What Are Properties of 8011 Aluminum Closure Sheet

The reason aluminum foil 8011 has become a common material in the bottle cap industry lies in its multiple properties that precisely match packaging scenarios. As a material that comes into direct contact with food and pharmaceuticals, a food-grade safety substrate is paramount.

It must pass heavy metal migration testing to ensure that the migration of harmful substances such as lead and cadmium remains below the stringent standard of 0.01mg/kg. This is the core reason for its widespread use in aluminum-plastic caps for oral liquids and beer closures.

Formability directly determines production efficiency. High-quality 8011 bottle cap material requires high elongation and low lug ratio. After optimization in the cold rolling and annealing processes, its elongation meets deep drawing requirements, enabling easy punching into tall caps exceeding 50mm.

Keeping the lug ratio to a very low level reduces geometric scrap losses. Furthermore, surface flatness is a fundamental requirement. A material free of rolling marks, scratches, and stains can prevent printing misalignment and discoloration.

Barrier properties and stability are crucial to the shelf life of the contents. 8011 aluminum foil naturally possesses excellent moisture and light-blocking properties, effectively blocking oxygen and light. With a precisely controlled thickness of 0.20-0.23mm, it provides long-lasting protection for beverages and pharmaceuticals.

Crucially, after undergoing an intermediate annealing treatment at 320°C, the material maintains stable strength even after baking, preventing breakage or deformation during opening.

Surface Treatment

Surface treatment is a key step in upgrading the value of 8011 bottle cap material, requiring a balanced approach to adhesion, hygiene, and aesthetics. Chemical conversion treatment is the predominant pretreatment step. Treatments such as chromate phosphate or zirconium phosphate can form a dense film on the surface, increasing paint adhesion by over 30% and fundamentally addressing the problem of color fading.

The cleaning process is directly related to food safety. High-quality suppliers utilize multiple finishing cleaning steps to ensure the material is completely degreased and pinhole-free, minimizing the risk of microbial adhesion. For high-end applications, such as liquor anti-counterfeit caps, additional bending, straightening, and slitting finishing steps are added to ensure the slices are free of burrs and ruffles, laying the foundation for subsequent stamping of anti-counterfeiting labels.

Post-processing focuses on functional upgrades: pharmaceutical bottle caps require an additional hygienic passivation treatment to prevent chemical migration; beverage bottle caps are often coated with a glossy varnish to enhance both texture and wear resistance. These refined treatments make 8011 material suitable for the high-speed processing demands of automated production lines.

Price

The price of aluminum sheet 8011 is not fixed; it is a dynamic indicator influenced by a combination of raw materials, processing, and market conditions. The core anchor is the price of aluminum ingots. As a bulk commodity, daily fluctuations in aluminum ingot prices are directly transmitted to the terminal price of bottle cap material, making it the most price-elastic variable.

Product characteristics determine price differences: Thinner aluminum foil is more difficult to process and therefore more expensive. For example, a 0.20mm foil is 5%-8% more expensive than a 0.23mm foil. Products with special surface treatments (such as sanitary passivation) or customized properties (such as high barrier properties) can command a 10%-15% premium. Furthermore, order size and shipping costs also influence the final price. Bulk purchases can offer discounts, while long-distance shipping logistics costs can account for 3%-5% of the total cost.

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