1235 Aluminum Foil

1. Introduction

1.1 Definition of 1235 Aluminum Foil

1235 aluminum foil is a high-purity aluminum alloy belonging to the 1000 series (Al ≥ 99.35%) with minimal impurities (Si + Fe ≤ 0.65%).

It stands out for its exceptional balance of flexibility, corrosion resistance, and electrical conductivity, making it a cornerstone material in industries ranging from packaging to electronics.

1.1.1 Specific Properties of 1235 Aluminum Alloys

1235 aluminum foil is a high-purity aluminum alloy (Al 1235) with minimal alloying elements.

Its composition ensures superior ductility, formability, and corrosion resistance compared to standard aluminum grades like 1100 or 3003. Key features include:

• Ultra-thin gauge capabilities (down to 0.006 mm).
• Excellent surface quality for decorative or functional coatings.
• Cost-effective production due to low alloying costs.

1.2 Importance of 1235 Aluminum Foil in Various Industries

1.2.1 Applications in Packaging, Insulation, etc.

1235 aluminium foil plays a crucial role in several industries, particularly in packaging and insulation.

Its barrier properties make it an excellent choice for food packaging, pharmaceutical packaging, and other applications where protection from moisture and light is essential.

Additionally, it is used in insulation materials for buildings and appliances, contributing to energy efficiency.

1.2.2 Advantages over Other Aluminum Alloys

Compared to other aluminum alloys, 1235 aluminum foil offers several advantages:

• High Purity: The high aluminum content ensures excellent conductivity.
• Flexibility: It can be easily formed into various shapes without cracking.
• Corrosion Resistance: It withstands exposure to moisture and chemicals better than many other alloys.

2. Material Properties of 1235 Aluminum Foil

2.1 Chemical Composition

The chemical composition of 1235 aluminum foil is primarily aluminum, with the following typical composition:

This composition contributes to the foil’s excellent properties, making it suitable for various applications.

2.2 Physical Properties

2.2.1 Thickness and Gauge Specifications

1235 aluminum foil is available in various thicknesses, typically ranging from 0.006 mm to 0.2 mm.

The gauge specifications can vary based on the application requirements, with thinner gauges being used for flexible packaging and thicker gauges for insulation and structural applications.

2.2.2 Mechanical Properties

2.2.3 Thermal and Electrical Conductivity

1235 aluminium foil exhibits excellent thermal and electrical conductivity, making it suitable for applications in electronics and electrical insulation.

Its thermal conductivity is approximately 235 W/m·K, while its electrical conductivity is around 62% IACS (International Annealed Copper Standard).

2.3 Corrosion Resistance

2.3.1 Behavior in Different Environments

1235 aluminum foil forms a natural oxide layer (Al₂O₃) that protects against:

• Acidic Environments: Resists mild acids in food packaging.
• Humidity: Prevents oxidation in high-moisture conditions.
• Saline Atmospheres: Suitable for marine applications with proper coatings.

2.3.2 Protective Coatings and Treatments

• Anodizing: Increases corrosion resistance and enables colored finishes.
• Lamination: Bonds with polymers for enhanced barrier properties.
• Oil Coating: Reduces friction during rolling and prevents oxidation.

3. 1235 Aluminum Foil Production Process

3.1 Raw Material Preparation

3.1.1 Purchasing Aluminum Ingots

High-purity aluminum ingots (≥99.35%) are sourced and tested for impurity levels.

3.1.2 Melting and Alloying Processes

• Melting: Ingots are melted at 700–750°C in gas-fired furnaces.
• Refining: Impurities are removed using argon gas and flux.
• Alloying: Silicon and iron are added to meet 1235 specifications.

3.2 Rolling Processes

3.2.1 Hot Rolling and Cold Rolling

• Hot Rolling: The cast slab is rolled at 540°C to 6.5–7.5 mm thickness.
• Cold Rolling: Further reduced to 1.0–1.2 mm, improving strength and surface finish.

3.2.2 Techniques to Achieve the Required Thickness

• Tandem Rolling: Multi-stage rolling for precise thickness control.
• Reverse Rolling: Alternates rolling direction to minimize defects.

3.3 Annealing and Finishing

3.3.1 Importance of Annealing in Improving Performance

• Intermediate Annealing: Conducted at 500–530°C for 8 hours to relieve stress.
• Final Annealing: Performed at 450°C for 4.5 hours to enhance ductility.

3.3.2 Surface Treatment and Quality Control Measures

• Surface Cleaning: Solvent washing removes oils and contaminants.
• Coating Application: Protective layers (e.g., PVDF) are applied for corrosion resistance.
• Quality Checks: Laser scanners detect pinholes (<0.5 per m²) and measure thickness.

4. Main Applications of 1235 Aluminum Foil

4.1 Packaging Industry

The packaging industry widely adopts 1235 aluminium foil for its exceptional moisture, oxygen, and light barrier performance:

• Food Packaging: It protects food from moisture, light, and oxygen, extending shelf life.
• Drug Packaging: Pharmaceutical companies use it to package medications, ensuring protection from environmental factors.
• Cigarette Packaging: Its barrier properties help maintain the freshness of tobacco products.

4.2 Electronics and New Energy

In the electronics sector, 1235 foil finds applications in:

• Lithium Batteries: Used as a current collector, it enhances battery performance.
• Capacitors: Its conductivity makes it suitable for use in various capacitor types.
• Electromagnetic Shielding: Provides protection against electromagnetic interference in electronic devices.

4.3 Industry and Construction

Industries leverage this material extensively for both construction and industrial uses due to its:

• Heat Exchangers: Its thermal conductivity makes it ideal for use in heat exchange systems.
• Solar Energy: Used in solar panels for its reflective properties.
• Decorative Materials: Employed in architectural applications for aesthetic purposes.

5. Comparison with Other Alloys

When comparing 1235 aluminum foil with other aluminum alloys, such as 1100 and 3003, several key differences emerge:

Summary of Key Differences

• Purity: 1235 aluminum foil has the highest purity, making it ideal for applications requiring excellent conductivity.
• Strength: 3003 and 8011 alloys provide higher tensile strength compared to 1235, making them suitable for more demanding applications.
• Corrosion Resistance: 1100 aluminum foil offers the best corrosion resistance, while all alloys provide good resistance in various environments.
• Applications: While 1235 is primarily used in packaging, 8011 and 8079 are favored for flexible packaging due to their strength and barrier properties.

6. FAQs

Q: Can 1235 aluminum foil be used in high-temperature applications?
A: Yes, it withstands temperatures up to 650°C, making it suitable for industrial ovens and heat exchangers.

Q: What industries benefit most from 1235 aluminum foil?
A: Packaging, electronics, and renewable energy sectors rely on its purity and versatility.

Q: What makes 1235 foil ideal for food packaging?
A: Its superior moisture, aroma, and light barrier plus FDA compliance ensure product safety and shelf‑life.

Q: Can 1235 foil serve as battery cathode?
A: Yes—12–25 µm H18 foil offers uniform coating and mechanical strength for Li‑ion cathodes.

Q: How recyclable is 1235 aluminum foil?
A: Aluminum recycling saves ~ 95% energy vs. primary production; foil scrap re‑entry supports circular economy.

Q: What are standard thickness tolerances?
A: ± 3% on gauges down to 0.006 mm across widths up to 1 600 mm.

Q: How does 1235 aluminium foil compare to other aluminum alloys?
A: 1235 aluminium foil has a higher aluminum content than many other alloys, resulting in better electrical and thermal conductivity, making it ideal for specific applications.

7. Why Choose Langhe 1235 Aluminum Foil

Langhe’s 1235 aluminum foil stands out for:

• Cutting-Edge Technology: State-of-the-art rolling mills ensure tight thickness tolerances.
• Quality Assurance: ISO 9001 and IATF 16949 certifications guarantee consistency.
• Custom Solutions: Tailored gauges and coatings meet specific industry needs.
• Sustainability: 95% of recycled foil retains original properties, reducing environmental impact.

8. Conclusion

1235 aluminum foil is a versatile and essential material in various industries, from packaging to electronics and construction.

Its high purity, excellent barrier properties, and conductivity make it a preferred choice for many applications.

As industries continue to evolve, the demand for high-quality aluminum foil will likely grow, making 1235 aluminum foil a critical component in modern manufacturing.

Understanding its properties, production processes, and applications equips manufacturers and consumers with the knowledge to leverage this material effectively.