Frozen line IQF belt

In the frozen department of a food manufacturer, the IQF conveyor belt used to freeze corn was cleaned the hard way. The team relied on manual rinsing and scrubbing, with long pre-rinses, significant labour, and constant pressure to meet strict hygiene criteria. The belt often appeared clean at the end, but swab tests revealed that residues remained on it.

The manufacturer decided to explore whether an automated cleaning system could do two things at the same time:

1) Cut cleaning time

2) Deliver documented hygiene that both their customers and the internal quality team could accept

The existing routine had two main pain points:

• Time and labour – Cleaning the IQF belt was slow and resource-intensive. Pre-rinsing alone took a sizeable chunk of time, eating into available production hours.
• Hygiene documentation – It wasn’t enough to say “it looks fine”; the manufacturer needed consistent numbers from infeed and outfeed to meet the customers’ criteria for ATP and microbiology.

The target was clear: design an automated solution that effectively cleans and disinfects the IQF belt, reduces manual effort, and does not compromise hygiene – ideally improving it.

An automated test system was installed on the IQF conveyor and benchmarked against the existing manual routine.

The test set-up combined:

An automated cleaning and disinfecting cycle using a dual-purpose product suggested by their chemical supplier

• A nozzle layout covering infeed and outfeed across the full belt width
• A 20-bar pump and dedicated buffer tank capacity
• Two separate systems: one serving the IQF and cool-down sections, one serving the chiller

Trials were run on three occasions: a baseline with manual cleaning, an initial automated trial with partial success, and a second automated trial with optimised nozzle positions and settings. Each run included visual checks, ATP swabbing before and after cleaning, and microbiological surface swabs at infeed and outfeed.

One of the most striking outcomes was the reduction in cleaning time.

With the automated cleaning system in place, overall cleaning time for the belt was reduced by 50% compared to the manual routine. A big part of this came from the pre-rinse step, where the automated cycle could remove soils far more efficiently than manual hosing.

The use of a dual-purpose detergent also meant that the disinfection step (plus the subsequent contact time and rinse steps) was eliminated.

In practice, that means:

• Shorter cleaning windows, enabling more production time
• Less labour tied up on the IQF belt, freeing operators for higher-value tasks
• A more predictable, repeatable process

The time savings would not mean much if hygiene performance dropped. The trials, therefore, paid close attention to ATP values and microbiological counts.

ATP performance

Across all test points, both manual and automated cleaning achieved at least 95% cleanliness, meeting the agreed hygiene standard. However, once the automated cleaning system was fine-tuned in the second trial, ATP results improved further and outperformed the normal manual method by far.

The ATP table clearly illustrates that:

• Contamination before cleaning was very high in all cases.
• After manual cleaning, ATP values dropped significantly but still left a measurable amount of residue.
• After the optimised automated cycle, ATP values were lower again, giving a higher % cleanness and a more comfortable margin against the criteria.

*RLU (Relative Light Units) is the number shown by the ATP test device. The device turns any food residue or microbes on the surface into a tiny flash of light and measures its brightness. The more light (higher RLU), the more organic contamination is present; the lower the RLU, the cleaner the surface.

Microbiological performance

Surface swabs were taken at both infeed and outfeed and analysed for five types of microorganisms. In all cases, the results remained within the specified limits when using the automated cleaning system.

In other words, the automated process not only kept up with the manual method on ATP and microbiology – after optimisation, it did a better job of removing organic residues while still meeting all microbiological requirements.

The conclusion from the trials is straightforward:

• The plant reduced cleaning time for the IQF belt by around 50%, freeing up valuable production hours and reducing the labour costs.
• At the same time, the automated cleaning system delivered improved ATP results after optimisation and microbiology safely within limits on both infeed and outfeed, enabling the manufacturer to document stronger hygiene performance to customers.

Cleaning the IQF conveyor with the automated cleaning system is significantly more effective in meeting hygiene criteria while reducing time and labour compared to the existing manual method.