny day PLA won't do. PLA is also very sensitive to UV rays.

    Can you expand on "discontinuities" please? My ABS is popping. It was only opened from its sealed bag about a week ago and I like to think my house is warm and dry. Mine is "popping" and some of my prints have brown streaks in which makes me think that the moisture is making the ABS burn rather than melt. Is this likely?

    @DA. it is possible to print tiny parts with ABS without a heated bed and get good results, but only for tiny parts.

    I would disagree with PLA being weaker. I have done tests with ABS and PLA and using the same file I found PLA to be ~20% stronger than ABS. But the big thing is PLA is brittle were ABS can take stress before breaking.

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Content dated before 7/24/2021 11:53 AM

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