Main structure

Mostly knob or pressure screw design, emphasizing the re-sealability after multiple openings (such as whisky caps).

Mushroom stopper + metal crown cap composite structure (e.g. champagne bottle cap), or reinforced thread design to withstand high pressure.

Anti-theft ring

Single-ring or double-ring anti-theft teeth, to meet the anti-theft can be (torque 1.2-2.5N-m).

Double anti-theft ring or thickened breakpoint design is required to prevent accidental opening due to high pressure gas shock (torque ≥ 3.0N-m).

Internal support

Inner cushion is thin (0.3-0.5mm), mainly PE/PVC.

Inner cushion thicker (0.8-1.2mm), using elastomer materials (such as TPE), to enhance the pressure cushioning.

Aluminum thickness

Conventional thickness 0.20-0.25mm to meet the basic strength.

Thickened to 0.30-0.35mm, even local stamping reinforcement, to cope with ≥ 6 bar internal pressure (such as beer bottle cap).

Coating treatment

Focus on corrosion protection and appearance (anodizing/color printing).

High-pressure resistant friction coatings (e.g. ceramic overlay) are required to prevent scratching of the aluminum when opening the cap.

Sealing technology

Single gasket, focusing on long-term static sealing.

Dual sealing system: primary gasket + secondary gas barrier (e.g. Saranex™ barrier film).

Pressure resistance test

Conventional pressure resistance 0.3-0.5 MPa, simulating transportation vibration

High-pressure test ≥1.2 MPa (champagne up to 6 bar), holding pressure for 30 minutes without leakage

Air tightness test

Helium leakage detection rate ≤1×10-⁶ Pa-m³/s

Required to pass CO2 permeation test (permeation <0.1g/year)

Cycle life

Maintain sealing ≥90% after repeated opening 50 times

One-time opening design, but need to ensure the safety of residual pressure release after the first opening (anti-burst)

International Standards

ISO 9001 (Quality Management), FDA 21 CFR

EN 13047 (Pressure Resistant Cap Standard), AS 4766 (Gas Packaging Test)

Special tests

Migration test (ethanol tolerance)

Burst pressure test (≥1.5 times working pressure)