ASTM D 3108 : 2007

1.1 This test method covers the measurement of the kinetic frictional properties of a moving yarn in contact with a solid material. For determining yarn-to-yarn friction, refer to Test Method D 3412.

1.2 This test method specifies a relative speed of 100 m/min. The test method may be used at other speeds, although with a possible change in precision and coefficient of friction.

1.3 This test method covers the measurement of the coefficient of kinetic friction between yarn and solid surface or surfaces of constant radius in the contact area. If a yarn of uniform value is used, comparisons of frictional properties of different solid materials can be made with relation to that yarn. If a given solid material is used, comparisons of frictional properties of different yarns, or yarns with different finishes, can be made with relation to that particular solid material.

1.4 This test method specifically recommends wrap angles of 3.14 and 6.28 radian (180 and 360), but other wrap angles may be used, again with a possible change in precision and level. The angle of wrap should not be so great, especially for yarns having high coefficients of friction, that it causes the output tension to exceed the yield value for the yarn being tested. Also, in every case the angle of wrap should not be less than 1.57 rad (90).

1.5 This test method has been applied to yarns having linear densities ranging between 10 and 80 tex (90 and 720 denier) and having coefficients of friction ranging between 0.1 and 0.5 but may also be used with yarns outside these ranges of linear densities and coefficients of friction.

1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 7.