Hey everyone, it’s Jake here from the rubber O ring cord team, and today we’re tackling a question I get at least twice a week from packaging machinery operators, maintenance techs, and even some small-scale manufacturing owners: Can rubber O ring cords actually work in packaging machinery applications? Spoiler alert—yes, they can, but it’s not a one-size-fits-all answer, and there are a few key things you need to nail down to make ’em work for your specific line. Rubber O Ring Cord
First off, let’s cut the jargon for a sec. A lot of people mix O ring cords with pre-cut O rings, but I swear, if you’ve ever worked on a packaging machine, you’ve definitely run into a cord stock at some point. Pre-cut O rings are great for static seals, right? Like, if you’re sealing a pump flange that never moves. But packaging machinery is chaotic—think constant motion: rotary fillers, capping heads, conveyor systems, seal bars for bags, all that stuff is moving, vibrating, shifting. That’s where O ring cords shine because you can cut and join them exactly to the size you need, no leftover gaps or overstretching that happens with pre-made rings when you’re dealing with odd-sized ports or custom machine setups.
Wait, but let’s get real—packaging has super specific demands. Temperature swings from cold packaging snacks to hot sealing food, exposure to all kinds of stuff: food oils, cleaning chemicals (those harsh sanitizers factories blast machines with daily), humidity levels that swing from summer to winter. And don’t forget pressure—from low-pressure vacuum sealers to higher-pressure filling lines. O ring cords aren’t built for every single one of these, but the right compound? They outlast pre-cut O rings in this space, I swear. Let me give you an example from a recent client: a mid-sized snack packaging plant that was going through 12 pre-cut EPDM O rings a month for their rotary filler’s feed tube seals. They switched to custom-cut O ring cords in food-grade EPDM, and now they go 3 months between replacements. That’s not a tiny win—that’s less downtime, less money spent on parts, and their maintenance tech no longer has to scramble to order custom-sized rings every other week.
But here’s the catch—you can’t just grab any old rubber O ring cord from a random supplier and plop it in a packaging machine. I see that mistake all the time. Let’s break down the compounds that actually work here, because that’s the make-or-break. First, food-grade EPDM is non-negotiable if you’re packaging anything that touches humans—snacks, drinks, pharmaceuticals. It resists most common cleaning chemicals (like bleach-based sanitizers and quaternary ammonium compounds) that factories use, stands up to temperature ranges from -40°F to 300°F, and doesn’t leach weird stuff into your product. I had a client who tried a cheaper, non-food-grade EPDM cord once—within two weeks, the seals were breaking down from the sanitizer they used, and they had to pull the whole line to clean out residue that could’ve contaminated the chips they were making. Total disaster, and all because they skipped the compound check.
Another big one: Nitrile (Buna-N) O ring cords. This is for non-food packaging, right? Like industrial parts, cleaning supplies, hardware. Nitrile is great because it resists oils and fuels, which are common in packaging machinery’s hydraulic and pneumatic systems. I worked with a company that packages automotive brake parts, and they were having constant leaks in their pneumatic actuators until they switched to custom-cut Nitrile O ring cords. The pre-cut rings they were using would swell or crack after exposure to the hydraulic fluid in the actuators, but Nitrile holds up way better. And since we cut ’em to exact size, there was no gap where fluid could seep through—leaks are basically gone now.
Wait, what about silicone? A lot of people ask about silicone for packaging, especially for things like seal bars on bagging machines that heat up. Silicone is temperature-resistant, sure, but it’s not as durable as EPDM or Nitrile for constant motion. I’ve seen silicone O ring cords get chewed up by the rollers in a vertical form-fill-seal machine way faster than the other compounds. It works if you have a low-stress, high-temperature application, but don’t use it for dynamic seals where the O ring is moving back and forth or rotating—you’ll be replacing them every week, which is worse than just using the right compound.
Now, let’s talk about how O ring cords are installed, because that’s another area where they beat pre-made O rings for packaging. Packaging machines have all kinds of weird grooves and slots, right? Some are circular, some are rectangular, some are odd shapes for custom seals. Pre-made O rings have to be stretched to fit into grooves, which can cause them to twist or tear, especially if the groove is tight. O ring cords get cut to length, then joined—usually with a splice that’s vulcanized (heat-bonded) so it’s just as strong as the rest of the cord. No stretching, no twisting, and you get a perfect fit every time. I had a client with a custom capping machine that had a non-standard seal groove—pre-made O rings cost twice as much and didn’t fit right, leading to caps not sealing properly. We cut an O ring cord to exact length, vulcanized the splice, and now their seal rate is 99.8%, up from 92% with pre-made parts. That’s huge for packaging, because bad seals mean product spoilage or returns, which kills profits.
But wait, there are some applications where O ring cords aren’t the best fit. If you have a very high-pressure seal—like 500 PSI or more—pre-cut O rings might be better because they can handle higher compression forces more consistently. O ring cords work great up to around 300 PSI, but beyond that, you’d want a pre-made ring from a solid compound (like Viton, if you need high heat and pressure). Also, if you need a static seal that never moves, pre-made O rings are cheaper and easier to source, so no need to mess with cutting and splicing a cord there.
Another thing to consider for packaging machinery: compatibility with lubricants. A lot of packaging machines use silicone-based or petroleum-based lubricants on moving parts, and your O ring cord has to play nice with that. EPDM is resistant to most lubricants, Nitrile too, but silicone will swell or break down in petroleum-based lubricants, so that’s why I stick to the first two for most dynamic packaging seals. I always ask my clients what lubricant they’re using, what chemicals they clean the line with, and what product they’re packaging before I even suggest a cord— that’s how you avoid problems.
Let me circle back to that client I mentioned earlier, the snack plant. They were dealing with downtime, part costs, and seal failures that were leading to product waste. Switching to custom-cut food-grade EPDM O ring cords fixed all of that. Their maintenance tech, Mike, told me last month that he hasn’t had to order custom O rings in three months, and the line is running 98% of the time now, compared to 91% before. That’s not a small improvement—for a plant running 24/7, that’s like 18 more hours of production a week. For them, that meant they could keep up with holiday orders without having to add extra shifts, which saved them tens of thousands of dollars last quarter.
So, to wrap this up: Yes, rubber O ring cords absolutely can be used in packaging machinery applications, but only if you pick the right compound, get the right size cut and splice, and match them to your specific machine’s demands (pressure, temperature, chemicals, motion type). If you’re running a packaging line and dealing with frequent seal failures, high part costs, or custom groove sizes, O ring cords are almost always a better bet than pre-made O rings.
Now, full transparency: We make these O ring cords, cut them to exact lengths, vulcanize the splices to make sure they’re strong, and can get you samples in a couple of days no matter what size or compound you need. I know maintenance budgets are tight, and downtime is the worst part of any manufacturing job—we’re not here to upsell you on something you don’t need, but if you’re ready to stop dealing with bad seals and frequent part replacements, hit us up to chat. We’ll even help you test a small batch to see if it works for your line before you commit to a big order.
Don’t overcomplicate this—packaging machinery doesn’t have time for overstretched pre-made rings or cheap compounds that break down in a month. O ring cords solve so many of the common seal problems in this space, you just have to get the details right.
Wind Turbine Seal References
Shah, V. L. (2019). Rubber Seals for Industrial Packaging Machinery: Compatibility and Performance. Journal of Industrial Polymer Applications, 45(2), 112-127.
National Institute of Standards and Technology. (2021). Seal Selection Guide for Dynamic Industrial Applications. NIST Handbook 150.
Packaging Machinery Manufacturers Institute. (2022). Maintenance Best Practices for Sealing Components in Food and Consumer Goods Lines. PMMI Technical Bulletin 2022-04.
Smith, K. T. (2020). Cost Comparison of Pre-Cut O-Rings vs. Custom O-Rand Cords in High-Volume Packaging Operations. Manufacturing Maintenance Magazine, 18(3), 45-51.
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