1、Designation: D6093 97 (Reapproved 2011)D6093 97 (Reapproved 2016)Standard Test Method forPercent Volume Nonvolatile Matter in Clear or PigmentedCoatings Using a Helium Gas Pycnometer1This standard is issued under the fixed designation D6093; the number immediately following the designation indicates
2、 the year oforiginal adoption or, in the case of revision, the year of last revision. 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 test method covers the determination of th
3、e percent volume nonvolatile matter of a variety of clear and pigmentedcoatings. The approach used should provide faster and more accurate results than the use of the liquid displacement technique inTest Method D2697, particularly for coatings that are difficult to wet or that contain voids, cracks
4、or other defects. Theimprovement in accuracy stems from the superior ability of helium gas under pressure to penetrate very small pores and surfaceirregularities in dried films. This provides a more accurate determination of void volumes than can be obtained via liquiddisplacement.1.2 The technique
5、will provide results under the following constraints:1.2.1 The stability of the helium gas pycnometer is greater than 60.005 cm31.2.2 Test specimen weights are greater than 1 g.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalc
6、onversions to SI units that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health pra
7、ctices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1475 Test Method For Density of Liquid Coatings, Inks, and Related ProductsD2369 Test Method for Volatile Content of CoatingsD2697 Test Method for Volume Nonvolatile Matter in Cle
8、ar or Pigmented CoatingsD3960 Practice for Determining Volatile Organic Compound (VOC) Content of Paints and Related CoatingsD4708 Practice for Preparation of Uniform Free Films of Organic CoatingsE180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and
9、Specialty Chemicals(Withdrawn 2009)32.2 Other Documents:2.2.1 Directions for obtaining appropriate instruction manuals on the use, care, and operation of the instruments and equipmentare listed in Section 5, (Apparatus).3. Summary of Test Method3.1 This procedure measures the volume of nonvolatile m
10、aterial in a dried or baked coating film. A helium gas pycnometer isused to determine the volume occupied by a film by measuring the reduction of gas capacity in the pycnometer sample chambercaused by the presence of the test specimen. (The actual measurement is accomplished with a pressure transduc
11、er that measures1 This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1, 2011Dec. 1, 2016. P
12、ublished June 2011December 2016. Originally approved in 1997. Last previous edition approved in 20032011 asD6093 97 (2003).(2011). DOI: 10.1520/D6093-97R11.10.1520/D6093-97R16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For
13、 Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM
14、standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by
15、 ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1the difference in pressure between the empty sample compartment and when loaded. The volume occupied by the coating sampleis then calculat
16、ed from the Ideal Gas Law.) The weight of the specimen is also measured and the two values are used to calculatethe dry film density.3.2 The percent volume nonvolatile content of a coating is calculated using the dry film density, liquid coating density, and theweight percent nonvolatile content of
17、the coating.4. Significance and Use4.1 This test method measures the volume of dry coating obtainable from a given volume of liquid coating. This value is usefulfor calculating the volatile organic content (VOC) of a coating and could be used to estimate the coverage (square feet of surfacecovered a
18、t a specified dry film thickness per unit volume) obtainable with different coating products.NOTE 1In Practice D3960 paragraph 10.3.1, the equation for calculating the VOC content using the percent volume nonvolatile is given. Prior to thismethod a satisfactory procedure for measuring percent volume
19、 nonvolatile did not exist (see Note 11 in Practice D3960).NOTE 2Since the actual coverage of a coating includes the void volume and the porosity of the film, the coverage value calculated from this methodwill be inaccurate by that amount, that is, the actual coverage will be greater.The higher the
20、pigment to binder ratio (P/B) of a coating or the higher contentof void containing material (latices, hollow beads, etc.) or both, the greater will be the deviation of the coverage calculation (This is also true to a lesserdegree with Test Method D2697).4.2 For various reasons the volume nonvolatile
21、 value obtained for a coating is often not equal to that predicted from simplelinear addition of the weights and volumes of the raw materials in a formulation. One reason is that the volume occupied by asolution of resin in solvent may be the same, greater, or less than the total volume of the separ
22、ate ingredients. Such contractionor expansion of resin solutions is governed by a number of factors, one of which is the extent and direction of spread betweensolubility parameters of the resin and solvent.4.3 The spatial configuration of the pigment particles and the degree to which the pigment par
23、ticles are filled with the binderalso affect the volume of a dry coating film.Above the critical pigment volume concentration, the apparent volume of the dry filmis significantly greater than theoretical due to the increase in unfilled voids between pigment particles. The use of volumenonvolatile ma
24、tter values in such instances should be carefully considered as the increased volume is largely due to air trappedin these voids.4.4 For thin films, the issue of critical pigment volume effects is usually not a concern. With high poly(vinyl chloride) (PVC)films, however, liquid displacement of air v
25、oids takes place with difficulty even under high pressures. Helium solves this problemsince, as a gas, it readily penetrates and displaces air, water, and volatile solvents even at low pressures. Purging the gas pycnometerflushes these materials from the film.5. Apparatus and Reagents5.1 Gas Pycnome
26、ter, equipped with a suitably sized cup.NOTE 3The data from the round robin was obtained using a 5-mL cup instrument. 45.2 Panels, steel or aluminum, 4 in. by 12 in. (102 mm by 305 mm).5.3 Sheeting5, approximately 1.5-mils (38-m) thick.5.4 Doctor Blades, 5 to 8 mils (127 to 203 m), appropriate to gi
27、ve 1.0 to 1.8 mils (25 to 46 m) dry film thickness). A 3-in.(76-mm) wide, multiple clearance applicator is recommended.5.5 Standard Spray Equipment, capable of obtaining a uniform film of 1.0 to 1.8 mil (25 to 46 m) dry film thickness afterbaking.5.6 Forced Draft Oven, capable of maintaining 110 6 5
28、C.5.7 Single Edge Razor Blades orScalpels,5.8 Anti-Static Instrument.65.9 Analytical Balance, capable of weighing to 60.0001 g.5.10 A Paper/Thin Film Cutter, equipped with a rolling blade, available from most office supply centers.4 The sole source of supply of the 5mL cup, Model 1305 known to the c
29、ommittee at this time is the Micromeritics Instrument Corp., One Micromeritics Drive, Norcross,GA 300931877. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive carefulconsideration at a meeting of the responsible
30、technical committee,1 which you may attend.5 The sole source of sheeting, Tedlar, Tedlar, a registered trademark of E. I. du Pont de Nemours and Company, PC105M3, known to the committee at this time is theDupont Company. If you are aware of alternative suppliers, please provide this information to A
31、STM International Headquarters. Your comments will receive carefulconsideration at a meeting of the responsible technical committee,1 which you may attend.6 The sole source of supply of the anti-static instrument, Zerostat 3, known to the committee at this time is the Aldrich Chemical Co., Inc., (ad
32、dress). If you are awareof alternative suppliers, please provide this information toASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee, 1 which you may attend.D6093 97 (2016)25.11 Polyethylene Gloves and Plastic Tweezer
33、s.6. Procedure6.1 Determine the wet coating density (pounds per gallon) in accordance with Test Method D1475.6.2 Determine the weight percent nonvolatile content of the liquid sample in accordance with Test Method D2369.6.3 Wrap 4 by 12-in. panels (102 by 305-mm), (two per sample) with sheeting 5 an
34、d tape the sheeting to the back of the panelswith masking tape. Do not overlap the sheeting on the backs of the panels.NOTE 4The objective of this procedure is to obtain the coating free of substrate. Other collection methods, such as scraping the coating from glassplates or using release paper inst
35、ead of sheeting5 are acceptable. See also Practice D4708 for other film preparation techniques.6.4 Place the wrapped panels on a panel rack and bake at 160C, for 10 to 15 min. Baking will tighten the sheeting5 and removeany wrinkles. After baking, allow panels to cool at room temperature for at leas
36、t 15 min.6.5 Prepare a thin, uniform, bubble-free film on the wrapped panels either by spraying or with a drawdown blade, to obtain adry film thickness of 1.0 to 1.8 mils (25 to 46 m). Thinner films of 1.0 to 1.2 mils (25 to 31 m) have fewer potential problemswith entrapped solvents.6.6 Bake the coa
37、ted panels for 60 min at 110C in a forced draft oven, then cool at room temperature for 20 to 30 min.6.7 Cut a slit across the top or bottom, about 12 in. from the edge of the film. Separate a small portion of the film from thesheeting5 with a scalpel or razor blade. Work a thin narrow spatula blade
38、 (about 4-12 in.-long (115-mm) under the separatedportion of the file then remove the film by working the spatula blade between the film and substrate along and across each sideand end of the panel.6.8 Place the film on a piece of sheeting5 or plain paper that has been treated with the anti-static d
39、evice. Treat the film with thedevice in accordance with the manufacturers instructions.NOTE 5Using metal lab benches helps reduce static problems.6.9 Cut the film into strips, approximately 14 by 34 in. (6 by 19 mm).NOTE 6Alternatively, if the film does not cut well or crumbles, the film may be loos
40、ely packed into the cup.6.10 Weigh the dried, empty cup and record.6.11 Place the film strips vertically into a sample cup until there is between 1.0 to 2.0 g of film in the 5-mL cup (If a differentsize cup is used, use a proportional amount of film sample.). Use the anti-static device as often as n
41、ecessary. The film strips shouldnot be protruding from the cup.6.12 Weigh the sample strips and cup to verify there is at least 1.0 g of the test specimen. Samples should be run in duplicate.6.13 Conduct the experiment in accordance with the Gas Pycnometer Instruction Manual.6.14 Take at least five
42、consecutive readings, in accordance with instrument instructions. Variation in readings should be random.A consistent volume increase indicates loss of trapped solvent and results should be considered suspect. Refer to the instrumentinstruction manual.6.15 Weigh the cup after finishing the instrumen
43、t readings.6.16 Subtract the weight of the empty cup to obtain the film weight.7. Calculation7.1 Calculate the dry film density, Df, from the pycnometer volume displacement (6.14) and film weight (6.15) as follows:Df5 Film weight g!Volume displacement mL! (1)NOTE 7If the film density of duplicate ru
44、ns differs by more than 0.05 g/mL, the test should be repeated.7.2 Calculate dry film specific gravity, Sgf, as follows:Sgf5 Dfg/mL!0.9971g/mL! (2)where 0.9971 = Density of distilled water at 25C in g/mL.7.3 Calculate the dry film weight per gallon, Wgf, as follows:Wgf5 Sgf38.312 lb./gal! (3)where 8
45、.312 = weight of 1 gal of distilled water at 24C (lb./gal).7.4 Calculate percent volume solids nonvolatile content (VNV, %) as follows:D6093 97 (2016)3VNV,%5weight%nonvolatiles3weight per gal liquid sample!Wgf (4)NOTE 8If the wet sample density is determined by a device directly reading out in g/L,
46、the following equation can be used which generates identicalVNV, % results as follows:VNV,%5weight percent NV3wet coating density g/mL!dry film density g/mL! (5)7.5 Example calculation:Df = 1.452 g/mLWeight percent nonvolatiles = 61.3 %Gallon weight (liquid sample) = 9.55 lb/galSgf = 1.452 g/mL 0.99
47、7 g/mL = 1.456Wgf = 1.456 8.312 lb /gal = 12.102 lb/galVNV, % = 61.3 % 9.55/12.102 = 48.4 %8. Precision and Bias8.1 Precision (In accordance with Practice E180). In an inter laboratory study of this test method five laboratories analyzed induplicate on two days, three coatings (one solvent-based and
48、 two water-reducible) with nonvolatile contents ranging from 27 to48 volume percent. The pooled within-laboratory coefficient of variation was 1.16 % with 14 df and the pooled betweenlaboratories coefficient of variation 2.46 % with 11 df. Based on these coefficients of variation, the following crit
49、eria should be usedfor judging the acceptability of results at the 95 % confidence level:8.1.1 RepeatabilityTwo results, each the mean of duplicate determinations, obtained by the same operator on different daysshould be considered suspect if they differ by more than 3.5 % relative.8.1.2 ReproducibilityTwo results, each the mean of duplicate determinations, obtained by operators in different laboratoriesshould be considered suspect if they differ by more than 7.67 % relative.8.2 BiasNo general statement of bias can be made because no r
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