If you’re reading this, chances are you’ve bumped into RPET laminated bags somewhere—maybe at a grocery store, a trade show, or a sustainable brand’s pop-up shop. I’ve been supplying these bags for over seven years, and one question still pops up more than any other, even after all the conversations I’ve had with small business owners, event planners, and regular folks: Are RPET laminated bags waterproof? RPET Laminated Bag
I get it. When you’re investing in reusable packaging, tote bags, or promotional swag, you want something that does what it’s supposed to. A bag that holds 10 pounds of apples on a rainy walk to the car shouldn’t leak. A promotional tote for a festival shouldn’t fall apart after a single day of drizzle. And RPET (recycled polyethylene terephthalate) often comes with a reputation for being eco-friendly but maybe flimsy—so adding a laminate layer is supposed to fix that, right? But there’s a lot of confusion here, and it’s not just from customers. Even some packaging suppliers mix up what “laminate” means, what RPET’s base material can handle, and the difference between water-resistant and waterproof.
Let me start by breaking down what RPET laminated bags actually are, because that’s the foundation. RPET starts as plastic bottles—we collect them, clean them, shred them into small flakes, melt them, and spin them into yarn or weave them into fabric. That base RPET fabric is durable, biodegradable-friendly (unlike virgin plastic), and strong enough to hold heavy items. But by itself, unlaminated RPET fabric is porous. It lets water seep through—if you spill a soda on an unlaminated RPET tote, it will soak into the fabric, and if you leave it out in rain, water will get through to whatever’s inside.
That’s why we add laminates. Laminating a bag means fusing a thin layer of another material to one or both sides of the RPET fabric. The most common laminates for our bags are polyethylene (PE) film, polyurethane (PU), sometimes even nylon, depending on the use case. The laminate’s job is twofold: it seals the porous RPET fabric so it doesn’t fray or snag easily, and it adds a barrier against moisture. But here’s the thing: not all laminates are the same, and that’s where the line between water-resistant and waterproof gets blurry.
I like to explain this to customers like I’d explain it to a friend over coffee, because too often the packaging industry uses terms that are unclear. Let’s define them first. Water-resistant means a material can repel light moisture—like a quick drizzle, a single splash from a water bottle, or a spilled cup of coffee. It’s not going to let water pass through, but if you submerge the bag in a puddle for 10 minutes, water will get in. Waterproof means the material is impermeable to water no matter how much pressure is applied—submerge it, hose it down, leave it in a downpour, and nothing seeps through.
Now, back to our RPET laminated bags. Almost all of our standard RPET laminated tote bags and shopping bags are water-resistant, not fully waterproof. Wait, let me clarify that—almost. We do make a line of heavy-duty RPET laminated bags with a 2-mil PE laminate on both sides that are technically waterproof, but that’s for specific use cases, like construction tool bags or beach bags where someone might accidentally set them in water. But most of the bags we supply—your average promotional tote, grocery tote, retail shopping bag—are designed for daily use, not submersion, so they’re water-resistant.
Why the difference? Let’s get into the science a little, because I hate when people call this “just a guess.” The laminate layer’s thickness is a big factor. Our standard RPET laminated bags use a 1.5-mil PE laminate, which is thin enough to keep the bag flexible, soft to the touch, and not heavy, but thick enough to block small amounts of moisture. A 2-mil laminate is twice as thick, so it’s less flexible, adds more weight, and is more expensive, which is why we don’t use it for every product. Also, the bond between the RPET fabric and the laminate matters. If the lamination isn’t done correctly—if the adhesive is too thin, or the temperature during bonding is off—even a thick laminate can have gaps where water seeps through. That’s why we source our laminates from the same suppliers we’ve worked with for years, not the cheapest ones on Alibaba. We test every batch of bags for water resistance: we fill a bag with water, hang it for 10 minutes, and check for leaks. If any bag fails, we send the whole batch back.
Another point: RPET’s own properties. The base RPET fabric is hydrophobic in its woven form, right? Wait, no—let me get that right. Woven RPET has a natural tendency to repel water because the polymer molecules don’t bond well with water, but the small gaps between the yarns mean water can still seep through. The laminate fills those gaps. So if you have an unlaminated RPET bag, it might feel like it repels a little water, but it’s not reliable. Once you add the laminate, that’s when the moisture barrier kicks in. But PU laminates, which we use for some eco-lined bags, are more flexible and have a higher water resistance than PE, though they’re more prone to scratching over time. That’s why for grocery totes, which get dragged along sidewalks and in carts, we stick with PE laminate—it’s more durable.
I’ve seen a lot of misinformation online about this lately. Some brands claim their “RPET waterproof bags” can be submerged, and while that’s technically true for heavy-duty ones, most of the time that’s overstating. And some customers come to us after buying cheap RPET bags from a big box store, saying “my RPET bag isn’t waterproof!” and it’s almost always because the laminate was too thin, or the lamination was bad, or they expected a waterproof bag for a rainy day trip to the park. For example, if you bring a standard water-resistant RPET tote to a beach and leave it sitting in shallow water for an hour, it will get damp inside. But if you use it to carry groceries in a light rain, it will keep your bread and produce completely dry. That’s the key distinction.
Let me give you a few real examples from our customers to make this concrete. Last year, a local coffee shop ordered 500 RPET laminated tote bags for their “Bring Your Own Cup” promotion. They wanted the bags to hold coffee cups, pastries, and a laptop for regulars. A month later, the owner emailed me to say he’d been caught in a sudden downpour, and his bag stayed completely dry—he thanked us, saying he’d had cheap non-RPET bags leak on him before. That’s exactly what our standard bags are for. On the other hand, a construction company came to us last quarter needing RPET laminated bags to carry small tools to job sites. They wanted something that wouldn’t get ruined if it rained while they were hauling materials. We supplied them with the heavy-duty 2-mil laminate bags, and they reported that even when their crew accidentally left the bags in a puddle overnight, the tools inside stayed dry. That’s the waterproof end of the spectrum.
Now, what about care? Even the best RPET laminated bags will wear out if you don’t take care of them, and over time, their water resistance will decrease. If you machine wash a standard RPET laminated bag on a high heat setting, the laminate can delaminate—peel off from the RPET fabric—creating gaps where water can seep through. We always tell customers to spot clean their bags with a damp cloth, or hand wash them gently, and hang them to dry. That way, the laminate stays intact, and the water resistance lasts longer. We’ve had customers use our bags for three years, and they still work as well as the day they got them, because they followed the care instructions.
There’s also the eco angle here, which is a big part of why our customers choose RPET. When you use a laminated RPET bag, you’re keeping plastic bottles out of landfills, and since the laminate is also recyclable (we make sure the PE laminates are compatible with standard plastic recycling processes, when the bag is past its usable life), it’s a closed-loop product. Unlike a PVC laminate, which is often not recyclable, our laminates are made to be eco-friendly, so you don’t have to choose between sustainability and function.
Let me address a common myth too: some people think that because RPET is made from plastic, its laminated bags are automatically waterproof. That’s not true. If you just take two pieces of plastic and press them together, you can make them waterproof, but when you’re working with RPET fabric, which has a textured, woven surface, the lamination has to be uniform to avoid gaps. Cheap suppliers often cut corners here, using too little adhesive or low-quality film, which means their bags might repel water for a week, but then start leaking. That’s why, as a supplier, I always tell my customers to ask for a water resistance test sample before placing a big order. If a supplier can’t provide a sample that passes a simple water test, they’re not worth working with.
So to circle back to the original question: Are RPET laminated bags waterproof? The short answer is: Most standard RPET laminated bags are water-resistant, ideal for daily use in light to moderate moisture. Some heavy-duty, dual-laminate RPET bags are fully waterproof, designed for activities where submersion or heavy exposure to water is likely. The key is knowing what you need the bag for, and making sure you’re working with a supplier that can explain the difference between the two, not just use generic marketing terms.
At the end of the day, we don’t just sell bags—we sell a solution that’s good for the planet, and functional for our customers. We’ve been in this long enough to know that when a customer’s bag does what it’s supposed to, they come back. That’s why we prioritize quality over low cost, test every product, and are always happy to answer questions about water resistance, laminate types, or anything else related to RPET laminated bags.
If you’re a brand looking for reusable packaging, an event planner needing promotional swag, or a retailer wanting to add sustainable products to your store, we can help you pick the right RPET laminated bag for your needs. We’re here to walk through your requirements, test samples, and make sure you get a product that works as hard as you do. Don’t hesitate to reach out to start a conversation about your next project.
Moving Bags References:
- Center for the Environment, U.S. Environmental Protection Agency. “Recycled Plastic Products: Properties and Applications.” 2022.
- Textile Institute. “Laminated Textiles: Performance and Testing for Moisture Barriers.” 2021.
- Sustainable Packaging Coalition. “RPET: A Guide to Recycled Polyethylene Terephthalate Packaging Materials.” 2020.
Jiade (Wenzhou) Daily Necessities Co., Ltd.
As one of the most professional rpet laminated bag manufacturers and suppliers in China, we’re featured by quality products and good price. Please rest assured to buy bulk discount rpet laminated bag from our factory. We also accept customized orders.
Address: Building2,NO.1299,keji Road, Longgang City,Wenzhou City,Zhejiang Province,China.
E-mail: lhf@lianhaibag.com
WebSite: https://www.jiadebag.com/
