Testing packaging seals’ reliability enables manufacturers to ensure that food packaging offers the necessary product protection. Seal integrity tests are routinely used in manufacturing to check seal strength and certify that packaging seals do not break during transportation. While the equipment used to assess the seal integrity can be either destructive or non-destructive, operators need to understand their requirements and weigh the benefit of cost optimization and waste minimization when selecting an appropriate system for their applications.
The Sealtick TSE6086b flexible packaging leak tester is widely used in the industry to check for the seal integrity of food packaging using the non-destructive vacuum decay testing principle. Compared with the traditional underwater leak tester, it can determine whether the package leaks without damaging it. This test method allows the products to be returned to the production lines after the test, thus minimizing production waste and saving costs. The TSE6086b non-destructive leak tester is ideal for highly perishable products or packages containing high-value items such as milk powder, snack food, etc.
In the packaging industry, leak testing has been widely implemented. This practice ensures that contaminants such as air, oxygen, moisture, bacteria and soil, which could compromise the integrity of the products, do not leak into the packaging. This is because, in the event of a leak, the contaminants could ruin the contents by decreasing their shelf life and making them unfit for consumption.
For instance, when moisture comes in contact with food or organic products, it will act as a catalyst to speed up its decomposition and promote the growth of aerobic bacteria and mold. Therefore, ensuring that the packages are air-tight ensures that the contents will stay fresh and last until after their stated expiry date. The packaging industry also injects modified gases such as carbon dioxide and nitrogen to preserve their content and increase the product’s shelf life.
Visual leak testing of packages is undesirable and ineffective. There is always a possibility of a microleak that cannot be detected visually. While most consumers check for the physical appearance of the packages, they will not notice the leak and consume the damaged products, which will cause them various health issues. Therefore, it is recommended that reliable leak testers are used to assess the integrity of package seals before the packages make their way to consumers.
Technologies used for Testing Packaging Leaks
Underwater Leak Testing
In the underwater leak testing, the packages are submerged underwater in a closed pressurized chamber and are put into a vacuum. Leaks are located by looking at the bubble that rises from the suspected leak location. While this technique can identify the exact location of the leak, it relies on the operator to make an appropriate judgment. Therefore, this technique can be unreliable after long hours of operations due to fatigue. This test method produces waste as the tested packages must be discarded and cannot be returned to the production line.
Pressure decay testing
Pressure decay leak testing involves inserting the package in a sealed chamber where the air is evacuated to create a controlled vacuum environment. Leaks are identified if the chamber takes longer or never reaches the preset vacuum level. This method can detect even the fine-sized leaks represented by the rapid pressure decay towards atmospheric pressure after vacuum stabilization is turned off. This test can also be programmed to set the standard passing value depending on the maximum allowable leak rates and package types.
Optical Laser-Based detection system
Comparatively new technology, the optical laser-based detection system, enables manufacturers to test nearly all MAP-based packaging in the production line to accomplish 100% quality testing. However, this test is especially applicable for MAP-based packaging that uses CO2. The detection system sends a laser beam with a narrow wavelength range in the infrared band to the detector. The system identifies a leak if the receiver detects the presence of CO2 gases in the chamber, quantified by the wavelength intensity of the emitted beam. Currently, this technique is only applicable for MAP-based packaging that uses CO2 as the filling gas.
Quality control and seal testing in the packaging line
In a factory setting, thousands of products pass through each packaging line per minute. Manufacturers who intend to incorporate leak testing as part of routine quality control, must first identify their requirements and then select the most suitable leak testing systems for their needs.
For instance, if the manufacturers aim for 100% product testing, a laser-based detection system will be appropriate since it can perform automated, quick, accurate leak testing without disturbing the production line. However, if the manufacturing plant has several production lines, they must invest significant capital in installing the machines on each production line. They will also be limited in the application to test only products that use CO2 as the filling gases.
On the other hand, underwater leak testing can accurately pinpoint the leak location. Understanding where it leaks allows the manufacturer to identify the faulty machinery along the packaging line and make an immediate adjustment with minimum downtime. However, the test itself is time-consuming and unreliable as it is operator-dependent. Moreover, packages will be damaged after the test and cannot be repacked. If they need to test hundreds of products daily for each production line, it is a significant profit loss and creates tremendous waste.
The vacuum decay leak tester offers compromise to allow reliable testing with minimum intervention. The method only takes about 5 to 20 seconds to complete each test. While this system has limitations of not enabling 100% testing, manufacturers can still accomplish the main goal by sampling enough packages. Operators can add more equipment to the production line if more tests are required. As the test is non-destructive, each tested product can be returned to the packing line, reducing manufacturing waste.
Types of Packaging for Testing
The Sealtick TSE6086b non-destructive vacuum decay packaging leak testers have been successfully used for leak testing applications in food and pharmaceutical manufacturing. Manufacturers of dried snacks including chips, biscuits, and other snacks, as well as producers of canned foods and coffee beans are a few examples of customers that use Sealtick TSE6086b for their leak testing applications.
Sealtick vacuum decay leak testers can be used in nearly all packaging leak testing situations as long as the packages contain gases. The test is independent of gases used to fill the packages because leakages are quantified by the rate of pressure decline rather than detecting the leak of a gaseous substance. As a result, it offers countless opportunities for applications in a variety of fields, including process, medical, and pharmaceutical businesses, in addition to those that produce food.
The devices are available in various models and configurations to test the seal integrity of cans and heavy bag seals. For example, the sample will be placed into the custom-designed annulus instead of flexible bags in can testing applications. This configuration is meant to reduce the air volume in the chamber to achieve a better resolution reading.
There are many different types, qualities, and configurations of consumer packaging. Each packaging needs a unique test procedure for accurate leak quantification. The TSE6086b may not reliably test for leaks in liquid products or products that contain a high moisture content, as the moisture may form bubbles that could conceal the leak. In addition, the TSE6086b is also unsuitable for testing vacuum-packed products such as cheese or cured/processed meats due to the absence of air.
Industrial Capability
The Sealtick system delivers long-lasting capability even when utilised in an industrial environment due to the sturdy stainless-steel housing. All test results are kept in the device’s internal memory for 30 days, where they can be simply exported for analysis and quality control via USB or Ethernet.
While the TSE6086b can reliably identify packaging leaks without hindering production, it cannot inform the operator of the precise leak location. Using the TSE6086b together with an underwater leak tester can be advantageous. Operators can insert the failed packages from the TSE6086b into this water bath to locate the leaking point. The bubble leak tester is not employed as the leading equipment for quality control but rather as a secondary system to help operators find the leak.
Local Technical Expertise and Support
In the manufacturing and B2B sectors, having quick access to local technical help is essential since prolonged downtime caused by system failure is expensive for the company. The Sealtick leak testing system is manufactured and continuously improved in our in-house facility by our engineers at Bestech Australia. With our extensive knowledge and experience, we can help you with all of your packaging leak testing needs.
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