ASTM D4147-18(2023)

Standard Practice for Applying Coil Coatings Using Wire-Wound Drawdown Bars

SIGNIFICANCE AND USE
3.1 This practice is useful in the laboratory to simulate roll-coated films.
SCOPE
1.1 This practice covers a procedure for applying a coil coating film of uniform thickness on a flat metal panel using wire-wound drawdown bars.  
1.2 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.  
1.3 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-Sep-2023
• ICS: 87.040 - Paints and varnishes
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.53 - Coil Coated Metal

Relations

• Replaces: ASTM D4147-18 - Standard Practice for Applying Coil Coatings Using Wire-Wound Drawdown Bars
• Effective Date: 01-Oct-2023
• Referred By: ASTM D3794-22 - Standard Guide for Testing Coil Coatings
• Effective Date: 01-Oct-2023
• Referred By: ASTM D823-18(2022) - Standard Practices for Producing Films of Uniform Thickness of Paint, Coatings and Related Products on Test Panels
• Effective Date: 01-Oct-2023

Overview

ASTM D4147-18(2023), Standard Practice for Applying Coil Coatings Using Wire-Wound Drawdown Bars, provides a standardized laboratory procedure for applying uniform coil coating films to flat metal panels. Developed by ASTM International, this practice ensures consistent preparation and evaluation of coil coatings by simulating real-world roll-coated films. Using wire-wound drawdown bars, the methodology achieves controlled, repeatable film thicknesses critical for testing and quality assurance in coating development and research.

By following internationally recognized standardization principles under the World Trade Organization’s Technical Barriers to Trade (TBT) Committee guidelines, ASTM D4147-18(2023) supports global harmonization in coil coating application techniques.

Key Topics

• Drawdown Bar Selection and Use

  • Wire-wound drawdown bars are chosen based on desired dry film thickness and coating properties.
  • Numeric identifiers on each bar assist users in selecting the proper equipment for uniform film application.

• Panel Preparation and Securing Methods

  • Panels are deburred and positioned flat using devices such as magnetic chucks, vacuum plates, tape, or mechanical drives, depending on the panel type (steel or nonmagnetic).

• Coating Application Process

  • Coatings are applied by pouring an ample amount across the panel, placing the bar behind the coating, and drawing it across at a uniform speed and pressure.
  • Only a single pass is used to minimize film disturbance and achieve evenness.
  • Special attention is paid to trim edges for multi-layer applications due to heavier film accumulations.

• Safety and Environmental Considerations

  • Adequate ventilation is required, especially when working with solvents with low flash points.
  • Personal protective measures should be implemented to prevent inhalation and skin contact, per the coating’s safety data sheet (SDS).

Applications

ASTM D4147-18(2023) is widely used in:

• Research and Development: Enables laboratories to simulate coil coating processes, facilitating comparison among different coatings and application techniques.
• Quality Control: Provides a repeatable baseline for evaluating coating consistency, thickness, and performance before commercial production.
• Comparative Testing: Supports formulation refinements and qualification of new coatings or panels by replicable lab drawdowns.
• Training and Standardization: Serves as a reference to train personnel in uniform coating application practices and ensures industry-wide consistency.

Through its structured procedure, this standard promotes reliability and reproducibility in coil coating testing, strengthening quality benchmarks for metal finishing and related industries.

Related Standards

The following standards are commonly used in conjunction with ASTM D4147-18(2023):

• ASTM D823 - Practices for Producing Films of Uniform Thickness of Paint, Varnish, and Related Products on Test Panels
• ASTM D7091 - Standard Practice for Nondestructive Thickness Measurement of Nonmagnetic Coatings on Ferrous and Nonferrous Base Metals
• ASTM D1005 - Test Method for Measurement of Dry Film Thickness of Organic Coatings Using Micrometers

For additional international harmonization, refer to guidance under the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Summary

ASTM D4147-18(2023) establishes a clear, reliable framework for the application and testing of coil coatings using wire-wound drawdown bars. It enhances laboratory practices within the coil coating sector, offering critical methodologies for research, quality assurance, and standardization. By adhering to the safety, health, and environmental guidelines outlined, users can achieve consistent, high-quality results suitable for global industrial contexts.

Keywords: coil coatings, drawdown bars, ASTM D4147, wire-wound bar application, laboratory coating methods, uniform film thickness, coating quality control, standard practice for coil coatings.

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: D4147 − 18 (Reapproved 2023)
Standard Practice for
Applying Coil Coatings Using Wire-Wound Drawdown Bars
This standard is issued under the fixed designation D4147; 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 and the volume solids of the coating under test. Each bar is
provided a numeric identifier to help in selecting the correct bar
1.1 This practice covers a procedure for applying a coil
to provide a specific dry film thickness.
coating film of uniform thickness on a flat metal panel using
wire-wound drawdown bars.
4.2 Devices for Securing Panels:
4.2.1 Magnetic Chuck for securing steel panels to eliminate
1.2 This standard does not purport to address all of the
bowing.
safety concerns, if any, associated with its use. It is the
4.2.2 Vacuum Plate for securing very lightweight nonmag-
responsibility of the user of this standard to establish appro-
netic panels.
priate safety, health, and environmental practices and deter-
4.2.3 Tape for securing the top of thin-gage panels.
mine the applicability of regulatory limitations prior to use.
4.2.4 Mechanical Drives for securing panels and automat-
1.3 This international standard was developed in accor-
ing the drawdown procedure.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
5. Hazards
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5.1 The flash points of most solvents used in coatings and
Barriers to Trade (TBT) Committee.
related products are low enough that adequate ventilation is
needed to avoid exceeding 25 % of the lower explosive limits
2. Summary of Practice
of the solvent when preparing and baking the panels. These
2.1 A flat panel is secured on a firm horizontal surface. An
solvents could be toxic, care should be taken to avoid inhala-
ample amount of coating is poured across one end of the panel
tion of the vapors and unnecessary contact of the solvents with
and the drawdown bar placed behind the coating. The bar is
the skin. Consult the corresponding SDS for the specific
then drawn with uniform pressure and speed along the length
coating to be applied for additional hazards.
of the panel toward the operator to apply a uniform film. The
wet and dry film coating thickness obtained is dependent on the
6. Procedure
combination of the bar used, the volume solids of the coating,
6.1 Deburr panels so edges are smooth. Secure a flat panel
and the speed of the drawdown motion.
to be coated on a firm, uniform, level surface. To provide
sufficient testing surface pour an ample amount of coating
3. Significance and Use
across the top end of the panel. Place the drawdown bar behind
3.1 This practice is useful in the laboratory to simulate
the coating and pull into the coating. Rotate the drawdown bar
roll-coated film
...