For years, one dairy plant disinfected plastic cups and lids with hydrogen peroxide before filling.
The method worked, but it came with a growing operational problem: the disinfectant became more expensive, supplies became less predictable, and the process itself required regular handling, storage and replenishment of chemicals.
That led to a practical question:
Can packaging be treated without using a liquid disinfectant at all?
One option was ultraviolet treatment directly on the conveyor.
Why the process had to change
The original setup used hydrogen peroxide to wash or treat the packaging before filling.
This meant that the production process depended not only on the filling equipment itself, but also on a consumable chemical.
The plant wanted to reduce:
dependence on regular chemical deliveries;
handling and storage of disinfectant;
operating complexity;
additional process steps before filling.
At the same time, packaging hygiene could not simply be sacrificed.
Any replacement method had to fit into the existing conveyor and operate continuously.
Why UV was considered
UV treatment is fundamentally different from chemical disinfection.
Instead of applying a reagent to the packaging, the surface is exposed to germicidal ultraviolet radiation for a defined period of time.
For a moving conveyor, this creates a relatively simple process:
empty cups or lids enter the irradiation zone;
they pass beneath the UV source;
the surface receives a calculated UV dose;
the packaging continues toward the filling machine.
There is no chemical solution to prepare or replenish.
But this simplicity only works if the UV section is correctly designed.
Conveyor speed matters
The UV dose received by the packaging depends on two main factors:
UV dose = irradiance × exposure time
For a conveyor, exposure time is determined largely by belt speed and the length of the irradiation zone.
This means that changing the production speed can change the actual treatment conditions.
A system that works at one conveyor speed may deliver a lower dose if the line is accelerated later.
That is why UV treatment should be considered part of the production process rather than just a lamp installed above the belt.
Distance to the packaging matters too
In this project, the UV section was installed approximately 15–20 cm above the packaging.
This distance affects the intensity reaching the surface.
Too far away, and the irradiance decreases.
Too close, and the system can become harder to integrate mechanically and may create uneven treatment depending on the shape of the packaging.
The final distance therefore has to balance:
UV intensity;
conveyor geometry;
product height;
maintenance access;
shielding.
Equipment configuration
The conveyor unit used a stainless-steel housing with ozone-free amalgam UV lamps.
According to the project specification:
lamp power: up to 64 W per lamp;
lamp type: ozone-free amalgam;
housing material: stainless steel;
mounting height: approximately 15–20 cm above the conveyor.
A separate control cabinet was used for power supply and operating control.
The lamps were also supplied in an anti-shatter configuration, which is particularly relevant when glass components are installed above food packaging.
Why anti-shatter design matters
In food production, lamp failure is not only an electrical problem.
If a glass UV lamp is installed above an open conveyor, mechanical damage can create a contamination risk.
An anti-shatter design reduces the risk of fragments entering the production area if a lamp is damaged.
This is one of those details that may not affect the UV dose calculation, but matters greatly in real production.
Integration without rebuilding the line
The UV section was adapted to the existing conveyor rather than requiring a new transport system.
It was mounted above the packaging using brackets, and the control equipment was installed separately.
That allowed the treatment stage to be added without significantly changing the production layout.
For retrofit projects, this is often the main challenge: the new equipment has to work within the space that already exists.
Can UV simply replace hydrogen peroxide?
Not automatically.
That is probably the most important point in this kind of project.
Hydrogen peroxide and UV are different treatment methods, and their effectiveness depends on different parameters.
For UV, the result depends on:
delivered UV dose;
distance to the surface;
conveyor speed;
packaging geometry;
shadowed areas;
cleanliness of the packaging;
type of microorganisms being targeted.
The source project confirms installation and operation of the UV equipment, but it does not provide microbiological validation data proving direct equivalence to the previous hydrogen peroxide process.
So from an engineering perspective, a change like this should be followed by production-level verification.
Packaging geometry can be a hidden problem
Flat surfaces are relatively easy to irradiate.
Cups and lids are more complicated.
A cup may contain:
curved sidewalls;
recessed areas;
rims;
internal surfaces;
shadows created by its own geometry.
UV only works effectively where the radiation reaches the surface.
That means lamp positioning can be just as important as lamp power.
In some applications, treatment from several directions may be required to reduce shadow zones.
What this project shows
Replacing chemical treatment with UV is not simply a matter of swapping one device for another.
It changes the process itself.
The main advantages can include:
no liquid disinfectant consumption;
fewer chemical handling operations;
easier integration into continuous conveyor operation.
But a successful conversion also requires control of:
UV dose;
conveyor speed;
mounting distance;
packaging geometry;
lamp condition;
operator protection.
The interesting part is that the UV system becomes another controlled stage of the production line.
And just like temperature, filling volume or conveyor speed, its operating parameters need to remain within the validated range.
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