1、Designation: D 3108 07Standard Test Method forCoefficient of Friction, Yarn to Solid Material1This standard is issued under the fixed designation D 3108; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of the kineticfrictional properties of a moving yarn in contact with a solidmaterial.NOTE 1For
3、 determining yarn-to-yarn friction, refer to Test MethodD 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 apossible change in precision and coefficient of friction.1.3 This test method covers the measurement of the coeffi-c
4、ient of kinetic friction between yarn and solid surface orsurfaces of constant radius in the contact area. If a yarn ofuniform value is used, comparisons of frictional properties ofdifferent solid materials can be made with relation to that yarn.If a given solid material is used, comparisons of fric
5、tionalproperties 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 anglesof 3.14 and 6.28 radian (180 and 360), but other wrap anglesmay be used, again with a possible change in precision
6、 andlevel. The angle of wrap should not be so great, especially foryarns having high coefficients of friction, that it causes theoutput tension to exceed the yield value for the yarn beingtested. Also, in every case the angle of wrap should not be lessthan 1.57 rad (90).1.5 This test method has been
7、 applied to yarns having lineardensities ranging between 10 and 80 tex (90 and 720 denier)and having coefficients of friction ranging between 0.1 and 0.5but may also be used with yarns outside these ranges of lineardensities and coefficients of friction.1.6 The values stated in SI units are to be re
8、garded as thestandard. The values given in parentheses are for informationonly.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and dete
9、rmine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 1776 Practice for Conditioning and Testing TextilesD 1907 Test Method for Linear Density of Ya
10、rn (YarnNumber) by the Skein MethodD 2258 Practice for Sampling Yarn for TestingD 3412 Test Method for Coefficient of Friction, Yarn toYarnD 4849 Terminology Relating to Yarns and Fibers3. Terminology3.1 For all terminology relating to D13.58, Yarns andFibers, refer to Terminology D 4849.3.1.1 The f
11、ollowing terms are relevant to this standard:coefficient of friction, friction, kinetic friction, radian, staticfraction, wrap angle.3.2 For all other terminology related to textiles, refer toTerminology D 123.4. Summary of Test Method4.1 A length of yarn is run at known speeds and in contactwith ei
12、ther single or multiple friction surfaces using a specifiedwrap angle. (See Fig. 1.) The yarn input and output tensions aremeasured, and the coefficient of friction is calculated by meansofAmontons law (see 11.4).Alternatively, apparatus is used inwhich the ratio of output tension to input tension i
13、s measuredallowing the coefficient of friction to be indicated directly.5. Significance and Use5.1 Test Method D 3108 for the determination of kineticfriction between yarn and solid materials may be used for theacceptance testing of commercial shipments of yarn, butcaution is advised since between l
14、aboratory precision is knownto be poor. Comparative tests as directed in 5.1.1 may beadvisable.5.1.1 If there are differences or practical significance be-tween reported test results for two laboratories (or more),comparative tests should be performed to determine if there is1This test method is und
15、er the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.Current edition approved Jan. 1, 2007. Published January 2007. Originallyapproved in 1972. Last previous edition approved in 2001 as D3108 01.2For referenced ASTM standard
16、s, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
17、9428-2959, United States.a statistical bias between them, using competent statisticalassistance.As a minimum, test samples that are as homogenousas possible, drawn from the material from which the disparatetest results were obtained, and randomly assigned in equalnumbers to each laboratory for testi
18、ng. The test results from thetwo laboratories should be compared using a statistical test forunpaired data, at a probability level chosen prior to the testingseries. If a bias is found, either its cause must be found andcorrected, or future test results for that material must beadjusted in considera
19、tion of the known bias.5.2 The frictional properties of textile yarns and of machin-ery components such as yarn guides are of general interest andhave many applications. Because the frictional properties ofyarns will affect the performance and life of yarn guides,sewing and knitting needles, and oth
20、er contact surfaces, themodifying effects of surface finishes and lubricants are ofspecial interest. Frictional properties also affect the quality andperformance properties of yarns and subsequently of productsmade from them. As a consequence, frictional properties are ofinterest in research, contro
21、l, and product design.5.3 It is stressed that there is no coefficient of friction for asingle body such as a yarn or a surface. A coefficient of frictionmeasures the interaction between two bodies or elements suchas a yarn running over a surface.5.4 Although this method lays down standardized condi-
22、tions of test, nonstandard conditions may be used for researchor diagnosis but should be reported as such.5.5 This method covers determination of the mean frictionover a specified length of yarn.5.6 Additional information has been reported in the litera-ture.3,4,56. Apparatus6.1 Friction Testing App
23、aratus (Indirect)6(Fig. 2)Apparatus in which the input tension is measured or controlledto a set value, the output tension is measured, and thecoefficient of friction is calculated within or outside theapparatus.6.1.1 Yarn Tension Input ControlA means of controllingthe yarn input tension to the near
24、est 61mN(60.1 gf). Ademand-fed apparatus with a fixed weight is suitable.6.1.2 Yarn Input Tension MeasurementThe yarn inputtension is measured to within 61mN(60.1 gf) using asuitable tension gage producing an electrical signal. The signalis recorded as mN (gf) or is used in combination with the yarn
25、output tension measurement to calculate the coefficient offriction.6.1.3 Yarn Output Tension MeasurementThe yarn outputtension is measured to within 61mN(60.1 gf) using asuitable tension gage producing an electrical signal. The signalis recorded as mN (gf) or is used in combination with the yarninpu
26、t tension measurement to calculate the coefficient offriction. A suitable chart recorder may be used.6.2 Friction Testing Apparatus (Direct) (Fig. 3)Apparatusin which the ratio of output to input tensions is establisheddirectly and the coefficient of friction indicated on a scale ordisplay. The comp
27、arison may be mechanical.6.2.1 Yarn Tension Input ControlSince this type of appa-ratus automatically derives the ratio of output-to-input-tension,close control of input tension is not usually required. However,because the absolute level of input tension can affect themeasured coefficient of friction
28、 for certain yarns, particularlylow-twist yarns, the general level of input tension should bepreset, for example with a dead weight disk tensioner.6.2.2 Coeffcient of Friction IndicatorThe nature of thiswill depend on the instrument being used. Typically, a pointer3Olsen, J.S., “Frictional Behaviour
29、 of Textile Yarns,” Textile Research Journal,Vol 39 No 1, 1969, pp 3137.4Lyne, D.G., “Dynamic Friction Between Cellulose Acetate Yarn and a MetalCylinder,” Journal of the Textile Institute , Vol 46, 1955, p 112.5Rubenstein, C., “Review of the Factors Influencing the Friction of Fibres, Yarnsand Fabr
30、ics,” “Wear” Vol 2, 195859, p 296.6Equipment meeting these requirements may be commercially obtained fromLawson Hemphill (Sales) Inc., PO Drawer 6388, Spartanburg, SC 29304.FIG. 1 Schematic Diagram of Angle of WrapD3108072or a chart recorder pen is displaced by the movement of thecomponents that bri
31、ng the system into balance and the productof the input tension and the distance from the axis equals theproduct of the output tension and the distance from the axis(see Fig. 3).6.3 Friction Surface, may be changeable on some equip-ment.6.3.1 Standard Friction SurfaceFriction surfaces having adiamete
32、r of 0.5 in. (12.7 mm) and a chrome surface of 4 to 6m roughness. The use of one, two, or three pins in sequencehas been found satisfactory although there may be a differencein the results (theoretically only the total angle of wrap and notthe number of pins should affect the results). (See 12.3.4).
33、6.3.2 Other Friction SurfacesUnless the apparatus has afriction surface that cannot be altered, friction surfaces ofdifferent materials, sizes, and surface finish may be used butmust be specified in the report (see 12.3.4).6.4 Drive System, consisting of a controlled speed yarntransporting device wi
34、th appropriate controls to record andadjust the linear or throughput speed. Generally, a speed of lessthan 300 m/min has been found preferable. The yarn transport-ing device should be constructed to eliminate yarn slippage bythe use of high-friction surface.6.5 Cotton Yarn For CleaningA thoroughly s
35、coured cot-ton yarn that is highly absorbent (see section 10.2.2 and AnnexA1).FIG. 2 Schematic Diagram of Typical Yarn Friction Measuring Apparatus, Indirect TypeFIG. 3 Schematic Diagram of Typical Yarn Friction Measuring Apparatus, Direct TypeD31080736.6 SolventSee 10.2.7. Hazard7.1 Refer to the ma
36、nufacturers material safety data sheetfor information on storage, handling, use, and disposal ofchemicals used in this test method.8. Sampling8.1 Lot SampleAs a lot sample for acceptance testing,take at random the number of shipping units directed in anapplicable material specification or other agre
37、ement betweenthe purchaser and the supplier, such as an agreement to usePractice D 2258. Consider shipping cases or other shippingunits to be the primary sampling units.NOTE 2An adequate specification or other agreement between thepurchaser and the supplier requires taking into account the variabili
38、tybetween shipping units, between packages or ends within a shipping unit,and between specimens from a single package so as to provide a samplingplan with a meaningful producers risk, consumers risk, acceptablequality level, and limiting quality level.8.2 Laboratory SampleAs a laboratory sample for
39、accep-tance testing, take at random from the each shipping unit in thelot sample the number of packages or ends directed in anapplicable material specification or other agreement betweenthe purchaser and the supplier such as an agreement to usePractice D 2258. Preferably, the same number of packages
40、should be taken from each shipping unit in the lot sample. Ifdiffering numbers of packages are to be taken from shippingunits in the lot sample, determine at random which shippingunits are to have each number of packages drawn.8.3 Test SpecimensTest one specimen from each packagein the laboratory sa
41、mple.9. Conditioning9.1 Preparation of Test PackagesRemove sufficient yarnfrom the test packages to avoid testing nonrepresentativelayers. If in doubt, remove about 10 % of the length of yarn onthe package.9.2 The strand to be tested must have a uniform moisturecontent along its length. Atmospheric
42、conditions must there-fore be stable and the strand must be in equilibrium with theprevailing atmosphere. To satisfy this condition, testing shouldbe carried out after thorough conditioning in the standardatmosphere for testing textiles.9.3 PreconditioningPrecondition packages of yarn for atleast3hi
43、nanatmosphere with a relative humidity between 5and 25 % and a temperature not exceeding 50C (120F).9.4 ConditioningCondition the preconditioned packagesof yarn in the standard atmosphere for testing textiles (relativehumidity 65 6 2 % and temperature 21 6 1C (70 6 2F) inmoving air until it has reac
44、hed moisture equilibrium for testingas directed in Practice D 1776.10. Procedure10.1 Test all specimens in the standard atmosphere fortesting textiles which is 21 6 1C (70 6 2F) and 656 2%relative humidity.10.2 Prior to each test, thoroughly clean the friction ele-ments, input rolls, and any other s
45、urfaces with which the yarncomes in contact up to and including the friction element, usingone of the following:10.2.1 A solvent which contains no trace oils, orNOTE 3Precaution: If solvent is used, appropriate health and safetyprecautions must be taken. (See Section on Hazards)10.2.2 A thoroughly s
46、coured cotton yarn7that is highlyabsorbent used as a cleaning yarn. See Annex A1 for details.10.3 Check the surface properties of the friction elementsfor wear, gouging, or channeling. Some textile yarns, specifi-cally glass, stainless steel, delustered yarns, and other high-modulus yarns, are known
47、 to create excessive wear on mostguide surface materials, including chromium. Check for evi-dence of surface wear periodically by the use of control yarns,microscopic examination, or other forms of examining ormeasuring surface uniformity. Replace or refurbish frictionelements which show signs of we
48、ar, gouging, or channeling.10.4 Take care not to contaminate the yarn test specimen orthe cleaned yarn-contacting surfaces of the apparatus.10.5 Feed the yarn through the apparatus. Use identical pinlocations, friction surfaces, and input tensions for all tests to becompared directly.10.5.1 If the a
49、pparatus requires the input tension to bestandardized, adjust it to 9.8 6 1 mN/tex (0.1 gf/den).NOTE 4When yarns heavier than 80 tex (720 den) are being tested, aninput tension of less than 9.8 mN/tex (0.1 gf/den) may have to be used.Report any such change with the test results.10.5.2 If the yarn linear density (tex or denier) is not known,determine this property as directed in Test Method D 1907,Option 1. It is important that the linear tex (denier) of the yarnbe determined accurately as the proper input tension in terms ofmillinewtons per tex o
