PCS LIQUID FOOD

Solution for in-line leak detection by measuring the total pressure in the headspace of each individual closed container of food preserves and baby-food.

The inspection uses laser spectroscopy, which exploits a peculiar characteristic of molecules in a gaseous state: their ability to absorb light only at specific wavelengths. This approach allows for direct, precise and versatile inspection.

Laser technology makes inspection possible regardless of the type of cap or material of the container and is able to monitor in real time both the individual product and the average pressure level of the entire production, allowing constant optimization of quality and processes.

The system is installed after the container capping phase and is calibrated to verify the measurement of vacuum or the concentration of gas molecules presumed to be present in the headspace, depending on the specific characteristics of the product.

In particular, in hot-filled or pasteurized containers, PCS verifies the correct creation of the vacuum by measuring pressure in the headspace.

A pressure that is too similar to atmospheric pressure indicates that the vacuum has not been correctly created, thus signaling a malfunction in the process, or maintained, thus highlighting a leak in the container. The system then discards the product, ensuring that only vacuum-packed products, and therefore with the expected shelf-life, continue in the production line.

As regards PET bottles of nitrogen dosed products, the production process requires that after filling and immediately before capping, a small quantity of nitrogen is added, which, passing from the liquid to the gaseous state, increases its volume and, consequently, the internal pressure of the bottle, improving its mechanical resistance.

For this type of product, PCS is configured to verify the correct pressure in the headspace due to the presence of nitrogen. Otherwise, the system will report the presence of leaking bottles, which are eliminated from the production line.

By measuring the headspace pressure, the system is also able to signal a malfunction of the N₂ dispenser. This is a fundamental check since insufficient or excessive pressure causes deformation of the bottle, with problems related to its transport, its appearance, long-term sealing and costs due to the waste of the product, the containers and the nitrogen itself, in case of overdose.

The system offers a rapid visualization of production trends, promptly reports deviations before they cause waste and allows the causes of defects to be identified; for example, highlighting the presence of under or over deviations repeated at each cycle of the doser/capper and therefore identifying the dosing valve or capping head on which to intervene.