定价： 2663元 / 折扣价： 2371 元 加购物车

定价： 2705元 / 折扣价： 2408 元 加购物车

定价： 3038元 / 折扣价： 2704 元 加购物车

定价： 2331元 / 折扣价： 2075 元 加购物车

定价： 2081元 / 折扣价： 1853 元 加购物车

定价： 358元 / 折扣价： 319 元 加购物车

定价： 2081元 / 折扣价： 1853 元 加购物车

定价： 2081元 / 折扣价： 1853 元 加购物车

定价： 590元 加购物车

5.1 This test method for testing yarn-to-yarn friction is being used, but is not recommended, for acceptance testing of commercial shipments since between-laboratory precision is known to be poor.5.1.1 In some cases, the purchaser and supplier may have to test a commercial shipment of one or more specific materials by the best available method even though the method has not been recommended for acceptance testing of commercial shipments. In case of a dispute arising from differences in reported test results when using Test Method D3412/D3412M for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens that are as homogeneous as possible and that are from a lot of material of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before the testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.5.2 This test method is intended for the determination of yarn-to-yarn boundary friction coefficients measured over a specified length of yarn.5.3 The test method is useful for quality control, research, and the characterization of yarn boundary lubricants.NOTE 3: Because the geometry of the yarns is different, Options 1 and 2 should not be expected to give the same numerical values on the same yarns.1.1 This test method covers the measurement of frictional properties for both continuous filament and spun-staple yarns under boundary friction conditions.1.2 This test method has been used with yarns having linear densities ranging from 1.5 to 400 tex, but may be used with yarns outside these ranges [15 to 3600 denier].NOTE 1: For coefficient of friction, yarn to metal, see Test Method D3108/D3108M.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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.

定价： 590元 加购物车

5.1 Test Method D3108 for the determination of kinetic friction between yarn and solid materials may be used for the acceptance testing of commercial shipments of yarn, but caution is advised since between laboratory precision is known to be poor. Comparative tests as directed in 5.1.1 may be advisable.5.1.1 If there are differences or practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, test samples that are as homogenous as possible, drawn from the material from which the disparate test results were obtained, and randomly assigned in equal numbers to each laboratory for testing. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias.5.2 The frictional properties of textile yarns and of machinery components such as yarn guides are of general interest and have many applications. Because the frictional properties of yarns will affect the performance and life of yarn guides, sewing and knitting needles, and other contact surfaces, the modifying effects of surface finishes and lubricants are of special interest. Frictional properties also affect the quality and performance properties of yarns and subsequently of products made from them. As a consequence, frictional properties are of interest in research, control, and product design.5.3 It is stressed that there is no coefficient of friction for a single body such as a yarn or a surface. A coefficient of friction measures the interaction between two bodies or elements such as a yarn running over a surface.5.4 Although this method lays down standardized conditions of test, nonstandard conditions may be used for research or diagnosis but should be reported as such.5.5 This method covers determination of the mean friction over a specified length of yarn.5.6 Additional information has been reported in the literature.3,4,51.1 This test method covers the measurement of the kinetic frictional properties of a moving yarn in contact with a solid material.NOTE 1: For determining yarn-to-yarn friction, refer to Test Method D3412.1.2 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 1.57, 3.14 and 6.28 radian (90, 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 1.5 and 400 tex [14 and 3600 denier] and having coefficients of friction ranging between 0.1 and 1.0 but may also be used with yarns outside these ranges of linear densities and coefficients of friction.1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.7 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.Specific precautionary statements are given in Section 7.1.8 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.

定价： 590元 加购物车

定价： 590元 加购物车

定价： 590元 加购物车

定价： 515元 加购物车

定价： 590元 加购物车