ASTM D6093-97(2022)

Standard Test Method for Percent Volume Nonvolatile Matter in Clear or Pigmented Coatings Using a Helium Gas Pycnometer

SIGNIFICANCE AND USE
4.1 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).  
4.2 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.  
4.3 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...
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Nov-2022
• ICS: 25.220.01 - Surface treatment and coating in general
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.21 - Chemical Analysis of Paints and Paint Materials

Relations

• Refers: ASTM D2369-24 - Standard Test Method for Volatile Content of Coatings
• Effective Date: 01-Feb-2024
• Refers: ASTM D4708-24 - Standard Practice for Preparation of Uniform Free Films of Organic Coatings
• Effective Date: 15-Jan-2024
• Refers: ASTM D4708-19 - Standard Practice for Preparation of Uniform Free Films of Organic Coatings
• Effective Date: 01-Mar-2019
• Refers: ASTM D3960-05(2018) - Standard Practice for Determining Volatile Organic Compound (VOC) Content of Paints and Related Coatings
• Effective Date: 01-Jun-2018
• Refers: ASTM D2369-10(2015)e1 - Standard Test Method for Volatile Content of Coatings
• Effective Date: 01-Jun-2015
• Refers: ASTM D3960-05(2013) - Standard Practice for Determining Volatile Organic Compound (VOC)Content of Paints and Related Coatings
• Effective Date: 01-Nov-2013
• Refers: ASTM D1475-98(2012) - Standard Test Method For Density of Liquid Coatings, Inks, and Related Products
• Effective Date: 01-Nov-2012
• Refers: ASTM D4708-12 - Standard Practice for Preparation of Uniform Free Films of Organic Coatings
• Effective Date: 01-Jul-2012
• Refers: ASTM D2369-10e1 - Standard Test Method for Volatile Content of Coatings
• Effective Date: 01-Jul-2011
• Refers: ASTM D2369-10 - Standard Test Method for Volatile Content of Coatings
• Effective Date: 01-Jul-2010
• Refers: ASTM D2697-03(2008) - Standard Test Method for Volume Nonvolatile Matter in Clear or Pigmented Coatings
• Effective Date: 01-Nov-2008
• Refers: ASTM D1475-98(2008) - Standard Test Method For Density of Liquid Coatings, Inks, and Related Products
• Effective Date: 01-Jun-2008
• Refers: ASTM D4708-07 - Standard Practice for Preparation of Uniform Free Films of Organic Coatings
• Effective Date: 01-Nov-2007
• Refers: ASTM D2369-07 - Standard Test Method for Volatile Content of Coatings
• Effective Date: 01-Jul-2007
• Refers: ASTM D3960-05 - Standard Practice for Determining Volatile Organic Compound (VOC) Content of Paints and Related Coatings
• Effective Date: 01-Jul-2005

Overview

ASTM D6093-97(2022) sets out the standard test method for determining the percent volume nonvolatile matter in clear or pigmented coatings using a helium gas pycnometer. Developed by ASTM International, this method provides a reliable and accurate approach for measuring the actual dry coating volume derived from a given volume of liquid coating. Its significance lies in supporting key calculations such as volatile organic compound (VOC) content and expected coating coverage, which are vital for compliance, quality control, and product development in the coatings industry.

Key Topics

• Helium Gas Pycnometry: This test uses a helium gas pycnometer, offering improved accuracy over liquid displacement techniques, especially for coatings that are hard to wet or contain pores and voids.
• Nonvolatile Matter Measurement: The method determines the volume of nonvolatile (dry) ingredients in coatings, important for product formulation and performance assessment.
• VOC Calculations: Provides essential data for calculating VOC content, which is critical for regulatory compliance and environmental impact assessments.
• Sample Preparation and Constraints:
  • Specimen weight must exceed 1 gram.
  • Equipment stability should be better than ±0.005 cm³.
• Impact of Coating Formulation: Physical attributes such as pigment-to-binder ratio and the presence of air-void-containing materials can influence the test results, affecting accuracy if not properly accounted for.
• Limitations: The test does not address all possible safety considerations and requires users to implement proper safety and environmental practices.

Applications

ASTM D6093 finds broad application across the paints and coatings industry, quality control laboratories, and regulatory testing agencies:

• Paint and Coating Formulation: Vital for R&D teams to evaluate the volume of usable material in their products, influencing consistency and substrate coverage.
• VOC Reporting and Compliance: Provides a tested method for calculating VOC levels, supporting manufacturers in meeting environmental regulations.
• Coverage Estimation: Determining percent volume nonvolatile matter helps estimate the number of square feet a coating will cover at a specific dry film thickness per unit volume.
• Process Efficiency: The helium gas technique offers faster and more repeatable results, especially for coatings with voids or surface irregularities unsuited to liquid displacement methods.
• Quality Assurance: Ensures uniformity and proper formulation, helping producers maintain high standards and reduce variability between batches.

Related Standards

This standard is often used alongside other ASTM methods and practices for comprehensive coating analysis:

• ASTM D1475: Test Method for Density of Liquid Coatings, Inks, and Related Products
• ASTM D2369: Test Method for Volatile Content of Coatings
• ASTM D2697: Test Method for Volume Nonvolatile Matter in Coatings (liquid displacement method)
• ASTM D3960: Practice for Determining VOC Content of Paints and Related Coatings
• ASTM D4708: Practice for Preparation of Uniform Free Films of Organic Coatings

Practical Value

Employing ASTM D6093 ensures accuracy in calculating the percent volume nonvolatile matter in coatings, directly supporting regulatory compliance, efficient product formulation, and quality control. This method empowers organizations to optimize paint and coating performance, improve environmental responsibility, and maintain reliable product specifications. By leveraging helium gas pycnometry, companies gain a technical advantage in handling complex formulations and achieving precise, repeatable results.

Keywords: ASTM D6093, nonvolatile matter, coatings testing, helium gas pycnometer, VOC content, paint coverage, quality control, standard paint methods, coating formulation.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6093 − 97 (Reapproved 2022)
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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the determination of the percent
D1475 Test Method for Density of Liquid Coatings, Inks,
volume nonvolatile matter of a variety of clear and pigmented
and Related Products
coatings. The approach used should provide faster and more
D2369 Test Method for Volatile Content of Coatings
accurate results than the use of the liquid displacement
D2697 Test Method for Volume Nonvolatile Matter in Clear
technique in Test Method D2697, particularly for coatings that
or Pigmented Coatings
aredifficulttowetorthatcontainvoids,cracksorotherdefects.
D3960 PracticeforDeterminingVolatileOrganicCompound
The improvement in accuracy stems from the superior ability
(VOC) Content of Paints and Related Coatings
of helium gas under pressure to penetrate very small pores and
D4708 Practice for Preparation of Uniform Free Films of
surface irregularities in dried films. This provides a more
Organic Coatings
accurate determination of void volumes than can be obtained
E180 Practice for Determining the Precision of ASTM
via liquid displacement.
Methods for Analysis and Testing of Industrial and Spe-
cialty Chemicals (Withdrawn 2009)
1.2 The technique will provide results under the following
constraints:
2.2 Other Documents:
1.2.1 The stability of the helium gas pycnometer is greater 2.2.1 Directions for obtaining appropriate instruction manu-
als on the use, care, and operation of the instruments and
than 60.005 cm .
equipment are listed in Section 5, (Apparatus).
1.2.2 Test specimen weights are greater than 1 g.
1.3 The values stated in inch-pound units are to be regarded
3. Summary of Test Method
as standard. The values given in parentheses are mathematical
3.1 This procedure measures the volume of nonvolatile
conversions to SI units that are provided for information only
material in a dried or baked coating film. A helium gas
and are not considered standard.
pycnometerisusedtodeterminethevolumeoccupiedbyafilm
1.4 This standard does not purport to address all of the
by measuring the reduction of gas capacity in the pycnometer
safety concerns, if any, associated with its use. It is the sample chamber caused by the presence of the test specimen.
responsibility of the user of this standard to establish appro-
(The actual measurement is accomplished with a pressure
priate safety, health, and environmental practices and deter- transducer that measures the difference in pressure between the
mine the applicability of regulatory limitations prior to use. empty sample compartment and when loaded. The volume
occupied by the coating sample is then calculated from the
1.5 This international standard was developed in accor-
Ideal Gas Law.) The weight of the specimen is also measured
dance with internationally recognized principles on standard-
and the two values are used to calculate the dry film density.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.2 The percent volume nonvolatile content of a coating is
mendations issued by the World Trade Organization Technical calculated using the dry film density, liquid coating density,
Barriers to Trade (TBT) Committee. and the weight percent nonvolatile content of the coating.
1 2
This test method is under the jurisdiction of ASTM Committee D01 on Paint For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Related Coatings, Materials, andApplications and is the direct responsibility of contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 1, 2022. Published December 2022. Originally the ASTM website.
approved in 1997. Last previous edition approved in 2016 as D6093 – 97 (2016). The last approved version of this historical standard is referenced on
DOI: 10.1520/D6093-97R22. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6093 − 97 (2022)
4. Significance and Use 5.3 Sheeting , approximately 1.5-mils (38-µm) thick.
4.1 This test method measures the volume of dry coating 5.4 Doctor Blades, 5 mils to 8 mils (127 µm to 203 µm),
obtainable from a given volume of liquid coating.This value is appropriate to give 1.0 mils to 1.8 mils (25 µm to 46 µm) dry
useful for calculating the volatile organic content (VOC) of a film thickness). A 3 in. (76 mm) wide, multiple clearance
coating and could be used to estimate the coverage (square feet applicator is recommended.
of surface covered at a specified dry film thickness per unit
5.5 Standard Spray Equipment, capable of obtaining a
volume) obtainable with different coating products.
uniform film of 1.0 mil to 1.8 mil (25 µm to 46 µm) dry film
thickness after baking.
NOTE 1—In Practice D3960 paragraph 10.3.1, the equation for calcu-
lating the VOC content using the percent volume nonvolatile is given.
5.6 Forced Draft Oven, capable of maintaining 110 °C 6
Prior to this method a satisfactory procedure for measuring percent
5 °C.
volume nonvolatile did not exist (see Note 11 in Practice D3960).
NOTE 2—Since the actual coverage of a coating includes the void
5.7 Single Edge Razor Blades or Scalpels,
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 5.8 Anti-Static Instrument.
will be greater. The higher the pigment to binder ratio (P/B) of a coating
5.9 Analytical Balance, capable of weighing to 60.0001 g.
or the higher content of void containing material (latices, hollow beads,
etc.) or both, the greater will be the deviation of the coverage calculation
5.10 A Paper/Thin Film Cutter, equipped with a rolling
(This is also true to a lesser degree with Test Method D2697).
blade, available from most office supply centers.
4.2 For various reasons the volume nonvolatile value ob-
5.11 Polyethylene Gloves and Plastic Tweezers.
tained for a coating is often not equal to that predicted from
simple linear addition of the weights and volumes of the raw
6. Procedure
materials in a formulation. One reason is that the volume
6.1 Determine the wet coating density (pounds per gallon)
occupied by a solution of resin in solvent may be the same,
in accordance with Test Method D1475.
greater, or less than the total volume of the separate ingredi-
ents. Such contraction or expansion of resin solutions is
6.2 Determine the weight percent nonvolatile content of the
governedbyanumberoffactors,oneofwhichistheextentand
liquid sample in accordance with Test Method D2369.
direction of spread between solubility parameters of the resin
6.3 Wrap 4-in. by 12-in. panels (102-mm by 305-mm), (two
and solvent.
per sample) with sheeting and tape the sheeting to the back of
4.3 The spatial configuration of the pigment particles and
the panels with masking tape. Do not overlap the sheeting on
the degree to which the pigment particles are filled with the
the backs of the panels.
binder also affect the volume of a dry coating film. Above the
NOTE 4—The objective of this procedure is to obtain the coating free of
critical pigment volume concentration, the apparent volume of
substrate. Other collection methods, such as scraping the coating from
the dry film is significantly greater than theoretical due to the
glass plates or using release paper instead of sheeting are acceptable. See
increase in unfilled voids between pigment particles. The use also Practice D4708 for other film preparation techniques.
of volume nonvolatile matter values in such
...