Aluminum screw caps are a common type of metal bottle cap used in mineral water bottle packaging. Made of aluminum, they are screwed onto the glass bottle neck for a tight seal. Made of food grade aluminum alloy 3105 or 8011, typically 0.2-0.3mm thick, custom thickness is available upon request. Aluminum alloy has excellent corrosion resistance, will not rust, ensuring the safety and hygiene of the mineral water and preventing adverse effects on water quality.

Structural design of aluminum screw caps for mineral water bottles:

- Precision threads:

Utilizing a precision thread design that matches the thread of the mineral water bottle neck, it achieves a good seal, effectively preventing leakage of the mineral water inside the bottle, while also isolating it from external air, moisture, and microorganisms, extending the product's shelf life.

- Anti-theft design:

Some aluminum screw caps have an anti-theft ring or tamper-evident strip, which is broken upon first opening of the cap to prove that the packaging has not been tampered with, ensuring product security.

- Gasket sealing:

Bottle caps typically feature internal sealing gaskets, such as PE gaskets, PVC gaskets, or other custom gaskets, to enhance the seal and prevent the entry or escape of gas and moisture.

Appearance of aluminum screw caps for mineral water bottles:

- Surface Treatment:

Bottle cap surfaces can undergo various treatment processes, such as anodizing and spraying, to achieve different colors and gloss levels, enhancing the product's aesthetics and texture.

- Customization:

Customization is available based on customer needs, including printing brand logos, patterns, and text, which helps businesses promote their brand and differentiate their products.

Aluminum screw caps for mineral water bottles are suitable for mineral water bottles made of various materials such as PET and glass, and compatible with processes such as pasteurization and hot filling, meeting the needs of different production processes. Aluminum alloy material has excellent recyclability, reducing the environmental impact of waste and meeting environmental protection requirements.

Common sizes of aluminum screw caps for mineral water bottles are categorized by bottle mouth diameter, primarily 22mm, 24mm, 26mm, 28mm, 30mm, and 38mm. Different sizes correspond to different capacities and application scenarios.

- 28mm aluminum screw caps for mineral water bottles:

The most mainstream and universal size, suitable for mainstream small-capacity mineral water bottles such as 500ml, 550ml, and 600ml (e.g., the standard sizes of most bottled drinking water brands).

Thread parameters: Commonly 1-start thread, approximately 120 knurled lines, pitch approximately 2.5-3mm, and height mostly around 15mm (e.g., ROPP 28x15 aluminum cap).

Features: High versatility, mature matching bottle preforms, standardized tamper-evident ring design, making it the main sales driver for aluminum threaded caps.

- 30mm aluminum screw caps for mineral water bottles:

Suitable for medium-capacity mineral water bottles of 1L and 1.5L; also used in some brands' sports water bottles.

Thread parameters: Mostly 3-start threads, approximately 90 knurled grooves, 3mm pitch, 9mm lead (the 3-start thread design reduces the number of turns, improving opening and closing efficiency).

Note: Some manufacturers label it as "30/25mm," referring to a major diameter of 30mm and a minor diameter of 25mm, requiring compatibility with the bottle neck.

- Other sizes:

18mm, 20mm, 22mm: Primarily used for mini (50-100ml) mineral water or portable sample bottles. The threads are finer (1.5mm pitch), but aluminum is less commonly used; plastic caps are more common.

Applications of aluminum screw caps for mineral water bottles:

- Mineral water packaging:

As the mainstream cap type for mineral water glass bottles, aluminum screw caps are widely used in mid-to-high-end mineral water products, such as Evian and Perrier, meeting consumer demands for quality and safety.

- Beverage packaging:

In addition to mineral water, aluminum screw caps are also used in glass bottle packaging for non-carbonated beverages such as juice and tea, providing a reliable seal and opening experience.

- Health product and pharmaceutical packaging:

Some health products or pharmaceuticals use a combination of glass bottles and aluminum screw caps to ensure product stability and safety while also being convenient for consumers.

Aluminum screw caps for mineral water bottles are widely used in the drinking water industry due to their excellent performance and adaptability, making them popular with many manufacturers.