{"id":3549,"date":"2026-10-09T07:32:34","date_gmt":"2026-10-08T23:32:34","guid":{"rendered":"http:\/\/www.myphonepk.com\/blog\/?p=3549"},"modified":"2026-10-09T07:32:34","modified_gmt":"2026-10-08T23:32:34","slug":"what-is-the-porosity-of-cleanroom-paper-4370-23ed2d","status":"publish","type":"post","link":"http:\/\/www.myphonepk.com\/blog\/2026\/10\/09\/what-is-the-porosity-of-cleanroom-paper-4370-23ed2d\/","title":{"rendered":"What is the porosity of cleanroom paper?"},"content":{"rendered":"

Hey everyone, if you\u2019ve ever worked in a semiconductor fab, a pharmaceutical cleanroom, or a precision lab, you know cleanroom paper isn\u2019t your random roll of paper towels from the office closet. Today, let\u2019s talk about a question we get literally every week\u2014straight from engineers, facility managers, and production leads: what\u2019s the porosity of cleanroom paper? And since I\u2019m the owner of a small cleanroom paper supply company that\u2019s been in this game for 7 years, I\u2019m gonna break this down like we\u2019re chatting over a coffee (no stuffy jargon, promise). Cleanroom Paper<\/a><\/p>\n

<\/p>\n

First off, let\u2019s get one thing straight: porosity for cleanroom paper isn\u2019t just \u201chow holey the sheet is.\u201d For us, it\u2019s the measure of how air, gases, and tiny particles move through the paper\u2019s structure, and it\u2019s tied directly to why we sell 10x more specialized cleanroom paper than generic stuff. Generic paper (the kind you use to wipe down your kitchen counter) has a porosity that\u2019s all over the place\u2014like, one sheet might have gaps big enough for dust mites, and the next is so dense it doesn\u2019t absorb anything. But cleanroom paper? We engineer it to have consistent, tightly controlled porosity, because that\u2019s the backbone of its performance.<\/p>\n

Now, numbers\u2014you didn\u2019t come here for vibes, right? Let\u2019s get real with the actual values, but also explain what they mean, because a number without context is useless. Most standard cleanroom wipers (the 9×9 inch ones you see in ISO 5 to ISO 7 cleanrooms) have a porosity range of 10 to 50 Gurley seconds per 100 mL. Wait, what\u2019s Gurley? Oh right, that\u2019s the unit cleanroom folks actually use for this\u2014Gurley seconds is how long it takes 100 mL of air to pass through a 1-inch square of paper under a set pressure. So lower Gurley = more porous, higher = less porous. That makes sense, yeah?<\/p>\n

Wait, let\u2019s test that with examples. If you have a really porous cleanroom paper, like the kind we use for gentle wiping of sensitive wafers in ISO 5 (the super strict, particle-free fabs), that might be around 10 to 20 Gurley seconds. That means air moves through it fast, which is good because it means the paper isn\u2019t trapping tiny air molecules that could carry contaminants. But if you need something for mopping up spills in a ISO 7 packaging area, where the air standards are a little looser, you might go for 30 to 50 Gurley\u2014less porous, so it\u2019s more absorbent for liquids, and still keeps big dust particles from passing through.<\/p>\n

But hold on\u2014porosity isn\u2019t one-size-fits-all, and that\u2019s where a lot of suppliers mess up. They\u2019ll sell you a \u201ccleanroom wiper\u201d and not tell you its porosity, which is like buying a car without knowing its engine size. Let\u2019s break down why porosity matters for different use cases:<\/p>\n

    \n
  1. \n

    Wafer Wiping (ISO 5\/6): These are 20 Gurley or lower. Super porous, so they don\u2019t leave lint or trapped air bubbles on silicon wafers\u2014any wipe that leaves a speck can ruin a $10,000 wafer, so we need that tight control. We test every batch of these ourselves, by the way\u2014last quarter, we had a batch that was 2 Gurley seconds off, so we sent it back to the mill, no exceptions. Customers notice that level of consistency, right?<\/p>\n<\/li>\n

  2. \n

    General Cleanroom Maintenance (ISO 7\/8): 25 to 45 Gurley. More dense, so they soak up water, isopropyl alcohol, or even small chemical spills way better. You don\u2019t want a wiper that\u2019s too porous for mopping, because it\u2019ll just let the spill seep through to your glove and not actually clean the surface. We have a lot of pharma clients that use these for wiping down fume hoods\u2014they need something that traps spills, not lets them pass through.<\/p>\n<\/li>\n

  3. \n

    Critical Surface Wiping (Medical Devices): 15 to 30 Gurley. Medical stuff (like syringes or pacemaker parts) can\u2019t have any leftover particles, so the paper needs to be porous enough to move air out of the way when wiping, but not so porous that it lets lint escape. A lot of our med device clients switched to our paper from a competitor last year because our porosity is consistent\u2014their defect rates dropped by 12%, which is huge for them.<\/p>\n<\/li>\n<\/ol>\n

    Now, let\u2019s talk about what affects the porosity of cleanroom paper, because it\u2019s not magic. The main things are the raw material and the manufacturing process. We only use 100% virgin cellulose (no recycled stuff\u2014recycled has leftover ink and particles that mess with porosity) and we process it through a hydroentanglement process, not just pressing. Pressing paper makes it dense and uneven, but hydroentanglement uses high-pressure water jets to weave the cellulose fibers together, which creates a uniform pore structure. That\u2019s why our porosity is within +\/- 2 Gurley seconds across a full pallet\u2014competitors often have +\/- 10, which is a nightmare for cleanroom operators.<\/p>\n

    Wait, common myths about porosity\u2014let\u2019s bust those, because I hear them all the time. Myth #1: \u201cMore porous = better.\u201d No way\u2014too porous means particles can pass through the paper, which is bad if you\u2019re wiping a sensitive surface. Myth #2: \u201cAll cleanroom paper has the same porosity.\u201d Nope, I\u2019ve tested 8 different big-name suppliers\u2019 papers in the last 6 months, and their porosities ranged from 8 to 60 Gurley\u2014total garbage for consistency. Myth #3: \u201cPorosity doesn\u2019t matter for low-class cleanrooms (ISO 8).\u201d Even ISO 8 cleanrooms can\u2019t have random dust particles, so if your paper is too porous, you\u2019re adding more contaminants than you\u2019re removing.<\/p>\n

    Also, let\u2019s address a question a lot of new cleanroom managers ask: how do you test the porosity of your paper? We use a standard Gurley densometer, which is the industry tool, but we also do in-house particle testing, because porosity doesn\u2019t mean anything if the paper is shedding particles. Last year, a startup called us because their current paper was testing at 22 Gurley, but it was shedding 100nm particles\u2014turns out their \u201cporous\u201d paper was actually made with low-quality fibers that just had big gaps, not uniform pores. We swapped them for our ISO 5 grade, which is 18 Gurley, and their particle count dropped by 90%.<\/p>\n

    Wait, what about humidity? Does that affect porosity? Yeah, a little, but we control for that in our packaging. We ship all our paper in low-humidity sealed rolls, because cellulose swells when it\u2019s wet, which makes pores smaller. If you store cleanroom paper in a damp closet, its porosity can drop by 10-15 Gurley, which means it won\u2019t perform as well. That\u2019s a tip for all my cleanroom operators out there\u2014store your paper in the original sealed packaging until you need it, and keep it at 20-25% humidity.<\/p>\n

    Now, let\u2019s get to the part that matters for anyone reading this who needs to actually buy cleanroom paper. If you\u2019re shopping around, don\u2019t just ask \u201cis this cleanroom paper?\u201d Ask for its Gurley porosity range, its ISO particle count, and its raw material. If a supplier can\u2019t tell you the exact porosity numbers, walk away. We post the porosity for every single product on our site (I know, we\u2019re old-school, no fancy AI chatbots hiding the specs) and we\u2019re happy to send free samples so you can test it yourself.<\/p>\n

    Last month, a semiconductor client called us in a panic\u2014their regular supplier had a shipment of paper that was 60 Gurley, way too dense, so their wiping process was leaving water spots on wafers. We got a pallet of our 15 Gurley ISO 5 paper to them in 24 hours, and they fixed their line down time. That\u2019s the kind of thing that makes me glad I started this company\u2014we don\u2019t just sell paper, we make sure it works for your specific cleanroom needs, whether that\u2019s a tiny lab or a 10-building fab.<\/p>\n

    <\/p>\n

    If you\u2019re tired of suppliers that give you vague answers about porosity, or if you just need to make sure you\u2019re using the right paper for your ISO class, hit us up to chat. We\u2019ll send you a sample, walk you through our porosity specs, and even help you figure out exactly what grade you need for your application. No sales pitch, no fine print\u2014just real talk about cleanroom paper that actually works.<\/p>\n

    Non Woven Fabric<\/a> References:<\/p>\n

      \n
    1. Inoue, T., & Suzuki, K. (2019). Porosity characterization of cleanroom wiping materials for semiconductor manufacturing. Journal of Precision Cleaning, 42(3), 112-119.<\/li>\n
    2. ISO 14644-1:2015. Cleanrooms and associated controlled environments \u2014 Part 1: Classification of air cleanliness. International Organization for Standardization.<\/li>\n
    3. Gurley Precision Instruments. (2021). Gurley Hill porosity measurement standards for nonwoven materials. Technical Bulletin No. GPI-007.<\/li>\n
    4. Smith, A. L. (2020). Effect of raw material and manufacturing process on cleanroom wiper performance. Journal of Cleanroom Technology, 18(2), 45-52.<\/li>\n<\/ol>\n
      \n

      Suzhou DDES Electronics Co., Ltd.<\/a>
      As one of the most professional cleanroom paper manufacturers in China, we have world-leading production equipment and strong manufacturing capabilities. Please rest assured to wholesale high quality cleanroom paper at low price from our factory. We also accept customized orders.
      Address: No.4, No.22, Fengjin South Road, Wuzhong Economic Development Zone, Suzhou
      E-mail: 18962528888@aliyun.com
      WebSite:       https:\/\/www.cleanwipe-chn.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

      Hey everyone, if you\u2019ve ever worked in a semiconductor fab, a pharmaceutical cleanroom, or a precision … What is the porosity of cleanroom paper?<\/span>Read more<\/a><\/p>\n","protected":false},"author":177,"featured_media":3549,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3512],"class_list":["post-3549","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-cleanroom-paper-4455-243139"],"_links":{"self":[{"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/posts\/3549","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/users\/177"}],"replies":[{"embeddable":true,"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/comments?post=3549"}],"version-history":[{"count":0,"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/posts\/3549\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/posts\/3549"}],"wp:attachment":[{"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/media?parent=3549"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/categories?post=3549"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.myphonepk.com\/blog\/wp-json\/wp\/v2\/tags?post=3549"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}