For standard 500ml can sizes (diameter 66mm±0.5mm, height 122mm±1mm), aluminium material (AA3004/3104 alloy) is currently the optimum overall performance option. According to the 2023 data of the International Aluminium Institute (IAI), the lightweight structure of the aluminum tank (tank wall thickness 0.24mm) has a compressive strength of ≥210N, axial load capacity of >230N (ISO standard requirement ≥200N), and weight of only 14.5g±0.3g, 52% lighter than traditional steel tanks. A good example is Red Bull. Its aluminum can production line achieves 8% aluminum conservation through thinning process, 12 million US dollars in costs annually, with up to 75% recovery rate (the steel can has only 46% recovery rate).
Tinplate (tinplate) is still used by a few manufacturers due to its low cost (unit cost is 18% less than aluminium), but it has obvious drawbacks when used in 500ml can size. 2024 tests showed that the wall thickness of tinplate cans needed to be 0.28mm in order to achieve the same compressive strength (220N), the weight of the can increased to 30.2g, and the transportation cost increased by 12%. AB InBev’s plant in Brazil previously suffered up to 1.2% yearly loss rate due to the rust problem of iron cans (with a corrosion rate of 0.05mm after 6 months in an environment of humidity > 80%), while the corrosion rate of aluminum cans was below 0.001mm under the same condition.
PET (polyethylene terephthalate) has emerged as an alternative material in the transparency requirement of 500ml can sizes. The limited edition PET can (0.4mm wall thickness) launched by Kirin Beer of Japan in 2023 has a compressive strength of 180N, but its temperature resistance is relatively weak (it has a tendency to deform above 60℃). Its filling line speed has to be reduced from 2,000 cans per minute for aluminum cans to 1,200 cans per minute, an efficiency reduction of 40%. Although its recycling rate can be up to 90% ( statistic from the European PET Recycling Organization), its carbon footprint is 23% higher than that of aluminum cans (CO₂ emissions per thousand cans: PET 48kg vs. Aluminium 39kg).
New bio-based materials (e.g., PLA polylactic acid) have been preferred due to their environmental protection characteristics, but the availability for 500ml can sizes is not ready. The 2024 Carlsberg trial project demonstrated that PLA tanks were inferior to aluminum tanks in compressive strength (150N) and sealability (leakage rate 0.08%), and 2.3 times more costly (unit price 0.12vs). Aluminum can 0.051. However, its biodegradability (breakdown ≥90% within 180 days) complies with the EU’s Single-Use Plastics Directive, and future technological developments may bridge the performance gap.
In the industry innovation case, the Infinity aluminum can of Ball Corporation, through topological optimization design, increased the curvature radius of the bottom dome of the can from 25mm to 28mm while maintaining the 500ml can dimensions unchanged, and enhanced the internal pressure resistance capacity by 15% (≥620kPa). Meanwhile, reduce the stress concentration coefficient (from 1.8 to 1.2). The actual test conducted by Coca-Cola’s European factory in 2023 showed that this design reduced the loss rate of the filling line from 0.1% to 0.02%, saving 800,000 US dollars in maintenance costs annually.
Overall, aluminium products, with the advantages of strength, lightness and circular economy, remain the gold standard for 500ml can sizes. However, under exceptional conditions (such as transparent packaging and ultra-low temperature cold chain), local innovation in PET and bio-based materials is driving the industry towards a diversified material system.
