{"id":3510,"date":"2026-10-14T12:46:45","date_gmt":"2026-10-14T04:46:45","guid":{"rendered":"http:\/\/www.dibenzoylmethane.com\/blog\/?p=3510"},"modified":"2026-10-14T12:46:45","modified_gmt":"2026-10-14T04:46:45","slug":"can-a-courier-bag-making-machine-produce-waterproof-courier-bags-45bc-5e3bba","status":"publish","type":"post","link":"http:\/\/www.dibenzoylmethane.com\/blog\/2026\/10\/14\/can-a-courier-bag-making-machine-produce-waterproof-courier-bags-45bc-5e3bba\/","title":{"rendered":"Can a courier bag making machine produce waterproof courier bags?"},"content":{"rendered":"

Hey there, it\u2019s Jake from the courier bag making machine team\u2014you know, the guy who\u2019s spent the last 8 years walking factories through buying, setting up, and troubleshooting these machines. Just this week, I got three DMs back-to-back asking basically the same thing: \u201cJake, can your courier bag making machine actually pump out waterproof courier bags?\u201d Courier Bag Making Machine<\/a><\/p>\n

<\/p>\n

Let me cut to the chase here: I\u2019m not gonna sugarcoat it\u2014yes, it can, but only if you\u2019re setting up the machine right for waterproof specs. I\u2019ve seen too many folks either overcomplicate the \u201cwaterproof\u201d part or assume all machines are the same, so let\u2019s break this down like I would with a factory owner sitting across my desk.<\/p>\n

First, let\u2019s get real about what makes a courier bag waterproof. Most cheap courier bags you see at gas stations? They\u2019re just polypropylene (PP) film, and that\u2019s basically a sieve when it rains. For actual waterproof courier bags, you\u2019re usually working with something like polyethylene (PE), high-density PE (HDPE), or even laminating two different films together\u2014like a PE layer and a light film of polyethylene terephthalate (PET) to add durability. The actual waterproofing isn\u2019t magic, it\u2019s about the material and how you seal the edges, right? That\u2019s where the machine comes in.<\/p>\n

Now, not all courier bag making machines are built equal. You can\u2019t grab a basic entry-level machine that\u2019s only set up for PP and expect it to handle waterproof materials. The biggest difference here is the sealing unit. Let me explain: when you make a regular PP courier bag, you heat-seal the edges, and PP seals just fine with standard heat settings. But for waterproof PE? If you use too much heat, you melt the film so bad you get tiny holes that let water through. If you use too little, the seal doesn\u2019t stick at all\u2014so the bag splits open when it drops in a puddle.<\/p>\n

Our machines (I\u2019m talking specifically about the mid-range to heavy-duty ones we sell) come with adjustable ultrasonic sealing units for exactly this. Ultrasonic sealing uses high-frequency vibrations to melt the film edges together without applying too much heat\u2014no over-melting, no weird holes, and the seal is strong enough to pass a quick test: I\u2019ve had factory guys bring me finished bags, spray them with a garden hose for 5 minutes, and not a single drop got in. Wait, but there\u2019s a catch\u2014you can\u2019t just slap an ultrasonic sealer on any old machine. You also need a film unwinder that\u2019s stable enough for thin waterproof films. A flimsy unwinder will make the film slip, leading to uneven seals, which leads to leaks.<\/p>\n

Another thing most people miss: the printing and finishing parts. Waterproof courier bags usually have a matte or glossy print that doesn\u2019t smudge when wet, right? Our machines let you swap in UV printing units instead of regular ink. Regular ink runs when it gets wet, so even if the bag itself is waterproof, the address label or logo looks like a mess. UV ink cures instantly with UV lights, so it stays crisp whether it\u2019s raining or someone wipes the bag with a wet cloth.<\/p>\n

I get it\u2014factory owners hate unexpected costs, so let\u2019s talk about the downfalls of trying to make waterproof bags with a cheap machine. Last year, a guy from a small e-commerce shop drove 2 hours to see me, saying his entry-level machine he bought online was making \u201cwaterproof\u201d bags but 20% were leaking. Turns out, he was forcing it to seal PE with a standard heat sealer, because he didn\u2019t know ultrasonic was an option. We retrofitted a used ultrasonic sealer on his machine for a fraction of a new unit\u2019s cost, and his leak rate dropped to less than 1%. That\u2019s not some fancy fix\u2014just matching the machine\u2019s parts to the material you\u2019re using.<\/p>\n

Wait, let\u2019s also address the myth that you need a whole separate machine for waterproof bags. No, most of our higher-end courier bag making machines are modular. You can switch between regular PP bags and waterproof PE bags in like 20 minutes\u2014just swap out the sealing unit settings, adjust the unwinder tension, and you\u2019re good to go. That\u2019s huge for small to medium factories that don\u2019t want to invest in two separate lines.<\/p>\n

But here\u2019s the reality check: no machine is perfect. If you use a flimsy waterproof film (like super-thin low-density PE), even the best machine can\u2019t make a bag that\u2019ll hold up in a monsoon. We always tell buyers: if you need waterproof bags that can handle extreme conditions (like shipping outdoor gear), go for a 70+ micron HDPE film. If you just need to stop light rain and splashes for online orders, a 50 micron PE film works fine. The machine can handle it, but the input material matters too.<\/p>\n

I\u2019ve also seen factories skip a step that kills waterproofing: the edge trimming. When you make a bag, the machine cuts the edges, and if those edges are ragged, even a good seal can have tiny gaps. Our machines have precision rotary cutters that trim the edges to a uniform, smooth line before sealing\u2014so every seal is tight, no loose bits that cause leaks.<\/p>\n

Let me share a quick success story to make this real. Last quarter, a logistics company that ships 100k+ packages a month reached out. They were using third-party waterproof bags that were getting expensive, and they wanted to make their own. They got one of our heavy-duty courier bag machines, went with 60 micron HDPE film, and adjusted the ultrasonic sealing settings\u2014now they make their own waterproof bags for 30% less than they were paying a supplier. They even added a small custom logo with UV ink, so their bags are now a walking ad for their brand. That\u2019s the kind of win we love seeing.<\/p>\n

Now, what if you\u2019re just starting out? Our entry-level machines can make basic waterproof bags, but you gotta do your homework. Don\u2019t buy the cheapest machine you find\u2014check if it has adjustable sealing (not just fixed heat settings), and ask the supplier if they can hook you up with the right tips for working with waterproof films. If a supplier can\u2019t answer that, keep looking.<\/p>\n

At the end of the day, yes\u2014your courier bag making machine can produce high-quality waterproof courier bags, but only if you pair the right machine features with the right materials and settings. It\u2019s not rocket science, but it\u2019s not \u201cplug and play\u201d either. You gotta know what parts to look for, and how to adjust the machine for the material you\u2019re using.<\/p>\n

<\/p>\n

If you\u2019re currently stuck\u2014either your current machine\u2019s leaking waterproof bags, you\u2019re looking to switch to in-house production, or you just wanna ask more about specs\u2014hit me up. I don\u2019t do pushy sales calls (I hate those as much as you do), I just walk you through what you need based on your order volume and budget. No fine print, no weird add-ons.<\/p>\n

Courier Bag Making Machine<\/a> References<\/p>\n

    \n
  1. Industrial Packaging and Processing Machinery Association. (2022). Guide to Sealing Technologies for Plastic Packaging Films. IPPMA Publications.<\/li>\n
  2. National Institute of Standards and Technology. (2021). Performance Metrics for Waterproof Packaging Materials. NIST Technical Note 1998.<\/li>\n
  3. Courier Industry Association. (2023). In-House Packaging Production Best Practices for E-Commerce Logistics. CIA White Paper.<\/li>\n<\/ol>\n
    \n

    Zhejiang Ruitai Packaging Machinery Co., Ltd.<\/a>
    Zhejiang Ruitai Packaging Machinery Co., Ltd. is one of the most professional courier bag making machine manufacturers and suppliers in China, featured by quality products and good service. Please rest assured to wholesale advanced courier bag making machine from our factory. Customized orders are welcome.
    Address: D6 Building, No.66 Tingchao Road, Shangwang Town, Ruian, Zhejiang, China.
    E-mail: ruiandavid2020@gmail.com
    WebSite:     https:\/\/www.rtbagmachine.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    Hey there, it\u2019s Jake from the courier bag making machine team\u2014you know, the guy who\u2019s spent … Can a courier bag making machine produce waterproof courier bags?<\/span>Read more<\/a><\/p>\n","protected":false},"author":958,"featured_media":3510,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3473],"class_list":["post-3510","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-courier-bag-making-machine-4779-5f1451"],"_links":{"self":[{"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/posts\/3510","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/users\/958"}],"replies":[{"embeddable":true,"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/comments?post=3510"}],"version-history":[{"count":0,"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/posts\/3510\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/posts\/3510"}],"wp:attachment":[{"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/media?parent=3510"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/categories?post=3510"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.dibenzoylmethane.com\/blog\/wp-json\/wp\/v2\/tags?post=3510"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}