TESTING OF RELIABILITY OF NONDESTRUCTIVE PRESSURE DIFFERENTIAL PACKAGE LEAKAGE TESTERS WITH SEMIRIGID ASEPTIC CUPS

The sensitivity and reliability of two commercial non-destructive leak testers were studied using commercially manufactured semi-rigid asept ic cups with headspace filled with milk pudding. The lids of some of t he aseptic cups had artificially constructed holes 10-60 mu m in diame ter leak testing was based either on defection or external vacuum deca y in a test chamber or internal pressure decay in the package during m echanical compression. The effect of leak testing itself on the cup in tegrity was also examined. From the evaluated methods, the external va cuum decay method showed greater sensitivity and reliability for detec tion of leakages. External vacuum and internal pressure decay methods did not reliably detect holes of 29 and 60 mu m in diameter respective ly. Furthermore, neither of the methods could reliably detect the thre shold leakage of 10 mu m in diameter for bacterial penetration (determ ined earlier using aseptic cups with artificially made holes). Blockin g of the holes with pudding greatly decreased the sensitivity of both leak testers. Leak testing did not affect the integrity of intact cups . (C) 1998 Elsevier Science Ltd. All rights reserved.