1、Designation: D 1210 05Standard Test Method forFineness of Dispersion of Pigment-Vehicle Systems byHegman-Type Gage1This standard is issued under the fixed designation D 1210; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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 measurem
3、ent of the degree ofdispersion (commonly referred to as “fineness of grind”) of thepigment in a pigment-vehicle system such as liquid coatingsand their intermediates. It may also be used to assess theinclusion of particulates by a cleanliness (or texture) rating.1.2 The values stated in SI units are
4、 to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 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
5、 and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1316 Test Method for Fineness of Grind of Printing Inksby the NPIRI Grindometer3. Summary of Test Method3.1 Tapered GageThe product is spread by means of ascraper in a machined taper
6、ed path. At some point in this path,particles or agglomerates, or both, will become visible.Adirectreading from the graduated scale is then made at the pointwhere the particles form a definite pattern. When the singlepath gage is used it is also possible to rate “cleanliness” (see6.2).3.2 Stepped Ga
7、geThe product is spread by means of ascraper on a stepped gage. There are 2 delimited sections onthis gage, each of 6.5 cm2(1 in.2) area, and of two differentdepths. A count is made of the particles deposited in the twodelimited areas, and cleanliness (texture) reading is deter-mined.4. Significance
8、 and Use4.1 In making pigmented products, the pigment is usuallydispersed in a portion of the vehicle in some sort of mill.At thisstage, it is necessary to be able to judge if the pigmentagglomerates have been sufficiently broken up so as not tointerfere with the smoothness of the finished coating f
9、ilm. Thistest method describes a way of making this judgment.5. Apparatus5.1 Tapered GageA hardened steel, stainless steel, orchrome-plated steel block (Fig. 1) approximately 170 mm (6.7in.) in length, and 15 mm (0.6 in.) in thickness. The top surfaceof the block shall be ground smooth and planar an
10、d shallcontain one or two paths 127 mm (5 in.) in calibrated length.The path shall be tapered uniformly in depth lengthwise fromabout 4 mils (100 m) at 10 mm from one end to zero depth atthe other with intermediate calibrations in accordance with thedepth at those points. Preferred calibrations are
11、Hegman unitsand micrometers (Note 1). Three path widths are covered bythis test method:5.1.1 Two Parallel Paths, each 12.5-mm (0.5-in.) wide andspaced 0.5-in. apart centered in a block 65-mm (2.5-in.) wide(see Fig. 1).5.1.2 One Path, 50 mm (2 in.) in width centered in a block90-mm (3.5-in.) wide (se
12、e Fig. 1).5.1.3 One Path, 25 mm (1 in.) in width centered in a block65-mm (2.5-in.) wide (see Fig. 1a).NOTE 1Several arbitrary scales and modifications of the gage areused by industry. In order that readings obtained with these arbitrary scales1This test method is under the jurisdiction of ASTM Comm
13、ittee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.24 on Physical Properties of Liquid Paints and Paint Materials.Current edition approved March 1, 2005. Published April 2005. Originallyapproved in 1952. Last previous edition appro
14、ved in 2004 as D 1210 96 (2004).2For referenced ASTM standards, 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
15、, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.and modifications can be reported in the preferred units, the approximaterelationship of these scales to gage depth is shown in the followingexample:HegmanScaleADepth,mBDepth,milsBPC or FSPTScaleCNPIRIScaleD0 100 4
16、 0 401 90 3.5 114 35275 212 303 65 2.5 334 25450 5205 40 1.5 614 15625 712 107 15 0.5 834 580 00ASometimes referred to in error as the North Standard scale.BRounded to nearest 5 m or 0.5 mil.CFederation of Societies for Paint Technology scale.DNational Printing Ink Research Institute scale, 0 to 10
17、on the NPIRI ProductionGrindometer, but extended on many gages to 20 or 30 (see Test Method D 1316).5.2 Stepped GageA hardened steel, stainless steel, orchrome-plated steel block (Fig. 1a), approximately 170 mm(6.7 in.) in length, and 15 mm (0.6 in.) in thickness. A path25-mm (1-in.) wide shall be c
18、ut the length of, and centered ina block 65-mm (2.5-in.) wide. The path will be cut to twodifferent depths, each for half of its length. The two depths willbe 3 mils, and 1 mil, or as agreed upon between the buyer andthe seller. There shall be two tick marks, above and below the“step,” and spaced 25
19、 mm (1 in.) from it.5.3 ScraperA double-edged hardened steel, stainlesssteel, or chrome-plated steel blade (Fig. 2) 95-mm (3.75-in.)long, 40-mm (1.5-in.) wide, and 6.4-mm (0.25-in.) thick. Thetwo edges on the 3.75-in. sides shall be rounded to a radius of0.38 mm (0.015 in.).5.4 IlluminationThe gage
20、shall be illuminated for viewingwith a fluorescent tube, mounted approximately 250 mm (10in.) above the gage with the length of the tube parallel to thelength of the gage. The tube will be mounted so that the anglebetween the plane of the gage, and the tube is 75 to 80. Aviewing box is not mandatory
21、 for illumination, but if one isdesired, a proposed design for a viewing box is contained inAppendix X1.6. Care of Gage6.1 Clean the gage immediately after each use. Use asolvent and a soft cloth. Keep the gage covered or encased atall times when not in use. Protect gages that lie idle forextended p
22、eriods of time from rust with an oil coating or oilsoaked wrap.FIG. 1 Fineness GagesD12100526.2 Do not allow any hard materials to come in contact withthe gage surface or scraper in any manner that might result inscarring or nicking. Avoid tapping or scratching with othermetal.6.3 The scraper may be
23、 rendered unsatisfactory for use bywear or nicks of the contact edge or warpage (Note 2). Replaceor recondition unsatisfactory blades.NOTE 2Wear or warpage of the scraper may be noted by facing theedge of the scraper down on the smooth level face of the gage, theninspecting the contact edge by means
24、 of a strong light, placed behind thegage. Rocking the scraper forward or back will reveal poor contact due towear or warpage. Any light coming through between scraper and gageface shows that the scraper has been damaged and is not satisfactory foruse.7. Visual Standards7.1 The diagrams in Fig. 3 ar
25、e reproductions of six typicalfineness-gage patterns with the double-path gage in 5.1.1, andthey should be viewed with the purpose of standardizing therelationship of particle distribution to fineness designation. Thearrow in each drawing represents the end point (reading) forthat distribution. Thes
26、e patterns are to be used for notation offrequency of particles and should not be interpreted accordingto the size of the dots. Although called “standards,” they arereally examples of fineness readings to be used as a guide,since no two particle distributions will be exactly the same.7.2 Similarly,
27、Fig. 4 exhibits typical fineness gage patternsfor the 50-mm (2-in.) gage in 5.1.2, or the 25-mm (1-in.) gagein 5.1.3. These diagrams are to be used like those for thedouble-path gage except that a “cleanliness” rating is alsoshown. “Cleanliness” is descriptive of the number of particlesthat appear i
28、n the path above the fineness designation. Threeratings are indicated: A (0 to 8 specks), B (9 to 15 specks), andC (16 or more specks).1-in. single path gage Texture GageFIG. 1 a Fineness Gages (continued)NOTE 11 in. = 25.4 mm.FIG. 2 ScraperD12100538. ProcedureTapered Gage8.1 Place the gage on a hor
29、izontal flat, nonslippery surfaceand wipe clean immediately before the test. Be sure the gagesurface is free of lint.8.2 Hand stir the specimen (Note 3) vigorously for 2 min,taking care that air bubbles are not whipped into the paint. Tobe sure of an accurate grind reading, specimens must be free of
30、air bubbles.NOTE 3For this test method to function properly, the pigmentparticles in the specimens to be tested should be free to settle to the bottomof the gage channel after the drawdown. Therefore, before testing,high-viscosity intermediate specimens that have little ability to flowshould be redu
31、ced with a compatible liquid. Reduction should be inapproximately the same proportion as the intermediate will be reduced inpractice.8.3 Immediately place the material to be tested in the deepend of the path, or paths, so that it overflows the path slightly.When using the double-path gage, place mat
32、erial in both paths.8.4 Holding the scraper in both hands, nearly vertical butinclined slightly toward the operator, draw the material downthe length of the path toward the shallow end of the gage witha uniform, brisk motion in approximately 1 to 3 s. Exert uponthe scraper only sufficient pressure t
33、o clean excess materialfrom the face of the gage. Within 10 s of placing the specimenon the gage, make a reading as follows:8.4.1 View the gage from the side, perpendicular to thelength of the path. Keeping the gage between the operator andthe light source, make the angle between the face of the gag
34、eand the line of vision so that the image of the fluorescent tubeappears in the material on the gage.FIG. 3 a Typical Fineness Gage PatternsD1210054NOTE 4Clear finishes may have to be viewed at a lower angle or theymay have to be opacified with a finely ground colorant or dye in order tosee the part
35、icles better.8.4.2 It is important to decide in which direction to scan thegage (from the deep end (0 Hegman or 100 m) toward theshallow end (8 Hegman or 0 m) or from the shallow end to thedeep end.) It is preferable to scan from the shallow end towardthe deep end, since this allows the operator to
36、just decide whenthe dense pattern breaks, rather than trying to decide whetherthe pattern has less dense areas within it. (See Fig. 4c). Whenusing the two-path gage, average the values in the two paths tothe nearest14 Hegman unit. This average is considered onereading. The two protocols for reading
37、the fineness are:8.4.2.1 Shallow end toward deep endStart at the shallowend of the gage and observe where the first break in the densepattern of particles occurs. This is the fineness reading.8.4.2.2 Deep end toward shallow endObserve the pointwhere the material first shows a definite speckled patte
38、rn, notjust isolated specks (see Fig. 3 and Fig. 4). This is the finenessreading.8.5 After the first drawdown and reading, which are pre-liminary for establishing proper test conditions and locating theposition of the fineness reading, repeat the procedure twice,beginning with 8.3, to obtain two tes
39、t readings. This processallows the two test readings to be made with limited timeFIG. 3 b Typical Fineness Gage Patterns (continued)D1210055lapses between completion of drawdown and reading. (Do notconsider any reading for the reported fineness when the timelapse exceeds 10 s.) Average the two readi
40、ngs to the nearest14Hegman units (5 m).8.6 Interpretation of Dispersion Pattern:8.6.1 Inspect the initial drawdown for pattern and theapproximate fineness. Determine the point in the particledistribution that approximates a similar end point pattern tothat of the pictorial standards.8.6.2 Judge clea
41、nliness on the one-path gage either bycomparison to the typical fineness patterns (shown only at a 6Hegman level but applicable by analogy to any fineness level)or by counting nibs coarser than the selected fineness level (see7.2 for cleanliness ranges).9. ProcedureStepped Gage9.1 Place the gage on
42、a horizontal flat, nonslippery surfaceand wipe clean immediately before the test. Be sure the gagesurface is free of lint.9.2 Hand stir the specimen (Note 3) vigorously for 2 min,taking care that air bubbles are not whipped into the paint. Tobe sure of an accurate grind reading, specimens must be fr
43、ee ofair bubbles.FIG. 3 c Typical Fineness Gage Patterns (continued)D1210056NOTE 5For this test method to function properly, the pigmentparticles in the specimens to be tested should be free to settle to the bottomof the gage channel after the drawdown. Therefore, before testing,high-viscosity inter
44、mediate specimens that have little ability to flowFIG. 4 a Typical Fineness Gage PatternFIG. 4 b Typical Fineness Gage Pattern (continued)FIG. 4 c Typical Fineness Gage Pattern (continued)FIG. 4 d Typical Fineness Gage Pattern (continued)D1210057should be reduced with a compatible liquid. Reduction
45、should be inapproximately the same proportion as the intermediate will be reduced inpractice.9.3 Immediately place the material to be tested in the deepend of the path, or paths, so that it overflows the path slightly.When using the double-path gage, place material in both paths.9.4 Holding the scra
46、per in both hands, nearly vertical butinclined slightly toward the operator, draw the material downthe length of the path toward the shallow end of the gage witha uniform, brisk motion in approximately 1 to 3 s. Exert uponthe scraper only sufficient pressure to clean excess materialfrom the face of
47、the gage. Within 10 s of placing the specimenon the gage, make a reading as follows:9.4.1 View the gage from the side, perpendicular to thelength of the path. Keeping the gage between the operator andthe light source, make the angle between the face of the gageand the line of vision so that the imag
48、e of the fluorescent tubeappears in the material on the gage.NOTE 6Clear finishes may have to be viewed at a lower angle or theymay have to be opacified with a finely ground colorant or dye in order tosee the particles better.9.4.2 Count the number of particles on each side of the step,between the s
49、tep and the tick mark. This area is equal to 6.5cm2(1 in.2). Calculate the texture (cleanliness) of the materialusing the following formula that weights the coarse fraction(3-mil side of gage) 4 times heavier than the fine fraction(1-mil side).Texture cleanliness!510 2 int c 3 0.4 1 f 3 0.1 1 0.9!where:c = coarse fraction (3-mil side of gage),f = fine fraction (1-mil side of gage), andint = drop decimals.NOTE 7It is suggested that each side be counted only to a maximumof 20.10. Report10.1 Report the following information:10.1.1 Which tapered gag
