ASTM D4920-2008 Standard Terminology Relating to Conditioning Chemical and Thermal Properties《环境负荷 化学和热性能相关标准术语》.pdf

1、Designation: D4920 08Standard Terminology Relating toConditioning, Chemical, and Thermal Properties1This standard is issued under the fixed designation D4920; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio

2、n. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This standard is the compilation of definition of techni-cal terms related to conditioning, chemical, and thermalproperties in tex

3、tiles. Terms that are generally understood oradequately defined in other readily available sources are notincluded.1.2 For other ASTM defined conditioning terms, refer toTerminology E41. For other terms associated with textiles,refer to Terminology D 123, Relating to Textiles.2. Referenced Documents

4、2.1 ASTM Standards:2D 123 Terminology Relating to TextilesE41 Terminology Relating To ConditioningD 578 Specification for Glass Fiber StrandsD 579 Specification for Greige Woven Glass FabricsD 580 Specification for Greige Woven Glass Tapes andWebbingsD 581 Specification for Glass Fiber Greige Braide

5、d TubularSleevingD 885 Test Methods for Tire Cords, Tire Cord Fabrics, andIndustrial Filament Yarns Made from ManufacturedOrganic-Base FibersD 1776 Practice for Conditioning and Testing TextilesD 1907 Test Method for Linear Density of Yarn (YarnNumber) by the Skein MethodD2118 Practice for Assigning

6、 a Standard CommercialMoisture Content for Wool and its ProductsD 2494 Test Method for Commercial Mass of a Shipment ofYarn or Manufactured Staple Fiber or TowD 2970/D 2970M Test Methods for Testing Tire Cords, TireCord Fabrics, and Industrial Yarns Made From GlassFilamentsD 3887 Specification for T

7、olerances for Knitted FabricsD 4772 Test Method for Surface Water Absorption of TerryFabrics (Water Flow)3. Terminology3.1 Definitions:absolute humidity, nthe mass of water vapor present in aunit volume of air.DISCUSSIONCommon units of measure for absolute humidity aregrams per cubic metre or grains

8、 per cubic foot. The amount of watervapor is also reported in terms of mass per unit mass of dry air, forexample, grams per kilogram, or grains per pound, of dry air. This valuediffers from values calculated on a volume basis and should not bereferred to as absolute humidity. It is designated as hum

9、idity ratio,specific humidity, or moisture pick-up.absorption, na process in which one material (the absor-bent) takes in or absorbs another (the absorbate); as theabsorption of moisture by fibers. (See also adsorption, andmoisture equilibrium for testing. Compare desorption andresorption.) D 4772ad

10、sorption, na process in which the surface of a solid takeson or adsorbs in an extremely thin layer molecules of gases,of dissolved substances, or of liquids with which it is incontact. (See also absorption and moisture equilibrium fortesting. Compare desorption and resorption.)atmosphere for testing

11、, nair at ambient conditions ofrelative humidity and temperature in which tests or experi-ments are conducted. (See also standard atmosphere fortesting.)DISCUSSIONIn the hierarchy of terms, atmosphere is the genericterm where the air is ambient with conditions “controlled” by localweather and theref

12、ore variable. Atmosphere for testing is a delimitedterm in which the use of the atmosphere is restricted for a certainpurpose. In a standard atmosphere for testing, the conditions arespecified (standardized) and controlled for routine testing and fortesting reproducibility. On this basis, there is n

13、o real reason for notreferring to the specified atmospheres that have been traditionally usedfor testing glass textiles or tire cords, etc., as standard atmospheresfor testing those materials.1This terminology is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility

14、 of Subcommittee D13.51 on Conditioning and,Chemical and Thermal Properties.Current edition approvedJuly 1, 2008. Published August 2008 . Originallyapproved in 1989. Last previous edition approved in 2003 as D 4920 98 (2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcon

15、tact 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 19428-2959, United States.bicomponent fiber, na

16、 fiber consisting of two polymerswhich are chemically different, physically different, or both.birefringence (double refraction), na property of anisotro-pic materials which manifests itself as a splitting of a lightray into components having different vibration directionswhich are transmitted at di

17、fferent velocities.DISCUSSIONThe vibration directions of the components are theprincipal axes of the material and the corresponding indices ofrefraction are its principal (maximum of minimum) refractive indices.Numerically, birefringence is the difference between the maximum andminimum refractive in

18、dices.bulk density, napparent mass per unit volume.DISCUSSIONIn testing the termal transmittance of fabrics, bulkdensity is calculated from the fabric weight per unit area and thethickness value used to calculate thermal conductivity.clo, nunit of thermal resistance defined as the insulationrequired

19、 to keep a resting man (producing heat at the rate of58 W/m2) confortable in an environment at 21C, airmovement 0.1 m/s, or roughly the insulation value of typicalindoor clothing. (Syn. intrinsic clo).DISCUSSIONNumerically the clo is equal to 0.155 Km2/W.commercial allowance (CA), nan arbitrary valu

20、e, equal tothe commercial moisture regain, plus a specified allowancefor finish, used with the mass of scoured, oven-dried yarn, tocompute (1) yarn linear density, (2) the commercial or legalmass of a shipment or delivery of any specific textilematerial (see also commercial moisture regain), or (3)

21、themass of a specific component in the analysis of fiber blends.D 1907, D 2494, D 3887commercial mass, nbilled mass as determined by a gener-ally accepted method or as agreed upon between the pur-chaser and seller. D 2494commercial moisture content, nin wool, the moisturecalculated as a percentage o

22、f the mass of the wool, top, noils,yarn, fabric, etc., in the “as-is” condition; that is, containingwhatever moisture, oil, grease, or other extraneous matterthat may be present. D2118commercial moisture regain (CMR), na formally adopted,arbitrary value, to be used with the oven-dried mass oftextile

23、 fibers, when calculating the commercial mass of ashipment or delivery.DISCUSSIONThe assigned commercial moisture regain value isusually higher than the experimental moisture regain value for the samematerial.condition, vto bring a material to moisture equilibrium witha specified atmosphere.density,

24、 nmass per unit volume.DISCUSSIONDue to the volume of included air, the apparent densityof fibers and yarns will differ from the densities of the materials ofwhich the fibers and yarns are composed. Test results for fiber densitywill also vary depending on the test method used. Density is commonlyex

25、pressed as grams per cubic centimetre (g/cm3), but the preferred termin the International System of Units is kilograms per cubic metre(kg/m3). Multiply g/cm3by 1000 to obtain kg/m3and mulitply lb/ft3by16.018 to obtain kg/m3.desorption, na process in which a sorbed material isreleased from another ma

26、terial, as the desorption of moisturefrom fibers; the reverse of absorption, adsorption, or both.dew point, nthe temperature below which condensation ofwater vapor begins to take place when the atmosphere iscooled.DISCUSSIONAs air is cooled, the amount of water vapor which it canhold decreases. If a

27、ir is cooled sufficiently, the saturation water-vaporpressure becomes equal to the actual water-vapor pressure and anyfurther cooling beyond this point will normally result in the conden-sation of moisture.effective insulation ratio, nindicates the increase in insula-tion afforded by the fabric in c

28、omparison to the uncoveredtest plate under specified conditions of test.extractable matter, nnonfibrous material in or on a textilenot including water, which is removable by a specifiedsolvent or solvents as directed in a specified procedure.DISCUSSIONNonfibrous material is usually oily, waxy, resin

29、ous, orpolymeric in nature, but may also include other material, such asprotein, particularly if ethyl alcohol is used, or in, the extractingsolvent.fiber birefringence, nthe algebraic difference of the index ofrefraction of the fiber for plane polarized light vibratingparallel to the longitudinal a

30、xis of the fiber and the index ofrefraction for light vibrating perpendicular to the long axis.DISCUSSIONFiber birefringence may be either positive or negative,and is not necessarily referred to the principal optical axes of thematerial.fiber density, nmass per unit volume of the solid matter ofwhic

31、h a fiber is composed, measured under specified condi-tions.DISCUSSIONUnless otherwise indicated, fiber density is understoodto be measured by immersion (buoyancy) techniques, at 21 6 1C,excluding effects due to included air and swelling or dissolving of thefiber by the immersion fluid.heat transfer

32、 coefficient, nsee thermal transmittance.humidity, nthe condition of the atmosphere in respect towater vapor. (Compare absolute humidity and relativehumidity.)hygrometer, nany instrument for measuring the humidity ofthe atmosphere.intrinsic clo, nsee clo.mean temperature, nthe average of the hot pla

33、te tempera-ture and the temperature of the calm, cool air that prevailedduring the test.moisture, nas used with textiles, water absorbed, adsorbed,or resorbed by a material. (See also water.)moisture as-is, ndeprecated term. See moisture content.moisture as-received, ndeprecated term. See moistureco

34、ntent.moisture content, nthat part of the total mass of a materialthat is absorbed or adsorbed water, compared to the totalmass. (Compare moisture pick-up and moisture regain.)D4920 082DISCUSSIONMoisture is usually expressed as a percentage and iscalculated using the equation:C 5 100 A 2 D!/Awhere:C

35、 = moisture content, %,A = mass of material before drying, andD = mass of the dried material.There is a relationship between moisture content and mois-ture pick-up since both may be calculated from the same data.The difference is in the bases used for calculating the percent-ages, original versus dr

36、ied material mass. The relationshipbetween moisture content and moisture pick-up is shown bythe equations:C 5 100 P/100 1 P!P 5 100 C/100 2 C!where:C = moisture content, %, andP = moisture pick-up, %.moisture content, nat moisture-equilibrium, the moisturecontent of a material in equilibrium with ai

37、r of known, orspecified, temperature and relative humidity.DISCUSSIONA frequently prescribed condition for determiningmoisture content at moisture-equilibrium is use of a standard atmo-sphere, for example, 21 6 1C (70 6 2F) and 65 6 2 % relativehumidity, for textiles, both in establishing the equili

38、brium and as airsupply for the drying oven.moisture content (dry-basis), ndeprecated term. See mois-ture pick-up.moisture (dry-basis), ndeprecated term. See moisturepick-up.moisture equilibrium, nthe condition reached by a materialwhen it no longer takes up moisture from, or gives upmoisture to, the

39、 surrounding atmosphere. (Comparemoisture-free.)DISCUSSIONThe establishment of equilibrium between a materialand the surrounding atmosphere is dependent upon the exposure time,the difference in moisture levels between the material and the atmo-sphere, and motion of the air about the material. The le

40、vel at which themoisture in the textile reaches equilibrium depends upon the side fromwhich equilibrium is approached. Because of this difference, equilib-rium for textiles should be approached from the dry (but not moisture-free) side which is faster. Equilibrium with air in motion is consideredto

41、be achieved when successive weighings at specified time intervals donot show a change in mass greater than the tolerance established for thematerial. If there is no established tolerance, consider 0.1 % of the massafter a 2-h exposure as satisfactory.moisture equilibrium, nfor preconditioning, the m

42、oisturecondition reached by a material during free exposure tomoving air in the standard atmosphere for preconditioning.D 1776moisture equilibrium, nfor testing, the condition reachedby a material during free exposure to moving air in aspecified atmosphere for testing. D 885, D 885M, D 1776moisture-

43、free, adjin textiles, a descriptive term for a mate-rial that (1) has been exposed to a flow of desiccated air ata specified temperature until there is no further significantchange in mass, or (2) has been treated by a distillationprocess using a suitable solvent. (Syn. zero-moisture.)(Compare moist

44、ure equilibrium.)DISCUSSIONMoisture determinations frequently involve the changein mass of an oven-dried specimen. If the air in the oven containsmoisture, the oven-dried specimen will also contain some moistureeven though it no longer shows a significant change in mass. This is dueto the establishm

45、ent of moisture equilibrium under the existing condi-tions. To ensure that the specimen is actually moisture-free, it must beexposed to desiccated air until it shows no further significant change inmass.Although heating textiles in dessicated air to temperatures as highas 110C increases the rate of

46、moisture loss without changing the finalequilibrium mass of the moisture-free textile, heating also increases thepossibility of removing other matter. The distillation process may besubstituted provided the textile does not contain any distillable,water-soluble matter.moisture pick-up, nthe mass of

47、absorbed and adsorbedwater that is held by a material, compared to the mass of thedried material. (Compare moisture content and moistureregain.)DISCUSSIONMoisture pick-up is usually expressed as a percentagebased on the dried mass of the material and is calculated using theequation:P 5 100 A 2 D!/Dw

48、here:P = moisture pick-up, %A = mass of material before drying, andD = mass of the material after drying under specifiedconditions.There is a relationship between moisture pick-up and mois-ture content since both may be calculated from the same data.The difference is in the bases used for calculatin

49、g the percent-ages, original versus dried material mass. The relationshipbetween moisture content and moisture pick-up is shown bythe equations:C 5 100 P/100 1 P!P 5 100 C/100 2 C!where:C = moisture content, %, andP = moisture pick-up, %.Since moisture pick-up, like moisture content, involves theoriginal mass, or “as-is, where-is” (from a location withunknown temperature and humidity conditions) state of thematerial, it is generally unknown if the loss in mass on dryingis caused by the loss of any materials other than