{"id":3460,"date":"2026-10-14T12:46:46","date_gmt":"2026-10-14T04:46:46","guid":{"rendered":"http:\/\/www.matsmaket.com\/blog\/?p=3460"},"modified":"2026-10-14T12:46:46","modified_gmt":"2026-10-14T04:46:46","slug":"what-is-the-humidity-tolerance-of-a-side-sealing-bag-making-machine-441d-65dd42","status":"publish","type":"post","link":"http:\/\/www.matsmaket.com\/blog\/2026\/10\/14\/what-is-the-humidity-tolerance-of-a-side-sealing-bag-making-machine-441d-65dd42\/","title":{"rendered":"What is the humidity tolerance of a Side Sealing Bag Making Machine?"},"content":{"rendered":"

If you\u2019re in the flexible packaging manufacturing space, chances are you\u2019ve invested in a side sealing bag making machine\u2014they\u2019re the workhorses that turn thin films, laminates, and specialty materials into everything from grocery produce bags to snack pouches. But here\u2019s a question I get asked at least a dozen times a week, often from new customers troubleshooting issues or vetting a machine before pulling the trigger: \u201cWhat\u2019s the humidity tolerance of a side sealing bag making machine?\u201d Side Sealing Bag Making Machine<\/a><\/p>\n

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I get why this is such a critical question. I\u2019ve been supplying these machines for 12 years now, and I\u2019ve seen too many operators ignore humidity concerns only to end up with faulty bags, downtime, or thousands in wasted material. Back in my early days in this industry, I had a customer out in Florida who ran his plant at 82% relative humidity (RH) in the summer months, thinking a \u201cgood industrial machine\u201d could handle it. He ran his standard polyethylene (PE) side sealing bags for three days before his sealing bars started corroding at an alarming rate, and his web tension control slipped so bad that half the production run had wavy, unsealed edges. He lost $12,000 in film material and 48 hours of production time, all because he skipped checking the humidity specs. That\u2019s the kind of story that sticks with you, and it\u2019s the reason I never sugarcoat this topic for potential clients.<\/p>\n

First, let\u2019s break down why humidity matters so much for these machines. A side sealing bag making machine works by feeding a continuous roll of film through a series of rollers, printing stations (if you\u2019re adding logos or product info), and then heating its longitudinal sealing bars to fuse the two edges of the film together, plus heat-cutting the final bags to size. All of these moving and heating parts are sensitive to moisture in the air, but the impact varies depending on two big factors: the machine\u2019s construction and the type of material you\u2019re processing.<\/p>\n

Let\u2019s start with machine construction, because that\u2019s where the humidity tolerance is defined. Not all side sealing bag machines are built the same, and the materials used to make them will dictate how well they hold up in humid environments. The core components that react most to moisture are the electrical parts, the sealing hardware, and the metal framing.<\/p>\n

Standard, entry-level side sealing machines\u2014often the ones marketed to small startups or hobbyist operations\u2014are typically made with mild steel framing and uncoated electrical connectors. These machines, in my experience, have a maximum humidity tolerance of around 45-55% RH. Why? Mild steel rusts when exposed to consistent moisture, even in industrial settings. Rust builds up on the linear bearings that guide the sealing head, for example, creating friction that makes the machine\u2019s movement jerky. That jerky movement can throw off the web tension of the film, leading to misaligned seals or bags that are cut too short or too long. The electrical connectors on these entry-level machines are usually cheap plastic with minimal sealing, so condensation from high humidity can cause short circuits in the control panel, stopping production cold. I\u2019ve seen these types of machines fail entirely within 18 months in a plant that runs at 70% RH year-round.<\/p>\n

Now, mid-range and industrial-grade side sealing machines\u2014this is the line I supply to most of my clients\u2014are built with humidity resistance in mind. We use galvanized steel or stainless steel for all high-contact metal parts, including framing, sealing bar housings, and linear rails. The control panels are sealed with industrial-grade gaskets, and all internal electrical components are potted in epoxy or housed in dust-proof, moisture-resistant enclosures. For these machines, the baseline humidity tolerance is 60-70% RH, depending on other factors like operating temperature and how often the plant is ventilated. I had a customer in Houston, where summer RH regularly hits 75%, run one of our mid-range machines for two years straight without a single humidity-related breakdown. His only caveat was that he installed a small dehumidifier near the sealing station, where the heating elements can add extra moisture to the air around the critical parts.<\/p>\n

If you\u2019re running an industrial side sealing machine that needs to operate in even more humid environments\u2014like coastal areas (where salt air amplifies corrosion) or regions with consistent 75-80% RH\u2014we offer a heavy-duty, corrosion-resistant upgrade line. These machines use 304 or 316 stainless steel for all metal parts, conformal coating on all circuit boards, and air-purged control panels that keep dry, filtered air inside to prevent condensation. The humidity tolerance for these upgraded machines tops out at around 85% RH, with proper ventilation and minimal dust exposure. We have a seafood packaging client in New Orleans that uses one of these upgraded models to make ice and seafood bags, and they run the machine 22 hours a day in an environment that\u2019s often 80% RH. They\u2019ve only had one minor issue in three years, which was a simple part replacement after a routine maintenance check.<\/p>\n

But wait\u2014humidity tolerance isn\u2019t just about the machine itself. It\u2019s also tied to the material you\u2019re running through the machine, and how humidity interacts with that material, which in turn affects the machine\u2019s performance. Let\u2019s talk about that, because it\u2019s a common mistake I see operators make: assuming the machine\u2019s specs are all that matter, without accounting for the film or laminate.<\/p>\n

Most side sealing bags are made from PE, polypropylene (PP), or laminated films of PE and aluminum foil, polyester, or other materials. Each of these materials reacts differently to humidity, and that reaction can make a well-built machine perform poorly even if it\u2019s within its humidity tolerance range. For example, PE film is relatively hydrophobic\u2014it doesn\u2019t absorb much moisture\u2014but high humidity can cause static electricity to build up on the film. Static electricity is a big problem for side sealing machines because it attracts dust, which can get caught between the sealing bars and the film, leading to weak seals. It can also throw off the optical sensors that align printed graphics on the film, resulting in misaligned designs or off-center bag cuts. If you\u2019re running PE film in an environment over 65% RH, you might need to add a static eliminator bar near the film feed to keep those issues at bay\u2014even if your machine is rated for 70% RH.<\/p>\n

Laminated films, on the other hand, are more sensitive to humidity. The layers of different materials can absorb moisture at different rates, causing the film to expand or warp slightly. This warping makes it hard for the machine\u2019s rollers to feed the film evenly, leading to inconsistent seal thickness or gaps along the side seams. I\u2019ve seen a client try to run a potato chip bag laminate in a machine rated for 70% RH, but the laminate\u2019s dimensional stability dropped off sharply above 62% RH, resulting in 15% of the bags having broken side seals. We adjusted their facility\u2019s humidity to 60% with small dehumidifiers, and the defect rate dropped to less than 1%. That\u2019s a perfect example of how the material\u2019s interaction with humidity can override the machine\u2019s specs\u2014so it\u2019s not enough to just ask the machine\u2019s tolerance; you have to match that to your material.<\/p>\n

There are also a few edge cases that push humidity tolerance beyond standard specs, and these are important to note for anyone operating in extreme conditions. For example, if you\u2019re running a machine that\u2019s only used for short production runs (a few hours a day, not 24\/7), you might be able to get away with running it at 75% RH, even if it\u2019s a mid-grade model. The key here is that the machine isn\u2019t running long enough to build up significant corrosion or condensation. But if you\u2019re running a machine 24\/7, you need to stick to the lower end of its tolerance range, because the constant heat from the sealing bars and the air circulation from the motor fans will trap moisture in the components over time, leading to faster wear.<\/p>\n

Another edge case is high temperature and humidity combined. If your plant is 90\u00b0F and 70% RH, that\u2019s a different environment than 70\u00b0F and 70% RH. The higher temperature accelerates corrosion and causes condensation more quickly, even if the RH is the same. For that reason, we always adjust the humidity tolerance specs for operating temperature: for every 5\u00b0F above 80\u00b0F, we recommend dropping the maximum RH by 5%. So a machine rated for 70% RH at 70\u00b0F would only handle 60% RH at 90\u00b0F\u2014something most customers don\u2019t know, until they call us complaining that their machine is failing in their hot plant.<\/p>\n

Now, I know what some of you are thinking: \u201cI can just run my air conditioning to lower the humidity, right?\u201d Well, yes, that works, but it\u2019s not always cost-effective. If you\u2019re running a small operation, cranking the AC 24\/7 to keep humidity below 55% can add 10-15% to your monthly utility bill, which is a big hit for thin-margin packaging runs. That\u2019s why so many clients opt for the upgraded corrosion-resistant machine, which costs a bit more upfront but saves them money on utility bills over time, especially if they\u2019re in a consistently humid area.<\/p>\n

The most common question I get after covering all this is: \u201cHow do I test my machine\u2019s actual humidity performance, instead of just relying on specs?\u201d That\u2019s a great question, and it\u2019s something every operator should do before ramping up production. The easiest way is to do a trial run: set your plant\u2019s RH at different levels (using a hygrometer, which every operator should have handy) and run a small batch of your material through the machine, checking for defects like seal gaps, misaligned cuts, or sensor errors. If you\u2019re within the machine\u2019s rated humidity, and your material is performing well, your defect rate should be under 2% (the industry standard for high-quality bags). If defects spike, you either need to adjust the humidity, add maintenance steps, or upgrade your machine.<\/p>\n

At the end of the day, the humidity tolerance of a side sealing bag making machine isn\u2019t a one-number answer\u2014it\u2019s a range that depends on the machine\u2019s build quality, the material you\u2019re processing, your operating schedule, and your facility\u2019s conditions. Over my 12 years in this business, I\u2019ve never seen a \u201cone-size-fits-all\u201d spec that works for every client, which is why I always take the time to walk through each client\u2019s specific setup before recommending a machine.<\/p>\n

<\/p>\n

If you\u2019re in the market for a side sealing bag making machine and want to make sure it\u2019s the right fit for your humidity levels, or if you\u2019re having issues with your current machine and need to troubleshoot humidity-related problems, I\u2019m here to help. Don\u2019t guess on specs or cut corners on testing\u2014 that\u2019s how you end up with wasted material, downtime, and lost revenue. Reach out to my team to discuss your production needs, facility conditions, and any questions you have about humidity tolerance, and we\u2019ll help you find the right solution for your business.<\/p>\n

Zipper Bag Making Machine<\/a> References:<\/p>\n

    \n
  1. Flexible Packaging Association. (2022). Industrial Flexible Packaging Machinery Operation and Maintenance Guidelines.<\/li>\n
  2. American Society of Mechanical Engineers (ASME). (2021). Humidity Effects on Industrial Manufacturing Equipment.<\/li>\n
  3. International Electrotechnical Commission (IEC). (2020). Standard for Environmental Conditions for Electrical Equipment in Industrial Machinery.<\/li>\n<\/ol>\n
    \n

    Zhejiang Ruitai Packaging Machinery Co., Ltd.<\/a>
    Zhejiang Ruitai Packaging Machinery Co., Ltd. is one of the most professional side sealing bag making machine manufacturers and suppliers in China, featured by quality products and good service. Please rest assured to wholesale advanced side sealing 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":"

    If you\u2019re in the flexible packaging manufacturing space, chances are you\u2019ve invested in a side sealing … What is the humidity tolerance of a Side Sealing Bag Making Machine?<\/span>Read more<\/a><\/p>\n","protected":false},"author":492,"featured_media":3460,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3423],"class_list":["post-3460","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-side-sealing-bag-making-machine-4dac-661e6a"],"_links":{"self":[{"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/posts\/3460","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/users\/492"}],"replies":[{"embeddable":true,"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/comments?post=3460"}],"version-history":[{"count":0,"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/posts\/3460\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/posts\/3460"}],"wp:attachment":[{"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/media?parent=3460"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/categories?post=3460"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.matsmaket.com\/blog\/wp-json\/wp\/v2\/tags?post=3460"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}