1、Designation: D 1475 98 (Reapproved 2003)Standard Test Method ForDensity of Liquid Coatings, Inks, and Related Products1This standard is issued under the fixed designation D 1475; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers the
3、measurement of density ofpaints, inks, varnishes, lacquers, and components thereof, otherthan pigments, when in fluid form.1.2 For higher precision when working with nonpigmentedmaterials (drying oils, varnishes, resins and related materials),Test Method D 1963 can be used to determine specific grav
4、ityand, thence, density.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly,1.4 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 s
5、tandard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. A specific precau-tion statement is given in 8.1.1.1.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 1963 Test Method for Specific
6、 Gravity of Drying Oils,Varnishes, Resins and Related Materials at 25/25CD 4052 Test Method for Density and Relative Density ofLiquids by Digital Density MeterE 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 691 Practice for
7、 Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 densitythe mass of a unit volume of a material at aspecified temperature. In this method, it is expressed as theweight in grams per millilitre, or as the weight in poundsavoirdupois of
8、one U. S. gallon, of the liquid at the specifiedtemperature; in the absence of other temperature specification,25C is assumed.3.1.2 specific gravity (relative density)the ratio of themass of a unit volume of a material at a stated temperature tothe mass of the same volume of distilled water at the s
9、ametemperature.4. Summary of Test Method4.1 The accurately known absolute density of distilled waterat various temperatures (Table 1) is used to calibrate thevolume of a container. The weight of the paint liquid contentsof the same container at the standard temperature (25C) or atan agreed-upon temp
10、erature is then determined and density ofthe contents calculated in terms of grams per millilitre, orpounds per gallon at the specified temperature.5. Significance and Use5.1 Density is weight per unit volume. It is a key property inthe identification, characterization, and quality control of awide
11、range of materials. Density measurements in terms ofweight per gallon are commonly used to check paint quality. Ifthe density is not within specification, there is a good chancethat there was a mischarge or other serious problem.5.2 This test method is suitable for the determination ofdensity of pai
12、nt and related products and components when inliquid form. It is particularly applicable when the fluid has toohigh a viscosity or when a component is too volatile for adensity balance determination.5.3 This test method provides for the maximum accuracyrequired for hiding power determinations. It is
13、 equally suitablefor work in which less accuracy is required, by ignoring thedirections for recalibration and consideration of temperaturedifferentials, and using as the container a “weight-per-gallon”cup.5.4 Automatic equipment for measuring density is available(see Test Method D 4052) from several
14、 manufacturers. Suchapparatus has been used for resins and latices as well as for oilsand solvents. Before such equipment is used for a given1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility of
15、Subcommittee D01.24 on Physical Properties of Liquid Paints and Paint Materials.Current edition approved Dec. 1, 2003. Published December 2003. Originallyapproved in 1957. Last previous edition approved in 1998 as D 1475 98.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcont
16、act 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.product, results must
17、be checked very carefully. Particularlywith paints, inks, and resins, there are possibilities of gum-ming, fouling, and other interferences with operation.6. Interferences6.1 Highly viscous materials may entrap air and giveerroneous low density values.6.2 Paint or ink liquids may be trapped in the g
18、round glassor metal joints of the pieces of apparatus and give erroneous,high density values.7. Apparatus7.1 Cup or PycnometerAny metal weight-per-gallon cupor glass pycnometer may be used, provided that it may be filledreadily with a viscous liquid, adjusted to exact volume, coveredto exclude loss
19、of volatile matter, and readily cleaned.NOTE 1For materials that contain solvents that evaporate rapidly, aglass pycnometer of the weld type, with a narrow stopper and a covershould be used.7.2 Thermometers, graduated in 0.1C, such as are suppliedwith glass pycnometers.7.3 Constant-Temperature Bath,
20、 held at 25 6 0.1C isdesirable.7.4 Laboratory Analytical Balance.NOTE 2The usual weight-per-gallon cup and similar specializedpycnometers may have filled weights that exceed the capacity of the usuallaboratory analytical balance. In such cases, use of a hanging pan,triple-beam balance, with scales g
21、raduated to 0.01 g has been found toprovide results the mean of which was consistent with the overallprecision and accuracy of the method.7.5 Desiccator and Desiccated Balance, or a room ofreasonably constant temperature and humidity are desirable.8. Calibration of Cup or Pycnometer8.1 Determine the
22、 volume of the container at the specifiedtemperature by employing the following steps:8.1.1 Clean and dry the container and bring it to constantweight. Chromic acid (see 8.1.1.1) or other effective glasscleaner and nonresidual solvents may be used with glasscontainers and solvents with metal contain
23、ers. For maximumaccuracy, continue rinsing, drying, and weighing until thedifference between two successive weighings does not exceed0.001 % of the weight of the container. Fingerprints on thecontainer will change the weight and must be avoided. Recordthe weight, M, in grams.8.1.1.1 WarningChromic a
24、cid cleaning solution is corro-sive to skin, eyes and mucous membranes and can cause severeburns. Avoid contact with eyes, skin or clothing. In makingdilute solution, always add acid to water with care. Chromicacid cleaning solution is a strong oxidizer. Avoid contact withorganic or reducing substan
25、ces as a fire could results. Seesuppliers Material Safety Data Sheet for further information.Other cleaners are much safer and may be equally effective.8.1.2 Fill the container with reagent water conforming toType II of Specification D 1193 at a temperature somewhatbelow that specified. Cap the cont
26、ainer, leaving the overfloworifice open. Immediately remove excess overflowed water orwater held in depressions by wiping dry with absorbentmaterial. Avoid occluding air bubbles in the container.8.1.3 Bring the container and contents to the specifiedtemperature using the constant-temperature bath or
27、 room ifnecessary. This will cause further slight flow of water from theoverflow orifice due to the expansion of the water with the riseof the temperature.8.1.4 Remove the excess overflow by wiping carefully withabsorbent material, avoiding wicking of water out of orifice,and immediately cap the ove
28、rflow tube where such has beenprovided. Dry the outside of the container, if necessary, bywiping with absorbent material. Do not remove overflow thatoccurs subsequent to the first wiping after attainment of thedesired temperature (Note 3). Immediately weigh the filledcontainer to the nearest 0.001 %
29、 of its weight (Note 4). Recordthis weight, N, in grams.NOTE 3Handling the container with bare hands will increase thetemperature and cause more overflow from the overflow orifice, and willalso leave fingerprints; hence, handling only with tongs and with handsprotected by clean, dry, absorbent mater
30、ial is recommended.NOTE 4Immediate and rapid weighing of the filled container isrecommended here to minimize loss of weight due to evaporation of thewater through orifices, and from overflow subsequent to the first wipingafter attainment of temperature where this overflow is not retained by acap.8.1
31、.5 Calculate the container volume as follows:V 5 N 2 M!/r (1)where:V = volume of container, mL,N = weight of container and water, g (8.1.4),M = weight of dry container, g (8.1.1), andr = absolute density of water at specified temperature,g/mL (see Table 1).8.1.6 Obtain the mean of at least three det
32、erminations.9. Procedure9.1 Repeat the steps in Section 8, substituting the sample forthe reagent water and a suitable nonresidual solvent for theacetone or alcohol (see Note 5). Record the weight of the filledcontainer, W, and the weight of the empty container, w,ingrams.NOTE 5Trapping of paint or
33、ink liquids in ground glass or metal jointsis likely to result in high values of density that appear to increase with theTABLE 1 Absolute Density of Water, g/mLC Density15 0.99912716 0.99897117 0.99877218 0.99862319 0.99843320 0.99823121 0.99802022 0.99779823 0.99756624 0.99732425 0.99707226 0.99681
34、127 0.99654028 0.99626029 0.99597230 0.995684D 1475 98 (2003)2viscosity and density of the material; such errors should be minimized byfirm seating of the joints.NOTE 6Trapping of air bubbles results in low values for density. Thetendency to trap air increases with increasing viscosity. Specimens sh
35、ouldnot be tested if they contain bubbles or foam. Slow stirring, standing, orthe application of a vacuum may remove bubbles. If these do not work, adilution may be necessary (see Appendix X1).9.2 Calculate the density in grams per millilitre as follows:Dm5 W 2 w!/V (2)where:Dm= density, g/mL.9.3 Ca
36、lculate the density in pounds per gallon as follows:D 5 W 2 w!K/V (3)where:D = density, lb/gal,K = 8.3454 (Note 7), andV = volume of container, mL (see 8.1.6).NOTE 7The factor K, 8.3454, is calculated from volume-weightrelationship as follows:8.345404 = (2.54)3A3 (231.00)B/(453.59237)CA(2.54)3is the
37、 conversion factor for millilitres to cubic inches.B231.00 is the conversion factor for cubic inches to gallons.C453.59237 is the conversion factor for grams to pounds.10. Report10.1 In reporting the density, state the test temperature to thenearest 0.1C, the units, and the value calculated to three
38、 places(for example, D = x.xxx lb/gal at 25C); state the mean, therange, and the number of replicate determinations.11. Precision and Bias11.1 PaintsThe precision estimates are based on an inter-laboratory study in which one operator in each of six differentlaboratories analyzed in duplicate on two
39、different days fivesamples of paint ranging in density from 8.5 to 12.5 lb/gal. Theresults were analyzed statistically in accordance with PracticeE 180. The within-laboratory coefficient of variation was foundto be 0.20 % relative with 25 df and the between-laboratorycoefficient of variation was 0.6
40、1 % relative with 20 df. Basedon these coefficients, the following criteria should be used forjudging the acceptability of results at the 95 % confidencelevel:11.1.1 RepeatabilityTwo results, each the mean of dupli-cate determinations, obtained by the same operator on differentdays should be conside
41、red suspect if they differ by more than0.6 % relative.11.1.2 ReproducibilityTwo results, each the mean of du-plicate determinations, obtained by operators in different labo-ratories should be considered suspect if they differ by morethan 1.8 % relative.11.2 InksA separate interlaboratory study of th
42、is testmethod was carried out for inks. In this study, one operator ineach of seven laboratories made three determinations on fourdifferent paste ink samples. Paste inks were chosen becausetheir viscosities are high and they would be expected to providea difficult test for the method. The inks repre
43、sented a densityrange of 8.4 to 8.9 lb/gal and exhibited viscosities ranging froma very soft news black to a relatively heavy sheet-fed offset ink.The results were analyzed statistically in accordance withPractice E 691. The within-laboratory standard deviation was0.030 lb/gal and the pooled laborat
44、ory standard deviation was0.045 lb/gal. Based on these values, the following criteriashould be used for judging the acceptability of results at the95 % confidence level:11.2.1 RepeatabilityTwo results obtained by the sameoperator should be considered suspect if they differ by morethan 0.084 lb/gal (
45、1 %).11.2.2 ReproducibilityTwo results obtained by operatorsin different laboratories should be considered suspect if theydiffer by more than 0.125 lb/gal (1.5 %).11.3 Bias (Paint and Inks)Since there is no acceptedreference material, bias cannot be determined.12. Keywords12.1 density; pycnometer; w
46、eight per gallon; weight pergallon cupAPPENDIXES(Nonmandatory Information)X1. DILUTING OF A MATERIAL TO IMPROVE AIR RELEASEX1.1 To reduce viscosity and improve air release, a knownweight of a material that traps air may be diluted with a knownweight of a solvent or another diluent of known density.
47、Aftercareful blending to achieve homogeneity and release air, thedensity of the diluted material is measured by the techniquedescribed in this test method. The following equation may beused to calculate the density of the original material:Do5WoWo1 WdDd12WdDd2(X1.1)where:Do= density of original mate
48、rial,Dd1= density diluted measured in test,Dd2= density diluent,Wo= original weight, andWd= diluent weight.D 1475 98 (2003)3X2. CENTRIFUGING OF MATERIAL TO REMOVE EXCESS AIRX2.1 To reduce the variation in the density method, air isremoved from the specimen by centrifuging the material,resulting in g
49、reater homogeneity between replicates. Thisgreatly improves reproducibility and repeatability and resultsin slightly higher density readings.X2.2 ApparatusX2.2.1 Centrifuge, capable of a maximum of 4000 r/min3,X2.2.2 Standard Density Cup,X2.2.3 Thermometer.X2.3 ProcedureX2.3.1 Fill the centrifuge tube to the top (approximately150 % of the density cup volume), adjust to the recommendedtemperature of 25C 6 1. Place the tube in the centrifuge.X2.3.2 Turn on the centrifuge and set the speed control to2/3 power to attain a speed of 2700 to 3000 r/min.X2.
