Vacuum Leak Test Definition

A vacuum leak test is a non-destructive quality control procedure used to identify and locate leaks in sealed packages or containers. The test involves placing the packaged item inside a sealed chamber and evacuating the air to create a vacuum. If a leak is present, air or gas will escape from the package into the chamber. This is detected either by a pressure rise in the evacuated chamber in the Vacuum Decay method setup,  or by observing bubbles escaping from the package while submerged in a water bath in the Bubble Emission method setup. This method is essential for verifying the seal integrity of packaging, ensuring it protects the contents from environmental factors. The reliability of this test depends on the use of calibrated precision test instruments to apply and monitor the vacuum level accurately. It is widely applied in industries like food, pharmaceuticals, and medical devices to prevent contamination and preserve product shelf life.

Vacuum Leak Test Procedure

The standard vacuum leak test procedure begins by placing the package into the vacuum chamber, which is then securely sealed. The air is evacuated from the chamber to a predetermined vacuum level, which is held for a specified time. During this period, the vacuum chamber is monitored for pressure change, indicating a leak. In bubble emission method setup,  the package can be submerged in water, where a stream of bubbles will emanate from any leak path. The entire process must be carefully controlled, with parameters like vacuum level and dwell time set according to the package’s material and design specifications. We at Labthink provide equipment that automates much of this process, ensuring consistent and repeatable results. Proper procedure execution is critical for accurate pass/fail determinations and maintaining product quality.

Vacuum Leak Test Results

The test result is determined by comparing the observed pressure increase  during the measurement cycle against a validated threshold. A result is considered a ‘Pass’ only if the pressure rise remains within the statistical limits of a non-leaking reference sample.

A pass result indicates that the package seal is intact and provides an effective barrier, which is critical for product safety and longevity. A fail result means a leakage in the packaging and the integrity of the container is compromised. These results are quantitative, allowing for comparison against established acceptance criteria and quality standards.

Accurate results help manufacturers identify flaws in their packaging processes, enabling corrective actions to be taken prevent non-conforming products from reaching the market.

Conclusion

Labthink manufactures test instruments for evaluating packaging material physical properties such as leak and seal integrity, and tensile strength, as well as permeability test instruments that measure the transmission rates of gases like oxygen, water vapor, and carbon dioxide through packaging materials.  These instruments are used for quality assurance in industries including pharmaceuticals and food. For your testing needs, we offer specific product models like the C190H Air Permeability Tester, the C403H Oxygen/Water Vapor Transmission Rate Test System, and the C690H Nondestructive Package Leak Detector.

The principle of volatile corrosion inhibition is by using VCI, volatile corrosion inhibitor which can be evaporated under normal temperature so as to achieve saturation in the closed environment; VCI molecules are absorbed onto the metal surface to form a transparent protection film of several molecules thick after complicated physical and chemical reactions. This transparent protection layer is water proof, difficult to be dissolved and thus, can stop further corrosion. Evaporated VCI molecules can reach anywhere in the package with best anti-rust performance. VCI plastic material is manufactured by polyolefin resin with VCI under processes.

Volatile corrosion inhibiting film testing should adopt US military specification MII.PRF-22019D “Barrier Materials, Transparent, Flexible, Sealable, Volatile Corrosion Inhibitor Treated” and other domestic and international standards.

1.VCI Thickness Testing

Whether the thickness of VCI plastic film is even or not is the basic for VCI film and its performances. Uneven thickness would affect the tensile strength, permeation of different parts of the package; and would affect the following processing. Thickness testing methods are varied. For VCI plastic film thickness measurement, ISO 4593 and GB/T 6672-2001 are applicable.

Labthink PARAM CHY-C2 and CHY-CA Thickness Testers are both high precision thickness testers for VCI plastic film thickness testing with the resolution upto 0.1um. Labthink PARAM CHY-CA Thickness Tester, besides its high precision, high efficiency and other characteristics and functions to similar PARAM CHY-C2, is equipped with automatic feeding system to satisfy the constant and effective testing requirements of the clients with greater testing efficiency.

2. VCI Plastic Film Impact Testing Instruments

VCI (Volatile Corrosion Inhibition) plastic film impact property and its control could avoid package breakage owing to the insufficient toughness, so as to effectively get rid of product rustiness caused by inferior impact or shock resistance of the VCI plastic packages during circulation.

VCI plastic film impact testing is in compliance with ASTM D3420, GB/T 8809-1958 and other international standards. Labthink PARAM FIT-01 Film Impact Tester is in strict compliance with these standards and with more advanced functions. For example, Labthink PARAM FIT-01 Film Impact Tester is of pneumatic specimen clamping and pneumatic pendulum releasing, which is completely different from other products that are manual clamping. Pneumatic clamping is rapid and effective with even clamping force on the four sides of the film, and will not slide during impact with inaccurate results. Besides, the precision of PARAM FIT-01 Film Impact Tester is up to 0.001J, whereas other impact testers are mostly of mechanical type with low precision through reading the graduation on the board.

3. VCI Plastic Film Tear Resistance Testing

The VCI (Volatile Corrosion Inhibition) packaging material may be torn by exterior forces during storage and transportation. Sufficient tear resistance can reduce the transmission of tear and avoid rusting caused by leakage. The testing for tear performances of VCI packaging material is of Elmendorf method; and Labthink PARAM SLY-S1 Tearing Tester can be applied for this test. This tester is computer control, display and horizontal adjustment that guarantees reliable and accurate testing results; the unique ‘3-ring’analysis technology can help the operators with more direct analysis and evaluation.

4. VCI Seal Performance Testing

VCI (Volatile Corrosion Inhibition) packages, owing to strict requirements, its seal performance testing is quite important. Seal performance is defined as the characteristic of avoiding alien substance entering into or contents coming out of the package. Usual testing methods are as follows:

4.1 Underwater Decompression Method:

Labthink PARAM MFY-01 Leak Tester is on underwater decompression method according to GB/T 15171-94 Test Method for Leaks in Sealed Flexible Packages. Put a certain amount of distilled water into the vacuum chamber, and put the sealed vacuum container into the distilled water completely. Then, set the testing pressure and testing time. Usually, the vacuum degrees are 20, 30, 50 and 90 kPa, etc. Start testing. When the leak tester has reached a certain vacuum degree, stop vacuumizing and observe. The inner-out pressure difference of the specimen will cause inferior quality specimen leak so as to test leakage.

4.2 Pressured Testing Method

Labthink PARAM LSSD-01 Leak and Seal Strength Detector is of pressured testing method. Imposing high pressure gas into the vacuum container and test the pressure resistance, sealing degree and leak indexes so as to test integration and seal performance of the vacuum container.

Labthink, the excellent provider of testing instruments and testing services, is devoted to provide most excellent and complete quality control solutions for pharmaceutical, foodstuff, cosmetics, packaging, printing, adhesive, automotive, petrochemistry, environment, biology, new energy, construction, aviation and electronic industries worldwide.

5. Barrier property testing

Barrier property is defined as the barrier performance of packaging material against liquid or gas permeable substances. The entry of oxygen would greatly increase the possibility of oxidization of metal contents, and the water vapor barrier property is of even more importance.

For gas barrier property, Labthink introduces PERME VAC series Gas Permeability Testers and Labthink PERME OX2/230 Oxygen Transmission Rate Test System that comply with relevant ASTM, ISO or GB standards (such as GB 1038 and GB 1037). For water vapor barrier property testing, Labthink PERME TSY-T series Water Vapor Permeability Testers and Labthink PERME W3/330 Water Vapor Transmission Rate Test System are applicable.

Further details please feel free to contact Shirley via:
TEL: 0086-531-85061080
FAX: 0086-531-85062108
EMAIL: trade2@labthink.cn
SKYPE: shirley-labthink
MSN: shirleywu_labthink@hotmail.com

More about Labthink(http://www.labthink.cn/en):
Labthink focusing on the laboratory testing instruments R&D and production and laboratory IT services, is dedicated to provide professional quality control solutions for customers in packaging, food, pharmaceutical, medical, daily chemistry, printing, adhesive, automotive, petrochemistry, bioscience, construction, new energy and other industries.

Customers worldwide(parts):

Labthink, think for you only!

1. Underwater Decompression Method:

Labthink PARAM MFY-01 Leak Tester is on underwater decompression method according to GB/T 15171-94 Test Method for Leaks in Sealed Flexible Packages. Put a certain amount of distilled water into the vacuum chamber, and put the sealed vacuum container into the distilled water completely. Then, set the testing pressure and testing time. Usually, the vacuum degrees are 20, 30, 50 and 90 kPa, etc. Start testing. When the leak tester has reached a certain vacuum degree, stop vacuumizing and observe. The inner-out pressure difference of the specimen will cause inferior quality specimen leak so as to test leakage.

2. Pressured Testing Method

Labthink PARAM LSSD-01 Leak and Seal Strength Detector is of pressured testing method. Imposing high pressure gas into the vacuum container and test the pressure resistance, sealing degree and leak indexes so as to test integration and seal performance of the vacuum container.

Further details please feel free to contact Shirley via:
TEL: 0086-531-85061080
FAX: 0086-531-85062108
EMAIL: trade2@labthink.cn
SKYPE: shirley-labthink
MSN: shirleywu_labthink@hotmail.com

More about Labthink(http://www.labthink.cn/en):
Labthink focusing on the laboratory testing instruments R&D and production and laboratory IT services, is dedicated to provide professional quality control solutions for customers in packaging, food, pharmaceutical, medical, daily chemistry, printing, adhesive, automotive, petrochemistry, bioscience, construction, new energy and other industries.