ASTM F2029-16 (R2021) pdf free download.Standard Practices for Making Laboratory Heat Seals for Determination of Heat Sealability of Flexible Barrier Materials as Measured by Seal Strength.
1. 1 These practices cover laboratory preparation of heat seals. These practices also cover the treatment and evaluation of heat seal strength data for the purpose of determining heat sealability of flexible barrier materials. It does not cover the required validation procedures for the production equipment.
1 .2 Testing of seal strength or other properties of the heat seals formed by these practices is not included in this standard. Refer to Test Method F88 for testing heat seal strength. These practices do not apply to hot tack testing, which is covered in Test Methods F1921.
1 .3 The practices of this standard are restricted to preparing heat seals using a sealer employing hot-bar or impulse sealing methods, or both.
1.4 These practices are intended to assist in establishing starting relationships for sealing flexible barrier materials. Additional guidance may be needed on how to set up sealing conditions for flexible barrier materials on commercial? production sealing equipment.
1 .5 Seals may be made between webs of the same or dissimilar materials. The individual webs may he homogeneous in structure or multilayered (coextruded, coated, laminated, and so forth).
1.6 Strength of the heat seal as measured by Test Method F88 is the sole criterion for assessing heat sealability employed in these practices.
1.7 Other aspects of heat sealahility, such as seal continuity, typically measured by air-leak, dye penetration, visual examination, microorganism penetration. or other techniques, are not covered by these practices.
1 .8 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
3. 1 .4. 1 Discussion—Since heat seal strength can he measured either while the seal is still hot (hot tack) or after cooling and stabilizing (ultimate seal strength), a complete evaluation of heat sealability of a material may include both tests.
3.1.5 hot tack, n—a measure of the seal strength of a hot seal measured at a specified time interval after completion of the sealing cycle but prior to the temperature of the seal reaching ambient. Refer to Test Methods Fl 921.
3. 1 .6 seal initiation temperature, n—on a heat seal curve, the sealing temperature/dwell pressure at which heat seal strength tirsi begins to trend upward from zero heat seal Strength.
3.1.7 sealing inteiface, n—the interface of the two web surfaces being sealed.
3. 1.8 sealing pressure, n—the force per unit area of seal applied to the material by the sealing jaws during the sealing process.
3. 1.9 sealing temperature, n—the set point of each temperature-controlled sealing jaw. The set point temperature is the controller setting which will produce the desired surface temperature. Often, the set point temperature will be higher than the surface temperature.
3.1.10 ultimate seal strength, n—the final value of strength that is reached after the heat seal has both cooled to ambient temperature and achieved stability in strength.
3.1. 10. 1 Discussion—Some materials, when cooling from a melt, continue to change in strength over extended periods of time after reaching ambient temperature.ASTM F2029 pdf download.