Why have aluminum cans become the “golden packaging” for beer, soda, and energy drinks? The answer lies in their properties of lightweight durability, 100% recyclability, and a balance of efficiency and environmental friendliness. Whether ordinary consumers want to know “how beverage cans are made” or businesses are seeking efficient and eco-friendly packaging solutions, understanding the aluminum can manufacturing process is crucial. This article will break down the entire production process of aluminum beverage cans and analyze the sustainable advantages behind it.​

I. Step 1 of Aluminum Can Manufacturing: Material Selection – The Core Foundation Determining Can Quality​

The starting point of a high-quality aluminum can is an aluminum alloy sheet that combines “strength” and “ductility,” which directly determines whether the can can achieve the characteristic of being “thin, lightweight yet durable.”​

Core Raw Material:  aluminum alloy sheets (the industry’s preferred material) are used, with a thickness of only 0.2-0.3mm (thinner than a standard A4 paper). They can withstand subsequent stretch forming while ensuring the can body’s pressure resistance.​

Pretreatment Process: The sheets first undergo two steps – “ultrasonic cleaning → high-temperature drying” – to completely remove surface oil, dust, and other impurities, preventing contamination of the can body or adverse effects on coating adhesion during subsequent processing.​

Expert Perspective: Recycling Advantages of Aluminum Cans (High Google Search Point)​
Aluminum is one of the most recyclable materials globally:​
Producing new cans from recycled aluminum reduces energy consumption by 95% compared to primary aluminum (Source: International Aluminum Institute), significantly cutting carbon emissions;​
The purity of recycled aluminum does not decrease, allowing for infinite circular reuse and fundamentally reducing resource waste.​

II. Step 2 of Aluminum Can Manufacturing: Stretching and Forming – Key Technology for Seamless Can Bodies​
The core competitiveness of two-piece aluminum cans (separate can body and lid) lies in their “seamless can bodies,” which are achieved entirely through the precision process of “stretching + ironing.” The specific process is divided into 3 steps:​

① Blanking: Creating the Initial “Embryo” of the Can Body​
High-speed punch presses cut aluminum alloy sheets into circular blanks (industrially called “slugs”) with a diameter of 10-12cm. Each punch press can process over 500 blanks per minute, ensuring efficient large-scale production.​

② Deep Drawing: Preliminary Shaping​
The aluminum blank is placed in a custom mold, and a punch applies high pressure (approximately 200-300MPa) to press it into a “short cylinder with a base” (similar to a small cup), with a height of about 5cm. This step lays the basic shape of the can body.​

③ Ironing: The Core of Can Body “Thinning and Elongation”​
This is the key step determining the thickness and height of the can body:​
Multiple sets of conical molds perform secondary stretching on the sidewall of the “short cylinder,” uniformly reducing the wall thickness from 0.2mm to less than 0.1mm;​
At the same time, the height of the can body is stretched from 5cm to 12-15cm (adjusted according to beverage volume, e.g., 330ml cans vs. 500ml cans), finally forming a “slender, seamless” can body structure.​

Quality Control: A Critical Link to Avoid Defects​
Every batch of can bodies undergoes inspection by automated dimension testing equipment:​
Real-time monitoring of deviations in diameter, height, and wall thickness (tolerance must be ≤0.02mm);​
Checking for dents and scratches on the can body to ensure consistent shape of each can, preventing liquid leakage during subsequent filling.​

III. Step 3 of Aluminum Can Manufacturing: Cleaning and Coating – Ensuring Safety and Taste​
After stretching, the can body must go through three steps – “trimming → cleaning → coating” – to meet food packaging standards:​
Trimming: After stretching, burrs form at the can mouth. High-speed cutting tools trim the can mouth to ensure tight fitting with the lid during subsequent sealing.​

Secondary Cleaning: Food-grade cleaning agents are used to rinse the inside and outside of the can body, removing residual lubricating oil from the stretching process to prevent beverage contamination.​
Inner Wall Coating (Mandatory Step):​
A food-grade epoxy resin coating (compliant with FDA standards) is sprayed to evenly cover the inner wall of the can body;​
Function: Prevents chemical reactions between acidic beverages (e.g., cola, beer) and aluminum, avoiding can corrosion and preventing metallic taste from affecting beverage flavor. Without this coating, acidic drinks like soda may corrode the can wall within 3 days.​

IV. Step 4 of Aluminum Can Manufacturing: Printing and Decoration – The “Visual Window” for Brand Identification​
After the can body is formed, it enters the high-speed printing stage, which is crucial for brands to convey information:​
Printing Efficiency: High-speed rotary offset printing machines are used, capable of printing over 2,000 can bodies per minute to meet the needs of large-scale orders;​
Process Details: First, a base color is printed, followed by overlapping brand logos, product information, and patterns. Finally, a layer of wear-resistant varnish is sprayed to prevent pattern scratching during transportation;​

Environmental Friendliness: Water-based eco-friendly inks are used, which contain no volatile organic compounds (VOCs) and comply with global packaging environmental standards.​
At this point, the “finished can body” of the aluminum beverage can is completed. Subsequent steps only require assembling with the lid, filling with beverages, and sealing before being delivered to supermarket shelves. (The next article will detail the filling technology and capping process of aluminum cans – follow us to learn the complete process!)​

Frequently Asked Questions (FAQ) About Aluminum Can Manufacturing​

1. How long does the production cycle of aluminum cans take from raw material to finished product?​
The manufacturing cycle of standard aluminum cans (excluding filling) is approximately 1-2 days. If starting from “recycled aluminum,” the entire process of “recycling → melting → new can → shelf placement” can be completed in as little as 60 days.​

2. Can all aluminum cans be 100% recycled?​
Yes. The purity of aluminum in aluminum cans does not decrease during recycling, allowing infinite circular reuse. Moreover, most regions worldwide have mature aluminum can recycling systems (e.g., curbside recycling bins, supermarket collection points).​

3. The wall of aluminum cans is so thin (0.1mm) – why is it not easily deformed?​
This is because 3004-series aluminum alloy (containing manganese and magnesium) is used, which combines ductility and strength. Additionally, the cylindrical structure of the can body disperses pressure, preventing deformation even under slight extrusion.​

4. Is the inner wall coating of aluminum cans safe? Will it contaminate beverages?​
It is safe. The inner wall coating is a food-grade epoxy resin (compliant with FDA and EU EFSA standards). It does not dissolve or release harmful substances at room temperature and has passed high-temperature sterilization tests (e.g., beer pasteurization), with no reaction with beverages.​

5. Are aluminum cans more eco-friendly than plastic bottles?​
Yes. The energy consumption for aluminum can recycling is over 70% lower than that for plastic bottles, and aluminum cans can be recycled infinitely. In contrast, plastic bottles (e.g., PET bottles) can usually only be recycled 2-3 times, after which they become non-degradable waste.​

Conclusion: Aluminum Cans – The “Benchmark of Efficiency and Environmental Friendliness” in Modern Packaging​
Behind every aluminum can lies a combination of “precision engineering + environmental responsibility”: from the precise selection of aluminum alloy, to the seamless stretching process, and to the 60-day recycling cycle. Aluminum cans not only meet the beverage industry’s needs for “efficient filling and safe storage” but also align with the global environmental trend of “carbon reduction and circular economy.”​
Whether consumers are choosing more eco-friendly packaging or businesses are seeking cost-effective packaging solutions, aluminum cans are a choice that combines “practicality” and “responsibility.”​