Many people are reluctant to inspect the condition of food packaging material while they are grocery shopping. However, consumers must be aware of leaks in packaged foods since the reliability of the leak detection equipment used by the manufacturer is not always 100% correct. Leaks in packaged foods can cause food poisoning as it may contain organisms which might contaminate it. To solve this problem the consumer needs to be aware of methods and equipment used to detect leaks in packaged foods.
There are six methods used for leak testing.
Method # 1: Ultrasonic Measurement
All leaks produce sounds relative to their size, and the frequency produced by the sound can either be high or low. In the case of small leaks the sound produced has a high frequency thus the ultrasonic leak detector is applied to detect the sound.
Ultrasonic detectors are small gadgets which are hand held, and they are accompanied with a pair of headphones, a meter, and a sensitive adjustment nozzle. Leaks found in the food packaging material are easily measured using the ultrasonic detector. In addition, the device can identify the leak rate.
Method # 2: Bubble Test
Unlike the previous method, the application of this method is quite simple. In case the consumer suspects a leak in the food packaging material, the customer is expected to pressure the package, and submerge it water basin. The presence of bubbles in the emerging from the water surface confirms that the packaging material is leaking.
Method #3: Pressure Decay
According to scientific laws, the presence of a leak in packaging material reduces the internal pressure of the object. Therefore, before testing for the leak, the packaging material needs to be charged using dry air or nitrogen at a set pressure level. The recorded pressure is then monitored over a given period. When the pressure of the material reduces, it confirms that the food packaging material is leaking. Many people prefer to apply this method since it is simple, compact and reliable. In addition, the method is relatively cheap and free from bias.
Method #4: Vacuum Decay Test
Vacuum decay test is the complete opposite of pressure decay testing. It involves complete evacuation of a certain part of the packaging material, and its pressure has to be stabilized. Any pressure that builds up after the stabilization is measured. This method, however, requires food packaging material that can survive being in a vacuum. Applying this procedure is better since it cannot be affected by temperature changes and it is very sensitive in identifying leaks.
Method # 5: Helium Sniff
For this procedure to be effective, a helium sniffer is necessary since it is the leak detection equipment. Pressurized helium is charged into the food packaging material, and the surface is scanned with a helium sniffer. When the material has a leak, the concentration of the helium in the area the atmospheric air is leaking will be identified by the sniffer. The method is efficient since it identifies the exact location of the leak.
Method #6: Helium Spray
First, the part of the food packaging material to be tested is separated through a pumping system, which is attached to the helium detector. In case the isolation is successful, helium gas is then sprayed to the part being tested. Any leaks in the material will allow the gas to penetrate into the material. The helium detector can sense the gas the immediate time it enters the material. There are several advantages associated with the procedure such as detecting leaks with a high level of sensitivity, it compact and stable, and it is functional in mediums of low atmospheric pressure.