Products News
0102030405
How to test the sealing performance of liquid packaging bags?
2026-01-15
1. Introduction: Importance of Liquid Packaging Seal Performance Test
1.1 Critical Role of Seal Integrity in Liquid Packaging
Risks of poor seal performance: product leakage, microbial contamination, oxidation deterioration, and brand reputation damage. Industry impact: food, pharmaceutical, daily chemical, and industrial sectors’ strict requirements for Liquid Packaging seal performance.
1.2 Objectives of This Liquid Bag Seal Test Guide
Address the search intent: answer "how to test the seal performance of Liquid Packaging bags" comprehensively, provide actionable testing methods and standard guidance, help readers avoid misjudgment and ensure testing accuracy.
1.3 Key Questions on Liquid Packaging Seal Performance Test Answered
What are the reliable test methods for liquid packaging bag seal performance? Which international/domestic standards should be followed? How to select suitable testing equipment? What are the common operational mistakes and solutions? How to apply testing methods in different industry scenarios?
2. Core Test Methods for Liquid Packaging Seal Performance
2.1 Colored Liquid Penetration Test for Low-Air-Content Liquid Bags
Test principle: Use colored aqueous solution with obvious color difference from filter paper to detect micro-leakage. Detailed operation steps: sample preparation, liquid filling, sealing, placement on filter paper, 5-minute observation, and flip testing. Advantages: simple operation, low cost, suitable for rapid preliminary screening. Limitations: low sensitivity for tiny leaks.
2.2 Underwater Vacuum Test: Most Reliable for Liquid Packaging Seal
2.2.1 Vacuum Pump Method for Liquid Bag Seal Test
2.2.2 Vacuum Generator Method for Precise Liquid Seal Test
2.3 Air Tightness Test for Liquid Packaging Transportation Simulation
Test principle: Fill the test chamber with gas, detect pressure changes to calculate leakage rate. Operation steps: sample placement, vacuum pumping (-0.05MPa), nitrogen filling (20kPa), 10-minute pressure holding, and leakage rate calculation (leakage rate = (ΔP × V) / (t × A)). Advantages: simulates real transportation environment, suitable for liquid and Powder Packaging.
2.4 Comparison of Liquid Packaging Seal Test Methods
Table comparing colored liquid penetration test, underwater vacuum test, and air tightness test in terms of sensitivity, cost, operation difficulty, and applicable packaging types.
3. International & Domestic Standards for Liquid Bag Seal Test
3.1 ASTM D3078: US Standard for Flexible Liquid Packaging Seal Test
Standard overview: Latest version ASTM D3078-02(2021)e1, core requirements, test principle, and operation specifications (vacuum升压 speed: 1 inch Hg/sec; vacuum degree: 0.5~1.5bar; pressure holding time: 30s). Qualification criteria: no continuous bubbles, packaging volume expansion rate ≤5%.
3.2 GB/T 15171: China Standard for Liquid Packaging Seal Performance Test
Key content: Focus on underwater decompression method (Method A), applicable scope, test parameters (vacuum degree: -30kPa to -90kPa; pressure holding time: 30~60s), technical points (vacuum degree control, environmental stability, data traceability), and qualification judgment criteria.
3.3 Industry-Specific Standard Selection for Liquid Seal Test
Food industry: Compliance requirements for both domestic and export markets. Pharmaceutical industry: GMP-compliant data traceability requirements. Daily chemical industry: Adaptation to different liquid viscosity packaging testing.
4. Equipment Selection & Operation for Liquid Packaging Seal Test
4.1 Core Equipment for Liquid Bag Seal Performance Test
Key technical parameters: vacuum degree range, precision, bubble resolution, test efficiency, and data management functions. Common equipment models: BOGOO MFY-01A, Puchuang LT-03A, Quankeuruida LEAK-01.
4.2 Industry & Budget-Based Seal Test Equipment Selection
Small and medium-sized enterprises: Cost-effective options (basic vacuum generators). Large enterprises/pharmaceutical industry: High-precision equipment with GMP compliance, data export, and cloud storage functions.
4.3 Step-by-Step Operation for Liquid Seal Test Equipment
Pre-operation inspection, sample preparation, parameter setting (vacuum degree, pressure holding time), test execution, result recording, and post-test cleaning. Safety precautions: avoiding over-vacuum leading to packaging damage.
4.4 Maintenance & Calibration for Seal Test Equipment Accuracy
Regular maintenance items: vacuum pump oil replacement, seal ring inspection, and cleaning. Calibration cycle and standards: annual professional calibration to ensure parameter accuracy.
5. Common Failures & Solutions in Liquid Packaging Seal Test
5.1 Seal Failure Phenomena & Root Causes in Liquid Bag Test
Leakage at the seal: Causes include low heat-sealing temperature, insufficient time, uneven pressure, and contaminated seal area. Packaging rupture during testing: Excessive vacuum degree or poor material toughness. False positives/negatives: Unstable pressure or improper sample placement.
5.2 Targeted Solutions for Liquid Packaging Seal Failures
Optimizing heat-sealing parameters: Temperature (180-220℃), time (0.5-1.5s), and pressure adjustment. Material improvement: Selecting high-toughness composite films (e.g., LDPE+CPP). Equipment adjustment: Ensuring parallel upper and lower heat-sealing molds, regular cleaning of heat-sealing knives. Testing parameter optimization: Setting appropriate vacuum degree based on Packaging Material characteristics.
5.3 Case Study: Resolving Liquid Pharmaceutical Bag Seal Test Failures
Case overview: Leakage in infusion bag seal testing. Root cause: Contaminated seal area. Solution: Adjusting equipment parameters to prevent content contamination, using anti-contamination films. Test verification and effect evaluation.
6. Industry Applications & Best Practices for Liquid Seal Test
6.1 Food Industry Liquid Packaging Seal Test Requirements
Key requirements: Preventing microbial contamination and oxidation. Suitable test methods: Underwater vacuum test and air tightness test. Standards compliance: GB/T 15171 and relevant food safety standards.
6.2 Pharmaceutical Industry Liquid Bag Seal Test Standards
Critical requirements: Sterility assurance and data traceability. Suitable test methods: High-precision underwater vacuum test. Standards compliance: ASTM D3078 and GMP requirements.
6.3 Daily Chemical & Industrial Liquid Seal Test Applications
Key requirements: Preventing leakage during transportation and storage. Suitable test methods: Colored liquid penetration test (preliminary screening) and underwater vacuum test (precision verification).
Key requirements: Corrosion resistance and high barrier performance. Suitable test methods: Air tightness test and high-pressure underwater vacuum test.
6.4 FAQ & Best Practices for Liquid Packaging Seal Test
6.4.1 Key FAQs on Liquid Bag Seal Performance Test
7.1.2 How to determine the appropriate vacuum degree for different liquid Packaging Bags? (Answer: Based on material toughness and content characteristics, conduct gradient tests to find the critical vacuum degree.)
7.1.3 Is the colored liquid penetration test suitable for all liquid packaging bags? (Answer: No, it is mainly for low-air-content composite bags; not suitable for high-air-content or porous materials.)
6.4.2 Efficient & Accurate Liquid Seal Test Best Practices
Establishing standardized test procedures (SOP): Sample selection, equipment operation, and result recording. Conducting regular personnel training: Ensuring proficient operation and accurate result judgment. Implementing batch sampling inspection: Balancing testing efficiency and quality control.
6.5 Conclusion & Future Trends of Liquid Packaging Seal Test
Recap of core test methods, standard compliance, equipment selection, failure solutions, and industry-specific applications.
Manufacturers: Establish a comprehensive quality control system integrating testing into the production process. Testing personnel: Strictly follow standard operating procedures and conduct regular equipment maintenance. Purchasers: Prioritize suppliers with qualified seal performance testing capabilities.
Development direction: Intelligent testing (AI-assisted bubble recognition), automated data analysis, and integration of pressure-time curve analysis for quantitative leakage grading.