FAQ · Aluminum Can
Aluminum Can Filling — Frequently Asked Questions
Selection, technical, installation, certification and commercial questions, answered with parameters for can lines.
6,000–36,000
CPH can lines
202/211
Common can diameters
444+
Lines delivered
71+
Countries exported
9+
Countries with service
Short answer: Aluminum cans are filled on a filler then double-seamed, not capped. Carbonated drink needs isobaric counter-pressure valves; juice and tea need hot-fill at 85–88 °C; still drinks use gravity or volumetric valves. Can lines run up to about 36,000 CPH because the can is rigid and seaming is quick. This page answers the questions buyers ask most, grouped by subject.
🎯 Key takeaways
- Cans are seamed, not capped — filler plus seamer, no capper
- CSD and beer: isobaric; juice/tea: hot-fill 85–88 °C
- Can lines run to ~36,000 CPH; speed is the lower of valve count and seamer heads
- CO₂ recovery pays back on every carbonated run
- Scope-normalise quotations — CO₂ recovery, seam check and commissioning are common exclusions
- Ask three questions in writing: sustained output on your can, exclusions, changeover time
On this page
1. Selection questions
The questions buyers ask before a specification exists. The full selection logic is in the aluminum can selection guide.
What output should I size a can line for?
On the volume you can sell within roughly two years, not the market you hope to hold in ten. A regional start-up is usually served by 6,000–18,000 CPH. Idle capacity still carries installed power, footprint and a larger spare part inventory. Plan the building for a second line rather than over-sizing the first.
Can one machine run still, carbonated and hot-fill product?
Across the same filler only if the valve family supports it. Still uses gravity or volumetric valves; beer and CSD need isobaric; juice and tea need hot-fill. A line built with isobaric valves can run still product but not the reverse without a different filler. Multi-product plants specify the broadest valve they will use and accept the cost.
Do I need a combiblock for cans?
No. A combiblock blows PET from a preform and only applies to PET. Cans run as a filler-plus-seamer with no blow moulder. See the selection guide for why the blowing stage is absent and the seamer replaces the capper.
What information does a supplier need to quote?
- Target output at a named can size and fill volume
- Every can size and end you intend to run, including later ones
- Can drawing: diameter, height, end diameter, coating
- Product and fill temperature (ambient, chilled, or 85–88 °C hot-fill)
- Site conditions: power, compressed air, CO₂, building dimensions and door openings
- Scope items: CO₂ recovery, CIP, seam verification, labeller, packer, palletiser
2. Technical questions
Which filling principle is most accurate for cans?
Volumetric or load cell dosing, followed by gravity and mechanical level filling. For products sold by exact volume, measured dosing removes the scatter that level filling shows when can volume varies. Still drinks with a normal tolerance are usually fine on level filling.
Why are can lines faster than bottle lines?
Because the can is rigid and seaming is quick. There is no blowing and no fragile bottle to handle gently, and a seamer closes a can in a fraction of a second, so filler and seamer throughput is high. The limit is the slower of the filler valve count and the seamer head count, not the handling.
How is the line cleaned?
Through a CIP circuit on the product path: rinse, detergent circulation, intermediate rinse, sanitisation and final rinse. Can lines benefit from CIP specified with the line rather than added later, because retrofitting a cleaning loop into an installed path is expensive.
What causes fill-level or seam variation?
| Symptom | Most common cause | Check first |
|---|---|---|
| Drift across a shift | Tank level or supply pressure change | Level control and feed pump |
| Scatter can to can | Can volume variation | Can weight and coating consistency |
| One valve different | Worn seat or blocked vent | That valve's service history |
| Seam leaker | Seam roll wear or setup | Seam teardown and roll condition |
| Slow drift over months | Meter or calibration drift | Calibration log and interval |
3. Installation and commissioning questions
What does the building need?
- Level floor with load capacity and any foundation work done
- Power at correct voltage and frequency, stable to the machine
- Compressed air and CO₂ supply sized for the filler and seamer
- Treated water for CIP at required quality and flow
- Drainage, ventilation and lighting in the production area
- Access route for machine sections, including door widths and lift capacity
How long does commissioning take?
In phases: mechanical installation, utility connection, water running, product running and speed ramp, then training. Still and juice commission faster than carbonated product because there is no foaming to tune; hot-fill adds a temperature-stability step. Delays are usually site readiness — power, air or CO₂ not ready when engineers arrive.
What is checked at the factory acceptance test?
Mechanical operation, controls, safety interlocks, output at rated speed and fill and seam quality on your own cans and ends. Send real cans and ends in production quantity; testing on generic items then finding yours differ defeats the purpose. Agree acceptance criteria in writing first.
4. Certification and compliance questions
What certification does Sunswell hold?
ISO 9001 and CE certification, with SGS audit. Equipment is built in a 20,000 m² facility and 444+ lines have been delivered to 71+ countries. These are company and equipment credentials; market-entry approval for your destination is a separate process with your importer.
Who handles destination-market certification?
Handled with your importer, because the scheme depends on the destination and on who is the responsible importer. Sunswell supplies the technical documentation, drawings and declarations. Start it early — certification runs in parallel with manufacturing.
What food-contact documentation is available?
Material specifications for product-contact parts, including stainless steel grades and elastomer types, supplied with the machine documentation. State the destination market at quotation if a specific food-contact standard applies, because it can change the gasket and seam specification.
5. Commercial questions
How much does a can filling line cost?
Price scales with output, valve family, valve count, seamer head count and automation, then with contact-part material and downstream scope. Figures without a defined scope mislead. Send the can drawing, format mix and target output and request a written quotation against a stated scope. Tiers are compared in can machine configurations compared.
What is usually missing from a cheap quotation?
CO₂ recovery, CIP, seam verification, labeller, packer, palletiser, format parts for extra sizes, installation, commissioning, training and a commissioning spare part set. Build one scope list, send it to every supplier and require line-by-line answers including exclusions.
What are the main running costs?
Electricity and CO₂ first, then water for CIP, labour, consumables such as ends and labels, and spare and wear parts including seam rolls. Seam roll life is a real recurring cost specific to canning, so track it from commissioning.
What after-sales support is available?
Sunswell runs local service in 9+ countries and supports installations across 71+ export markets with remote diagnostics, spare parts and engineer visits. Agree response expectations and the spare part list in the contract rather than after the first breakdown.
Three questions that prevent most disputes. Ask every supplier, in writing: what is the sustained output on my can; what is excluded from this quotation; and what is the changeover time between my two most common formats. Those three separate comparable quotations from ones that only look comparable.
6. Related resources
Longer treatments of the subjects above:
- Aluminum can filling machine selection guide — output, can format and valve by product
- Aluminum can machine configurations compared — economy, mainstream and high-speed tiers with TCO
- Filling valve types compared — gravity, mechanical, isobaric, volumetric and load cell
- Aluminium can filling machines — the full range
- Beer production line solution — complete can lines
Reference installations include C004 Dahman, a 24,000 CPH canning line for CSD in Syria.
Frequently asked questions
Can a can be filled on a combiblock?
No. A combiblock blows PET from a preform and seams no can. Aluminum cans arrive as finished empties and run on a filler-plus-seamer, with no blow moulder and no capper. The seamer is the can equivalent of a capper and must be paced to the filler.
Which valve do I need for beer or CSD in cans?
An isobaric counter-pressure valve. It equalises can pressure with CO₂ before filling so carbonation stays in solution and foam stays controlled. Mechanical or gravity valves cannot hold carbonation through the fill.
What fill temperature is used for juice and tea in cans?
Hot-fill at 85–88 °C for shelf-stable juice and tea filled at ambient. The hot product heat-treats the can and end at fill, then cools and the headspace is snifted. The can and end must be rated for the temperature, which is a package specification as much as a machine one.
How fast can a can line run?
Up to about 36,000 CPH on standard 330 ml beer and CSD, set by filler valve count and seamer head count together. Larger or irregular cans run slower because the valve dwell and seaming cycle take longer.
Does can size limit the machine?
Yes. Diameter sets the pitch on the filler and seamer; height sets guarding and infeed. Slim and standard diameters share a pitch band, but a wide or tall can needs fewer valves at the same turret size. Send the can drawing so pitch and seamer are specified for your actual can.
Why is CO₂ recovery worth specifying?
Because displaced gas on an isobaric filler is recovered to the tank rather than vented, which cuts gas cost and product loss on every carbonated run. On a high-volume CSD line the recovery pays for itself in run cost, so it belongs in the scope, not as an option.
What spare parts should be held for a can line?
Seals and gaskets for the valves, seam rolls and seamer tooling, and a commissioning set of wear items. For isobaric, CO₂ path seals. Identify long-lead items at handover and keep a spare seam roll set.
Is training included with a can line?
Operator and maintenance training is delivered during commissioning and should be written into the contract with defined duration and scope. It covers running, changeover, CIP, seam verification and first-line fault diagnosis, in the languages your team uses.
About the author
Written by the Sunswell engineering team — led by Howie SUN, Founder & CEO, with 14 years in filling and blow-moulding equipment R&D and turnkey project delivery across 71+ countries.
Last reviewed: 2026-08-10 · Reviewed by Sunswell engineering team
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