Leak Detectors for Seal Integrity
Seal Integrity is a vital aspect of quality control in Modified Atmosphere Packaging (MAP)
The importance of a leak detector for seal integrity
Sealing integrity is possibly the single most important element of quality control in MAP; if a package’s seal integrity is compromised, a leak will cause loss of the protective atmosphere and the shelf life of the food will be reduced, resulting in costly returns.
A package leak detector is therefore a vital part of MAP quality control. In recognition of this, Dansensor has developed state-of-the-art package leak detection equipment for testing the integrity of the seal.
Seal integrity can be compromised through a number of different routes. For example particles of the product being packaged may come between the tray and the seal. Another potential source of a breach in seal integrity is that the heating element that creates the thermal seal may be defective or misaligned, or there may be issues with the pressure, heat and duration of the sealing process. All these can result in seal integrity being compromised.
It is vital for quality control and quality assurance that leak detection equipment works as quickly and as accurately as possible. If seal integrity problems go undetected, issues are likely to arise with the product resulting in unwanted returns and potential damage to the relationship with a customer. Therefore, a reliable leak detector is vital to ensure seal integrity.
Package leak detection equipment for seal integrity
To ensure quality control and integrity of the seals, products coming off the packaging line must regularly undergo tests by package leak detector equipment.
The traditional way to undertake package leak detection to monitor seal integrity is to place the package in a water bath leak detector. The top of the vessel is then sealed and a vacuum applied to draw out the air. The reduced pressure in the bath causes the headspace gas within the package to expand producing a stream of bubbles in the water if integrity of the seal has been breached. These bubbles are visible to the package leak detection operator, who can then confirm the presence of a leak and a seal integrity problem.
This package leak detector system for seal integrity testing is a cumbersome, messy and time-consuming process, however.
Another seal integrity monitoring system, used for products such as cheese, is to keep the product in cold storage for a number of days to allow it to absorb all the carbon dioxide, which sucks the packaging material onto the surface to create a snug fit. If this tight fit is not seen, it suggests that a leak is present and the product must be repackaged. This, however, is a time-consuming and slow leak detector approach, and furthermore it needs a large amount of storage space.
Dansensor’s Package leak detection programme for seal integrity
MOCON Europe’s (Dansensor’s) leak detection systems offer both on-line and off-line leak detection of modified atmosphere packages and whole shipping crates for seal integrity assurance. Furthermore, Dansensor’s innovative leak detection equipment allows package leak detection non-destructively.
Off-line leak detector system for seal integrity
LeakPointer II is Dansensor’s off-line package leak detector system. The operator manually inserts the wrapped and sealed product into the testing chamber and lowers the lid. A pump evacuates the leak detector chamber, which is being constantly monitored for CO2.
If the seal integrity of the packaging has been compromised, the protective atmosphere will enter the chamber and the sensor in the package leak detector system will pick up the elevated level of CO2, a trace gas in many modified atmosphere packages. If the leak detection system does not indicate a leak – seal integrity is confirmed – the package remains intact and unspoilt.
On-line leak detector system for seal integrity
Automatic package leak detection is possible to integrate into the packaging line by using the innovative Dansensor® LeakMatic II on-line leak detector. The enlarged size of the Dansensor LeakMatic II leak detector allows it to accommodate and test complete transport boxes for seal integrity.
Packages coming off the line can feed directly into the Dansensor LeakMatic II leak detection control. As with the Dansensor LeakPointer II leak detector the test chamber is evacuated and a sensor monitors changes in CO2 concentration to monitor the sealing integrity. It is possible to incorporate Dansensor LeakMatic II at the end of the packaging line so that all units are tested.
An alternative approach is to divert random samples to a parallel conveyer which will feed these samples into the leak detector. For example, on a cheese production line one in every ten packages could be diverted into the Dansensor LeakMatic II to provide reliable quality assurance for that particular production line.
If the leak detector is triggered, an alarm sounds and the relevant leaking packet is diverted along a reject line. The Dansensor LeakMatic leak detector is also fast, and is able to test for sealing integrity in four to six shipping cartons each minute.
A cheese producer in the United Kingdom installed a Dansensor on-line leak detector and rapidly discovered that seal integrity had been compromised to a far greater extent than had previously been realised. With this leak detector the manufacturer was able to trace the fault to an upstream packaging problem and resolve the seal integrity issue (for more information on this leak detector success story, click on Case Study on the Dansensor LeakMatic II page by clicking Dansensor LeakMatic II on the side menu of this page).
Other Dansensor leak detector systems for ensuring seal integrity
MOCON Europe (Dansensor) has developed package leak detection equipment for seal strength and flexible and semi-rigid packages. The Dansensor® Lippke 4000 and 4500 are especially useful for packaging research and testing.
Testing seal integrity with a leak detector – summary:
- Seal integrity is vital in modified atmosphere packaging
- A leak detector is a key part of the seal integrity quality control process
- Dansensor has developed a state-of-the-art leak detector programme for seal integrity test methods
- The package leak detector methods are non-destructive
- Dansensor’s package leak detector equipment can be used to test seal integrity off-line or on-line
- Off-line seal integrity test methods are operated with a manual leak detector
- On-line seal integrity test methods operate with an automatic leak detector
- The on-line leak detector system is rapid, and can test up to six shipping cartons per minute for seal integrity
- An efficient seal integrity monitoring system with a first-rate leak detector can identify potential problems with the packaging process before these problems become serious
- Dansensor’s package leak detection equipment makes slow, old-fashioned seal integrity monitoring techniques such as a water bath leak detector redundant, and delivers much more efficient use of workers’ time
- A Dansensor seal integrity monitoring system on your site will save you time in your leak detector programme and result in an efficient production line with the minimum of problems caused by seal integrity issues
- An efficient leak detector saves time and money!
For further information on individual leak detector products to ensure seal integrity, click the relevant product in the menu bar on the left. To contact Dansensor about any of our leak detector products, click the ‘Contact’ button on the menu bar at the top of the page.
We can help ensure that you have a first-rate leak detector system on your production line so that you can be certain of your seal integrity!
MOCON Europe’s (Dansensor’s) leak detector range for seal integrity - Dansensor LeakPointer 3, Dansensor LeakMatic II, Dansensor Lippke 4000/4500.