1、Designation: D4920 13Standard 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 D123, Relating to Textiles.2. Referenced Documents2
4、.1 ASTM Standards:2D123 Terminology Relating to TextilesE41 Terminology Relating To ConditioningD578 Specification for Glass Fiber StrandsD579 Specification for Greige Woven Glass FabricsD580 Specification for Greige Woven Glass Tapes andWebbingsD581 Specification for Glass Fiber Greige Braided Tubu
5、larSleevingD885/D885M Test Methods for Tire Cords, Tire CordFabrics, and Industrial Filament Yarns Made from Manu-factured Organic-Base FibersD1776 Practice for Conditioning and Testing TextilesD1907 Test Method for Linear Density of Yarn (Yarn Num-ber) by the Skein MethodD2118 Practice for Assignin
6、g a Standard Commercial Mois-ture Content for Wool and its ProductsD2494 Test Method for Commercial Mass of a Shipment ofYarn or Manufactured Staple Fiber or TowD2970/D2970M Test Methods for Testing Tire Cords, TireCord Fabrics, and Industrial Yarns Made From GlassFilamentsD3887 Specification for To
7、lerances for Knitted FabricsD4772 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 p
8、er 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 humid
9、ity ratio,specific humidity, or moisture pick-up.absorption, na process in which one material (the absorbent)takes in or absorbs another (the absorbate); as the absorptionof moisture by fibers. (See also adsorption. Comparedesorption and resorption.) D4772accelerated conditioning, na process that us
10、es humiditygeneration and precise temperature controls to rapidly bringa textile to equilibrium in a standard atmosphere.DISCUSSIONAccelerated conditioning may be achieved in closedcabinets, rooms or process lines designed such that equilibrium can beachieved in a much shorter time, such as 2 to 10
11、min, compared totypical conditioning times.adsorption, 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.Compare desorption and r
12、esorption.)atmosphere for testing, 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 “contr
13、olled” by localweather and therefore 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 reproduci
14、bility. On this basis, there is no 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 Textile
15、sand is the direct responsibility of Subcommittee D13.51 on Conditioning and,Chemical and Thermal Properties.Current edition approvedJuly 1, 2013. Published August 2013 . Originallyapproved in 1989. Last previous edition approved in 2008 as D4920 08. DOI:10.1520/D4920-13.2For referenced ASTM standar
16、ds, 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
17、9428-2959. United States1bicomponent fiber, na 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 v
18、ibration directionswhich are transmitted at different 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 differenc
19、e between the maximum andminimum refractive indices.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 therma
20、l resistance defined as the insulationrequired 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
21、.commercial allowance (CA), na defined value, equal to thecommercial moisture regain, plus a specified allowance forfinish, 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 (se
22、e also commercial moisture regain), or (3) themass of a specific component in the analysis of fiber blends.D1907, D2494, D3887commercial mass, nbilled mass as determined by a gener-ally accepted method or as agreed upon between the pur-chaser and seller. D2494commercial moisture content, nin wool, t
23、he moisturecalculated as a percentage of 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,defined value, to be us
24、ed with the oven-dried mass of textilefibers, when calculating the commercial mass of a shipmentor 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 equilibriu
25、m witha specified atmosphere.density, 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 te
26、st method used. Density is commonlyexpressed 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 sorbe
27、d material is releasedfrom another material, as the desorption of moisture fromfibers; 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 v
28、apor which it canhold decreases. If air 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 in
29、sula-tion afforded by the fabric in comparison 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
30、material is usually oily, waxy, resinous, 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 vi
31、bratingparallel to the longitudinal axis 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 u
32、nit volume of the solid matter ofwhich a fiber is composed, measured under specified condi-tions.DISCUSSIONUnless otherwise indicated, fiber density is understoodto be measured by immersion (buoyancy) techniques, at standardatmosphere for testing, excluding effects due to included air andswelling or
33、 dissolving of the fiber by the immersion fluid.heat transfer 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.intrinsi
34、c clo, nsee clo.mean temperature, nthe average of the hot plate 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 c
35、ontent.moisture as-received, ndeprecated term. See moisture con-tent.moisture content, nat moisture equilibrium, that part of thetotal mass of a material that is absorbed or adsorbed water,compared to the total mass. (Compare moisture pick-up andmoisture regain.)D4920 132DISCUSSIONMoisture is usuall
36、y expressed as a percentage and iscalculated using the equation:C 5 100 A 2 D!/Awhere:C = moisture content, %,A = mass of material before drying, andD = mass of the dried material.There is a relationship between moisture content and moisturepick-up since both may be calculated from the same data. Th
37、edifference is in the bases used for calculating the percentages, originalversus dried material mass. The relationship between moisture contentand moisture pick-up is shown by the equations:C 5 100 P/1001P!P 5 100C/100 2 C!where:C = moisture content, %, andP = moisture pick-up, %.moisture content (d
38、ry-basis), ndeprecated term. See mois-ture pick-up.moisture (dry-basis), ndeprecated term. See moisture pick-up.moisture equilibrium, nthe condition reached by a materialwhen it no longer takes up moisture from, or gives upmoisture to, the surrounding atmosphere. (Comparemoisture-free.)DISCUSSIONThe
39、 establishment of equilibrium between a materialand the surrounding atmosphere is dependent upon the exposure time,the difference in moisture levels between the material and theatmosphere, and motion of the air about the material. The level at whichthe moisture in the textile reaches equilibrium dep
40、ends upon the sidefrom which equilibrium is approached. Because of this difference,equilibrium for textiles should be approached from the dry (but notmoisture-free) side which is faster. Superficial equilibrium is reachedvery rapidly when air comes into contact with the outer surfaces of atextile. M
41、oisture equilibrium can be reached in a reasonable time onlyif the air to which the sample is exposed is in motion. Moistureequilibrium, with air temperature (in motion) and relative humiditycontrolled to prescribed levels, is achieved when successive weighingsdo not show a progressive change in mas
42、s greater than the toleranceestablished for the textile. D1776, D885/D885Mmoisture-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
43、a distillationprocess using a suitable solvent. (Syn. zero-moisture.)(Compare moisture 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 t
44、hough it no longer shows a significant change in mass. This is dueto the establishment 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 heati
45、ng textiles in dessicated air to temperatures as highas 110C increases the rate of 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 do
46、es not contain any distillable,water-soluble matter.moisture pick-up, nat moisture equilibrium, the mass ofabsorbed and adsorbed water that is held by a material,compared to the mass of the dried material. (Comparemoisture content and moisture regain.)DISCUSSIONMoisture pick-up is usually expressed
47、as a percentagebased on the dried mass of the material and is calculated using theequation:P 5 100 A 2 D!/Dwhere: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 moisture
48、content since both may be calculated from the same data. Thedifference is in the bases used for calculating the percentages, originalversus dried material mass. The relationship between moisture contentand moisture pick-up is shown by the equations:C 5 100P/1001P!P 5 100C/100 2 C!where:C = moisture
49、content, %, andP = moisture pick-up, %.Since moisture pick-up, like moisture content, involves the originalmass, or “as-is, where-is” (from a location with unknown temperature andhumidity conditions) state of the material, it is generally unknown if theloss in mass on drying is caused by the loss of any materials other thanwater.moisture regain, nthe amount of water resorbed by a driedmaterial at specified equilibrium conditions of temperatureand humidity, compared to the mass of the dried material.(See standard moisture
