3105 belongs to the 3xxx series Al-Mn alloy family. It features excellent formability, ductility, and corrosion resistance, with low cost and a clean surface. These properties make it suitable for stamping, rolling, and deep drawing processes-commonly used in producing small bottle caps, induction sealing foil, and aluminum coil substrates.

For small vials (small diameter, small volume, high sealing and hygiene requirements), 3105 aluminum coil is often combined with induction sealing layers, coatings, or composite barrier films to provide secure sealing, oxygen resistance, and regulatory compliance. It is widely used in oral liquid bottles, antibiotic vials, sample wine bottles, etc.

Common tempers of 3105 aluminum closure sheet for vial sealing include O temper (annealed), H18, H24, and H26. Different tempers provide different strength and formability levels. O-temper material is especially suitable for deep drawing processes with high forming requirements. Thickness range: 0.2-0.5 mm, width range: 100-1600 mm, customizable according to customer needs.

Aluminum closure stock requires a flat surface, free of roll marks and oil stains, ensuring excellent printing quality and attractive finished appearance.

Performance Advantages of 3105 Aluminum Coil for Vial Seals

1. Excellent Ductility and Formability

3105 aluminum coil is easy to stamp, roll, and deep draw, meeting the sealing and forming requirements of small-diameter, complex-neck vials. This improves yield and processing efficiency.

2. Superior Corrosion Resistance

It offers natural corrosion resistance and performs well in humid or mildly acidic environments, ensuring the quality and safety of the liquid in the vial.

3. Smooth Surface, Compatible with Multiple Coatings

3105 aluminum coil has a smooth, clean surface suitable for applying hot-melt layers, EVOH/PVDC barrier films, or food-grade coatings, enhancing sealing performance and durability.

4. Lightweight and Easy to Process

Aluminum is lightweight, helping reduce packaging and transportation costs while maintaining sufficient mechanical strength. It is suitable for high-speed automated sealing lines.

5. Excellent Thermal Conductivity

During induction sealing, 3105 aluminum coil heats quickly and evenly, ensuring strong adhesion of hot-melt adhesive or barrier layers, improving sealing consistency.

6. Cost Advantage and Stable Supply

As a 3xxx-series aluminum alloy, 3105 offers competitive pricing and a mature supply chain-ideal for large-volume production.

7. High-Temperature Resistance

It withstands high-temperature sterilization and pasteurization processes required in pharmaceutical and food packaging.

8. Eco-Friendly and Recyclable

Aluminum is 100% recyclable with low energy consumption in the recycling process, supporting sustainable packaging.

3105 Aluminum Closure Sheet Specification

Typical Applications for Small Vial Sealing

• Pharmaceutical vials: Induction seals or aluminum caps for ampoules, injection vials, and oral liquid vials

• Cosmetic samples: Perfume, essential oils, skincare samples

• Food seasoning bottles: Small bottles of sesame oil, salad dressing, and sauce samples

• Chemical and lab reagents: Small reagent bottles requiring barrier performance and tamper-evident sealing

FAQ

Q1: Can 3105 aluminum coil be used directly for pharmaceutical-contact bottle caps?

A1: Yes, with specific surface treatment. The base material must comply with GB/T 3190 or EN 573 standards. More importantly, aluminum used in pharmaceutical packaging must be cleaned and coated. We apply food-grade epoxy resin or polyester coatings that comply with FDA or national pharmaceutical packaging standards to ensure safe, non-toxic contact.

Q2: For deep-type long-skirt ROPP caps, should I use 3105 or 8011 aluminum coil?

A2: 3105 is recommended.
Although 8011 is common for caps, 3105 contains manganese, providing higher strength and better elongation. For long-skirt caps over 40 mm or with large height-to-diameter ratios, 3105 significantly reduces cracking during stamping and produces stiffer, more deformation-resistant caps.

Q3: What is the earring rate of your 3105 aluminum closure stock?

A3: We control the earring rate within 2%-3%.
This is achieved through precise hot rolling and annealing processes, ensuring isotropic grain structure. Low earring rate reduces trimming waste and improves material utilization.

Q4: Can 3105 aluminum coil be used for multi-color printing?

A4: Absolutely.
3105 aluminum has excellent surface flatness and is ideal for color-coated (pre-painted) aluminum coil. The coating shows strong adhesion, withstands high-temperature sterilization, and works well with offset printing or screen printing. Logos and fine details can be printed clearly.

Q5: Are thickness tolerances critical for small vial caps?

A5: Very critical.
Small vial caps (such as oral liquid caps) require precise molds. Uneven thickness may cause die jamming or poor sealing. Our 3105 aluminum coil maintains a thickness tolerance of ±0.005 mm or tighter, ensuring smooth high-speed stamping production.