ASTM D6093-97(2011)
(Test Method)Standard Test Method for Percent Volume Nonvolatile Matter in Clear or Pigmented Coatings Using a Helium Gas Pycnometer
Standard Test Method for Percent Volume Nonvolatile Matter in Clear or Pigmented Coatings Using a Helium Gas Pycnometer
SIGNIFICANCE AND USE
This test method measures the volume of dry coating obtainable from a given volume of liquid coating. This value is useful for calculating the volatile organic content (VOC) of a coating and could be used to estimate the coverage (square feet of surface covered at a specified dry film thickness per unit volume) obtainable with different coating products.
Note 1—In Practice D3960 paragraph 10.3.1, the equation for calculating the VOC content using the percent volume nonvolatile is given. Prior to this method a satisfactory procedure for measuring percent volume nonvolatile did not exist (see Note 11 in Practice D3960).
Note 2—Since the actual coverage of a coating includes the void volume and the porosity of the film, the coverage value calculated from this method will be inaccurate by that amount, that is, the actual coverage will be greater. The higher the pigment to binder ratio (P/B) of a coating or the higher content of 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 lesser degree with Test Method D2697).
For various reasons the volume nonvolatile value obtained for a coating is often not equal to that predicted from simple linear addition of the weights and volumes of the raw materials in a formulation. One reason is that the volume occupied by a solution of resin in solvent may be the same, greater, or less than the total volume of the separate ingredients. Such contraction or expansion of resin solutions is governed by a number of factors, one of which is the extent and direction of spread between solubility parameters of the resin and solvent.
The spatial configuration of the pigment particles and the degree to which the pigment particles are filled with the binder also affect the volume of a dry coating film. Above the critical pigment volume concentration, the apparent volume of the dry film is significantly greater than theoretical due to the in...
SCOPE
1.1 This test method covers the determination of the percent volume nonvolatile matter of a variety of clear and pigmented coatings. The approach used should provide faster and more accurate results than the use of the liquid displacement technique in Test Method D2697, particularly for coatings that are difficult to wet or that contain voids, cracks or other defects. The improvement in accuracy stems from the superior ability of helium gas under pressure to penetrate very small pores and surface irregularities in dried films. This provides a more accurate determination of void volumes than can be obtained via liquid displacement.
1.2 The technique will provide results under the following constraints:
1.2.1 The stability of the helium gas pycnometer is greater than ±0.005 cm3
1.2.2 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 mathematical conversions 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 responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D6093 − 97 (Reapproved 2011)
Standard Test Method for
Percent Volume Nonvolatile Matter in Clear or Pigmented
Coatings Using a Helium Gas Pycnometer
This standard is issued under the fixed designation D6093; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D2697 Test Method for Volume Nonvolatile Matter in Clear
or Pigmented Coatings
1.1 This test method covers the determination of the percent
D3960 PracticeforDeterminingVolatileOrganicCompound
volume nonvolatile matter of a variety of clear and pigmented
(VOC) Content of Paints and Related Coatings
coatings. The approach used should provide faster and more
D4708 Practice for Preparation of Uniform Free Films of
accurate results than the use of the liquid displacement
Organic Coatings
technique in Test Method D2697, particularly for coatings that
E180 Practice for Determining the Precision of ASTM
aredifficulttowetorthatcontainvoids,cracksorotherdefects.
Methods for Analysis and Testing of Industrial and Spe-
The improvement in accuracy stems from the superior ability
cialty Chemicals (Withdrawn 2009)
of helium gas under pressure to penetrate very small pores and
2.2 Other Documents:
surface irregularities in dried films. This provides a more
2.2.1 Directions for obtaining appropriate instruction manu-
accurate determination of void volumes than can be obtained
als on the use, care, and operation of the instruments and
via liquid displacement.
equipment are listed in Section 5, (Apparatus).
1.2 The technique will provide results under the following
constraints:
3. Summary of Test Method
1.2.1 The stability of the helium gas pycnometer is greater
3.1 This procedure measures the volume of nonvolatile
than 60.005 cm
material in a dried or baked coating film. A helium gas
1.2.2 Test specimen weights are greater than 1 g.
pycnometerisusedtodeterminethevolumeoccupiedbyafilm
1.3 The values stated in inch-pound units are to be regarded by measuring the reduction of gas capacity in the pycnometer
as standard. The values given in parentheses are mathematical sample chamber caused by the presence of the test specimen.
conversions to SI units that are provided for information only (The actual measurement is accomplished with a pressure
and are not considered standard.
transducer that measures the difference in pressure between the
empty sample compartment and when loaded. The volume
1.4 This standard does not purport to address all of the
occupied by the coating sample is then calculated from the
safety concerns, if any, associated with its use. It is the
Ideal Gas Law.) The weight of the specimen is also measured
responsibility of the user of this standard to establish appro-
and the two values are used to calculate the dry film density.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
3.2 The percent volume nonvolatile content of a coating is
calculated using the dry film density, liquid coating density,
2. Referenced Documents
and the weight percent nonvolatile content of the coating.
2.1 ASTM Standards:
4. Significance and Use
D1475 Test Method For Density of Liquid Coatings, Inks,
and Related Products
4.1 This test method measures the volume of dry coating
D2369 Test Method for Volatile Content of Coatings
obtainable from a given volume of liquid coating.This value is
useful for calculating the volatile organic content (VOC) of a
coating and could be used to estimate the coverage (square feet
This test method is under the jurisdiction of ASTM Committee D01 on Paint
of surface covered at a specified dry film thickness per unit
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
volume) obtainable with different coating products.
Current edition approved June 1, 2011. Published June 2011. Originally
NOTE 1—In Practice D3960 paragraph 10.3.1, the equation for calcu-
approved in 1997. Last previous edition approved in 2003 as D6093 – 97 (2003).
DOI: 10.1520/D6093-97R11. lating the VOC content using the percent volume nonvolatile is given.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6093 − 97 (2011)
Prior to this method a satisfactory procedure for measuring percent
5.5 Standard Spray Equipment, capable of obtaining a
volume nonvolatile did not exist (see Note 11 in Practice D3960).
uniform film of 1.0 to 1.8 mil (25 to 46 µm) dry film thickness
NOTE 2—Since the actual coverage of a coating includes the void
after baking.
volume and the porosity of the film, the coverage value calculated from
this method will be inaccurate by that amount, that is, the actual coverage
5.6 Forced Draft Oven, capable of maintaining 110 6 5°C.
will be greater. The higher the pigment to binder ratio (P/B) of a coating
5.7 Single Edge Razor Blades orScalpels,
or the higher content of void containing material (latices, hollow beads,
etc.) or both, the greater will be the deviation of the coverage calculation
5.8 Anti-Static Instrument.
(This is also true to a lesser degree with Test Method D2697).
5.9 Analytical Balance, capable of weighing to 60.0001 g.
4.2 For various reasons the volume nonvolatile value ob-
5.10 A Paper/Thin Film Cutter, equipped with a rolling
tained for a coating is often not equal to that predicted from
blade, available from most office supply centers.
simple linear addition of the weights and volumes of the raw
materials in a formulation. One reason is that the volume
5.11 Polyethylene Gloves and Plastic Tweezers.
occupied by a solution of resin in solvent may be the same,
greater, or less than the total volume of the separate ingredi- 6. Procedure
ents. Such contraction or expansion of resin solutions is
6.1 Determine the wet coating density (pounds per gallon)
governedbyanumberoffactors,oneofwhichistheextentand
in accordance with Test Method D1475.
direction of spread between solubility parameters of the resin
6.2 Determine the weight percent nonvolatile content of the
and solvent.
liquid sample in accordance with Test Method D2369.
4.3 The spatial configuration of the pigment particles and
6.3 Wrap 4 by 12-in. panels (102 by 305-mm), (two per
the degree to which the pigment particles are filled with the
sample) with sheeting and tape the sheeting to the back of the
binder also affect the volume of a dry coating film. Above the
panels with masking tape. Do not overlap the sheeting on the
critical pigment volume concentration, the apparent volume of
backs of the panels.
the dry film is significantly greater than theoretical due to the
increase in unfilled voids between pigment particles. The use NOTE 4—The objective of this procedure is to obtain the coating free of
substrate. Other collection methods, such as scraping the coating from
of volume nonvolatile matter values in such instances should
glass plates or using release paper instead of sheeting are acceptable. See
be carefully considered as the increased volume is largely due
also Practice D4708 for other film preparation techniques.
to air trapped in these voids.
6.4 Place the wrapped panels on a panel rack and bake at
4.4 For thin films, the issue of critical pigment volume 5
160°C, for 10 to 15 min. Baking will tighten the sheeting and
effects is usually not a concern. With high poly(vinyl chloride)
remove any wrinkles. After baking, allow panels to cool at
(PVC) fil
...
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