GB/T 15171-2025 in English

Background and Significance of the Revision of GB/T 15171-2025 Standard

GB/T 15171-2025 "Test Method for Sealing Performance of Packaged Products" is a major revision of the 1994 version of the standard, reflecting the advancement of packaging testing technology and changes in industry needs. This revision not only expands the scope of application, but also introduces the advanced vacuum decay method, providing a more scientific and accurate technical means for packaging sealing performance testing.

Comparison of Main Technical Changes and Standard Framework

Technical Analysis of Core Test Methods

Principle and Application of Underwater Bubble Method

The underwater bubble method, based on the principle of pressure differential, determines sealing performance by observing bubble generation under vacuum conditions. This method requires the use of a transparent vacuum chamber and a transparent porous pressure plate to ensure that the test process is observable.

Key Parameter Control:The target vacuum level was set within the range of 20-90 kPa, the vacuum evacuation time was 30-60 seconds, and the pressure holding time was 30 seconds. The standardization of these parameters ensured the comparability of test results.

Technical Innovation in Vacuum Decay Method

The vacuum decay method quantitatively evaluates sealing performance by monitoring changes in the vacuum level within the test chamber. Precise measurements are achieved using a pressure sensor and a gas flow controller.

Technical Advantages:This method can detect minute leaks with high sensitivity and is unaffected by the hydrophilicity of the packaging material. The vacuum decay rate is calculated as: Q = (P₁ - P₂)/T, where Q is the vacuum decay rate (Pa/s), P₁ and P₂ are the pressures at the start and end of the test (Pa), respectively, and T is the test time (s).

Detailed Instrument Requirements

Underwater Bubble Method Instrument Configuration

The standard requires the instrument to consist of four major components: a vacuum source, a vacuum gauge, a vacuum chamber, and a control device. The vacuum source must be able to achieve a vacuum level of no less than 95kPa within 30-60 seconds, and the vacuum gauge must have an accuracy of no less than Class 1.

Innovations in Vacuum Decay Method Instrumentation

The vacuum decay method instrument structure differs for flexible and rigid packaging. Flexible packaging testing requires an air-conducting layer to ensure proper gas flow outside the specimen; rigid packaging uses a rigid test chamber design.

Key Components: The pressure sensor must have an accuracy requirement of no less than Class 1. A gas flow controller is used to verify test sensitivity, and a leak-free standard is used for system background correction.

Key Points and Common Problems in Test Implementation

Specimen Preparation and Handling

Specimens should be free of defects such as cracks and unsealed parts, and the number of specimens should be no less than three. For the vacuum decay method, specimens need to be conditioned at (23±2)°C and a relative humidity of (50±10)% for at least four hours.

Test Water Treatment

The new standard adds a test water treatment step, requiring the vacuum chamber to be evacuated and pressurized at a vacuum level no lower than the target vacuum level, and repeated until no bubbles that affect observation are generated, in order to remove dissolved gases in the water.

Result Judgment Criteria

Underwater Bubble Method: Qualified if no continuous bubbles are generated and no water infiltration occurs; Vacuum Decay Method: The vacuum decay rate must be calculated, and the test process must be monitored to ensure that the vacuum level does not meet the standard, falls below the reference vacuum level, or exceeds the measuring range.

Industry Applications and Practical Cases

Food Packaging Sealing Test

In the food industry, the sealing performance of packaging directly affects the shelf life of the product. The vacuum decay method can accurately detect tiny leaks, avoiding the problems that may be missed by traditional methods. After a well-known food company adopted the new standard, the product leakage complaint rate dropped by 42%.

Pharmaceutical Packaging Quality Control

Pharmaceutical packaging has extremely high requirements for sealing. The high sensitivity of the vacuum decay method is particularly suitable for detecting tiny defects in pharmaceutical packaging. Implementation cases show that this method can detect micropore leaks with a diameter of 0.1μm.

Industrial Product Packaging Verification

For moisture-proof packaging of industrial products such as electronic components and precision instruments, the new standard provides a more reliable detection method to ensure the integrity of the product during transportation and storage.

Standard Implementation Recommendations and Considerations

Laboratory Construction Requirements

Implementation of the new standard requires compliant testing equipment, particularly the vacuum decay method, which requires a specialized vacuum decay tester. The laboratory environment must maintain strict temperature and humidity control to ensure consistent testing conditions.

Personnel Training and Qualifications

Testers must undergo professional training and master the key operating points and result judgment criteria for both methods. In particular, equipment operation and data analysis for the vacuum decay method require specialized skills.

Method Selection Guide

The underwater bubble method is suitable for most routine testing and is relatively low-cost; the vacuum decay method is suitable for high-precision or automated testing scenarios. Companies should select the appropriate method based on product characteristics and quality requirements.

Compliance Transition Arrangements

Companies are advised to complete equipment upgrades and method conversions within six months of standard implementation. During this period, the two methods can be used in parallel for comparison to ensure the consistency and reliability of test results.

Technology Development Trends and Outlook

With the continuous development of packaging technology, sealing performance testing will develop in the direction of higher precision and greater intelligence. In the future, artificial intelligence-based leakage pattern recognition technology and high-level integration with production line online detection systems may appear.

The implementation of GB/T 15171-2025 will promote the improvement of my country's packaging testing technology level, provide more scientific and reliable technical support for corporate quality control, and promote the high-quality development of the packaging industry.