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.
Smithers Pira employs a Skye PT2000 Packtester for burst and pressure decay integrity testing.
Smithers 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