1235 Aluminum Foil

1235 aluminum foil belongs to the 1xxx series aluminum alloy(pure aluminum alloy, aluminum content ≥99.00%), which is a widely used industrial aluminum foil variety. Its core advantage lies in the balance of high purity, excellent processability, and cost-effectiveness, making it suitable for multiple fields such as packaging, electronics, and construction. Below is a detailed breakdown of its key information:

1. Core Definition & Alloy Classification

• Alloy Series: 1xxx series (pure aluminum-based, with trace alloying elements such as iron and silicon to optimize performance, no other major alloying elements like copper or magnesium).

• Grade Significance: "1235" is defined by the international aluminum alloy designation system (e.g., ASTM B209 in the US, GB/T 3198 in China). The last two digits "35" indicate that the aluminum content is ≥99.35%(the core indicator of 1235 alloy).

• Foil Thickness Range: Typically 0.006mm–0.2mm (can be customized to ultra-thin specifications like 0.004mm for specific scenarios such as electronic capacitors).

2. Chemical Composition (Key Elements)

The composition of 1235 aluminum foil is strictly controlled to ensure consistency in performance. The following table lists the main component content (taking GB/T 3198-2021 standard as an example):

3. Key Physical & Mechanical Properties

1235 aluminum foil’s properties are closely related to its high aluminum content, and annealing (heat treatment) can further adjust its hardness and ductility:

3.1 Physical Properties

• Density: ~2.70 g/cm³ (same as pure aluminum, lighter than most metals, easy for lightweight packaging).

• Melting Point: ~650°C (slightly lower than pure aluminum due to trace iron, suitable for high-temperature processes like sterilization in food packaging).

• Thermal Conductivity: ~230 W/(m·K) (excellent heat transfer, used in heat dissipation components for electronics).

• Electrical Conductivity: ~62% IACS (International Annealed Copper Standard, suitable for low-voltage electrical applications like capacitor electrodes).

• Corrosion Resistance: Excellent (forms a dense Al₂O₃ oxide film on the surface, resistant to most organic acids, alkalis, and atmospheric corrosion—no rusting like steel).

3.2 Mechanical Properties (Typical Values)

The mechanical properties vary with temper(hardness state), and the two most common tempers for 1235 foil are:

4. Main Application Fields

1235 aluminum foil’s performance characteristics make it a "multi-purpose" material, with the following core application scenarios:

4.1 Packaging Industry (Largest Application)

• Food Packaging: Used for flexible packaging (e.g., chocolate aluminum-plastic composite films), rigid packaging (e.g., yogurt lids), and thermal insulation (e.g., takeaway food containers). Advantages: barrier to oxygen/water vapor (extends food shelf life), non-toxic (complies with FDA, EU 10/2011 food contact standards).

• Pharmaceutical Packaging: Blister packs (for tablets/capsules) and aluminum-plastic composite bags (for powdered drugs). Requires high purity (no heavy metal migration) and stable barrier properties.

• Tobacco Packaging: Inner lining of cigarette packs (aluminum foil paper). Needs good printability and folding resistance (no cracking after repeated folding).

4.2 Electronic & Electrical Industry

• Capacitors: Ultra-thin 1235 foil (0.006–0.01mm) is used as electrode material for electrolytic capacitors. Advantages: high conductivity and uniform thickness (ensures stable capacitance).

• Battery Components: Current collectors for lithium-ion batteries (thin foil) or pole ears (H18 temper, high strength). Compatible with battery electrolytes (no chemical reaction).

4.3 Construction & Insulation

• Thermal Insulation Materials: Composite with glass wool or rock wool to make aluminum foil-faced insulation boards (used in walls/roofs). The foil reflects 90%+ of infrared radiation, improving insulation efficiency.

• Ducting: Aluminum foil tape for sealing HVAC ducts (good adhesion and corrosion resistance, prevents air leakage).

4.4 Other Fields

• Decorative Materials: Embossed 1235 foil (e.g., gold/silver-colored) for gift wrapping or decorative stickers.

• Household Products: Disposable aluminum foil trays (O temper, easy to shape) and kitchen wrapping foil.

5. Comparison with Common Aluminum Foils (e.g., 8011)

1235 foil is often compared with 8011 aluminum foil(8xxx series, aluminum-magnesium-silicon alloy). The following table clarifies their differences to help with material selection:

6. Production Process Overview

The manufacturing of 1235 aluminum foil involves strict process control to ensure quality:

1. Ingot Casting: Melt high-purity aluminum ingots (99.70%+ Al) and add trace iron/silicon, then cast into rolling ingots (thickness ~600–800mm).

2. Hot Rolling: Roll the ingot to a thick plate (6–10mm) at ~400°C (softens the alloy for subsequent cold rolling).

3. Cold Rolling: Roll the thick plate to a thin strip (0.1–0.3mm) at room temperature (multiple passes, with intermediate annealing to eliminate work hardening).

4. Foil Rolling: Further roll the strip to the target thickness (0.006–0.2mm) using a foil mill (requires high precision to control thickness deviation within ±5%).

5. Annealing: Heat treat the foil to adjust temper (O or H18)—full annealing at ~350°C for 2–4 hours (softens the foil); no annealing for H18 temper (retains cold work hardening).

6. Slitting & Inspection: Cut the large-width foil into small rolls (custom widths) and test for thickness, purity, and barrier properties.

7. Storage & Handling Notes

• Moisture Prevention: Store in a dry environment (relative humidity ≤60%) to avoid surface oxidation (white spots) caused by moisture.

• Avoid Scratching: The foil surface is soft—use plastic separators between rolls to prevent scratches (affects barrier properties for packaging).

• Temperature Control: Avoid long-term storage at temperatures >50°C (may cause temper changes, e.g., H18 foil softens slightly).

• Recyclability: 1235 foil is 100% recyclable (recycled aluminum retains 95% of its original properties, reducing energy consumption by 90% compared to primary aluminum production).

In summary, 1235 aluminum foil is a cost-effective, multi-functional material with high purity and stable performance. Its application scope covers daily life (food packaging) to high-tech fields (electronics), making it one of the most widely used aluminum foils globally.

The Product Specification