ASTM F2625-24 PDF

SIGNIFICANCE AND USE 5.1 The crystallinity of UHMWPE will influence its mechanical properties, such as creep and stiffness. The reported crystallinity will depend on the integration range used to determine the heat of fusion, and the theoretical heat of fusion of 100 % crystalline polyethylene used to calculate the percent crystallinity in an unknown specimen. Differential scanning calorimetry is an effective means of accurately measuring both heat of fusion and melting temperature. 5.2 This test method is useful for both process control and research. SCOPE 1.1 This quantitative test method discusses the measurement of the heat of fusion and the melting point of ultra-high molecular weight polyethylene (UHMWPE), and the subsequent calculation of the percentage of crystallinity. The method uses a differential scanning calorimeter and can be performed in the laboratory or in the field. 1.2 This test method can be used for UHMWPE in powder form, consolidated form, finished product, or a used product. It can also be used for irradiated or chemically crosslinked UHMWPE. 1.3 This test method does not suggest a desired range of crystallinity or melting points for specific applications. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 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. 1.6 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.