Testing for a path that allows gas or liquid to pass through a package or its closure.
Also called: blister leak test; leak detection; package leak testing.
Which leak test is best for a blister pack?
There is no method choice independent of the package and the question. Identify the protected boundary, expected defect path, material flexibility and available headspace first. A test of one pocket and a test of an entire card do not necessarily provide the same localization information.
Compare the actual signal and sample preparation rather than treating every integrity test as the same observation. A result for another material or fixture can inform a discussion, but does not establish performance on the proposed supplement pack.
Does no detected leak mean the package is leak-free?
It means that the defined test detected no defect under its conditions. Package construction, fixture, pressure and timing affect capability; a defect can remain undetected when the chosen test cannot reveal it. Retain demonstrated capability with the pass/fail label.
Retain the challenge-defect description and its location, not just a nominal hole diameter. Also distinguish discrete leakage from transmission through intact material: a satisfactory leak test alone does not provide WVTR, OTR or a shelf-life result.