Common Problems in Can Filling (Foaming, Leaking, Inaccurate Fill) and How to Fix Them

In modern beverage production, can filling plays a crucial role in ensuring product quality, operational efficiency, and consumer satisfaction. Whether producing carbonated soft drinks, juice, beer, energy drinks, or functional beverages, manufacturers rely on advanced can filling machines and automated canning lines to achieve fast, stable, and hygienic output. However, even advanced beverage filling equipment can experience common issues such as foaming, leaking, and inaccurate fill levels. If not corrected in time, these problems can lead to product losses, downtime, higher costs, and inconsistent product presentation.

This article provides an in-depth analysis of the most common problems in can filling operations, explains why they occur, and offers practical troubleshooting guidance to help beverage manufacturers optimize their canning line performance. The insights shared apply to both carbonated drink filling machines and non-carbonated can filling equipment, ensuring a wide application across beverage categories.

Why Can Filling Problems Occur: An Overview

Before addressing specific issues, it is important to understand the underlying factors that influence can filling performance. Key variables include:

Beverage Characteristics

Different beverages behave differently during filling:

Carbonated drinks contain CO₂, making them more sensitive to temperature and turbulence.

Juices with pulp or high viscosity require specialized filling valves.

Beers foam easily during pressure fluctuations.

Packaging Material

Aluminum cans are lightweight and convenient but also sensitive to:

dents and deformation

uneven seams

temperature changes

These conditions can trigger leaks or unstable fill levels.

Machine Conditions

A can filling machine’s performance depends on:

precision of filling valves

quality of pressurization system

integrity of seals and rubber parts

cleanliness of product contact surfaces

Line Integration

A canning line typically includes:

depalletizer

rinsing machine

can filling machine

seaming machine

conveyor system

date coding, labeling, and packaging equipment

Synchronization between each part is critical. Even small mismatches in speed or timing can disrupt filling accuracy.

Problem 1: Foaming

Foaming is one of the most common and frustrating issues in can filling, especially for carbonated beverages, beers, kombucha, and energy drinks.

What Causes Foaming?

Foaming is generally caused by:

High product temperature – Warm liquid releases CO₂ rapidly.

Incorrect filling pressure – Pressure imbalance between the tank and can leads to gas breakout.

Excessive turbulence – Poor fluid flow design or unstable filling valve operation.

Deformed or dirty cans – Surface defects trigger nucleation and foam generation.

Inadequate CO₂ purging – Air in the can triggers foam when the product enters.

High residual oxygen – Excess oxygen can react with CO₂ and generate bubbles.

How to Fix Foaming Issues

Lower the product temperature

For carbonated beverage filling, maintain 0–3°C for best results. Low temperature enhances CO₂ solubility and minimizes foam.

Optimize filling pressure

Ensure pressure between product tank and filling valve is stable. For carbonated drink filling machines, the tank pressure typically ranges from 0.2 to 0.4 MPa depending on CO₂ content.

Check and clean filling valves

Worn or dirty valves create turbulence. Regular CIP/SIP cleaning is essential.

Inspect can quality

Reject cans with dents or scratches before they reach the filler.

Improve CO₂ flushing process

Double pre-evacuation or effective CO₂ purging significantly reduces oxygen and foaming.

Use foam control features

Premium beverage filling equipment includes multi-stage filling, anti-foam valves, and gentle bottom-up filling mechanisms.

Problem 2: Leaking

Leakage can occur during filling, after seaming, or during storage and transportation. This not only wastes product but can contaminate equipment and lead to large recalls.

Common Causes of Can Leaking

Worn or misaligned filling valve seals

If gaskets or O-rings are damaged, product may drip or leak during filling.

Improper seaming

The seamer head must achieve perfect double seams; otherwise, micro-leaks occur.

Damaged cans entering the filler

Small invisible cracks at the rim can become major leaks after seaming.

Incorrect liquid level

Overfilled cans are more prone to leakage due to internal pressure.

Contamination on can rims

Juice, syrup, or oil on the rim prevents proper seaming.

How to Fix Leaking Issues

Replace sealing components regularly

Filling valve rubber parts have lifespans; monitor wear and replace proactively.

Ensure seamer setup accuracy

Adjust critical parameters:

first-operation roll height

second-operation roll pressure

chuck alignment

Enhance can inspection

Use sensors or manual checks to remove dented or out-of-round cans.

Maintain proper fill level

Most can filling machines use level sensors or liquid-level control features. Calibrate them regularly.

Clean can rims before seaming

Install foam or water jets to eliminate product residue.

Problem 3: Inaccurate Fill Levels

Inaccurate filling affects product consistency, brand credibility, and regulatory compliance. It can appear as underfilling or overfilling.

Causes of Filling Inaccuracy

Incorrect calibration of flow meters or level probes

Sensors may drift over time.

Wear in filling valves

Mechanical wear leads to fluctuating flow rates.

Inconsistent product supply pressure

Pressure dips cause underfilling; pressure spikes cause overfilling.

Temperature fluctuations

Hotter liquids expand and can trigger unintended cut-off levels.

Foaming interference

Foam in the can disrupts accurate volume detection.

How to Correct Inaccurate Fill Levels

Calibrate the filling system

Regularly verify:

flow meter accuracy

filling valve cut-off timing

tank level sensors

Maintain stable product feed conditions

Use buffer tanks, pressure control valves, and constant-speed pumps.

Perform preventive maintenance on filling valves

Replace moving components such as springs, plungers, and seals.

Control product temperature

Maintain stable temperature for juice filling machines and carbonated beverage filling systems.

Reduce foam

Follow the foaming solutions outlined above to ensure accurate volume measurement.

When to Upgrade or Replace Your Can Filling Machine

Even with proper maintenance, older or outdated can filling equipment may struggle to meet modern production demands. Consider upgrading if you experience:

frequent downtime

poor filling accuracy

limited compatibility with different can sizes

insufficient speed

high energy or CO₂ consumption

outdated hygiene or CIP systems

Modern can filling machines incorporate servo-controlled valves, positive pressure filling technology, PLC automation, real-time monitoring, and improved seaming systems. Upgrading can dramatically increase output and reduce operational costs.

Conclusion

Foaming, leaking, and inaccurate fill levels are common but solvable issues in can filling operations. With proper machine calibration, preventive maintenance, and optimized production processes, beverage manufacturers can significantly improve efficiency, reduce waste, and enhance product consistency.

Whether you operate a small-scale canning line or a large industrial beverage filling plant, investing in reliable can filling machines and maintaining strict operational discipline is essential for long-term success.

Alps Machine, founded in 2011, is a leading manufacturer of beverage filling machines, can filling equipment, PET bottle filling lines, water treatment systems, labeling machines, packing machines, and turnkey beverage production solutions. We not only provide machines but also offer complete project services including workshop layout, utility design, bottle and label development, and integrated production solutions to help customers build high-performance beverage plants and succeed in their market.