Seal Strength/ Lamination Bond Testing
Seal strength is related to the pack opening force and a measure of the consistency of the packaging process. The maximum seal force, average peel force and total energy absorbed in peeling the seal can be recorded.
The strength of seals in flexible barrier materials is routinely measured as part of the validation exercise on medical device packaging. Seal strength tests are typically performed on pouches and lidded trays as a measure of heat seal quality.
Dynamic seal strength testing is made in accordance with ASTM F88.
The resistance to log term creep separation of the seal is assessed using a static loading.
Lamination bond strength
The lamination bond strength of a material is determined using essentially the same test procedure as that described in ASTM F88 used to determine seal strength.
After initiating de-lamination between the relevant film plies, the average force required to peel the two "legs" of the test piece is recorded. The static loading methodology is also appropriate.
Although usually determined at ambient laboratory conditions, Smithers Pira is able to determine such tensile properties at sub-ambient or elevated temperatures using a "hot box" attachment to the tensile test apparatus.