ASTM D5138-23

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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
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Designation: D5138 − 16 D5138 − 23
Standard Classification System and Basis for Specification for
Liquid Crystal Polymers Molding and Extrusion Materials
(LCP)
This standard is issued under the fixed designation D5138; 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 classification system covers liquid crystal polymeric (LCP) materials suitable for injection molding and extrusion. This
classification system allows the use of liquid crystal polymers that are recycled, reconstituted, recycled-regrind, recovered, or
reprocessed, or a combination thereof, provided that the requirements as stated in this classification system are met. It is the
responsibility of the supplier and the buyer of liquid crystal polymers that are recycled, reconstituted, recycled-regrind, recovered,
or reprocessed, or a combination thereof, to ensure compliance.
1.2 The properties included in this classification system are those required to identify the compositions covered. Other
requirements necessary to identify particular characteristics important to specialized applications are allowed. These shall be
agreed upon between the user and the supplier, by using suffixes as given in Section 5.
1.3 This classification system and subsequent line callout (specification) are intended to be a means of calling out plastic materials
used in the fabrication of end-use items or parts. It is not intended for the selection of materials. Material selection can be made
by those having expertise in the plastics 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.
1.4 The values stated in SI units are to be regarded as standard.
1.5 The following precautionary caveat pertains only to the test method 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 and healthsafety, health, and environmental practices and determine the
applicability of regulatory limitations prior to use.
NOTE 1—There is no known ISO equivalent to this standard.
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.
This classification system is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic
Materials.
Current edition approved April 1, 2016Feb. 1, 2023. Published April 2016February 2023. Originally approved in 1990. Last previous edition approved in 20112016 as
D5138 - 11.D5138 - 16. DOI: 10.1520/D5138-16.10.1520/D5138-23.
*A Summary of Changes section appears at the end of this standard
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D5138 − 23
2. Referenced Documents
2.1 ASTM Standards:
D256 Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics
D618 Practice for Conditioning Plastics for Testing
D638 Test Method for Tensile Properties of Plastics
D648 Test Method for Deflection Temperature of Plastics Under Flexural Load in the Edgewise Position
D790 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials
D883 Terminology Relating to Plastics
D1238 Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer
D1600 Terminology for Abbreviated Terms Relating to Plastics
D3418 Test Method for Transition Temperatures and Enthalpies of Fusion and Crystallization of Polymers by Differential
Scanning Calorimetry
D3641 Practice for Injection Molding Test Specimens of Thermoplastic Molding and Extrusion Materials
D3835 Test Method for Determination of Properties of Polymeric Materials by Means of a Capillary Rheometer
D3892 Practice for Packaging/Packing of Plastics
D4000 Classification System for Specifying Plastic Materials
D5630 Test Method for Ash Content in Plastics
D7209 Guide for Waste Reduction, Resource Recovery, and Use of Recycled Polymeric Materials and Products (Withdrawn
2015)
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
2.2 IEC and ISO Standards:
IEC 112 Recommended Method for Determining the Comparative Tracking Index of Solid Insulation Materials
IEC 243 Recommended Methods of Test for Electrical Strength of Solid Insulating Materials at Power Frequencies
ISO 62 Plastics—Determination of Water Absorption
ISO 75-1 Determination of Temperature of Deflection Under Load—General Test Method
ISO 75-2 Determination of Temperature of Deflection Under Load—Plastics and Ebonite
ISO 178 Plastics—Determination of Flexural Properties of Rigid Materials
ISO 180 Plastics—Determination of Izod Impact Strength of Rigid Materials
TABLE LCP Liquid Crystal Polymers—Classification
A
Group Description Class Description Grade Description
01 unsubstituted or methyl substituted, wholly aromatic 1 high temperature 0
B
copolyester, polyether, or polyester amide DTUL >260°C
2 medium temperature 0
DTUL = 220–260°C
3 general purpose 0
DTUL <220°C
02 mixed aromatic/aliphatic copolyesters, polyethers, or 1 high temperature 0
polyester amides DTUL >260°C
2 medium temperature 0
DTUL = 220–260°C
3 general purpose 0
DTUL <220°C
03 aromatic copolyesters, polyethers, or polyesteramides 1 high temperature 0
with aliphatic sidechain DTUL >260°C
2 medium temperature 0
DTUL = 220–260°C
3 general purpose 0
DTUL <220°C
04 blends 1 high temperature 0
DTUL >260°C
2 medium temperature 0
DTUL = 220–260°C
3 general purpose 0
DTUL <220°C
00 other 0 other 0
A
Description unspecified.
B
DTUL is deflection temperature under load measured at 1.8 MPa and is determined in accordance with Table A or Table B.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
D5138 − 23
ISO 294-1 Plastics—Injection Moulding of Test Specimens of Thermoplastic Materials—General Principles for Injection
Molding
ISO 527-1 Plastics—Determination of Tensile Properties—General Principles
ISO 527-2 Plastics—Determination of Tensile Properties—Test Conditions for Moulding and Extrusion of Plastics
ISO 604 Plastics—Determination of Compressive Properties
ISO 3451-1 Plastics—Determination of Ash Content—Part 1: General Methods
ISO 11357-1 Plastics—Differential Scanning Calorimetry (DSC)—Part 1: General Principles
ISO 11357-3 Plastics—Differential Scanning Calorimetry (DSC)—Part 3: Determination of Temperature and Enthalpy of
Melting and Crystallization
ISO 11443 Plastics—Determination of the Fluidity of Plastics Using Capillary and Slit-Die Rheometers
ISO 20753 Plastics—Test Specimens
2.3 Military Standard:
MIL-M-24519 Molding Plastics—Electrical Thermoplastics
2.4 Underwriters Laboratories (UL):
UL 94 Test for Flammability of Plastic Materials for Parts in Devices and Appliances
2.5 National Technical Information Service (NTIS):
AD297457 Procedure and Analytical Method for Determining Toxic Gases Produced by Synthetic Compounds
3. Terminology
3.1 Definitions—Except for the terms defined below, the terminology used in this classification system is in accordance with
Terminologies D883 and D1600.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 liquid crystal polymer (LCP)—A family of thermoplastic polymers which upon heating to the processing temperature,
exhibit ordered structure and under shear, highly aligned chains that are retained in the solid state. Liquid crystal polymers are
polymers that in the molten state exhibit birefringence in polarized light.
4. Classification
4.1 The LCP materials are classified into groups according to their chemical composition. These groups are subdivided, whether
reinforced or not, into classes based on thermal performance as shown in Table LCP.
NOTE 2—An example of this classification system is as follows: The specification LCP0120 indicates the following LCP = liquid crystal polymer as found
in Terminology D1600:
01 = Unsubstituted, or methyl substituted, wholly aromatic
copolyester, polyether, or polyester amide (group)
2 = Medium temperature, DTUL = 220-260°C (class)
0 = Other (grade)
4.1.1 To facilitate the incorporation of future or special materials, the “other” category for Group (00), Class (0), and Grade (0)
is shown in Table LCP.
4.2 Reinforced, filled, and lubricated versions of LCP materials are classified in accordance with Tables LCP and Table A. Table
LCP is used to specify the group or the group and class of LCP and Table A is used to specify the property requirements.
NOTE 3—Test specimens shall be prepared in accordance with ISO 20753, Specimen Type A1 or Practice D3641 accordingly.
NOTE 4—A similar callout can be developed using Table B.
4.2.1 Reinforced, filled, and lubricated variations of the basic materials are identified by a single letter that indicates the filler, or
reinforcement used, or both, and two digits that indicate the nominal quantity in percent by weight. The reinforcement letter
designations and associated tolerance levels are shown in Table 4.
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Available from National Technical Information Service (NTIS), 5301 Shawnee Rd., Alexandria, VA 22312, http://www.ntis.gov.
D5138 − 23
TABLE A Property Requirements for Liquid Crystal Polymer Based on ISO Test Methods
0 1 2 3 4 5 6 7 8 9
1 Tensile ISO 527 unspecified 70 100 120 140 160 180 200 220 specify
strength, value
min, MPa
2 Flexural ISO 178 unspecified 4 8 12 16 20 24 28 32 specify
modulus, value
min, GPa
3 Notched ISO 180 unspecified 5 9 12 15 18 25 37 50 specify
izod value
impact,
min, kJ/m
A
4 DTUL at ISO 75/A unspecified 140 180 220 240 260 300 340 380 specify
1.8 MPa,
value
min,° C
5 To be unspecified specify
determined value
A
DTUL = Deflection temperature under load tested flatwise on 80 by 10 by 4-mm specimen.
TABLE B (Formerly Table A in D5138 – 90) Property Requirements for LCP Based on ASTM Test Methods
0 1 2 3 4 5 6 7 8 9
A
Tensile strength, MPa, min, unspecified 70 100 120 140 160 180 200 220 specify value
(D638)
B
Flex modulus, GPa, min, unspecified 4 8 12 16 20 24 28 32 specify value
(D790)
Notched Izod unspecified 40 75 100 125 150 200 300 400 specify value
impact, min,
C
J/m, (D256)
Deflection temperature, min, unspecified 140 180 220 240 260 300 340 380 specify value
D
°C at 1.8 MPa, (D648)
To be determined unspecified specify value
A
Type 1 tensile bar, 3.2 mm thick tested at 5 mm/min ± 25 % (minimum length 200 mm).
B
127 by 12.7 by 3.2-mm bar tested at 1.3 mm/min.
C
Bar thickness 3.2 mm.
D
Test Method D648, Method A.
A B
TABLE 4 Reinforcement-Filler Symbols and Tolerances
Tolerance
Symbol Material
A
(Based on Total Mass )
C carbon and graphite fiber ±2 %
G glass ±2 %
L lubricants (for example PTFE, depends upon material and
graphite, silicone, and process—to be specified
molybdenum disulfide)
M mineral ±2 %
R combinations of reinforcements ±3 % for the total
or fillers, or both
A
Ash content of filled, or reinforced material, or both, is determined using either
Test Method D5630 or ISO 3451-1 where applicable.
B
Additional symbols will be added to this table as required.
NOTE 5—This part of the system uses the percent of reinforcements or additives, or both, in the callout of the modified basic material. The types and
percentages of reinforcements and additives are shown on the suppliers’ technical data sheet unless they are proprietary in nature. If necessary, additional
callout of these reinforcements and additives can be accomplished by the use of the suffix part of the system (see Section 5).
4.2.2 Specific requirements shall be shown by a six-character specification. The specification will consist of the letter A and the
five digits comprising the cell numbers for the property requirements in the order as they appear in Table A.
4.2.2.1 Although the values listed are necessary to include the range of properties available in existing materials, this does not
imply that every possible combination of properties exists or can be obtained.
4.2.3 When the grade or class of the basic material is not known or is not important, the “0” classification shall be used.
NOTE 6—An example of this classification for specifying a reinforced LCP material is given as follows: The specification LCP0120G30A22450 would
indicate the following material requirements:
D5138 − 23
LCP = Liquid Crystal Polymer as found in Terminology D1600
01— = Unsubstituted or methyl substituted, wholly aromatic copolyester, polyether, or polyester amide (group),
2 = medium temperature (class)
0 = unspecified (grade)
G30 = G
...