Sākums » Retort Packaging: Ensuring Flex Durability Using Flex Tester and ASTM F392 Gelbo Flex Method

Retort Packaging: Ensuring Flex Durability Using Flex Tester and ASTM F392 Gelbo Flex Method

Retort packaging has become an essential solution for high-temperature food sterilization processes, offering long shelf life without refrigeration. Found in ready-to-eat meals, soups, sauces, and even pet foods, this packaging must endure harsh thermal processing and repeated handling without compromising its barrier properties. A key factor in maintaining seal integrity and product safety is the material’s elastības izturība, tested using a flex tester based on the Gelbo flex motion defined in ASTM F392.

In this article, we’ll explain why flex durability matters for retort packaging, introduce the ASTM F392 standard and Gelbo flex test, and recommend how manufacturers can optimize testing using Cell Instruments’ GFT-01 Gelbo Flex Tester.

Why Flex Durability Is Critical for Retort Packaging

During processing and transportation, retort packaging experiences repeated mechanical stress such as bending, twisting, and folding. These motions can create microcracks or pinholes in the flexible barrier materials, especially near seal areas or folds. Such defects may not be visible but can compromise oxygen and moisture barriers, leading to spoilage, nutrient degradation, or microbial contamination.

Testing the elastības izturība of retort films ensures:

Resistance to mechanical fatigue
Retention of barrier properties after flexing
Improved shelf life and consumer safety
Compliance with packaging standards and client specifications

To simulate real-world mechanical stress, the Gelbo flex test provides a repeatable, standardized method to measure a film’s resistance to flex-induced damage.

Flex Durability Evaluation with Flex Tester and ASTM F392 Standard

The ASTM F392 standard defines the Gelbo flex test method, which evaluates the flex resistance of flexible barrier materials. The test involves twisting and compressing a specimen under controlled cycles to simulate handling and transportation stress.

The key components of this test include:

Flex tester setup: A mechanical system that twists the specimen back and forth (typically ±440° twist and 38 mm compression).
Cycle count: The material is subjected to a specified number of flex cycles (e.g., 20, 100, 270 cycles).
Pinhole detection: After flexing, samples are analyzed for micro-perforations using a dye penetration method, vacuum decay, or visual inspection.
Result interpretation: The number and size of pinholes indicate the film’s elastības izturība.

Using a high-quality flex tester ensures consistent results aligned with ASTM F392, which is vital for internal quality checks, regulatory audits, and customer specifications.

Introducing the GFT-01 Gelbo Flex Tester by Cell Instruments

To accurately assess the durability of retort packaging films, the GFT-01 Gelbo Flex Tester from Cell Instruments offers a professional-grade, automated testing platform:

Compliance with ASTM F392 ensures standardized testing and easy data comparison.
Precision-controlled movement guarantees consistent twist-compression actions throughout all test cycles.
Customizable settings allow adjustment of flex angles, stroke distance, and cycle counts based on product type and durability requirements.
Optional pinhole detection attachments (e.g., vacuum decay modules) allow integrated analysis after flex testing.

By using the GFT-01 flex tester, labs and quality assurance teams can simulate real-world mechanical fatigue and evaluate how well a packaging structure performs under stress.

Applications and Advantages in Real-World Packaging

The importance of flex testing in retort packaging extends across several industries:

Food manufacturers can validate packaging shelf life and prevent spoilage.
Medical packaging developers ensure that sterilization pouches retain seal integrity after flexing.
Flexible film producers optimize material blends for better resistance to mechanical fatigue.
Regulatory testing labs can use ASTM F392-compliant data to support certification and compliance.

Benefits of proper flex durability testing include:

Reduced packaging failure rates
Enhanced customer satisfaction
Safer, longer-lasting products
Greater confidence in material sourcing and film conversion

Conclusion

Ensuring retort packaging can withstand mechanical fatigue is vital to maintaining safety, performance, and market acceptance. The Gelbo flex method, as defined by ASTM F392, provides a robust and repeatable way to assess elastības izturība. With the support of the GFT-01 Gelbo Flex Tester from Cell Instruments, quality assurance professionals can streamline their testing process, minimize risk, and confidently meet international standards.

For any business involved in food, medical, or flexible barrier packaging, implementing accurate flex testing is a crucial step toward delivering reliable, high-quality products to the market.

Retort Packaging: Ensuring Flex Durability Using Flex Tester and ASTM F392 Gelbo Flex Method