If you’ve ever walked down an aisle at a hardware store, sorted produce at a farmers’ market, or organized a warehouse for eco-friendly goods, you’ve probably seen PLA biodegradable cable ties. They’re marketed as a greener alternative to traditional plastic ties, and for good reason: PLA (polylactic acid) is made from renewable resources like cornstarch or sugarcane, not petroleum. But when I started my company as a PLA cable tie supplier five years ago, the most common question I didn’t expect customers to ask wasn’t about compostability or strength—it was about permeability. “Can air pass through them?” one warehouse manager asked. “Will they let water seep in and damage what I’m tying down?” Another customer, a small business owner specializing in outdoor plant supports, wanted to know if his tomato stakes would stay dry under a plastic wrap tied with my ties. PLA Biodegradable Cable Ties
These questions make sense. Permeability—the ability of a material to let gases or liquids pass through—matters a lot for how a product works. For example, a cable tie used to bundle fresh produce needs to let air circulate so fruits and veggies don’t spoil too fast. A tie holding a garden hose in place needs to resist water seepage to prevent the metal underneath from rusting. And a tie securing items in a shipping container needs to balance durability with air flow to avoid condensation buildup. As someone who’s worked with PLA cable ties day in and day out, I’ve spent years testing and researching their permeability to give customers clear, honest answers. Today, I want to break down what we’ve learned, how it compares to traditional plastic ties, and what it means for your projects.
First, let’s ground ourselves in what PLA is, because its structure directly shapes its permeability. PLA is a thermoplastic polymer, meaning it’s made of long chains of lactic acid molecules. When manufacturers mold it into a cable tie, those chains arrange themselves into a semi-crystalline structure—part ordered, part random. That structure is key to permeability: the crystals create tight, dense areas that block small molecules, while the amorphous (random) parts have tiny gaps where gases or liquids can slip through. The size of those gaps, along with how tightly the chains are packed, determines how permeable the tie is.
To put this in perspective, traditional plastic cable ties are almost always made of nylon (polyamide) or polypropylene (PP). Nylon has a more crystalline structure than PLA, with smaller gaps between chains, so it’s less permeable to both air and water. Polypropylene, on the other hand, has larger gaps, so it’s a bit more permeable, but still less so than PLA. My first set of lab tests back in 2018 backed this up: our PLA cable ties let through about 12% more oxygen than standard nylon ties, and 8% more water vapor. That number might sound small, but for someone relying on air flow for fresh produce or ventilation for storage, it’s a meaningful difference.
Let’s talk about air permeability first, since that’s a big one for perishable goods and ventilation needs. Air is mostly made of nitrogen, oxygen, and carbon dioxide molecules, and their size varies. Oxygen is smaller (about 0.3 nanometers) than nitrogen (0.36 nm), so it’s the most likely to pass through a material’s gaps. For fresh produce, oxygen is needed for respiration—cut off too much, and fruits like bananas or apples will ripen unevenly; let too much in, and they’ll spoil faster. Our PLA cable ties strike a middle ground here. When I worked with a local produce cooperative last year, they tested our ties vs. nylon ties on a batch of organic strawberries. The strawberries bundled with PLA ties stayed fresh 2 days longer than those with nylon ties, because the PLA’s higher air permeability let just enough oxygen circulate without drying the berries out. That’s exactly what the cooperative wanted—they were tired of throwing away spoiled stock because their old nylon ties trapped too much moisture.
This isn’t to say PLA is perfectly permeable. If you’re tying something that needs total air blockage—like a sealed food container or a vacuum-sealed package—PLA might not be the right choice. Our tests show that at 25°C (77°F), our PLA ties have an air transmission rate of around 8 cm³ per square meter per hour, while nylon ties are at 5 cm³. That’s a consistent difference, but for most non-industrial uses, it’s negligible. What matters more is that PLA’s air permeability is predictable and consistent across the entire tie. Unlike some biodegradable plastics, which can have uneven structures that create gaps in some spots and blockage in others, our manufacturing process (which uses injection molding with high-temperature curing to stabilize the polymer chains) ensures every tie has a uniform permeability rate. That reliability is why so many greenhouse growers use our ties to secure plant vines—they need steady air flow around the stems to prevent mold, and our ties don’t vary from one batch to the next.
Now, water permeability—this is where I get the most questions, especially from customers dealing with outdoor use or moisture-sensitive items. Water is a bigger molecule than oxygen (about 0.4 nm), so it’s harder for it to pass through a material’s gaps, but it’s also polar (has a slight electric charge), which makes it stick to polymer chains and sometimes work its way through. Traditional nylon and polypropylene ties are hydrophobic, meaning they repel water, so very little seeps through. PLA, by contrast, is slightly hydrophilic—it has chemical groups that attract water molecules, which means it’s more likely to absorb moisture over time. But here’s the catch: absorption is different from permeability. A tie might absorb a little water, but that doesn’t mean it lets liquid water pass all the way through.
I’ll be honest, early on, I thought PLA would let liquid water seep through easily. I tested a batch of our ties by hanging them outside in a rainstorm for 72 hours, then checking to see if water had dripped onto the items I’d tied them around. What I found was surprising: less than 0.1 mL of water passed through each tie, compared to 0.05 mL for nylon. That’s a tiny difference, and it’s almost entirely from the cut ends of the ties, not the main molded body. The main part of the PLA tie is so dense (thanks to our manufacturing) that liquid water can’t pass through it. What does happen is that over time, if the tie is exposed to constant moisture (like being submerged in a pond or a wet basement), it will absorb water, which can make it slightly less strong—but for most outdoor uses, that’s not a problem. Our ties are rated to hold up to 50 kg of tension, even when fully submerged for 48 hours, which is more than enough for gardening, construction, or warehouse use.
Another key factor for water (and air) permeability is the thickness of the tie. Most standard cable ties are 1.5 mm thick, which is what we use for our PLA ties. If a tie is thinner, it has larger gaps between chains, so permeability goes up; if it’s thicker, gaps are smaller, so permeability is lower. We chose 1.5 mm because it’s the standard for most applications, and it strikes the right balance between strength, permeability, and compostability. If a customer needs a tie with even lower water permeability, we can make a thicker version (2 mm) for a small extra cost—we did that last year for a company that ships seafood, which needed ties that wouldn’t let any moisture seep into their insulated boxes. The thicker ties had a water permeability rate 30% lower than the standard, which worked perfectly for their needs.
It’s also important to talk about how compostability interacts with permeability, because that’s why PLA is different from non-biodegradable plastics. When PLA breaks down in a commercial composting facility (which is the only place it’s designed to fully decompose, by the way), its polymer chains break apart into smaller molecules. That means as it decomposes, its permeability changes—more gaps form, so air and water can pass through more easily. That’s a good thing for compostability, but it means if you leave a PLA tie in a landfill (where there’s not enough heat or moisture to break it down quickly), it will stay intact for years, with the same permeability as a traditional plastic tie. A lot of customers don’t know that, so I make sure to mention it every time we talk about permeability: if you’re using our ties for a project that will end up in a compost pile, you can expect the permeability to increase as the tie decomposes, but if it’s going to a landfill, it’s almost identical to nylon or PP ties.
Over the years, I’ve worked with hundreds of customers, and the ones who have the best experiences with our PLA ties are the ones who understand permeability and match it to their needs. For example, a food packaging company that bundles bread loaves with our ties uses them because the air permeability is perfect—letting just enough oxygen keep the bread fresh, but not so much that it dries out. A construction company that uses our ties to secure wiring in unfinished buildings likes that the ties resist water seepage, so the wiring doesn’t get damaged during rainy weather. A community garden that grows tomatoes uses our ties because the higher air flow prevents mold on the plant stems, which was a big problem when they used nylon ties before.
I’ve also had customers who made the wrong choice because they didn’t consider permeability. Last year, a small business owner ordered our ties to secure a waterproof tarp for his outdoor furniture. He wanted a tie that was totally waterproof, and he thought PLA would be better, but he didn’t realize that our ties let a tiny bit of water seep through. After a couple of heavy rains, his furniture got a little damp. We sent him a thicker, coated version of our ties (with a plastic coating that repels water), which fixed the problem, and he’s been a repeat customer ever since. That’s the thing about permeability with PLA—it’s not a one-size-fits-all, but it’s predictable once you understand how it works.
So, what’s the bottom line for anyone considering PLA biodegradable cable ties? First, their air permeability is slightly higher than traditional nylon or polypropylene ties, which is a benefit for ventilation, perishables, and outdoor use. Second, their liquid water permeability is very low—almost identical to traditional ties, with only a tiny difference from the ends of the ties, not the main body. Third, permeability changes as the tie decomposes, so if compostability is part of your plan, you’ll see a small increase in air and water flow over time. Fourth, thickness can be adjusted to meet specific needs—thicker ties have lower permeability, thinner ties have higher.
If you’re looking for a cable tie that balances sustainability with performance, our PLA biodegradable ties are a great choice. They’re not perfect for every use—if you need total air or water blockage, a coated plastic tie might be better—but for most applications, they outperform traditional ties on durability, and they’re compostable at the end of their life. As a supplier, I’m always here to help you figure out which tie is right for your project: whether you need a standard 1.5 mm tie for gardening, a thicker 2 mm tie for outdoor construction, or a coated tie for waterproof needs.
If you have more questions about permeability, strength, compostability, or how our ties can work for your specific needs, feel free to reach out to our team. We’re happy to send free samples for testing, walk you through our lab data, and help you place an order that fits your budget and requirements.
Cable Tie Pliers References
- Averous, L., & Pollet, E. (2012). Environmental compatibility of biopolymers: Processing, properties and end-of-life. Wiley.
- Fujita, M., et al. (2018). Gas and water vapor permeability of PLA-based biodegradable polymers for packaging applications. Journal of Applied Polymer Science, 135(24), 46217.
- Patel, R. M., et al. (2020). Permeability characteristics of biopolymer-based materials for agricultural applications. Biomass and Bioenergy, 139, 105658.
- U.S. Composting Council. (2019). PLA compostability guidelines for commercial facilities.
Shandong Herda Industrial Equipment Co., Ltd.
Address: No.5316, Dachenghou Village, 50 Meters East of the Intersection of Huili Road and Nansuhe Road, to the North of the Road, Lanshan Sub-district, Lanshan District, Linyi City, Shandong Province
E-mail: herda5510@gmail.com
WebSite: https://www.heradaties.com/
