ASTM E1556-20

Standard Specification for Epoxy Resin System for Composite Skin, Honeycomb Sandwich Panel Repair

ABSTRACT
This specification covers the requirements for an epoxy resin system intended for the repair of sandwich panels for durable, rigidwall, relocatable structures. It must be usable in a field environment and shall not require the use of special equipment such as autoclaves or presses. The epoxy system covered by this specification shall be usable for simultaneous impregnation of a wet-layup composite skin and bonding of that skin to a substrate honeycomb core. The inspection and testing of the epoxy system shall be classified as qualification tests and quality conformance tests. The following test methods shall be performed to conform to the requirements specified: tensile lap shear strength; apparent horizontal shear strength; and flatwise tensile strength.
SIGNIFICANCE AND USE
5.1 Epoxy resin systems used in the repair of composite skin sandwich panels for durable, rigidwall, relocatable shelters must have a combination of mechanical property levels and environmental resistance that will assure long-term durability of the skins and the skin-to-core adhesive bonds when exposed to severe climatic exposures. In addition, these epoxy materials must have processability characteristics that permit their use in a variety of repair scenarios and environments.  
5.2 Intended Use—Epoxy systems conforming to this specification are intended for use in the repair of honeycomb panels at the maintenance field level. The material is intended for use with SAE-AMS-C-9084 glass cloth.  
5.2.1 This is a procurement control document for the procurement of the epoxy system and designers shall be aware that the test values specified herein are based upon tests performed with specific glass-resin composite adherends and shall not be used for design data.  
5.2.2 Epoxy systems covered by this specification are not intended for use in production bonding of sandwich construction.
SCOPE
1.1 This specification covers the requirements for an epoxy resin system intended for the repair of sandwich panels for durable, rigidwall, relocatable structures. It must be usable in a field environment and shall not require the use of special equipment such as autoclaves or presses. The epoxy system covered by this specification shall be usable for simultaneous impregnation of a wet-layup composite skin and bonding of that skin to a substrate honeycomb core. The material shall withstand exposure to temperatures from −54 °C to 93 °C (−65 °F to 199 °F) and high relative humidity, and also the combination of stress, temperature, and relative humidity that are expected to be encountered in service.  
1.2 The values stated in SI units are to be regarded as standard where only SI units are given or where SI units are given first followed by inch-pound units; where inch-pound units are given first followed by SI units, the inch-pound units are to be regarded as standard.  
1.3 The following safety hazards caveat refers only to the test methods described in this specification. 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-2020
• ICS: 83.140.20 - Laminated sheets
• Technical Committee: E06 - Performance of Buildings
• Drafting Committee: E06.53 - Materials and Processes for Durable Rigidwall Relocatable Structures

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: E1556 −20
Standard Specification for
Epoxy Resin System for Composite Skin, Honeycomb
1
Sandwich Panel Repair
This standard is issued under the fixed designation E1556; 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 mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This specification covers the requirements for an epoxy
resin system intended for the repair of sandwich panels for
2. Referenced Documents
durable,rigidwall,relocatablestructures.Itmustbeusableina
2
field environment and shall not require the use of special
2.1 ASTM Standards:
equipment such as autoclaves or presses. The epoxy system
C297/C297MTest Method for Flatwise Tensile Strength of
covered by this specification shall be usable for simultaneous
Sandwich Constructions
impregnation of a wet-layup composite skin and bonding of
D792Test Methods for Density and Specific Gravity (Rela-
that skin to a substrate honeycomb core. The material shall
tive Density) of Plastics by Displacement
withstand exposure to temperatures from −54°C to 93°C
D2344/D2344MTest Method for Short-Beam Strength of
(−65°F to 199°F) and high relative humidity, and also the
PolymerMatrixCompositeMaterialsandTheirLaminates
combination of stress, temperature, and relative humidity that
D2584Test Method for Ignition Loss of Cured Reinforced
are expected to be encountered in service.
Resins
D2734TestMethodsforVoidContentofReinforcedPlastics
1.2 The values stated in SI units are to be regarded as
D3165Test Method for Strength Properties ofAdhesives in
standard where only SI units are given or where SI units are
Shear by Tension Loading of Single-Lap-Joint Laminated
given first followed by inch-pound units; where inch-pound
Assemblies
units are given first followed by SI units, the inch-pound units
E631Terminology of Building Constructions
are to be regarded as standard.
E1091Specification for Nonmetallic Honeycomb Core for
1.3 The following safety hazards caveat refers only to the
Use in Shelter Panels
testmethodsdescribedinthisspecification. This standard does
E1749Terminology Relating to Rigid Wall Relocatable
not purport to address all of the safety concerns, if any,
Shelters
associated with its use. It is the responsibility of the user of this
3
2.2 Military Specification:
standard to establish appropriate safety, health, and environ-
MIL-I-24768Insulation, Plastic, Laminated, Thermosetting,
mental practices and determine the applicability of regulatory
Glass-Cloth, Epoxy-Resin
limitations prior to use.
3
1.4 This international standard was developed in accor- 2.3 Military Standards:
dance with internationally recognized principles on standard- MIL-STD-129Military Marking for Shipping and Storage
ization established in the Decision on Principles for the MIL-STD-1916DOD Preferred Methods for Acceptance of
Development of International Standards, Guides and Recom- Product
1 2
This specification is under the jurisdiction of ASTM Committee E06 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Performance of Buildings and is the direct responsibility of Subcommittee E06.53 contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
on Materials and Processes for Durable Rigidwall Relocatable Structures. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Sept. 1, 2020. Published October 2020. Originally the ASTM website.
3
approved in 1993. Last previous edition approved in 2012 as E1556–12. DOI: Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
10.1520/E1556-20. Philadelphia, PA 19111, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E1556 − 20
TABLE 1 Property Requirements for 24 h, 23 °C Cure
A
Number of Average Must Exceed Minimum Must Exceed,
Property Test Condition
Specimens MPa (psi) MPa (psi)
Tensile Lap Shear Strength in accordance 23 °C (73 °F), dry 5 6.9 (1000) 5.85 (850)
with 8.2.1, 8.3.1
Apparent Horizontal Shear Strength in 23 °C (73 °F), dry 5 15.5 (2250) 13.15 (1910)
accordance with 8.2.2, 8.3.2
A
All specimens tested must exceed these minimum values.
TABLE 2 Tensile Lap Shear Strength Requirements
...

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: E1556 − 12 E1556 − 20
Standard Specification for
Epoxy Resin System for Composite Skin, Honeycomb
1
Sandwich Panel Repair
This standard is issued under the fixed designation E1556; 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
1.1 This specification covers the requirements for an epoxy resin system intended for the repair of sandwich panels for durable,
rigidwall, relocatable structures. It must be usable in a field environment and shall not require the use of special equipment such
as autoclaves or presses. The epoxy system covered by this specification shall be usable for simultaneous impregnation of a
wet-layup composite skin and bonding of that skin to a substrate honeycomb core. The material shall withstand exposure to
temperatures from −54−54 °C to 93°C (−6593 °C (−65 °F to 199°F)199 °F) and high relative humidity, and also the combination
of stress, temperature, and relative humidity that are expected to be encountered in service.
1.2 The values stated in SI units are to be regarded as standard where only SI units are given or where SI units are given first
followed by inch-pound units; where inch-pound units are given first followed by SI units, the inch-pound units are to be regarded
as the standard.
1.3 The following safety hazards caveat refers only to the test methods described in this specification. 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 safety, health, and healthenvironmental 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:
C297/C297M Test Method for Flatwise Tensile Strength of Sandwich Constructions
D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
D2344/D2344M Test Method for Short-Beam Strength of Polymer Matrix Composite Materials and Their Laminates
D2584 Test Method for Ignition Loss of Cured Reinforced Resins
D2734 Test Methods for Void Content of Reinforced Plastics
D3165 Test Method for Strength Properties of Adhesives in Shear by Tension Loading of Single-Lap-Joint Laminated
Assemblies
1
This specification is under the jurisdiction of ASTM Committee E06 on Performance of Buildings and is the direct responsibility of Subcommittee E06.53 on Materials
and Processes for Durable Rigidwall Relocatable Structures.
Current edition approved Nov. 1, 2012Sept. 1, 2020. Published December 2012October 2020. Originally approved in 1993. Last previous edition approved in 20082012
as E1556 – 08.E1556 – 12. DOI: 10.1520/E1556-12.10.1520/E1556-20.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E1556 − 20
E631 Terminology of Building Constructions
E1091 Specification for Nonmetallic Honeycomb Core for Use in Shelter Panels
E1749 Terminology Relating to Rigid Wall Relocatable Shelters
3
2.2 Military Specifications:Specification:
MIL-I-24768 Insulation, Plastic, Laminated, Thermosetting, Glass-Cloth, Epoxy-Resin
3
2.3 Military Standards:
MIL-STD-129 Military Marking for Shipping and Storage
MIL-STD-1916 DOD Preferred Methods for Acceptance of Product
4
2.4 Commercial Standards:Standard:
SAE-AMS-C-9084 Cloth, Glass, Finished for Epoxy Resin Laminates
3. Terminology
3.1 Definitions—See Terminologies —For definitions of general terms related to building construction used in this specification,
refer to Terminology E631, and E1749 for definitions of general terms used in this
...