Paper Buckle and Cup Lid with Dual Air Chambers

The problem

Disposable paper cups typically use simple plastic or coated paper lids that rely on friction or a single seal point. When these cups are carried by consumers, especially during commuting or walking, tilting or shaking can cause the lid to shift slightly. This creates a gap at the drinking mouth, leading to spills of hot coffee or cold beverages. Furthermore, traditional multi-material lids complicate recycling streams because separating plastic components from paper bodies is difficult and costly. There is a need for a sealing mechanism that provides robust leak protection without relying on complex gaskets or mixed materials, ensuring the entire assembly remains compatible with standard paper recycling processes.

The solution

The patent proposes a combined cup cover made of two main paper components: a paper buckle piece and a paper cup cover.

1. The paper buckle piece includes an annular portion, a buckle separation part, a first buckle bottom, and a second buckle bottom. It also features an extension with a fastener.
2. The paper cup cover has a low-table separation part, an outer ring high-table part, and an inner ring low-table part.
3. During assembly, the buckle separation part of the paper buckle piece clamps onto the low-table separation part of the paper cup cover.
4. This interlocking action creates two distinct, separated air chambers: a first air chamber between the first buckle bottom and the first cup cover bottom, and a second air chamber between the second buckle bottom and the second cup cover bottom.
5. The extension part of the buckle piece crosses over the drinking mouth, where its fastener engages with the rim to further secure the opening.

Who it is for

• Coffee chains and beverage brands looking to replace plastic lids with fully recyclable paper alternatives that still offer reliable leak resistance for takeaway orders.
• Packaging manufacturers producing disposable cups who need a structural solution to reduce spillage complaints without adding silicone seals or complex injection-molded plastics.
• Eco-focused startups developing zero-waste or plastic-free product lines, requiring a closure mechanism that maintains integrity during transport but separates easily for composting or pulping.
• Office catering suppliers needing durable cup lids for delivery services where cups are stacked and moved frequently, reducing the risk of messy accidents upon arrival.

How it works

The main parts

Operating steps

1. Preparation: The paper cup cover is placed on the rim of the paper cup body. The annular rib fits around the cup’s upper edge.
2. Alignment: The paper buckle piece is positioned above the cup cover. The buckle separation part aligns with the low-table separation part of the cover.
3. Clamping: The user presses the buckle piece down. The separation parts interlock, forming the first and second air chambers.
4. Securing the Mouth: The extension part swings over the drinking mouth. The fastener snaps or tucks into place, covering the opening directly.
5. Transport: The dual-chamber structure acts as a buffer. If liquid moves toward the mouth, it encounters the barrier created by the air chambers and the fastener, preventing immediate escape.

Applications

Hot Beverage Takeaway

Customers buying coffee or tea for travel often face spills when navigating sidewalks or public transport. The dual-air-chamber design provides a mechanical lock that resists pressure changes and minor tilts, keeping hot liquids inside the cup longer than standard friction-fit lids.

Cold Drink Delivery

Delivery apps stack multiple cups in bags, causing them to shake and vibrate. This lid system prevents cold sodas or smoothies from leaking through the drinking port during transit, protecting the bag contents and the customer’s experience upon arrival.

Office Pantry Supplies

Companies stocking disposable cups for meetings need lids that stay closed when staff carry mugs from the kitchen to conference rooms. The interlocking paper pieces offer a sturdy closure that doesn’t pop off easily when bumped against desks or chairs.

Eco-Friendly Event Catering

Large-scale events aiming for sustainability goals require all-paper tableware. This lid allows organizers to serve beverages without plastic waste, as both the buckle and cover are made from vegetable fiber pulp, simplifying post-event cleanup and recycling sorting.

Where it is less suitable

• High-Temperature Steam Environments: While paper is heat-resistant, prolonged exposure to intense steam might degrade the structural integrity of the pulp faster than synthetic materials, potentially loosening the fit.
• Carbonated Beverages under High Pressure: If a soda is shaken vigorously, the internal pressure may exceed the mechanical holding force of the paper interlock, risking a burst rather than a slow leak.
• Refrigerator Storage: The porous nature of untreated paper pulp might allow moisture transfer if stored in humid fridges for extended periods, affecting the tightness of the seal.