D7138 (version 25)

1.1 Either of two test methods are used to determine the melting temperature of thermoplastic fibers, yarns, or threads.

1.2 Method 1 can be used to determine melting temperatures for blends of multiple fiber material types. Method 2 can only be used to determine the melting temperature of a single fiber material type.

1.2.1 Method 1, Differential Scanning Calorimetry (DSC), measures changes in heat capacity and will detect the glass transition, the crystalline melting and endothermic thermal degradation.

1.2.2 Method 2, a visual determination of melting, determines any change that visually appears as a transition from a solid to a liquid state.

1.2.3 Due to the differences in what each test method measures, the results from Method 1 and Method 2 cannot be compared.

1.3 The values stated in either SI units or other units are to be regarded separately. The values stated in each system are not exact equivalents; therefore, each system shall be used independently without combining values.

1.4 This 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.

1.5 This 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.