ASTM D8156-18

Standard Classification System for and Basis of Specifications for Thermoplastic Elastomer Copolyester Molding and Extrusion Materials (TPC)

SCOPE
1.1 This classification system covers segmented block copolyester elastomers suitable for molding and extrusion.  
1.2 This classification system allows for the use of segmented block copolyesther elastomers that are recycled provided that the requirements as stated in this classification system are met. The proportions of recycled material used, as well as the nature and amount of any contaminant, however, cannot be covered practically in this specification.  
1.3 The properties included in this classification system are those required to identify the compositions covered. It is possible that there are other requirements necessary to identify particular characteristics important to specialized applications. One way of specifying them is by using the suffixes as given in Section 5.  
1.4 This classification system and subsequent line callout (specification) are intended to provide a means of calling out plastic materials used in the fabrication of end items or parts. It is not intended for the selection of materials. Material selection is best made by those having expertise in the plastic field after careful consideration of the design and the performance required of the part, the environment to which it will be exposed, the fabrication process to be employed, the costs involved, and the inherent properties of the material other than those covered by this classification system.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 The following precautionary caveat pertains only to the test methods portion, Section 11, of this classification system. 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.
Note 1: This standard, ISO 14910-1, and ISO 14910-2 address the same subject matter, but differ in technical content.  
1.7 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-2018
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.15 - Thermoplastic Materials

Relations

• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2019
• Refers: ASTM D883-18a - Standard Terminology Relating to Plastics
• Effective Date: 01-Dec-2018
• Refers: ASTM D883-18 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2018
• Refers: ASTM D1600-18 - Standard Terminology for Abbreviated Terms Relating to Plastics (Withdrawn 2024)
• Effective Date: 01-Jan-2018
• Refers: ASTM D883-17 - Standard Terminology Relating to Plastics
• Effective Date: 15-Aug-2017
• Refers: ASTM D3892-15 - Standard Practice for Packaging/Packing of Plastics
• Effective Date: 01-Sep-2015
• Refers: ASTM D3641-14 - Standard Practice for Injection Molding Test Specimens of Thermoplastic Molding and Extrusion Materials
• Effective Date: 01-Mar-2014
• Refers: ASTM D1600-14 - Standard Terminology for Abbreviated Terms Relating to Plastics
• Effective Date: 01-Feb-2014
• Refers: ASTM D1600-13 - Standard Terminology for Abbreviated Terms Relating to Plastics
• Effective Date: 15-Apr-2013
• Refers: ASTM D883-12e1 - Standard Terminology Relating to Plastics
• Effective Date: 15-Nov-2012

Overview

ASTM D8156-18 is the internationally recognized classification system and basis of specifications for thermoplastic elastomer copolyester (TPC) molding and extrusion materials. Issued by ASTM International, this standard provides a systematic method for identifying, classifying, and specifying TPC materials, particularly those used in injection molding and extrusion processes. The standard encompasses requirements for both virgin and recycled copolyester elastomers, ensuring that materials conform to performance criteria regardless of their content, provided all outlined requirements are met.

Key Topics

• Material Classification: Segmented block copolyester elastomers are grouped according to their chemical structure, hardness, melting point, and melt mass-flow rate. This enables users to identify suitable materials for molding and extrusion applications.
• Recycled Content: ASTM D8156-18 allows for the inclusion of recycled copolyester elastomers as long as the finished material meets all specified requirements. However, precise limits on recycled content and contaminants are not covered in this standard.
• Specification System: The standard provides a unique designation (callout line) system that identifies the composition of the TPC materials using tables for group, class, grade, and flow determination.
• Suffixes for Special Requirements: Suffixes are used to indicate additional material features or requirements not covered by the basic classification, facilitating customization in specialized or advanced applications.
• Testing & Certification: All properties listed are identified using recognized ASTM and ISO test methods to ensure quality and repeatability. Certified materials must meet sampling, testing, and inspection criteria.
• SI Units: All values and measurements within this standard are stated in SI (International System of Units).

Applications

This standard is vital for industries and manufacturers using thermoplastic elastomer copolyesters in molded or extruded parts. Key applications include:

• Automotive Components: TPCs are frequently used for flexible, durable parts such as seals, boots, and interior elements where resilience and chemical resistance are essential.
• Industrial Products: Applications include hoses, belts, gaskets, and wire coatings which benefit from the flexibility and performance of copolyester elastomers.
• Consumer Goods: TPCs shaped via molding and extrusion are found in footwear, sporting goods, appliance parts, and flexible packaging.
• Electrical and Electronics: Insulative properties make TPCs valuable in wire and cable insulation and protective casings.
• Sustainable Solutions: The allowance for recycled material supports circular economy initiatives and sustainable manufacturing practices.

The classification system is intended to support specification and procurement rather than material selection, which should be conducted by knowledgeable professionals considering application-specific requirements.

Related Standards

Professionals referencing ASTM D8156-18 should also consider the following related standards for comprehensive compliance and best practices:

• ISO 14910-1 / ISO 14910-2: Parallel international standards addressing designation and test specimen preparation for thermoplastic elastomer copolyesters.
• ASTM D2240: Standard Test Method for Rubber Property-Durometer Hardness, used for hardness classification.
• ASTM D883 & D1600: Terminology standards for plastics.
• ASTM D3418: Test method for thermal properties by differential scanning calorimetry.
• ISO 1133 & ISO 11357-3: International methods for evaluating melt flow and thermal properties.
• ASTM D3641: Practice for molding test specimens.
• ASTM D3892: Guidelines for the packaging and marking of plastic materials.

Practical Value

Implementing ASTM D8156-18 ensures consistency, traceability, and performance across supply chains for TPC materials, aiding manufacturers, specifiers, and quality assurance professionals. Using this standard supports regulatory compliance, product reliability, and facilitates efficient sourcing, especially for applications requiring clear identification and conformity to recognized standards for thermoplastic elastomer copolyester molding and extrusion materials.

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:D8156 −18
Standard Classification System for and Basis of Specifications
for
Thermoplastic Elastomer Copolyester Molding and
Extrusion Materials (TPC)
This standard is issued under the fixed designation D8156; 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 health, and environmental practices and determine the appli-
cability of regulatory limitations prior to use.
1.1 This classification system covers segmented block co-
polyester elastomers suitable for molding and extrusion.
NOTE 1—This standard, ISO 14910-1, and ISO 14910-2 address the
same subject matter, but differ in technical content.
1.2 This classification system allows for the use of seg-
1.7 This international standard was developed in accor-
mented block copolyesther elastomers that are recycled pro-
dance with internationally recognized principles on standard-
vided that the requirements as stated in this classification
ization established in the Decision on Principles for the
system are met. The proportions of recycled material used, as
Development of International Standards, Guides and Recom-
well as the nature and amount of any contaminant, however,
mendations issued by the World Trade Organization Technical
cannot be covered practically in this specification.
Barriers to Trade (TBT) Committee.
1.3 The properties included in this classification system are
those required to identify the compositions covered. It is
2. Referenced Documents
possible that there are other requirements necessary to identify
2.1 ASTM Standards:
particular characteristics important to specialized applications.
D618 Practice for Conditioning Plastics for Testing
One way of specifying them is by using the suffixes as given in
D883 Terminology Relating to Plastics
Section 5.
D1600 Terminology forAbbreviatedTerms Relating to Plas-
1.4 This classification system and subsequent line callout tics
(specification) are intended to provide a means of calling out
D2240 Test Method for Rubber Property—Durometer Hard-
plastic materials used in the fabrication of end items or parts. ness
It is not intended for the selection of materials. Material D3418 Test Method for Transition Temperatures and En-
selection is best made by those having expertise in the plastic thalpies of Fusion and Crystallization of Polymers by
field after careful consideration of the design and the perfor- Differential Scanning Calorimetry
mance required of the part, the environment to which it will be D3641 Practice for Injection Molding Test Specimens of
exposed, the fabrication process to be employed, the costs Thermoplastic Molding and Extrusion Materials
involved, and the inherent properties of the material other than D3892 Practice for Packaging/Packing of Plastics
those covered by this classification system. D4000 Classification System for Specifying Plastic Materi-
als
1.5 The values stated in SI units are to be regarded as
D7209 Guide for Waste Reduction, Resource Recovery, and
standard. No other units of measurement are included in this
Use of Recycled Polymeric Materials and Products (With-
standard.
drawn 2015)
1.6 The following precautionary caveat pertains only to the
E29 Practice for Using Significant Digits in Test Data to
test methods portion, Section 11, of this classification system.
Determine Conformance with Specifications
This standard does not purport to address all of the safety
2.2 ISO Standards:
concerns, if any, associated with its use. It is the responsibility
ISO 294-1 Plastics—Injection Moulding of Test Specimens
of the user of this standard to establish appropriate safety,
of Thermoplastic Materials—Part 1: General Principles
and Moulding of Multipurpose and Bar Test Specimens
ISO 868 Plastics and Ebonite-Determination of Indentation
This test method is under the jurisdiction ofASTM Committee D20 on Plastics Hardness by Means of a Durometer (Shore Hardness)
and is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materi-
als.
Current edition approved June 1, 2018. Published July 2018. DOI:10.1520/ The last approved version of this historical standard is referenced on
D8156-18. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8156−18
ISO 1133 Plastics-Determination of the Melt Mass-Flow
TABLE A Reinforcements and Lubricants
Symbol Material Tolerance
Rate (MFR) and the Melt Volume–Flow Rate (MVR) of
C carbon and graphite ±2 %
Thermoplastics
fiber
ISO 11357-3 AMD 1 Plastics-Differential Scanning Calo- G glass ±2 %
L lubricants (for example, depends upon material
rimetry (DSC)—Part 3: Determination of Temperature
PTFE, graphite, and process—to be
and Enthalpy of Melting and Crystallization
silicone, and specified
ISO 7619:2010 Rubber, vulcanized or thermoplastic—
molybdenum disulfide)
M mineral ±2 %
Determination of indentation hardness—Part 1: Durom-
R combination of ±3 %
eter method (Shore hardness)
reinforcements or fillers,
ISO 14910-1 Plastics-Thermoplastic Polyester/ester and or both
Polyether/ester Elastomers for Moulding and Extrusion-
4.2.1 Reinforced, filled, and/or lubricated versions of the
Part 1: Designation System and Basis for Specifications
basicmaterialsareidentifiedbyasingleletterthatindicatesthe
ISO 14910-2 Plastics-Thermoplastic Polyester/ester and
reinforcement or filler used and two digits that indicate the
Polyether/ester Elastomers for Moulding and Extrusion—
nominal quantity in percent by weight. Thus, a letter designa-
Part 2: Preparation of Test Specimens and Determination
tionGforglass-reinforcedand33for%ofreinforcement,G33,
of Properties
specifies a filled material with a nominal glass level of 33 %.
The reinforcement letter designations and associated tolerance
3. Terminology
levels are shown in the following table:
3.1 Definitions—The terminology used in this classification
NOTE 3—This part of the classification system uses the percent of
system is in accordance with Terminologies D883 and D1600.
reinforcements or additives, or both, in the control of the modified basic
material. The types and percentages of reinforcements and additives are
4. Classification
sometimes shown on the supplier’s technical data sheet. If necessary,
additional callout of these reinforcements and additives can be accom-
4.1 Thermoplastic copolyester elastomers are classified into
plished by the use of the suffix part of the system (see Section 5).
groups in accordance with the material chemical structure.
NOTE 4—Examples of an unfilled and filled Thermoplastic copolyester
These groups are subdivided into classes by Hardness and with
elastomer of this classification system can be found in Table 5.
it, as the result of some relationship with modulus, Flexibility,
and are further subdivided into grades by melting point and
5. Suffixes
melt mass-flow rate, as shown in the Table 1TPC Group, Table
5.1 When additional requirements are needed that are not
2 TPC Classification, and Table 3 Property requirements.
covered by the basic requirements or cell-table requirements,
4.1.1 There are no callout-lines included in this standard.A
they shall be indicated through the use of suffixes.
designation, a callout-line, is drawn up by using Tables 1-4 as
‘building blocks’ (see Tables 1-4 and Fig. 1).
5.2 A list of suffixes can be found in Classification D4000
NOTE 2—Drawing up callout lines by using Tables 1-4 as ‘building (Table3)andcanbeusedtoindicateadditionalrequirementsas
blocks’ implies that addition of new callout lines is not necessary
appropriate. Additional suffixes will be added to that classifi-
anymore. In case of addition of a new TPC type, only the new material
cation system as test methods and requirements are developed
type need to be added to Table 1.
and requested.
4.1.2 To facilitate the incorporation of future or special
materials, the category unspecified (0) is shown in the Table
6. General Requirements
TPC group.
6.1 Basic requirements from the property or cell tables are
4.2 Reinforced, filled, and/or lubricated versions of the
always in effect unless superseded by
...