Aluminum closure sheets are usually made from high-purity aluminum or aluminum alloy coils through cold rolling, annealing, surface treatment, coating, and printing processes. Common alloys include 1060, 3105, 5052, and 8011, which offer advantages such as lightweight, corrosion resistance, and excellent formability. They are widely used in the production of ROPP caps, screw caps, wine bottle caps, beverage caps, and pilfer-proof caps.

The common tempers for bottle cap material include O (annealed), H14, H16, and H18, all with low ear-making rates, effectively reducing material waste and improving production efficiency. The product surface is smooth, free from scratches, oil stains, or roll marks, ensuring excellent performance for subsequent printing and surface treatment.

MC aluminum closure sheets are suitable for both transparent and opaque colored lacquer coatings, effectively isolating the aluminum from the contents.

Introduction to Aluminum Closure Sheet Alloys

1060 Aluminum Closure Sheet:
1060 aluminum closure sheet belongs to pure aluminum with an aluminum content of up to 99.6%. It has excellent ductility and stamping performance, making it easy to process into various shapes of bottle caps without cracking. With good surface gloss and relatively low cost, it offers high cost performance and is suitable for ordinary bottle caps where high strength is not required, such as cosmetic caps and common beverage caps.

3105 Aluminum Closure Sheet:
3105 aluminum closure sheet is an Al-Mn alloy with good deep drawing performance, moderate tensile and yield strength, low ear-making rate, and easy processing. With excellent anti-rust properties, it is widely used for wine bottle caps such as liquor caps and wine caps, as well as for beverage caps.

5052 Aluminum Closure Sheet:
5052 aluminum closure sheet is an Al-Mg alloy with excellent corrosion resistance, weldability, cold workability, and medium strength. After coating, its surface is bright and smooth, making it suitable for caps that require both corrosion resistance and strength, such as functional beverage bottle caps.

8011 Aluminum Closure Sheet:
8011 aluminum closure sheet is one of the most commonly used materials for pharmaceutical packaging caps. Available in tempers such as H14/H16, with a typical thickness range of 0.15-0.27 mm, it offers excellent stamping depth, oxidation performance, and deep drawing characteristics. With a low ear-making rate, it is ideal for direct stamping cap production. Apart from pharmaceutical caps, it is also widely used in liquor caps, wine caps, etc.

Product Features of Aluminum Closure Sheets

Excellent deep drawing performance: Ensures bottle caps do not crack or wrinkle during stamping or spinning.

High strength and toughness: Withstands sealing pressure at the bottle neck while maintaining good ductility.

Smooth and flat surface: Ideal for printing, spraying, and coating.

Strong corrosion resistance: Resists attack from alcohol, beverages, medicines, etc.

Food-grade safety: Complies with food-contact material standards; non-toxic, harmless, and eco-friendly.

Product Specifications

Application Fields of Aluminum Closure Sheets

• Alcohol Packaging: Wine caps, spirits pilfer-proof caps.

• Beverage Packaging: Carbonated drink caps, mineral water bottle caps, juice caps.

• Pharmaceutical Packaging: Oral liquid bottle caps, medical glass vial caps.

• Daily Chemical Packaging: Cosmetic bottle caps, care solution bottle caps.

Surface Treatment Methods for Aluminum Closure Sheets

Lubricant coating: To facilitate stamping and forming.

Pre-print coating: Epoxy varnish to enhance printing adhesion.

Anodized mirror coloring: Suitable for high-end cosmetic bottle caps.

Degreasing and cleaning: General cleaning to meet customer requirements.

Passivation treatment: Improves adhesion and provides corrosion resistance.

Bottle Cap Production Process

1. Stamping forming: Aluminum sheets are stamped and stretched into caps using dies.

2. Surface treatment: Cleaning and treatment for optimal performance.

3. Debris removal: Eliminating metal scraps from stamped caps.

4. Washing: Rinsing with water and cleaning agents to remove impurities.

5. Drying: Drying caps before packaging or further processing.

6. Packaging: Caps are packaged or riveted for final assembly.