ASTM D3926-05(2019)

Standard Test Methods for Percent Solids in Titanium Dioxide Slurries

SIGNIFICANCE AND USE
4.1 These test methods are intended as a quick and reliable procedure for measuring the titanium dioxide pigment content of aqueous slurries. Included with the pigment content in the percent solids are the various nonvolatile additives used in preparing a stable slurry. Because the aluminum and silica oxide treatments on the more highly treated titanium dioxide pigments may change somewhat with prolonged drying, in the oven method the solids of the slurry are considered dry after heating at 105°C for 60 to 65 min. The high temperature associated with the infrared moisture analyzer may also effect a change in the aluminum and silica oxide treatment on highly treated TiO2 products. Therefore, care in selection of time and temperature are critical to obtain accurate results with the infrared method. With the short duration of test associated with the microwave drying system, overdrying is not a concern.
SCOPE
1.1 These test methods cover the determination of the weight percent of solids in aqueous slurries of titanium dioxide pigments by either the use of a gravity-convection oven (Method A), infrared radiation moisture analyzer (Method B), or a microwave drying system (Method C).  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This test 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.  
1.4 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-Apr-2019
• ICS: 87.060.10 - Pigments and extenders
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.31 - Pigment Specifications

Relations

• Replaces: ASTM D3926-05(2011) - Standard Test Methods for Percent Solids in Titanium Dioxide Slurries
• Effective Date: 01-May-2019
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

Overview

ASTM D3926-05(2019) - Standard Test Methods for Percent Solids in Titanium Dioxide Slurries provides reliable procedures to measure the percent solids in aqueous slurries of titanium dioxide pigments. The test methods are designed for quick and accurate determination of pigment content, including any nonvolatile additives used for slurry stabilization. This standard is widely used in quality control, production monitoring, and research involving titanium dioxide (TiO₂) slurries in industries such as paints, coatings, and plastics.

The standard specifies three test methods:

• Gravity-convection oven method (Method A)
• Infrared radiation moisture analyzer (Method B)
• Microwave drying system (Method C)

This document ensures consistency, reproducibility, and comparability of results across laboratories and organizations by detailing precise procedures and measurement conditions.

Key Topics

• Purpose: Determination of weight percent solids in titanium dioxide slurries, encompassing both pigment and nonvolatile additives.
• Test Methods:
  • Gravity-Convection Oven (Method A): Samples are dried in a laboratory oven at 105°C for 60-65 minutes. This method requires careful control of drying time and temperature to ensure accuracy, especially for highly treated TiO₂ pigments.
  • Infrared Moisture Analyzer (Method B): Uses infrared lamps and a precision balance to rapidly measure moisture content. Correct time and temperature settings are critical to minimize changes in aluminum and silica oxide treatments on the pigment.
  • Microwave Drying System (Method C): Employs microwave technology for fast drying, with results displayed directly by the instrument. This method mitigates the risk of overdrying typically associated with prolonged heat exposure.
• Calculations: Percent solids are calculated based on the difference in weights before and after drying, or derived directly from instrument displays, ensuring straightforward data reporting.
• Precision and Reproducibility: The standard includes criteria for evaluating the reliability of results, such as acceptable differences between duplicate tests within and between laboratories.

Applications

ASTM D3926-05(2019) is essential for:

• Quality Control: Ensuring the correct composition of titanium dioxide slurries in manufacturing environments, leading to consistent pigment performance in end products.
• Product Development and Formulation: Supporting research and development teams in designing new pigment dispersions or modifying existing ones to meet specific application requirements.
• Regulatory Compliance: Facilitating documentation and process control to align with industry regulations and international trade standards.
• Process Optimization: Monitoring percent solids to optimize raw material use, energy consumption, and overall production efficiency in industries like:
  • Paints and coatings
  • Paper manufacturing
  • Plastics and polymers
  • Ceramics and other industrial applications

Related Standards

• ASTM D1193: Specification for Reagent Water, referenced for water purity in test methods.
• ISO and other ASTM pigment standards: Relevant for broader pigment characterization and quality assurance.
• WTO TBT Principles: This standard is developed in line with internationally recognized standardization principles of the World Trade Organization Technical Barriers to Trade (WTO TBT) Committee.
• Other Methods for TiO₂ Analysis: Complementary standards covering various physical and chemical testing of titanium dioxide pigments.

Keywords: percent solids, titanium dioxide slurry, TiO₂ pigment, ASTM D3926, quality control, pigment testing, microwave drying, infrared moisture analyzer, gravity oven method, nonvolatile content, paint industry standards, coating pigment analysis, industrial slurry testing.

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: D3926 − 05 (Reapproved 2019)
Standard Test Methods for
Percent Solids in Titanium Dioxide Slurries
This standard is issued under the fixed designation D3926; 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 3.3 Microwave Method:
3.3.1 2 to 4 g of slurry is placed between two glass fiber
1.1 These test methods cover the determination of the
pads and dried in a microwave drying system. The results are
weight percent of solids in aqueous slurries of titanium dioxide
obtained directly form the unit’s display panel.
pigments by either the use of a gravity-convection oven
(Method A), infrared radiation moisture analyzer (Method B),
4. Significance and Use
or a microwave drying system (Method C).
4.1 These test methods are intended as a quick and reliable
1.2 The values stated in SI units are to be regarded as
procedure for measuring the titanium dioxide pigment content
standard. No other units of measurement are included in this
of aqueous slurries. Included with the pigment content in the
standard.
percent solids are the various nonvolatile additives used in
1.3 This test standard does not purport to address all of the
preparing a stable slurry. Because the aluminum and silica
safety concerns, if any, associated with its use. It is the
oxide treatments on the more highly treated titanium dioxide
responsibility of the user of this standard to establish appro-
pigments may change somewhat with prolonged drying, in the
priate safety, health, and environmental practices and deter-
oven method the solids of the slurry are considered dry after
mine the applicability of regulatory limitations prior to use.
heating at 105°C for 60 to 65 min. The high temperature
1.4 This international standard was developed in accor-
associated with the infrared moisture analyzer may also effect
dance with internationally recognized principles on standard-
a change in the aluminum and silica oxide treatment on highly
ization established in the Decision on Principles for the
treated TiO products. Therefore, care in selection of time and
Development of International Standards, Guides and Recom-
temperature are critical to obtain accurate results with the
mendations issued by the World Trade Organization Technical
infrared method.With the short duration of test associated with
Barriers to Trade (TBT) Committee.
the microwave drying system, overdrying is not a concern.
2. Referenced Documents
5. Apparatus
2.1 ASTM Standards:
5.1 Oven Method:
D1193 Specification for Reagent Water
5.1.1 Oven—Laboratory oven capable of maintaining a
3. Summary of Test Method
temperature of 105 6 2°C (Note 1). The oven may be a
gravity-convection type or an oven with a low velocity, forced
3.1 Oven Method:
3.1.1 Slurry is weighed by difference into a tared aluminum draft. An oven with a high-velocity, forced-draft air change,
commonly used for baking finishes, is not suitable.
foil dish, dried at 105°C in an oven for 1 h, cooled in a
desiccator, and weighed.
NOTE 1—The temperature in the oven must be constantly monitored.
Many older ovens will no longer maintain 62°C; some will maintain this
3.2 Infrared Method:
tolerance for a while but occasionally the thermostat will “stick” and the
3.2.1 Slurry is dried under infrared lamps for a specified
temperature will vary considerably.
time and temperature. The results are obtained directly form
5.1.2 Balance—Laboratory analytical balance, accurate to
the unit’s display panel.
0.1 mg, with 1-g optical readout range for fast weighing.
These test methods are under the jurisdiction of ASTM Committee D01 on
NOTE 2—Periodically check the accuracy of the 1-g optical scale of the
Paint and Related Coatings, Materials, and Applications and are the direct
balance by use of a known 1-g weight; adjust the balance if needed. The
responsibility of Subcommittee D01.31 on Pigment Specifications.
zeroadjustmentoftheopticalscaleneedstobecheckedatleasteveryhour
Current edition approved May 1, 2019. Published May 2019. Originally
routinely and immediately if there is any possibility of a spill having
approved in 1980. Last previous edition approved in 2011 as D3926 – 05 (2011).
occurred on the balance.
DOI: 10.1520/D3926-05R19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 5.1.3 Desiccator—Standard laboratory desiccator utilizing
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
an indicating drying medium.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.2 Infrared Method:
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3926 − 05 (2019)
5.2.1 Infrared Moisture Analyzer—Automated moisture 7.1.7 Remove the dishes from the oven, cool in the desic-
analyzer combining infrared drying technology and a precision cator for 10 to 60 min, remove one dish at a time, and weigh
analytical balance in a single unit. immediately to the nearest 0.1 mg.This isW for each dish. Do
not cool longer than 60 min since there is a slight possibility of
5.3 Microwave Method:
an equilibrium moisture exchange between the drying medium
5.3.1 Microwave Drying System—A National Recognized
and some dried titanium dioxide pigments.
Testing Laboratory (NRTL) approved 630 W microwave dry-
ing system with 50 g, 0.1 mg readability internal balance to
7.2 Method B, Infrared Moisture Analyzer:
measure moisture/solids from 0.1 to 99.99 %.
7.2.1 Follow the manufacturer’s recommendations for
installation, set up, and calibration of the analyzer.
6. Reagents and Materials
7.2.2 Determine a time and temperature schedule that pro-
6.1 Oven Method:
duces slurry solids equal to those obtained with Method A,
6.1.1 Purity of Water—Unless otherwise indicated, refer-
gravity convection oven. Program that schedule into the
ences to water shall be understood to mean reagent water
analyzer as recommended by the manufacturer.
conforming to Type II of Specification D1193.
7.2.3 Using a new, empty disposable syringe or dropper,
6.1.2 Aluminum Foil Dish—Disposable aluminum foil
transfer the required amount of sample from a TiO slurry
dishes, approximately 60-mm diameter by 18 mm high, 1 to 2
prepared as in 7.1.2 to a sample holder appropriate for the
g in weight.
analyzer being used.
6.1.3 Disposable Syringe or Dropper—Disposable 2 or
7.2.4 Follow the manufacturer’s directions for drying the
3-mL syringes or 2 to 5-mL droppers.
sample. When the end point is reached, the display will show
6.2 Infrared Moisture Analyzer:
the percent solids.
6.2.1 Sample Holders, appropriate for the Infrared Moisture
7.2.5 Repeat the procedure with a fresh sample of slurry.
Analyzer.
7.3 Method C, Microwave Drying System:
6.2.2 Disposable Syringe (2 or 3-mL) or Dropper.
7.3.1 Turn microwave unit on and follow manufacturer’s
6.3 Microwave Drying System:
directions on warm-up time if required before running the test.
6.3.1 Sample Holders, appropriate for the Microwave Dry-
7.3.2 Open unit door and place a pair of glass fiber pads on
ing System.
the balance pan.
6.3.2 Disposable Syringe (2 to 3-mL) or Dropper.
7.3.3 Close the door and tare the panels following the
7. Procedures
manufact
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