Correlation Between Burst & Peel Tests Used for Ensuring Integrity of Medical Device Packages
The use of flexible sealed pouches for protective product containers has gained wide acceptance in the medical device industry where atmospheric contamination of the product must be prevented to preserve sterility of the product.
Such containers typically consist of two flat impermeable or semi-permeable membranes sandwiched together and sealed on three sides as supplied by their manufacturer. The medical device manufacturer then inserts the product under sanitary conditions and then seals the open side using a sealing machine. The pouches are then sterilized in-house or at an outside vendor's facility.
Seal integrity is crucial to maintaining the sterility of the product. Testing is needed to ensure integrity of sealed packages to prove that sterility is maintained. It is also needed to ensure durability during sterilization, handling, distribution, and storage. The peel test and burst test are the industry standards set forth by the American Society for Testing and Materials for testing the integrity of sealed edges.
The driving force for establishing and standardizing the correlation between the burst test and peel test is that the faster burst test alone could be used by manufacturers and pouch suppliers for quality control and validation purposes instead of the more expensive peel test.
The burst test is easier to perform, since it involves inserting a hollow needle through the membrane and pressurizing it until it bursts. This test can be completed in less time than the peel test. It also provides evaluation of the entire package system, including the seal. The peel test requires elaborate sample preparations followed by tests on a tensile machine. It is based on only a few strips (usually four) from the pouch and may not contain a weak spot that would be present in the pouch seal, and it does not provide evaluation of the entire package including the seal.
Once the two tests are properly correlated, suppliers can use the faster burst test technique to provide the derived peel test values directly to production and quality control personnel. Faster corrective actions will increase productivity and reduce labor and material costs.
Asit Ray, Professor of Chemical & Biochemical Engineering