ASTM D7568-23

Standard Specification for Polyethylene-Based Structural-Grade Plastic Lumber for Outdoor Applications

SCOPE
1.1 This specification covers a type of plastic lumber product, defined as polyethylene-based structural-grade plastic lumber (SGPL), for use as main framing members, including joists, stringers, beams, columns; and secondary framing members, including planking, posts and bracing; in outdoor structures such as decks, boardwalks, docks, and platforms.  
1.2 This specification is applicable to solid, rectangular SGPL products where polyethylene resin (non cross-linked) is the continuous phase and is at least 50 % of the product (by weight).  
1.3 This specification is not applicable to plastic lumber products containing cellulosic materials as additives, fillers or fiber reinforcements.  
1.4 SGPL products covered by this specification shall not be used as tensile members.  
1.5 SGPL products are produced using several different manufacturing processes. These processes utilize a number of polyethylene resin material systems that include varying proportions of fillers, fiber reinforcements, and other chemical additives.  
1.6 Due to thermodynamic effects that result in outer-surface densification during manufacture, SGPL products are typically non-homogeneous in the cross-section. This standard does not address materials that have been modified from their original cross-section.  
1.6.1 The cross-section non-homogeneity is addressed in the material property assessments in this document only for applications in which the product cross-section is not modified by cutting, notching, or drilling. For products modified in this manner, additional engineering considerations are required and they are beyond the scope of this document.  
1.7 For purposes of this standard, an SGPL product is a specific combination of polyethylene resin, together with fillers, reinforcements, and additives. Each formulation is to be identified as a distinct and different product, to be tested and evaluated separately.  
1.8 Diverse and multiple combinations of both virgin and recycled polyethylene material systems are permitted in the manufacture of SGPL products.  
1.9 Fiber reinforcements used in SGPL include manufactured materials such as fiberglass (chopped or continuous), carbon, aramid and other polymeric materials.  
1.10 A wide variety of chemical additives are typically added to SGPL formulations. Examples include colorants, chemical foaming agents, ultraviolet stabilizers, fire retardants, lubricants, anti-static products, heat stabilizers, and coupling agents.  
1.11 Diverse types and combinations of filler systems are permitted in the manufacturing of SGPL products. Fillers that cause the product to fail the requirements of 6.13 are not permitted in the manufacturing of SGPL products.  
1.12 In order for a product to be classified as SGPL, it must meet the minimum stress and modulus criteria consistent with the specific product as marked, and additionally the properties specified in Section 6 of this specification.  
1.13 This specification pertains to SGPL where any reinforcement is uniformly distributed within the product. When reinforcement is not uniformly distributed, the engineering issues become substantially more complex. For this reason, such products are not covered in this document.  
1.14 Products that fail at strains of less than 0.02 (2 %) when tested in flexure in accordance with 6.6 are not compatible with the underlying assumptions of Annex A1 and are beyond the scope of this standard (see Note 1).
Note 1: Calculation of time-dependent properties in Annex A1 is based on the assumption that the product does not fail in a brittle manner. The 2 % strain limit was selected based on the judgment of the task group members that created Annex A1.  
1.15 This specification addresses issues relevant to a buyer’s requirements for SGPL products and has therefore been developed in the format of a procurement specification.  
1.16 Criteria for design are included as part of this specification for SGPL product...

General Information

• Status: Published
• Publication Date: 31-Jan-2023
• ICS: 83.140.01 - Rubber and plastics products in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.20 - Plastic Lumber

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: D7568 − 23
Standard Specification for
Polyethylene-Based Structural-Grade Plastic Lumber for
1
Outdoor Applications
This standard is issued under the fixed designation D7568; 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* fillers, reinforcements, and additives. Each formulation is to be
identified as a distinct and different product, to be tested and
1.1 This specification covers a type of plastic lumber
evaluated separately.
product, defined as polyethylene-based structural-grade plastic
lumber (SGPL), for use as main framing members, including 1.8 Diverse and multiple combinations of both virgin and
joists, stringers, beams, columns; and secondary framing recycled polyethylene material systems are permitted in the
members, including planking, posts and bracing; in outdoor manufacture of SGPL products.
structures such as decks, boardwalks, docks, and platforms.
1.9 Fiber reinforcements used in SGPL include manufac-
1.2 This specification is applicable to solid, rectangular tured materials such as fiberglass (chopped or continuous),
SGPL products where polyethylene resin (non cross-linked) is carbon, aramid and other polymeric materials.
the continuous phase and is at least 50 % of the product (by
1.10 A wide variety of chemical additives are typically
weight).
added to SGPL formulations. Examples include colorants,
1.3 This specification is not applicable to plastic lumber chemical foaming agents, ultraviolet stabilizers, fire retardants,
products containing cellulosic materials as additives, fillers or lubricants, anti-static products, heat stabilizers, and coupling
fiber reinforcements. agents.
1.4 SGPL products covered by this specification shall not be 1.11 Diverse types and combinations of filler systems are
used as tensile members. permitted in the manufacturing of SGPL products. Fillers that
cause the product to fail the requirements of 6.13 are not
1.5 SGPL products are produced using several different
permitted in the manufacturing of SGPL products.
manufacturing processes. These processes utilize a number of
polyethylene resin material systems that include varying pro- 1.12 In order for a product to be classified as SGPL, it must
portions of fillers, fiber reinforcements, and other chemical meet the minimum stress and modulus criteria consistent with
additives. the specific product as marked, and additionally the properties
specified in Section 6 of this specification.
1.6 Due to thermodynamic effects that result in outer-
surface densification during manufacture, SGPL products are 1.13 This specification pertains to SGPL where any rein-
typically non-homogeneous in the cross-section. This standard forcement is uniformly distributed within the product. When
does not address materials that have been modified from their reinforcement is not uniformly distributed, the engineering
original cross-section. issues become substantially more complex. For this reason,
1.6.1 The cross-section non-homogeneity is addressed in such products are not covered in this document.
the material property assessments in this document only for
1.14 Products that fail at strains of less than 0.02 (2 %)
applications in which the product cross-section is not modified
when tested in flexure in accordance with 6.6 are not compat-
by cutting, notching, or drilling. For products modified in this
ible with the underlying assumptions of Annex A1 and are
manner, additional engineering considerations are required and
beyond the scope of this standard (see Note 1).
they are beyond the scope of this document.
NOTE 1—Calculation of time-dependent properties in Annex A1 is
1.7 For purposes of this standard, an SGPL product is a
based on the assumption that the product does not fail in a brittle manner.
specific combination of polyethylene resin, together with
The 2 % strain limit was selected based on the judgment of the task group
members that created Annex A1.
1.15 This specification addresses issues relevant to a buy-
1 er’s requirements for SGPL products and has therefore been
This specification is under the jurisdiction of ASTM Committee D20 on
Plastics and is the direct responsibility of Subcommittee D20.20 on Plastic Lumber. developed in the format of a procurement specification.
Current edition approved Feb. 1, 2023. Published February 2023. Originally
1.16 Criteria for design are included as part of this specifi-
approved in 2012. Last previous edition approved in 2017
...

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: D7568 − 17 D7568 − 23
Standard Specification for
Polyethylene-Based Structural-Grade Plastic Lumber for
1
Outdoor Applications
This standard is issued under the fixed designation D7568; 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*
1.1 This specification covers a type of plastic lumber product, defined as polyethylene-based structural-grade plastic lumber
(SGPL), for use as main framing members, including joists, stringers, beams, columns; and secondary framing members, including
planking, posts and bracing; in outdoor structures such as decks, boardwalks, docks, and platforms.
1.2 This specification is applicable to solid, rectangular SGPL products where polyethylene resin (non cross-linked) is the
continuous phase and is at least 50 % of the product (by weight).
1.3 This specification is not applicable to plastic lumber products containing cellulosic materials as additives, fillers or fiber
reinforcements.
1.4 SGPL products covered by this specification shall not be used as tensile members.
1.5 SGPL products are produced using several different manufacturing processes. These processes utilize a number of
polyethylene resin material systems that include varying proportions of fillers, fiber reinforcements, and other chemical additives.
1.6 Due to thermodynamic effects that result in outer-surface densification during manufacture, SGPL products are typically
non-homogeneous in the cross-section. This standard does not address materials that have been modified from their original
cross-section.
1.6.1 The cross-section non-homogeneity is addressed in the material property assessments in this document only for applications
in which the product cross-section is not modified by cutting, notching, or drilling. For products modified in this manner, additional
engineering considerations are required and they are beyond the scope of this document.
1.7 For purposes of this standard, an SGPL product is a specific combination of polyethylene resin, together with fillers,
reinforcements, and additives. Each formulation is to be identified as a distinct and different product, to be tested and evaluated
separately.
1.8 Diverse and multiple combinations of both virgin and recycled polyethylene material systems are permitted in the manufacture
of SGPL products.
1
This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.20 on Plastic Lumber.
Current edition approved March 1, 2017Feb. 1, 2023. Published March 2017February 2023. Originally approved in 2012. Last previous edition approved in 20132017
as D7568 – 13. DOI:10.1520/D7568–17.17. DOI:10.1520/D7568-23.
*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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D7568 − 23
1.9 Fiber reinforcements used in SGPL include manufactured materials such as fiberglass (chopped or continuous), carbon, aramid
and other polymeric materials.
1.10 A wide variety of chemical additives are typically added to SGPL formulations. Examples include colorants, chemical
foaming agents, ultraviolet stabilizers, fire retardants, lubricants, anti-static products, heat stabilizers, and coupling agents.
1.11 Diverse types and combinations of filler systems are permitted in the manufacturing of SGPL products. Fillers that cause the
product to fail the requirements of 6.13 are not permitted in the manufacturing of SGPL products.
1.12 In order for a product to be classified as SGPL, it must meet the minimum stress and modulus criteria consistent with the
specific product as marked, and additionally the properties specified in Section 6 of this specification.
1.13 This specification pertains to SGPL where any reinforcement is uniformly distributed within the product. When
reinforcement is not uniformly distributed, the engineering issues become substantially more complex. For this reason, such
products are not covered in this document.
1.14 Products that fail at strains of less than 0.02 (2 %) when tested in flexure in accordance with 6.6 are not compatible with the
underlying assumptions of Annex A1 and are beyond the scope of this standard (see Note 1).
NOTE 1—Calcul
...