Since the late 19th century, when William Painter invented the crown cap, this closure design featuring a 26mm diameter and 21 fluted edges, has gradually become a universal standard in the beverage packaging industry.
The 26mm size is one of the internationally recognized crown cap specifications and is widely compatible with various glass bottles used for carbonated beverages. When combined with a sealing liner, it can effectively withstand the internal pressure generated by carbonated drinks, ensuring carbonation retention and taste stability. Thanks to its strong compatibility and high universality, the 26mm aluminum crown cap can seamlessly integrate with mainstream bottling and filling equipment.
Structural Advantages of Aluminum Crown Caps
1. Scientifically Designed Crown Teeth Structure
Aluminum crown caps adopt a classic multi-tooth edge design. Through mechanical crimping, the cap tightly grips the glass bottle finish, forming a stable and reliable physical seal. This structure is especially suitable for carbonated beverages under high internal pressure.
2. Multi-Layer Liner System
High-quality aluminum crown caps are typically equipped with composite liner materials, such as PVC liners, PE liners, or environmentally friendly PET liners. These liners create a uniform pressure distribution at the moment of sealing, effectively preventing gas leakage.
3. Precise Dimensional Control
From bottle finish diameter to tooth count and tolerance control, all parameters are strictly manufactured in accordance with international standards. This ensures excellent compatibility with different carbonated beverage bottles and various filling line configurations.
Why Carbonated Beverages Choose Aluminum Crown Caps
1. High-Pressure Sealing Performance
The 26mm aluminum crown cap can withstand internal pressures of up to 0.7-0.8 MPa, which is the typical pressure range for carbonated beverages. Its unique 21-tooth design ensures uniform pressure distribution around the bottle mouth, avoiding localized stress concentration and potential seal failure.
2. Easy Opening
By optimizing the angle and depth of the fluted edges, the 26mm crown cap allows consumers to open bottles easily while maintaining sufficient holding force to prevent accidental opening during transportation. This balance keeps the opening torque within an ideal range of 5-10 inch-pounds.
3. Extended Shelf Life
High-quality 26mm aluminum crown caps help ensure that the carbon dioxide loss of carbonated beverages does not exceed 15% over a 12-18 month shelf life, which is significantly lower than the industry limit of 20%.
4. Excellent Barrier Properties
The liner system effectively limits oxygen transmission to extremely low levels, preventing oxidation and preserving the original flavor profile of the beverage.
5. Corrosion Resistance
The combination of food-grade aluminum and multi-layer protective coatings enables the cap to resist acidic components commonly found in carbonated drinks, maintaining surface appearance and structural integrity over time.
6. Environmentally Friendly and Recyclable
Aluminum offers a recycling rate of over 70%, far exceeding that of most plastic packaging materials.
Technical Specifications: Precision Parameters of Crown Caps
1.Dimensional Accuracy:
Outer diameter: 26.05 ± 0.10 mm
Height: 6.10 ± 0.15 mm
Number of flutes: 21 ± 0
These strict tolerances ensure full compatibility with global standard filling equipment.
2.Material Thickness:
High-quality 26mm aluminum crown caps typically use aluminum with a thickness of 0.22 ± 0.01 mm, providing sufficient structural strength while optimizing material cost.
3.Opening Torque:
The ideal opening torque range is 5-10 inch-pounds, ensuring both secure sealing and consumer-friendly opening.
4.Pressure Resistance:
After standard industry pressure testing, premium 26mm aluminum crown caps should withstand internal pressures of at least 0.7 MPa, well above the actual pressure of most carbonated beverages.
5.Liner Thickness:
Typical liner thickness ranges from 0.35-0.45 mm, offering adequate compression for effective sealing without causing premature liner fatigue.
