Aluminum src foil, also known as aluminum semi-rigid container foil, is one of the core materials in the modern packaging field, occupies an important position in food packaging, fast food containers, aviation tableware and other fields by virtue of its unique alloy properties, processing adaptability and environmental advantages.
First, the alloy and state: semi-rigid container foil “technology gene”.
Semi-rigid container foil is mostly made of aluminum alloys such as 8011, 3003, 8006, etc., among which 8011 alloy (Al-Fe-Si system) is the most widely used, and its iron content is about 1%, which has an excellent balance of formability and strength. By adjusting the processing state (e.g., H24, H22, etc.), the material can be both flexible and rigid – For example, the H24 state of aluminum alloy can be used to make aluminum foils. For example, the tensile strength of aluminum foil in the H24 state (semi-rigid state) is in between the soft and fully rigid states, allowing for stamping and forming requirements while maintaining the structural stability of the container.
Thicknesses typically range from 0.05-0.2mm, with specific designs to be tailored to the application scenario:
0.05-0.1mm: suitable for lightweight lunch boxes, disposable containers, taking into account the cost and strength;
0.15-0.2mm: for high temperature baking or repeated use of aviation tableware, to enhance the deformation resistance.
Second, the production process: precision rolling and surface treatment technology
Semi-rigid container foil production process covers the melting casting → hot rolling → cold rolling → annealing → slitting five major links. key technologies include:
– Rolling process: through the adjustment of roll gap and lubricant viscosity, the foil thickness uniformity is accurately controlled, and the surface roughness needs to be lower than 0.8μm to avoid subsequent stamping cracking;
– Annealing treatment: adopt segmented annealing technology (200-300℃) to eliminate cold rolling stress and balance material ductility and hardness;
– Surface treatment: some products need to be coated with food-grade oil lubricated to enhance the acid and alkali resistance, while supporting high-temperature heat sealing (180-220 ℃).
Third, the core advantage: from performance to environmental protection of the comprehensive breakthrough
– Excellent barrier performance
The dense crystal structure of aluminum foil can block oxygen, water vapor and ultraviolet rays, with water vapor transmission rate ≤0.5g/m²-24h and oxygen transmission rate <0.1cm³/m²-24h, which significantly extends the shelf life of food.
– High strength and formability
The cup convexity value (a measure of stamping performance) of H24 aluminum foil can reach 8.5mm or more, which can withstand the complex molding process of high-speed punching machines, and the edge is not easy to crack, so it is suitable for deep-drawing containers (such as round lunch boxes and multi-compartment lunch trays).
– Light weight and temperature resistance
Compared to traditional plastics, aluminum foil containers are 30% lighter and can withstand temperatures ranging from -40°C to 250°C. They can be directly heated in ovens and microwave ovens, avoiding deformation of the containers or the release of harmful substances.
– Environmentally Friendly and Sustainable
Aluminum foil is 100% recyclable, and the energy consumption for recycling is only 5% of that of primary aluminum. Some companies adopt the “aluminum water direct supply” technology, which reduces carbon emissions in the melting and casting process and fits the trend of green packaging.
Fourth, the application scene: from fast food to high-end food packaging
– Fast food and takeaway industry
The 0.07mm-thick 8011-H24 aluminum foil for food containers are both lightweight and pressure-resistant, and are suitable for pizza boxes and burger packages, etc. The brand logo can be printed on the surface to enhance the aesthetics.
– Aviation and hotel tableware
Using 0.15mm 3003 alloy aluminum foil with anodic oxidation treatment to make reusable plates, which can increase corrosion resistance by 50% and reduce operating costs.
– Bakery and Frozen Foods
PE-coated 0.1mm aluminum foil trays support -18℃ frozen storage and 220℃ direct baking, avoiding water loss of food and maintaining crispy texture.
Fifth, future trends: Technological Innovation and Market Expansion
With the dual demand of consumers for convenience and environmental protection, aluminum semi-rigid container foil is developing towards ultra-thinness and functional composite:
– Ultra-thin: Haomei Aluminum have achieved 13μm power battery foil mass production, the future or the technology will be transplanted to the aluminum container foil, to further reduce material costs;
– Intelligent coating: R&D of antibacterial, oxygen-absorbing and other functional coatings to extend the freshness period of fresh food, such as adding nano-silver particles to inhibit microbial growth.
In summary, aluminum src foil have demonstrated their irreplaceable value in a variety of fields, including food packaging and medical supplies, due to their superior mechanical properties, various thickness options and environmental protection characteristics. From fast food containers to airline trays, its technological evolution continues to drive the industry in the direction of efficiency and environmental protection.
