Requirements for Cable Aluminum Foil: A Multidimensional Analysis(I)

Cable aluminum foil, as a key material in cable manufacturing, its performance and quality directly affect the overall performance and service life of the cable. With the rapid development of the power and communication industries, the requirements for cable aluminum foil are becoming increasingly stringent, covering multiple dimensions from basic material properties to surface quality, dimensional accuracy, and special properties.

I. Material Property Requirements

(I) Alloy Composition

Cable aluminum foil usually uses industrial pure aluminum or aluminum alloys such as 1235, 8011, and 1060. Alloy 1235 has good formability and corrosion resistance. Its low impurity content can ensure the purity of the aluminum foil, thereby improving its electrical and processing properties. Alloy 8011 strikes a good balance between strength and formability and is widely used in the manufacture of cable aluminum foil. Pure aluminum 1060, due to its high purity, has excellent electrical conductivity and corrosion resistance and is suitable for cable scenarios with high requirements for electrical conductivity and corrosion resistance, such as the internal connection cables of some precision electronic devices. Different alloy compositions endow aluminum foil with different properties, and it is necessary to accurately select according to the specific application environment and performance requirements of the cable.

(II) Mechanical Properties

1. Strength: Although the standards for cable aluminum foil in the communication cable industry are not very high, most customers require its strength to be greater than 70MPa or 80MPa. This is because during the plastic film covering and cable winding processes, the aluminum foil needs to withstand a certain tension. If the strength is insufficient, especially after slitting into narrow strips (as narrow as 12mm), slight edge cracks or burrs will cause the aluminum foil to break due to stress concentration, affecting the production and use of the cable.
2. Elongation: Generally, cable aluminum foil is required to have a certain elongation, usually ≥15%. Sufficient elongation enables the aluminum foil to withstand a certain degree of tensile deformation without breaking during processing and use, ensuring its integrity in complex processes and practical applications. For example, when the cable is bent or stretched, the aluminum foil can deform accordingly while maintaining its shielding and protective functions.

II. Surface Quality Requirements

(I) Oil Content

Cable aluminum foil requires low surface oil content. Excessive residual rolling oil will affect the bonding effect between the aluminum foil and the plastic film and reduce the peel strength. Oil spots are a common problem, mainly caused by the mixing of engine oil into the rolling oil, high kinematic viscosity, or problems with the air nozzles at the mill outlet that cause the foil strip oil not to be blown clean. Solutions include preventing the mixing of engine oil, controlling the viscosity of the rolling oil, and reasonably setting the air nozzles to ensure the surface cleanliness of the aluminum foil and improve the bonding firmness with the plastic film.

(II) Hole Defects

There should be no holes on the surface of the aluminum foil. Holes will destroy the tightness and shielding properties of the aluminum foil, making the cable vulnerable to external interference and corrosion. During the production process, it is necessary to strictly control the process parameters of casting and rolling, cold rolling, etc., to avoid the generation of holes due to raw material impurities, equipment wear, etc., and ensure the integrity and functionality of the aluminum foil.

(III) Other Defects

1. Corrosion: Aluminum foil will be corroded when it encounters water or alkaline solutions, forming white ash on the surface, which seriously reduces the peel strength of the plastic-coated foil. Rainwater wetting during transportation, the infiltration of fog water condensation caused by temperature differences during long-distance transportation at night, etc., may all cause corrosion. Therefore, the aluminum coil packaging needs to be tight, and it is necessary to avoid transporting hot aluminum coils to prevent corrosion.
2. Overoxidation: Cooling aluminum materials with strong wind in a high-temperature state will cause overoxidation, discoloring the surface and reducing the peel strength of the plastic-coated foil. After the aluminum foil is annealed and 出炉，it should be cooled naturally to prevent overoxidation phenomena and ensure the surface quality and performance of the aluminum foil.