ASTM F88-06 pdf free download.Standard Test Method for Seal Strength of Flexible Barrier Materials.
3.1.1.1 Discussion—The average force normally is calculated by the testing machine from the digitized plot of force versus grip travel. The plot starts from zero force after slack has been removed from the Lest strip. The initial ramp-up from zero to the force level required to peel the seal is not indicative of seal strength. and data from that part of the curve should not be included in the calculation of average strength. nor should the return to zero following complete failure of the specimen. The amount of data actually discarded on each end of the measured seal-profile curve must be the same for all tests within any set of comparisons of average seal strength (see 6.1.1 and 9.8.1).
3. I .2 flexible, adj—indicates a material with flexural strength and thickness permitting a turn hack at an approximate 180 degree angle.
3. 1 .3 maximum seal strength. n—maximum force per unit width of seal required to separate progressively a flexible material from a rigid material or another flexible material. under the conditions of the test.
4. Significance and Use
4.1 Seal strength is a quantitative measure for use in process validation, process control, and capability. Seal strength is not only relevant to opening force and package integrity, but to measuring the packaging processes’ ability to produce ConSistent seals. Seal strength at some minimum level is a necessary package requirement, and at times it is desirable to limit the strength of the seal to facilitate opening.
4.1.1 The maximum seal force is important information. but for some applications, average force to open the seal may be useful, and in those cases also should he reported.
4.2 When a seal fails adhesively (peel seal) the value of the bond strength measured is reported. A cohesive failure of the bond, delamination, or failure elsewhere in the test strip indicates that the substrate, not the seal interface, would be the limiting factor in the strength of a package. In those cases seal strength may he reported as “no less than” the strength measured.
4.3 A portion of the force measured when testing materials may be a bending component and not seal strength alone.ASTM F88 pdf download.