Aluminum Strip for Transformer Winding

Aluminum strips for transformer windings, also known as transformer winding aluminum foil, are primarily used in the production of dry-type transformers. Common aluminum alloys for transformer windings include 1060, 1050, 1070, and 1350, with temper status of O, and thickness typically ranging from 0.2mm to 3.5mm.

Features of Transformer Winding Aluminum Strips

• 1. Burr-Free: The aluminum strips undergo precision processing, resulting in an extremely thin thickness and a smooth, flat surface without any burrs, ensuring safety and reducing losses.
• 2. Round Edge Design: The edges of the aluminum strips are specially treated to form rounded edges, preventing mechanical damage or electrical insulation issues during use, enhancing safety and reliability.
• 3. High Conductivity: Made from high-purity aluminum, the strips exhibit excellent electrical conductivity, which can effectively reduce energy loss and improve transformer efficiency.
• 4. High-Purity Material: The aluminum strips have extremely high purity, typically using aluminum with a purity of over 99.6%, ensuring excellent electrical performance and stability, suitable for demanding electrical applications.
• 5. Good Flexibility: The aluminum strips undergo full annealing treatment, providing them with good flexibility, making them easy to process and shape in transformer windings, while also enhancing service life and performance stability.
• 6. High Strength Standards: While ensuring high conductivity, the mechanical strength of the aluminum strips meets high standards, capable of withstanding various stresses and loads during manufacturing and operation, ensuring long-term stable operation of the transformer.

Electrical Conductivity of Aluminum Foil Strips for Transformers

• 1050: Better than 60% IACS.
• 1060: Better than 61.5% IACS.
• 1070: Better than 62.7% IACS.
• 1350: Better than 62% IACS.

Transformer Winding Aluminium Strips Specifications

Advantages of Using Aluminum Strips for Transformers

• 1. Excellent Flexibility: Aluminum strips exhibit outstanding flexibility, allowing them to be processed into ultra-thin sheets with thicknesses less than 0.08 mm. This characteristic makes them more adaptable during transformer winding, accommodating complex coil structures and enhancing manufacturing efficiency.
• 2. Easy Removal of Surface Oxide Layer: During the transformer winding process, the surface oxide layer on the aluminum strips can be easily removed without negatively affecting insulation performance. This ensures strong electrical insulation and safety, improving the long-term stability of the product.
• 3. High Ductility: The aluminum strips demonstrate excellent ductility, with a high elongation rate, allowing them to remain intact even when stretched more than 2 mm without breaking. This feature enhances their stress resistance during processing and helps prevent damage to transformer windings during use.
• 4. Excellent Plasticity: Aluminum strips have outstanding plasticity, enabling them to be shaped into various forms and sizes according to design requirements. This flexibility makes them an ideal winding material, suitable for a wide range of transformer designs.
• 5. Strong Interlayer Adhesion: Aluminum strips exhibit good adhesion between layers, which enhances the structural stability and electrical performance of the transformer, ensuring reliability and durability during operation.

Aluminum Strips for Transformers Chemical Composition

1050 O Aluminum Strips Chemical Composition

1060 O Aluminum Strips Chemical Composition

1070 O Aluminum Strips Chemical Composition

1350 O Aluminum Strips Chemical Composition

Transformer Aluminum Strip Thickness Tolerance

Transformer Aluminum Strip Width tolerance

Transformer Aluminum Strip Burrs and collapse

Types of Aluminum Strips for Transformers

Transformer Aluminum Strip 1050 O

The 1050 aluminum foil strip contains 99.5% aluminum, offering excellent conductivity and flexibility. It is fully annealed in the O temper, making the foil softer and easier to process. It is commonly used in transformer windings and is suitable for applications requiring high conductivity and good ductility.

The 1050 O aluminum strip is one of the most commonly used materials in transformers. It is frequently used as support material in transformer windings, which helps to reduce transformer losses and improve performance.

The thickness of the 1050 O aluminum strip used in transformers generally ranges from 0.1mm to 1mm. It is available in single or double-layer structures, which can effectively reduce magnetic leakage in coils and enhance insulation performance.

Transformer Aluminum Strip 1060 O

The 1060 aluminum foil strip has an aluminum content of up to 99.6%, offering excellent electrical conductivity and high corrosion resistance. In the O temper, 1060 aluminum foil is softer and easier to shape, making it suitable for winding transformer coils, especially where strict electrical and mechanical performance is required.

1060 O aluminum alloy has good plasticity but lower strength compared to other alloys. It is mainly used in various high and low voltage electrical devices, such as transformer windings.

Transformer Aluminum Strip 1070 O

The 1070 aluminum foil strip is based on high-purity aluminum with 99.7% aluminum content. It has outstanding conductivity and good flexibility and durability. The 1070 O temper foil can form stable coil structures during transformer winding, making it suitable for transformer designs that require higher conductivity and ductility.

The 1070 O aluminum foil for transformer windings can be used in dry-type transformers, oil-immersed transformers, and reactor windings.

The 1070 O aluminum foil for transformer windings has excellent heat dissipation properties, and does not increase the temperature rise of the coil during long-term operation, thus extending the coil's service life. Using 1070 O aluminum foil for transformer windings can reduce the cost of batch manufacturing transformers by 15%.

Transformer Aluminum Strip 1350 O

The 1350 aluminum foil strip is a high-purity aluminum foil with an aluminum content exceeding 99.5%, widely used in transformer windings. The 1350 O temper foil, after annealing, has excellent plasticity and flexibility, meeting the high conductivity and mechanical stability requirements for transformer winding materials.

The 1350 O aluminum foil for transformer windings is widely used in the transformer industry, including oil-immersed transformers and dry-type transformers.

The 1350 O aluminum foil for transformer windings is available in both bare and coated types. The bare type is mainly used as winding material for oil-immersed transformers, while the coated type is primarily used as interlayer insulation material.

Processing of Transformer Aluminum Strips

• 1. Raw Material Preparation and Heating: First, aluminum ingots are sent to the furnace for heating. The temperature in the furnace gradually increases to the appropriate range to melt the aluminum ingots. During the melting process, alloying elements are added and impurities are removed to improve the purity and performance of the aluminum.
• 2. Casting and Billet Cutting: After impurities are removed, the molten aluminum is cast into billets. The billets are then cut into aluminum plates of specific thickness, which will be used in the subsequent rolling process.
• 3. Rough Rolling: The cut thick plates are sent to a cold rolling mill for rough rolling. The cold rolling process gradually reduces the thickness of the aluminum plates and preliminarily adjusts the material's mechanical properties to meet the requirements for subsequent hot rolling.
• 4. Hot Rolling and Finishing: The rough-rolled aluminum plates are fed into a hot rolling mill for further processing. The hot rolling process, conducted at higher temperatures, effectively improves the ductility and toughness of the aluminum strips, resulting in finished aluminum strips that meet specifications.
• 5. Annealing: After rolling, the aluminum strips undergo annealing. Annealing involves heating the material to a certain temperature and maintaining it for a period to release internal stresses, improving ductility, flexibility, and corrosion resistance, and ensuring stable performance of the aluminum strips.
• 6. Cutting and Shaping: After annealing, the edges of the aluminum strips are cut with a shear to ensure precision in size and smooth edges.
• 7. Packaging and Shipping: Finally, after quality inspection, the finished transformer aluminum strips are coiled and packaged according to customer requirements. Once packaged, the strips are safely transported to the designated location, ready for use.

How to Select Aluminum Strips for Transformers?

1. Conductivity

Electrical conductivity is one of the most important properties of transformer aluminum strips, typically requiring a conductivity of 60% IACS or higher. The conductivity of the aluminum strips directly affects the efficiency and stability of the transformer. Therefore, when purchasing, ensure that the selected strips meet the standard conductivity to guarantee the transformer’s operational efficiency.

2. Mechanical Properties

Mechanical properties such as tensile strength and elongation are also key factors to consider. Transformer aluminum strips need to have good flexibility and appropriate strength to avoid breaking or deforming during winding. Therefore, ensure that the strips have been adequately annealed (e.g., O temper) to provide excellent ductility and good processing performance.

3. Surface Quality

The surface quality of the transformer aluminum strips directly impacts the smoothness of the winding process. The surface should be smooth, free of oil, scratches, oxidation spots, or other defects. High surface quality not only improves the appearance of the transformer but also avoids winding issues caused by defects. Therefore, carefully inspect the surface condition of the aluminum strips and request relevant quality inspection reports from the supplier.

4. Size Specifications

Select the appropriate thickness and width of the aluminum strips according to the transformer design requirements. Common thicknesses for transformer aluminum strips range from 0.2mm to 3.0mm, with widths customizable based on needs. Ensure that the size tolerances are within a reasonable range to maintain processing accuracy and performance stability of the transformer.

5. Supplier Reputation

Choose suppliers with a good reputation and stable, long-term supply capabilities. High-quality suppliers not only provide excellent products but also offer comprehensive after-sales service and technical support, ensuring stability and quality throughout the transformer production process.

6. Testing Reports and Certifications

Transformer aluminum strips typically need to comply with industry standards, such as ASTM or GB, to ensure quality. Request detailed testing reports from the supplier to ensure that the products meet requirements for mechanical properties, conductivity, and surface quality.