In the field of aluminum processing, the two pure aluminum foils 1100 and 1235 have formed differentiated application scenarios with their different composition designs and process characteristics.
The aluminum content of 1100 aluminum foil is ≥99.00%, and the main impurities are silicon (0.45%) and iron (0.35%). This composition design makes its production process relatively simple, and large-scale production can be achieved through conventional hot rolling-cold rolling processes, with significant cost advantages.
The aluminum content of 1235 aluminum foil is as high as 99.35%, and the total amount of impurities is controlled within 0.65%. It requires refined aluminum liquid combined with high-precision rolling technology (such as 20-roll mill + AGC/AFC system). The control of melt purification, rolling passes and annealing temperature during the production process is more stringent, which also causes its processing cost to be about 30% higher than that of 1100 aluminum foil.
Mechanical properties
The tensile strength of 1100 aluminum foil is 110-136MPa, and the elongation is 3-5%. This balance of strength and ductility makes it stable in scenarios that require certain structural support, such as stamping of food packaging containers.
The tensile strength of 1235 aluminum foil can be increased to 140-256MPa and the elongation can reach 3-8% through microalloying technology (such as adding trace titanium to refine the grains) and optimizing the annealing process. Especially in the field of battery aluminum foil, its high strength (≥256MPa) and high elongation (≥8%) can effectively avoid brittle fracture during charging and discharging.
Surface properties and cleanliness
The surface dyne value (wettability) of 1235 aluminum foil is ≥32dyn, which can be further increased to more than 50dyn through corona treatment or coating technology, ensuring the bonding strength with the positive electrode material is ≥1.5N/cm. The number of pinholes is controlled at ≤3/m² (ordinary aluminum foil is ≤20/m²), and the cleanliness is improved by 75%, which is crucial for high-end applications such as lithium batteries.
In contrast, the surface treatment requirements of 1100 aluminum foil are lower, and it is more suitable for scenes with less stringent cleanliness requirements.
Corrosion resistance and conductivity
The high purity of 1235 aluminum foil makes it exhibit better corrosion resistance in humid or salt spray environments, and is often used in cable shielding and hydrophilic aluminum foil. Its conductivity can reach more than 61% IACS, which is about 5% higher than 1100 aluminum foil, and is more suitable for battery collectors and electronic components that are sensitive to conductivity.
1100 Aluminum Foil
Food packaging: It meets food-grade standards and can be made into moisture-proof and light-shielding packaging bags, which are widely used in packaging for chocolate, medicines, etc.
Refrigeration industry: Its thermal conductivity and corrosion resistance make it the preferred material for air-conditioning heat exchanger fins.
Capacitor housing: Moderate strength and formability meet the structural requirements of electronic components.
Electronic shielding: In scenes such as chassis and wiring harnesses, electromagnetic interference protection is achieved through composite structures.
1235 Aluminum Foil
Lithium battery current collector: As a positive electrode current collector, its high purity (≥99.35%) and ultra-thin uniformity (15-25μm) can increase the battery energy density by 10-15%, while meeting the stability requirements of 500 charge and discharge cycles.
Precision packaging: Bottle cap materials, antenna tags, etc., which have extremely high requirements for flatness and surface quality.
Special industrial materials: Cable protection foil, tape substrates, etc., which require high shielding and anti-aging properties.
New Energy Frontier: In sodium-ion batteries, since both positive and negative electrodes use aluminum foil, the high purity advantage of 1235 is further highlighted.
Cost priority: For budget-sensitive large-scale packaging or general industrial applications, 1100 aluminum foil is a more economical choice.
Performance priority: In the fields of batteries, electronics, precision manufacturing, etc., 1235 alloy has become an irreplaceable solution with its high purity, high strength and excellent surface properties.