Seal Strength Package Testing

What is Seal Strength Integrity Testing?

Seal strength testing measures the strength of seals in flexible materials. This test type can also be conducted on seals between a flexible material and rigid material. Ultimately, this ensures the proper bonding of materials to maintain package integrity.

As an ISTA and ISO 17025 certified lab, we realize the importance of seal strength package testing. Meeting the seal integrity regulatory compliance requirements can be difficult. We understand the challenges and guide companies through the process.

Request a quote to learn why we are one of the fastest-growing package test labs in the country. Have a question about seal strength integrity testing? Contact us and we will determine the best course of action.

Why is Seal Strength Package Integrity Testing Important?

Seal strength package integrity testing plays a vital role in protecting product quality throughout the supply chain. Strong, reliable seals prevent contamination, spoilage, and degradation caused by moisture, oxygen, light, and other environmental factors. By verifying seal strength, manufacturers confirm that packaging preserves product freshness, performance, and shelf life.

For pharmaceuticals, medical devices, and food products, seal integrity is especially critical. Weak or defective seals can allow contamination, making products unsafe for use or consumption. In addition, seal failures may cause leaks, spills, or product exposure that create safety risks for consumers. By identifying these issues early, manufacturers can correct packaging defects before products reach the market.

Finally, many regulatory agencies require seal strength package integrity testing to demonstrate compliance with applicable safety and quality standards. As a result, routine testing helps manufacturers meet regulatory requirements while protecting both their products and their customers.

Seal Strength Package Testing Procedures

ASTM F88, Seal Strength Testing of Pouches and Flexible Materials establishes procedures for measuring the strength of seals in flexible barrier materials. Testing begins by selecting a representative sample of packaging units. Next, the samples are conditioned at 23°C and 50% relative humidity, typically for up to 40 hours, to ensure consistent test conditions.

After conditioning, technicians calibrate the tensile testing machine according to ASTM F88 requirements. They then select one of three approved test techniques based on the package design and seal configuration.

Technique A: Each tail of the specimen is secured in opposing grips while the seal remains unsupported throughout the test.

Technique B: Each tail is secured in opposing grips, but the seal is manually supported at a 90-degree angle to the specimen tails during testing.

Technique C: The less flexible tail is held flat against a rigid alignment plate secured in one grip. Meanwhile, the more flexible tail is folded 180 degrees over the seal and secured in the opposing grip. This configuration provides a consistent testing geometry for materials with different flexibilities.

Equipment Used for Seal Strength Package Testing

A tensile testing machine carries out the seal strength testing. The machine is equipped with a device for recording the tensile load and amount of separation of the grips. Flexible materials are indicated as materials with flexural strength and thickness permitting a turn back at an appropriate 180 degrees.

The maximum seal force must also be considered. However, for some applications, the average force to open a seal may be useful. The average force required to separate a test strip of material containing a seal may indicate a failure.

Lastly, a test report is written with the following information. The list below is not intended to be all-inclusive.

Identification of the material being tested
Equipment and test method used
Ambient conditions during testing
Grip separation rate
Initial grip separation distance
Number of specimens tested
Any pertinent information that can affect test results

Keystone Package Testing Seal Strength Equipment and Capabilities

Keystone Package Testing uses a wide range of pressure delivery systems, vacuum chambers, and open- and closed-package test fixtures to perform accurate seal strength package integrity testing. In addition, our environmental testing capabilities include dozens of thermal chambers, ranging from reach-in units to walk-in chambers with capacities up to 1,300 cubic feet.

Beyond seal integrity testing, Keystone operates multiple vibration systems, compression testers, and dynamic shock machines to support comprehensive package validation. As a result, customers can complete all of their package integrity testing with a single trusted laboratory.

Expert Regulatory Compliance Package Test Laboratory

In addition to sterile barrier compliance testing, Keystone Package Testing has a full scope of expertise including vibration, accelerated aging, and compression. We can accommodate flexible and rigid packages of all sizes, including large pallets. Our team strives to give our customers more time and energy on product development instead of testing.

Contact us to learn first hand why so many companies partner with Keystone to achieve their package certification needs. Request a quote to receive testing services customized to your specific needs. For more information on flexible package compliance testing, please refer to the following standards.

Interested in the EMC/EMI, climatic, dynamic, shielding effectiveness, or IP Code testing of a product? Follow the corresponding links or www.keystonecompliance.com for more information.

Request a Quote

Explore Similar Resources