Burst Strength


The burst strength of a flexible pack is determined by pressurizing the package until it bursts. The position and type (seal or material) of failure is recorded in addition to the burst pressure value. Alternatively the resistance to creep failure at a specified hold pressure can be determined.

The test is used as a means of evaluating the likelihood of pack failure when exposed to a pressure differential, such as may be experienced in autoclaving or air transport. A 95 kPa internal pressure test* is used to demonstrate compliance with UN packing instructions P620 for infectious substances packaging and Part 4 of ICAO technical instructions.

Pira employs a Skye PT1000 Packtester for burst and pressure decay integrity testing.Burst strength testing at Pira

Pira carries out testing in accordance with ASTM F1140 and ASTM F2054. These tests can be used to demonstrate compliance with the requirements for seal strength of ISO 11607 "Packaging for terminally sterilized medical devices - Part 1".

By placing the package between restraining plates, the weakest area of the seal is more likely to be detected as the stresses during pressurisation are more uniformly applied along the perimeter of the pack.

*For further information regarding the regulatory aspects of UN dangerous testing please contact the VCA dangerous goods office at http://www.vca.gov.uk/dangerousgoods/dangerous-goods-offi.asp

Expert Profile

  • Doug joined Pira in 1989 and has 20 years experience in the physical testing of packaging and packaging materials. He heads a team specialising in packaging and print related technical investigations. In 2004 Doug gained his postgraduate degree with distinction in Packaging Technology from Brunel University.

    Doug Leatherdale
    Doug Leatherdale

    Head of Physical Testing

    Pira International

    +44 1372 80 2108

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