ASTM F88/F88M-09 pdf free download.Standard Test Method for Seal Strength of Flexible Barrier Materials.
1.1 This lest method covers the measurement of the strength of seals in llexihlc barrier materials.
1 .2 The test may he conducted on seals between a flexible material and a rigid material.
1.3 Seals tested in accordance with this test method may he from any source. laboratory or commercial.
1 .4 This lest method measures the torce required to separate a lest strip of material containing the seal. It also identities the mode of specimen failure.
1.5 The values stated in either Si units or inch—pound units arc to he regarded separately as standard. The values stated in each system ma not he exact equivalents: therefore. each system shall be used independently of Lhc other. Combining values from the two systems may result in non-conformance wnh the standard.
3.1 . I uveruçe seal .crength. n—aerae force per Unit width of seal required to separate progressively a flexible material from a rigid matenal or another tiexihic material, under (he conditions of the lest.
3.1 .1 .1 Discuscion—The average lrcc normally is caicti— kited by the testing machine from the digitized plot of force versus grip travel. The plot starts from iero force after slack has been rerno ed from the test 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 thai part of the curve should not he included in the calculation of average strength. nor should the return to zero following complete failure ot the specimen. The amount of data actually discarded on each end of the measured seal-profile curve must he the same for all tests ithin any set of comparisons of average seal strength (see 6.1.1 and 9.8.1).
3. 1 .2 flexible. adj—indicates a material with Ocx ural strength and thickness permitting a turn back at an approximate 180 degree angle.
4. Significance and Use
4. 1 Seal strength is a quanhilalive measure for use in process validation, process control, and capability. Scat strength is not only releani to opening force and package integrity. hut to measuring the packaging processes’ ahilit) to produce Coflsistcnt seals. Seal strength at some rninimwn level is a necessary. package requirement. and at times ii 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 apphcations. average torce io open the seal ma’ he useful, and in those cases also should be reported.
4.2 A portion of the force measured when testing materials ma he a bending component and not seal strength alone. A number of fixtures and techniques have been devised in hold samples at various angles to the pull direction to control this bending force.ASTM F88/F88M pdf download.