In the application of aluminum foil, O temper and H18 are two extremely common material states, found in everything from food packaging and pharmaceutical blister packs to electronic components and industrial parts. Many people are confused when choosing between them: what are the differences between O temper and H18 aluminum foil, and how should one choose the right one?
O temper aluminum foil, also known as "annealed aluminum foil," is processed by first cold rolling to the target thickness, followed by thorough annealing. Annealing is like giving the aluminum foil a "relaxation spa," effectively eliminating the internal stress generated during rolling, allowing the aluminum foil grains to rearrange more evenly and loosely, ultimately resulting in a soft state.
H18 aluminum foil, on the other hand, is a "fully hard aluminum foil." Its processing involves cold rolling to the target thickness without any annealing, directly retaining the hardened state after cold rolling. This "extreme rolling" significantly compresses and deforms the aluminum foil grains, forming a dense structure, thus possessing extremely high hardness.
The difference in manufacturing process directly results in a vast difference in the mechanical properties of the two materials, which is also the most crucial reference indicator when selecting a material. We can use a set of key data for a direct comparison (taking the commonly used 8011 alloy and 0.020mm thick aluminum foil as an example):
In terms of tensile strength, H18 aluminum foil has a tensile strength ≥160N/mm², while O temper aluminum foil only has a tensile strength of 40-105N/mm². The strength of H18 is almost 1.5 times that of O temper. This means that H18 aluminum foil can withstand greater external tensile forces and is less prone to tearing.
However, this increased strength comes at a cost. H18 aluminum foil has extremely low elongation, only about 1%, and almost no plasticity, making it prone to cracking with slight bending. O temper aluminum foil, on the other hand, has an elongation of 50%-105%, possessing excellent ductility and plasticity, easily handling complex processing requirements such as deep drawing, stretching, and folding.
Furthermore, the two materials also differ significantly in terms of fracture strength, yield strength, and other indicators. H18 aluminum foil has a tensile strength ≥180kPa, making it suitable for applications requiring high strength support. O temper aluminum foil has a relatively lower tensile strength, but it's sufficient for the sealing requirements of standard packaging, and its good plasticity makes it less prone to breakage during heat sealing.
It's worth noting that both have similar elastic moduli, approximately 30GPa, only half that of bulk aluminum. This characteristic gives them excellent thinness and lightness, making them suitable for various precision applications.
Differences in Application Scenarios
O temper aluminum foil, due to its softness and high plasticity, is a "forming expert," especially suitable for applications requiring complex shaping. In food packaging, it's commonly used for yogurt cup lids, chocolate liners, and lunch boxes, easily stamped into various shapes and resistant to springback after forming. Its good ductility also ensures the packaging's airtightness.
In daily necessities and kitchenware, O temper aluminum foil can be used to manufacture lamp housings, tableware, and other products requiring deep drawing and stretching. Furthermore, in pharmaceutical packaging, some cold-stamped pharmaceutical foils also use O temper aluminum foil, leveraging its plasticity to achieve precise blister forming.
H18 aluminum foil, on the other hand, excels in strength, primarily used in applications requiring extremely high strength and hardness without complex molding. In pharmaceutical packaging, H18 is commonly used for PTP pharmaceutical aluminum foil. Its high strength ensures it doesn't easily break during heat sealing with PVC materials, while also providing excellent puncture resistance, effectively protecting drug safety.
In the electronics industry, H18 aluminum foil is an ideal material for lithium-ion battery positive electrode current collectors. It can withstand the strong shear forces of electrode rolling processes, ensuring the stability of the battery structure. A leading battery manufacturer uses H18 8079 aluminum foil, with a tensile strength of 175 MPa, meeting stringent industrial requirements. Furthermore, H18 aluminum foil can also be used in industrial components such as cable foil and transformer foil, leveraging its high strength and good electrical and thermal conductivity to ensure stable equipment operation. Welcome to get aluminium foil datasheet from us directly.