--- title: 3D Printering: Why Is My PLA So Brittle? | daily.dev description: PLA filament brittleness comes down to two intertwined material science issues: hydrolysis (moisture breaking down polymer chains) and crystallization (which... canonical: https://daily.dev/posts/3d-printering-why-is-my-pla-so-brittle--djm9jttoa twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: 3D Printering: Why Is My PLA So Brittle? | daily.dev og:description: PLA filament brittleness comes down to two intertwined material science issues: hydrolysis (moisture breaking down polymer chains) and crystallization (which... og:url: https://daily.dev/posts/3d-printering-why-is-my-pla-so-brittle--djm9jttoa og:image: https://api.daily.dev/og/posts/DJM9JTtoa.png og:image:alt: 3D Printering: Why Is My PLA So Brittle? og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # 3D Printering: Why Is My PLA So Brittle? **[Hackaday](https://daily.dev/sources/hackaday)** · 9 min read · 0 upvotes · 0 comments ## Summary PLA filament brittleness comes down to two intertwined material science issues: hydrolysis (moisture breaking down polymer chains) and crystallization (which increases rigidity and brittleness even in dry, sealed storage). The piece explains PLLA vs PDLA chiral forms, how blending and plasticizers like PEG or sunflower oil affect flexibility, and why commercial 'PLA with additives' formulas are largely opaque since manufacturers don't disclose specifics. A personal anecdote about a three-year-old Sunlu PLA spool illustrates how prolonged room-air exposure, even after vacuum sealing, causes significant degradation, with reheating above the glass transition temperature offering only partial recovery. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Why does my PLA filament become brittle after sitting around for a year or two? Brittleness in aged PLA filament comes from two combined effects: hydrolysis, which shortens polymer chains when moisture penetrates the material, and increased crystallization, which makes the filament more rigid and prone to snapping. Even filament stored in a supposedly airtight container can degrade this way if it isn't truly vacuum-sealed, since exposure to room air over one to two years is enough to cause noticeable damage. _Track deep dives like this PLA degradation research alongside your other maker interests on daily.dev._ ### Does vacuum sealing PLA filament actually prevent it from degrading over time? Yes, vacuum-sealed storage significantly slows PLA degradation. In a study storing additive-free PLA samples for three years at room temperature, samples kept in vacuum-sealed bags showed no significant degradation, while identical samples stored in ordinary zipper bags in a vacuum-free desiccator suffered significant hydrolysis, nucleation, and crystallization, resulting in noticeable brittleness. _Makers debating filament storage methods can follow findings like this on daily.dev._ ### Can baking or drying brittle PLA filament in a filament dryer fix it? Heating brittle PLA above its glass transition temperature, roughly 65°C or higher for a number of hours, can partially restore its semi-crystalline state, but the results depend on how much hydrolysis damage has already occurred and whether any plasticizer (such as PEG) originally in the filament has migrated out over time. If hydrolysis damage is severe or the plasticizer is gone, reheating may not fully restore ductility. _daily.dev helps 3D printing enthusiasts keep up with practical fixes like filament recovery techniques._ ## Similar posts on daily.dev - [Your 3D printer's easiest filament is also the one most likely to shatter](https://daily.dev/posts/your-3d-printer-s-easiest-filament-is-also-the-one-most-likely-to-shatter-pziezlq0a) · XDA Developers · 0 upvotes · 0 comments - [PETG: The PLA Filament Alternative That Just Works](https://daily.dev/posts/petg-the-pla-filament-alternative-that-just-works-xjq7gije3) · Hackaday · 0 upvotes · 0 comments - [I stopped printing these 5 things in PLA after watching them fail in real conditions](https://daily.dev/posts/i-stopped-printing-these-5-things-in-pla-after-watching-them-fail-in-real-conditions-rzv9ciltp) · XDA Developers · 0 upvotes · 0 comments - [Your 3D prints are failing because you're using the wrong material, and PLA is the culprit](https://daily.dev/posts/your-3d-prints-are-failing-because-you-re-using-the-wrong-material-and-pla-is-the-culprit-f2hwobruy) · XDA Developers · 0 upvotes · 0 comments - [Is That Ancient Reel Of PLA Any Good?](https://daily.dev/posts/is-that-ancient-reel-of-pla-any-good--eadhgc5iu) · Hackaday · 0 upvotes · 0 comments --- Tags: [#science](https://daily.dev/tags/science) [View this post on daily.dev](https://daily.dev/posts/3d-printering-why-is-my-pla-so-brittle--djm9jttoa) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"3D Printering: Why Is My PLA So Brittle?","url":"https://daily.dev/posts/3d-printering-why-is-my-pla-so-brittle--djm9jttoa","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/3d-printering-why-is-my-pla-so-brittle--djm9jttoa"},"datePublished":"2026-08-20T17:12:18.634Z","dateModified":"2026-08-20T17:12:45.782Z","description":"PLA filament brittleness comes down to two intertwined material science issues: hydrolysis (moisture breaking down polymer chains) and crystallization (which...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/be750d573386a669cc1fe850a471065f?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/be750d573386a669cc1fe850a471065f?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hackaday","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hackaday","logo":"https://media.daily.dev/image/upload/s--JhDfhy70--/f_auto,q_auto/v1767541814/logos/hackaday","url":"https://daily.dev/sources/hackaday"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/3d-printering-why-is-my-pla-so-brittle--djm9jttoa","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"science","timeRequired":"PT9M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hackaday","item":"https://daily.dev/sources/hackaday"},{"@type":"ListItem","position":3,"name":"3D Printering: Why Is My PLA So Brittle?"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/3d-printering-why-is-my-pla-so-brittle--djm9jttoa#faq","mainEntity":[{"@type":"Question","name":"Why does my PLA filament become brittle after sitting around for a year or two?","acceptedAnswer":{"@type":"Answer","text":"Brittleness in aged PLA filament comes from two combined effects: hydrolysis, which shortens polymer chains when moisture penetrates the material, and increased crystallization, which makes the filament more rigid and prone to snapping. Even filament stored in a supposedly airtight container can degrade this way if it isn't truly vacuum-sealed, since exposure to room air over one to two years is enough to cause noticeable damage. Track deep dives like this PLA degradation research alongside your other maker interests on daily.dev."}},{"@type":"Question","name":"Does vacuum sealing PLA filament actually prevent it from degrading over time?","acceptedAnswer":{"@type":"Answer","text":"Yes, vacuum-sealed storage significantly slows PLA degradation. In a study storing additive-free PLA samples for three years at room temperature, samples kept in vacuum-sealed bags showed no significant degradation, while identical samples stored in ordinary zipper bags in a vacuum-free desiccator suffered significant hydrolysis, nucleation, and crystallization, resulting in noticeable brittleness. 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