ASTM D570-22

Standard Test Method for Water Absorption of Plastics

SIGNIFICANCE AND USE
4.1 This test method for rate of water absorption has two chief functions: first, as a guide to the proportion of water absorbed by a material and consequently, in those cases where the relationships between moisture and electrical or mechanical properties, dimensions, or appearance have been determined, as a guide to the effects of exposure to water or humid conditions on such properties; and second, as a control test on the uniformity of a product. This second function is particularly applicable to sheet, rod, and tube arms when the test is made on the finished product.  
4.2 Comparison of water absorption values of various plastics made on the basis of values obtained in accordance with 8.1 and 8.4 have been found useful.  
4.3 Ideal diffusion of liquids4 into polymers is a function of the square root of immersion time. Time to saturation is strongly dependent on specimen thickness. For example, Table 1 shows the time to approximate time saturation for various thickness of nylon-6.  
4.4 The moisture content of a plastic is very intimately related to such properties as electrical insulation resistance, dielectric losses, mechanical strength, appearance, and dimensions. The effect upon these properties of change in moisture content due to water absorption depends largely on the type of exposure (by immersion in water or by exposure to high humidity), shape of the part, and inherent properties of the plastic. With nonhomogeneous materials, such as laminated forms, the rate of water absorption is sometimes known to be widely different through each edge and surface. Even for otherwise homogeneous materials, it has been observed to be slightly greater through cut edges than through molded surfaces. Consequently, attempts to correlate water absorption with the surface area must generally be limited to closely related materials and to similarly shaped specimens: For materials of widely varying density, relation between water-absorption values on a volume as well as ...
SCOPE
1.1 This test method covers the determination of the relative rate of absorption of water by plastics when immersed. This test method is intended to apply to the testing of all types of plastics, including cast, hot-molded, and cold-molded resinous products, and both homogeneous and laminated plastics in rod and tube form and in sheets 0.13 mm (0.005 in.) or greater in thickness.  
1.2 The values given in SI units are to be regarded as standard. The values stated in parentheses are for information only.
Note 1: This test method and ISO 62 are technically equivalent when the test specimen described in 6.2 is used.  
1.3 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.  
1.4 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: 31-Aug-2022
• ICS: 83.120 - Reinforced plastics
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.50 - Durability of Plastics

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: D570 − 22
Standard Test Method for
1
Water Absorption of Plastics
This standard is issued under the fixed designation D570; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 3. Terminology
1.1 Thistestmethodcoversthedeterminationoftherelative 3.1 For definitions of terms that appear in this practice
rate of absorption of water by plastics when immersed. This relating to plastics, refer to Terminology D883.
test method is intended to apply to the testing of all types of
3.2 For definitions of terms that appear in this practice
plastics, including cast, hot-molded, and cold-molded resinous
relating to quality and statistics (such as precision and bias),
products, and both homogeneous and laminated plastics in rod
refer to Terminology E456.
and tube form and in sheets 0.13 mm (0.005 in.) or greater in
thickness.
4. Significance and Use
1.2 The values given in SI units are to be regarded as
4.1 This test method for rate of water absorption has two
standard. The values stated in parentheses are for information
chief functions: first, as a guide to the proportion of water
only.
absorbed by a material and consequently, in those cases where
NOTE 1—This test method and ISO62 are technically equivalent when
therelationshipsbetweenmoistureandelectricalormechanical
the test specimen described in 6.2 is used.
properties, dimensions, or appearance have been determined,
1.3 This standard does not purport to address all of the
as a guide to the effects of exposure to water or humid
safety concerns, if any, associated with its use. It is the
conditions on such properties; and second, as a control test on
responsibility of the user of this standard to establish appro-
the uniformity of a product. This second function is particu-
priate safety, health, and environmental practices and deter-
larly applicable to sheet, rod, and tube arms when the test is
mine the applicability of regulatory limitations prior to use.
made on the finished product.
1.4 This international standard was developed in accor-
4.2 Comparison of water absorption values of various plas-
dance with internationally recognized principles on standard-
tics made on the basis of values obtained in accordance with
ization established in the Decision on Principles for the
8.1 and 8.4 have been found useful.
Development of International Standards, Guides and Recom-
4
mendations issued by the World Trade Organization Technical
4.3 Ideal diffusion of liquids into polymers is a function of
Barriers to Trade (TBT) Committee.
the square root of immersion time. Time to saturation is
strongly dependent on specimen thickness. For example,Table
2. Referenced Documents
1 shows the time to approximate time saturation for various
2
thickness of nylon-6.
2.1 ASTM Standards:
D883Terminology Relating to Plastics
4.4 The moisture content of a plastic is very intimately
E456Terminology Relating to Quality and Statistics
related to such properties as electrical insulation resistance,
dielectric losses, mechanical strength, appearance, and dimen-
2.2 ISO Standard:
3
sions. The effect upon these properties of change in moisture
ISO62 Plastics—Determination of Water Absorption
content due to water absorption depends largely on the type of
exposure (by immersion in water or by exposure to high
1 humidity), shape of the part, and inherent properties of the
ThistestmethodisunderthejurisdictionofASTMCommitteeD20onPlastics
and is the direct responsibility of Subcommittee D20.50 on Durability of Plastics.
plastic. With nonhomogeneous materials, such as laminated
Current edition approved Sept. 1, 2022. Published September 2022. Originally
approved in 1940. Last previous edition approved in 2018 as D570-98 (2018).
DOI: 10.1520/D0570-22.
2 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Additional information regarding diffusion of liquids in polymers can be found
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM in the following references: (1) Diffusion, Mass Transfer in Fluid Systems,E.L.
Standards volume information, refer to the standard’s Document Summary page on Cussler, Cambridge University Press, 1985, ISBN 0-521-29846-6, (2) Diffusion in
the ASTM website. Polymers, J. Crank and G.S. Park, Academic Press, 1968, and (3) “Permeation,
3
Available fromAmerican National Standards
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D570 − 98 (Reapproved 2018) D570 − 22
Standard Test Method for
1
Water Absorption of Plastics
This standard is issued under the fixed designation D570; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope Scope*
1.1 This test method covers the determination of the relative rate of absorption of water by plastics when immersed. This test
method is intended to apply to the testing of all types of plastics, including cast, hot-molded, and cold-molded resinous products,
and both homogeneous and laminated plastics in rod and tube form and in sheets 0.13 mm (0.005 in.) or greater in thickness.
1.2 The values given in SI units are to be regarded as standard. The values stated in parentheses are for information only.
NOTE 1—This test method and ISO 62 are technically equivalent when the test specimen described in 6.2 is used.
1.3 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.
1.4 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
E456 Terminology Relating to Quality and Statistics
2.2 ISO Standard:
3
ISO 62 Plastics—Determination of Water Absorption
3. Terminology
3.1 For definitions of terms that appear in this practice relating to plastics, refer to Terminology D883.
3.2 For definitions of terms that appear in this practice relating to quality and statistics (such as precision and bias), refer to
Terminology E456.
1
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.50 on Durability of Plastics.
Current edition approved Aug. 1, 2018Sept. 1, 2022. Published August 2018September 2022. Originally approved in 1940. Last previous edition approved in 20102018
ɛ1
as D570 - 98 (2010)(2018). . DOI: 10.1520/D0570-98R18.10.1520/D0570-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D570 − 22
4. Significance and Use
4.1 This test method for rate of water absorption has two chief functions: first, as a guide to the proportion of water absorbed by
a material and consequently, in those cases where the relationships between moisture and electrical or mechanical properties,
dimensions, or appearance have been determined, as a guide to the effects of exposure to water or humid conditions on such
properties; and second, as a control test on the uniformity of a product. This second function is particularly applicable to sheet,
rod, and tube arms when the test is made on the finished product.
4.2 Comparison of water absorption values of various plastics can be made on the basis of values obtained in accordance with
7.18.1 and 7.48.4. have been found useful.
4
4.3 Ideal diffusion of liquids into polymers is a function of the square root of immersion time. Time to saturation is strongly
dependent on specimen thickness. For example, Table 1 shows the time to approximate time saturation for various thickness of
nylon-6.
4.4 The moisture content of a plastic is very intimately related to such properties as electrical insulation resistance, dielectric
losses, mechanical strength, appearance, and dimensions. The effect upon these
...