If you’ve ever tried to pull apart a stack of ripple wall or double wall paper cups—only to find them jammed together like glue—you’re not alone. This issue has been voiced across online forums by baristas, café owners, and packaging staff alike.
In a post on Reddit’s r/barista, one user wrote:
“Anyone have any tips on how to consistently separate paper hot cups from the stack? I always seem to need to physically pry stuck cups apart like every 6–7 cups… It seems to primarily be an issue with our 12 and 16oz cups.”
— melolagniac, r/barista
From morning coffee rushes to high-speed packing lines, stuck cups aren’t just annoying—they slow down workflows, disrupt automation, and affect customer satisfaction. While many accept this problem as “just part of the industry,” at GMZ, we chose to fix it. And that’s exactly what we’ve done.
Why Do Paper Cups Stick?
Ripple wall and double wall paper cups are known for their insulation and durability, but they tend to stick together, often frustrating users during frequent cup separation in busy cafés, production lines, or daily packaging routines.
Why does this happen?
The root cause isn’t always obvious, but a closer look reveals that several factors—both physical and procedural—may contribute to this common issue. These include:
- Trapped Air and Vacuum Effect: When cups are tightly stacked, the narrow space between them may trap air. As you try to pull them apart, the air pressure doesn’t equalize quickly enough, potentially creating a light vacuum that causes the cups to cling together.
- Multi-Layered Construction and Friction Ripple and double wall cups are typically made by bonding two or more layers of paperboard with adhesive. While this enhances insulation, it also increases surface friction between cups, making separation more difficult, especially when stacked in bulk.
- Minor Variations in Manufacturing Tolerances: Small inconsistencies, such as slight differences in rim diameter, uneven compression during packaging, or misaligned glue lines, can accumulate during high-speed production and lead to stacks that are tighter than expected.
- Excessive Drop Force During Stacking: In the final stage of production, if the drop height from the conveyor to the collection bin is too great, cups may land with too much force. This can cause them to become overly compressed against each other, making separation even harder for the end user.
Having pinpointed these four root causes, our engineers tested each variable in isolation—rim tolerances, drop force, adhesive slip, and trapped air—until they found a fix that removes the friction without sacrificing insulation.
How We Solved the Stuck Cup Problem?
At GMZ, we know the frustration of stuck cups all too well—because we’ve been there ourselves. Like many in the industry, our earlier production processes occasionally resulted in cups that were stacked too tightly, making them difficult to separate during high-speed operations.
But instead of accepting this as an unavoidable side effect, we took it as a challenge. Over the past few months, our engineering and production teams conducted a full review of the problem, analyzing root causes, testing different material behaviors, and experimenting with adjustments across the manufacturing line. The final solution remains proprietary, but the improvement is easy to see and feel: our new ripple and double wall cups now separate smoothly, straight out of the stack.
No more aggressive pulling. No more wasted time. Whether you’re loading dispensers, prepping sleeves for packing, or simply pulling a cup in a busy café, the experience is cleaner, quicker, and frustration-free.
What Customers Are Saying?
Since rolling out the updated cups, we’ve heard one thing again and again from clients: “They’re finally easy to work with.”
Whether it’s warehouse teams packing sleeves, café staff preparing for a morning rush, or automated machines sorting cups by the thousands, everyone notices the difference. Cups separate more smoothly, interruptions are fewer, and daily routines simply run better.
Across the board, our customers are streamlining operations, reducing waste, and regaining efficiency where it matters most. It’s a small upgrade, but it’s delivering measurable results in the real world.
Small Fix, Big Difference — Just Try It Yourself
At GMZ, we believe innovation doesn’t always have to be flashy. Sometimes, the best improvements are the quiet ones—the ones that simply make your day easier. Our redesigned ripple and double-wall cups are proof of that. If you’re tired of dealing with stuck cups or simply want to upgrade your customer experience, our new lineup is ready. Contact us today to request samples, place an order, or learn how GMZ continues to refine the details that matter.
