Pouch Seal Integrity Testing
Seal integrity is extremely important for preventing contamination or spoilage of a canned food product. Here is why proper canned food or pouch seal integrity testing is an important and most effective method for evaluating seal integrity testing for canned food.
Why Seal Strength Testing Is Important?
Poorly sealed cans and pouches can cause major problems for food businesses. In addition to product waste, improperly sealed cans may result in spoilage of the product or contamination. That is why seal strength testing is important to ensure both these scenarios do not occur which will result in costly product recalls.
Another reason for employing can or pouch seal integrity testing is to reduce the risk of product recalls. Any company that sells canned food products risks its reputation if a canned product is recalled. Product recalls can result in lawsuits from vendors, liability for injury and illness and other monetary losses. Product recalls can also attract the attention of food safety regulators, which often results in fines and penalties. Seal strength testing will help reduce these risks and ensure to keep the reputation of the product and manufacturer from being tarnished.
What are Seal Integrity Test Methods and How to Perform Leak Tests?
Traditionally, visual observation is often used as a seal integrity test method by examining the seam and detecting leakage. Spoilage may result from leakage when improper pressure control is applied during the retorting and cooling operations. It results in stress on the seam of the can.
Examination of the defects and general exterior conditions of the can or pouch check on the quality of the seams, confirm if there are any mechanical defects, perforations, rust spots and dents.
Pressure and Vacuum Leak Testing
Pressure and vacuum leak tests are recommended for modern can and pouch seal integrity testing to detect any invisible micro leaks, either inside seams or double seams. A vacuum test is conducted by applying a vacuum to the can once it is sealed with the product inside. If leaks exist, the vacuum level surrounding the can will drop, indicating air leaking out of the can. The vacuum leak test is recommended over pressure tests because it is considered to be a more effective seal integrity test method.
Mead Jar Testing
Another seal integrity test method is the mead as tasting. A mead jar test is a non-destructive test that can determine the leakage paths for finished cans that have double seamed ends. It is typically used for dried or semi-dried products that have been vacuum packaged. The test is not generally used for items that have been thermally processed in metal cans.
Air Pressure Testing
Air pressure tests are performed in order to detect container leakage that is caused by perforations, pinholes and defective side seams. Air pressure testing as a seal integrity test method is also helpful for finding the source of double seam leaks. Air pressure testing can result in distortion of the double seams, which can result in minute leakage paths being sealed off or false leakage paths being produced. As a result, it is generally recommended to use this seal integrity testing method along with fluorescein testing or penetrant dye testing.
Other methods for can or pouch seal integrity testing that are currently under development include the laser holographic method and the helium leak test.