The demand for pre-packaged food items has been increasing in recent years. Retail groups and food service industries have responded with new and innovative packaging options. While packaging is essential to prevent the spoilage of food products, the quality of packaging may not be considered by the typical consumer. Ensuring that food contents are contained and protected means that packaging materials must be high quality and undamaged. Leak detection equipment can be used to assess the integrity of packaging materials. Here we describe five ways leak detection equipment can be used to test the quality of food packaging.
1. Bubble emission testing
Bubble emission tests can be used to detect leaks in packaged items with some headspace – the space that is unoccupied by the contents of the package. This method involves sealing the package and submerging it under water. The appearance of bubbles under the water is an indication that the packaging is damaged in some way. Observing where the bubbles are released can provide information on where the package quality is compromised.
2. Dry chamber method
The dry chamber method is used to detect a leakage in packaging with minimal headspace or air content. Dry chamber testing is best suited for packages with liquid contents. For the test, the package is placed on an absorbent material such as paper towel inside of a dry tank or chamber. The chamber is closed and a vacuum is activated inside the chamber. If the absorbent material beneath the package is moist after testing, the package is faulty.
3. Pressure decay
Packaging materials with a relatively small volume are best evaluated using the pressure decay method. In this method, dry air or another gas is used to increase the pressure inside the packaging to a set amount. The pressure level is monitored over time. If the pressure level drops at any point during the process, there is a leak in the packaging material. The pressure decay method is very fast and can be effective for industries with high volumes of packaging such as automotive and medical goods sectors.
4. Trace gas leak detection
Trace gas leak detection equipment uses sensors to detect amounts of trace gas released from the packaging. A trace gas such as helium or carbon dioxide is pumped into the packaging. As these gases are composed of very small molecules, they can leak easily from faulty packaging.
If sensors detect that some amount of trace gas has been released from the package, then the quality of the material is compromised. This technique is one of the more sensitive leak detection methods, and can also be beneficial when trying to determine the location of the leak.
5. Dye penetration
The dye penetration method involves injecting a colour-dyed solution into a sealed package. After injecting the dye, visual observations can be made to detect defects in the packaging. Any movement of dye through the seal indicates faulty packaging. Dye penetration can be useful for testing the strength of a product seal.