Source: Link Testing Instruments Co.,ltd
GB/T 15171-2025, "Test Methods for Sealing Performance of Packaging," was released in August 2025 and will be implemented in February 2026, replacing the 1994 version. It primarily addresses the insufficient detection capability of traditional methods for micro-leakage. This standard clarifies two non-destructive testing methods: the vacuum decay method and the underwater bubble method, and provides detailed specifications for equipment technical parameters and application scenarios.
I. Core Changes in the Standard
Expanded Scope of Application: Expanded from single flexible packaging to flexible, semi-rigid, and rigid packaging, covering diverse packaging forms such as instant noodle composite films, aluminum-plastic bags, glass bottles, and plastic bottles.
New Testing Methods: Retains the traditional underwater bubble method and adds the vacuum decay method, addressing the low sensitivity and high subjectivity issues of traditional methods.
Improved Testing Accuracy: Vacuum degree control accuracy reaches ±0.5kPa
Pressure Holding Time extended to 60 seconds
Significantly improved detection rate of minute leaks
Upgraded detection method: Shifting from qualitative to quantitative detection, quantifying the degree of leakage through "vacuum decay rate" (Pa/s)
II. Non-destructive sealing test method for micro-leakage
Test principle: The sample is placed in a vacuum chamber filled with test water. A vacuum is created in the chamber, generating a pressure difference between the inside and outside of the sample. The escape of gas from the sample and the infiltration of test water into the sample are observed to determine the sample's sealing performance.
Scope of application: Applicable to packaging where the test water has no significant impact on the outer material of the packaging (such as glass, metal, most plastics, and composite material containers).
Test Procedure:
Sample Preparation: Completely immerse the package to be tested in the water within the vacuum chamber, ensuring the top of the package is ≥25mm below the water surface.
Pre-degassing: Evacuate the vacuum chamber to remove trace gases from the water.
Evacuation: Reduce the pressure in the vacuum chamber to the set value (-30kPa to -90kPa).
Bubble Observation: Maintain the vacuum state for 30-60 seconds and observe whether continuous bubbles are generated on the surface of the package.
Result Judgment: If continuous bubbles appear (a single isolated bubble is not considered a leak), it is considered a leak.
Advantages: Intuitive operation, high sensitivity.
Limitations: Limited sensitivity, typically able to detect leaks in the 10μm range; affected by environmental factors such as water temperature and bubble surface tension.
Test Principle: The sample is placed in the test chamber, and a vacuum is evacuated to create a pressure difference between the inside and outside of the sample. A pressure sensor monitors the change in the vacuum level within the test chamber to determine the sample's sealing performance.
Application Scope: Applicable to sealing performance testing of various non-vacuum packaging materials, including flexible and rigid packaging.
Key Testing Parameters:
Vacuum Decay Rate (Pa/s): The core indicator for quantifying the degree of leakage.
Detection Sensitivity: Detects leakage channels of 3μm and above; some high-end instruments can detect leaks up to 1μm.
Test Time: Approximately 30 seconds.
Advantages:
Non-destructive Testing: Packaging remains intact after testing and can be used for subsequent inspection.
Quantitative Testing: Provides objective and traceable test data.
High Sensitivity: Far superior to traditional underwater bubble methods.
Wide Applicability: Covers flexible packaging, semi-rigid packaging, and rigid packaging.
III. Recommended Mainstream Testing Equipment
NDL-V301 Micro-Leakage Sealing Tester(Produced by Link Testing)
Core Advantages:
1. Intelligent Operation and Compliance
Industrial-grade touchscreen computer with Windows operating system, supporting one-click testing, real-time data display, and curve analysis, offering simple and intuitive operation.
Compliant with GMP requirements, supporting multi-level access control, audit trails, and data encryption to meet drug regulatory audit needs.
2. Flexible Adaptability to Multiple Scenarios
The test chamber features a pneumatic clamping design, compatible with various sample sizes such as vials, pre-filled needles, and food soft bags.
Single test time ≤ 30 seconds, supporting batch testing on production lines and improving efficiency.
IV. Application Cases and Industry Value
Pharmaceutical Industry: Used for aseptic validation of powder injection and lyophilized product packaging, avoiding contamination risks caused by micro-leakage.
Food Industry: Testing the sealing performance of milk powder cans and vacuum packaging, extending shelf life and ensuring food safety.
Medical Devices: Validating the antibacterial performance of sterile medical device packaging, conforming to YY/T 0681.18 standard.
Conclusion:
The implementation of GB/T 15171-2025 marks Chinese formal entry into an era of high precision, standardization, and intelligent testing for packaging seals. The vacuum decay method, as a newly added core testing method in the standard, possesses significant advantages such as non-destructive testing, high sensitivity, and quantifiability, and will become the mainstream method for non-destructive sealing testing of micro-leaking packaging in the future.
