Many industrial products must be leak-tight. Food, cosmetics, or pharmaceutical packaging, but also products such as lights in the automotive industry, electronics, or plastic components. But how can manufacturers test the leak-tightness of their products?
The entry-level solution is to test in a water bath. This is a very simple, yet effective method. The test specimen is held under water and the tester watches for rising air bubbles. Very intuitive.
The product is not inflated but tested in a vacuum chamber. The product inflates itself, and bubbles escape from leaks. The important thing is: You know that the packaging is leaking, and you recognize where, allowing weak points in the process to be detected and eliminated. It is not without reason that Witt’s Leak-Master Easy is used by so many customers.
Practically everything that must be leak-proof. Often it is packaging, tubular bags, stand-up pouches or thermoformed trays, even vacuum packaging can be tested with the Easy. Mostly it’s about meat or sausage products, salad, bread, snacks, dairy products, pet food or medical products. Even coffee capsules are possible. And lights, bubble wrap, or plastic parts must also be leak-tight.
If it’s just a matter of checking for leaks and finding the sources of leaks, these devices are very good indeed. But there are limitations: Testing in water usually means I can no longer put the product on sale. Also, the test is performed manually, placing high demands on personnel who may influence the result.
A leak test using specific test gas and sensor technology. With the Leak-Master Pro 2, we have a device that determines the leak tightness of relevant products, using CO2 sensors. A vacuum is created in a test chamber to draw gas out of the leaking packaging. The parameters such as vacuum and measurement time are defined in advance by the customer, so the test is performed automatically. The PRO 2 displays the result on a rotating light signal. If the device lights up red, CO2 has been detected and the product is leaking. The test is completely independent of the inspector, standardized, and reproducible. Everything is documented digitally and can be exported.
The more CO2 in the packaging, the faster you can find a leak. Eight to ten seconds are often sufficient. Leaks of 10 micrometers or more can be detected, the microleaks that cause problems for manufacturers. CO2 testing is also non-destructive. After testing, the leak-proof packages can be put on sale without any problems, saving waste and costs.
Water bath devices provide the cheapest method; they’ve been proven over many years and work reliably. If I want to find out where my product is leaking, I need a water bath in any case. And if I don’t have CO2 in the product, or I have a vacuum pack, the water bath is the best option.
For more standardization and automation, CO2 units are a good choice because they do not need to be inspected by a human inspector. The result is still reliable even after the umpteenth test at the end of a long working day. You can test the leak-tightness without destroying the product. And finally, testing without water is cleaner and less complicated as regular changing of water and cleaning are not necessary.
Ideally, I have both devices. With the CO2 device, I perform all spot checks safely and non-destructively. In the case of a leaking package, I can use the water bath to find the position of the leak and eliminate the weak spot.
Only a 100% inspection offers 100% certainty. So, I usually need an inline solution. Here, too, machines with CO2 sensors have become well established in practice. Witt’s Leak-Master MapMax is used by food producers all over the world ensuring perfect packaging and thus the quality of their products.
As with the Pro 2, the MapMax receives all the packages from the packaging machine. A vacuum is created in a chamber. Sensors detect escaping CO2.
There is an alarm directly on the device. In addition, leaking packages can be physically rejected. Everything is fully automatic, it’s very fast and reliable. The MapMax manages up to 15 cycles per minute.
The MapMax is used to directly test whole batches or cartons. There are indeed some faster machines on the market where pressure is applied to the package from a roller. However, this method is quite coarse and only finds very large leaks. This is not fine enough for most products. In fact, testing outer packaging is the safest because the testing is done at the very end of the process. After that, the packaging is no longer touched and cannot be damaged.
Whether random testing or inline is required depends greatly on the product, the packaging, the process, the Best Before Date, plus also the distribution channels. But in any case, inline offers the maximum confidence.