ASTM D7409-15(2020)

5.1This test method can be used for manufacturing quality control or manufacturing quality assurance purposes to determine the CEG concentration of PET yarns used in either geogrids or geotextiles.

5.2The CEG content of the PET yarns may have an influence on the properties of the geosynthetic, such as its hydrolysis resistance. The lower the value, the higher the hydrolysis resistance of the yarns.

5.3This test does not set the limiting (maximum) value for various engineering applications. Such a specification is a decision of the design engineer, owner, and/or regulator.

1.1This test procedure is based significantly on the GRI GG7 test procedure, Carboxyl End Group Content of Polyethylene Terephthalate (PET) Yarns.

1.2 This test method is used to determine the concentration, in mmol/kg, of carboxyl end groups (CEG) found in poly(ethylene terephthalate) (PET) yarns by titration.

1.3This test is applicable to geogrid yarns that are made from PET resin.

1.4The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.