ASTM D7734/D7734M-13(2020)
(Test Method)Standard Test Method for Determination of Open Time of Oxidative Printing Inks and Overprint Varnishes by a Manual Method
Standard Test Method for Determination of Open Time of Oxidative Printing Inks and Overprint Varnishes by a Manual Method
SIGNIFICANCE AND USE
3.1 When formulating printing inks and overprint varnishes that dry primarily by oxidation it is important to know the stay open time so that premature drying does not occur on the printing press rollers and other components.
3.2 The applied ink or OPV film used for testing is thicker than the film printed on the substrate and nominally represents the film on the printing press rollers.
SCOPE
1.1 This test method covers a manual procedure for determining the stay open time of oxidative drying printing inks and overprint varnishes by a finger transfer method. Open is defined as a wet ink/varnish film.
1.2 The amount of time required to reach the endpoint is recorded in hours.
1.3 Typical inks and overprint varnishes that dry by oxidation are oil based sheetfed offset, letterpress, and screen inks.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.
1.5 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.
1.6 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
- 31-May-2020
- Technical Committee
- D01 - Paint and Related Coatings, Materials, and Applications
- Drafting Committee
- D01.56 - Printing Inks
Relations
- Effective Date
- 01-Jun-2020
Overview
ASTM D7734/D7734M-13(2020) is the internationally recognized standard test method for determining the open time of oxidative printing inks and overprint varnishes using a manual, finger transfer technique. Developed by ASTM International, this standard plays a critical role in the quality control and formulation of oil-based inks and varnishes commonly used in offset, letterpress, and screen printing processes.
Accurately measuring the open time-how long a printing ink or overprint varnish remains wet and workable-is essential for preventing premature drying on press rollers and components. This standard provides a consistent manual procedure to ensure repeatable results for manufacturers and printers.
Key Topics
- Open Time Measurement: Defines “open time” as the period during which an ink or varnish film remains wet enough to be readily transferred by touch.
- Manual Finger Transfer Method: Utilizes a finger transfer technique to determine the point at which the ink or varnish is no longer open.
- Control of Film Thickness: Stresses the importance of applying a film thickness representative of printing press rollers, which is usually thicker than typical printed films.
- Importance of Environmental Conditions: Temperature and humidity are recorded, as they directly affect the drying and open time of oxidative inks.
- Applicability to Oxidative Drying Inks and Varnishes: Especially relevant for oil-based sheetfed offset inks, letterpress inks, and screen printing inks that rely on oxidation for drying.
- Use of SI and Inch-Pound Units: Measurements can be recorded in either SI units or inch-pound units, but the two systems should not be combined.
Applications
- Ink and Varnish Formulation: Ink manufacturers use this method to optimize formulations and ensure inks remain open long enough for successful printing, reducing the risk of downtime or print defects due to premature drying.
- Quality Control in Printing: Printing facilities rely on ASTM D7734/D7734M to verify that products meet the required open time specifications, improving print consistency and efficiency.
- R&D and Troubleshooting: Laboratories use this standardized method when developing new oxidative ink products or when investigating issues such as roller build-up or drying inconsistencies.
- Vendor and Customer Agreements: Ensures a common reference for open time expectations, facilitating better communication in purchase specifications and technical agreements.
Related Standards
- ASTM D3022: Standard Practice for Evaluation of Inks and Related Materials.
- ISO 2834-1: Graphic technology - Laboratory preparation of test prints.
- ASTM D5645: Standard Test Method for Measurement of Drying Time of Printing Inks by the Glass Plate Method.
- ISO 2836: Prints and printing inks - Assessment of resistance of prints to various physical and chemical agents.
Practical Value
Implementing ASTM D7734/D7734M-13(2020) helps printers and ink manufacturers:
- Improve Print Quality: By ensuring inks and varnishes have suitable open times, printers avoid common defects such as roller build-up and incomplete transfers.
- Enhance Production Efficiency: Proper open time prevents interruptions on the press, reducing waste and downtime.
- Ensure Regulatory Compliance: The standard aligns with international trade guidelines, facilitating acceptance of test results in global markets.
- Reliable Benchmarking: Provides consistent data for comparing different products or batches, supporting continuous improvement in manufacturing and printing operations.
Keywords
open time, oxidative printing inks, overprint varnishes, manual test method, finger transfer, ink drying, printing quality, ASTM D7734/D7734M, oil-based inks, print press rollers, laboratory ink testing, standard test method
Frequently Asked Questions
ASTM D7734/D7734M-13(2020) is a standard published by ASTM International. Its full title is "Standard Test Method for Determination of Open Time of Oxidative Printing Inks and Overprint Varnishes by a Manual Method". This standard covers: SIGNIFICANCE AND USE 3.1 When formulating printing inks and overprint varnishes that dry primarily by oxidation it is important to know the stay open time so that premature drying does not occur on the printing press rollers and other components. 3.2 The applied ink or OPV film used for testing is thicker than the film printed on the substrate and nominally represents the film on the printing press rollers. SCOPE 1.1 This test method covers a manual procedure for determining the stay open time of oxidative drying printing inks and overprint varnishes by a finger transfer method. Open is defined as a wet ink/varnish film. 1.2 The amount of time required to reach the endpoint is recorded in hours. 1.3 Typical inks and overprint varnishes that dry by oxidation are oil based sheetfed offset, letterpress, and screen inks. 1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.5 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. 1.6 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.
SIGNIFICANCE AND USE 3.1 When formulating printing inks and overprint varnishes that dry primarily by oxidation it is important to know the stay open time so that premature drying does not occur on the printing press rollers and other components. 3.2 The applied ink or OPV film used for testing is thicker than the film printed on the substrate and nominally represents the film on the printing press rollers. SCOPE 1.1 This test method covers a manual procedure for determining the stay open time of oxidative drying printing inks and overprint varnishes by a finger transfer method. Open is defined as a wet ink/varnish film. 1.2 The amount of time required to reach the endpoint is recorded in hours. 1.3 Typical inks and overprint varnishes that dry by oxidation are oil based sheetfed offset, letterpress, and screen inks. 1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.5 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. 1.6 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.
ASTM D7734/D7734M-13(2020) is classified under the following ICS (International Classification for Standards) categories: 87.040 - Paints and varnishes; 87.080 - Inks. Printing inks. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM D7734/D7734M-13(2020) has the following relationships with other standards: It is inter standard links to ASTM D7734/D7734M-13. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ASTM D7734/D7734M-13(2020) is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
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: D7734/D7734M − 13 (Reapproved 2020)
Standard Test Method for
Determination of Open Time of Oxidative Printing Inks and
Overprint Varnishes by a Manual Method
This standard is issued under the fixed designation D7734/D7734M; 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 open time so that premature drying does not occur on the
printing press rollers and other components.
1.1 This test method covers a manual procedure for deter-
mining the stay open time of oxidative drying printing inks and
3.2 The applied ink or OPV film used for testing is thicker
overprint varnishes by a finger transfer method. Open is than the film printed on the substrate and nominally represents
defined as a wet ink/varnish film.
the film on the printing press rollers.
1.2 The amount of time required to reach the endpoint is
4. Apparatus
recorded in hours.
4.1 Clean Dry Uniform Glass Plate, approximately 20 cm
1.3 Typical inks and overprint varnishes that dry by oxida-
wide by 25 cm long [8 by 10 in.].
tion are oil based sheetfed offset, letterpress, and screen inks.
4.2 Machined Wet Film Applicator, with the appropriate
1.4 The values stated in either SI units or inch-pound units
clearance gap typically in a range of 12 to 75 µm [0.5 to 3.0
are to be regarded separately as standard. The values stated in
mils] which provides a wet film thickness of 6 to 35 µm [0.25
each system are not necessarily exact equivalents; therefore, to
to 1.5 mils].
ensure conformance with the standard, each system shall be
4.3 Stop Watch or Timer, with alarm.
used independently of the other, and values from the two
systems shall not be combined.
4.4 Ink Knife(s).
1.5 This standard does not purport to address all of the
5. Reagents and Materials
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5.1 Clean up Solvent.
priate safety, health, and environmental practices and deter-
5.2 Clean up Rags.
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
6. Preparation of Apparatus
dance with internationally recognized principles on standard-
6.1 Ensure that the wet film applicator is clean and free of
ization established in the Decision on Principles for the
nicks or other defects.
Development of International Standards, Guides and Recom-
6.2 Ensure that the glass plate surface is clean, uniformly
mendations issued by the World Trade Organization Technical
level and free of any dust, solvent or residue.
Barriers to Trade (TBT) Committee.
2. Summary of Test Method 7. Conditioning
2.1 Inks and overprint varnishes are applied to a glass 7.1 Nominallaboratorystandardconditionsof23 62°C[73
surface using a wet film applicator and checked at time 6 3.5°F] temperature and 50 6 5 % relative humidity level are
intervals using a finger transfer method to determine the time recommended for this test. Deviations from these conditions
that the ink/varnish are no longer open. will affect results.
7.2 Glass plate should be located free from drafts or
3. Significance and Use
excessive air movement.
3.1 When formulating printing inks and overprint varnishes
that dry primarily by oxidation it is important to know the stay
8. Procedure
8.1 Select the appropriate clearance gap that will provide a
This test method is under the jurisdiction of ASTM Committee D01 on Paint
wet film thickness in the range of 12 to 75 µm [0.5 to 3.0 mils]
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.56 on Printing Inks. or as agreed upon by seller and purchaser.
CurrenteditionapprovedJune1,2020.PublishedJuly2020.Originallyapproved
8.2 Place the applicator on the glass and apply approxi-
in 2013. Last previous edition approved in 2013 as D7734/D7734M – 13. DOI:
10.1520/D7734_D7734M-13R20. mately an 8 cm [3 in.] wide samp
...
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