ASTM D6778-20

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: D6778 − 14 D6778 − 20
Standard Classification System and Basis for Specification for
Polyoxymethylene Molding and Extrusion Materials (POM)
This standard is issued under the fixed designation D6778; 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 classification system covers polyoxymethylene materials suitable for molding and extrusion. This classification system
allows for the use of polyoxymethylene plastic materials that are recycled, reconstituted, recycled-regrind, recovered, or
reprocessed, or combination thereof, provided that the requirements as stated in this specification are met. It is the responsibility
of the supplier and the buyer of recycled, reconstituted, recycled-regrind, recovered, or reprocessed polyoxymethylene plastic
materials, or combination thereof, to ensure compliance. (See Guide D7209).
1.2 The properties included in this standard are those required to identify the compositions covered. Other requirements
necessary to identify particular characteristics important to specialized applications are to be specified by using suffixes as given
in Section 5.
1.3 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 can be
made by those having expertise in the plastic field only 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 standard.
1.4 The values stated in SI units are to be regarded as the 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 safety, health, and healthenvironmental practices and determine the applicability
of regulatory requirementslimitations prior to use.
NOTE 1—This classification system is similar to ISO 9988-1/-2,29988-1/-2, although the technical content is significantly different.
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.
2. Referenced Documents
2.1 ASTM Standards:
D618 Practice for Conditioning Plastics for Testing
D883 Terminology Relating to Plastics
D1600 Terminology for Abbreviated Terms Relating to Plastics
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)
D6100 Specification for Extruded, Compression Molded and Injection Molded Polyoxymethylene Shapes (POM)
This classification 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 Aug. 1, 2014Feb. 1, 2020. Published September 2014March 2020. Originally approved in 2002. Last previous edition approved in 20122014
as D6778 - 12.D6778 - 14. DOI: 10.1520/D6778-14.10.1520/D6778-20.
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.
*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
D6778 − 20
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
2.2 ISO Standards:
ISO 75-1 Plastics—Determination of Temperature of Deflection under Load—Part 1: General Test Method
ISO 75-2 Plastics—Determination of Temperature of Deflection under Load—Part 2: Plastics and Ebonite
ISO 179-1 Plastics—Determination of Charpy Impact Properties—Part 1: Non-instrumented Impact Test
ISO 294-1 Plastics—Injection Moulding of Test Specimens of Thermoplastic Materials—Part 1: General Principles, and
Moulding of Multipurpose and Bar Test Specimens
ISO 527-1 Plastics—Determination of Tensile Properties—Part 1: General Principals
ISO 527-2 Plastics—Determination of Tensile Properties—Part 2: Test Conditions for Moulding and Extrusion Plastics
ISO 1133 Plastics—Determination of the Melt-Mass Flow Rate (MFR) and the Melt Volume-Flow Rate (MVR) of
Thermoplastics
ISO 11357-3 Plastics—Differential Scanning Calorimetry (DSC)—Part 3: Determination of Temperature and Enthalpy of
Melting and Crystallization
ISO 1183 Plastics—Methods for Determining the Density of Non-Cellular Plastics—Part 1: Immersion Method, Liquid
Pyknometer and Titration Method
ISO 3451-1 Plastics—Determination of Ash—Part 1: General Methods
ISO 9988-129988-1 Plastics—Polyoxymethylene (POM) Moulding and Extrusion Materials—Part 1: Designation System and
Basis for Specifications
ISO 9988-229988-2 Plastics—Polyoxymethylene (POM) Moulding and Extrusion Materials—Part 2: Preparation of Test
Specimens and Determination of Properties
ISO 20753 Plastics—Test Specimens
3. Terminology
3.1 The terminology used in this classification system is in accordance with Terminologies D883 and D1600.
4. Classification
4.1 Polyoxymethylene materials are classified into groups according to their composition. These groups are subdivided into
classes and grades, as shown in the Basic Property Table (Table POM).
A,B,C
TABLE POM Polyoxymethylene Materials, Detail Requirements (Natural and Black Color Only)
Tensile Tensile Charpy Deflection
Flow Melting
Strength, Modulus, Impact Temperature,
Rate Point, Density,
ISO ISO Resistance, ISO 75/
Group Description Class Description Grade Description ISO 1183,
ISO ISO
G H I J
D
3 527, 527 ISO 179 / Method A
, E F f
1133, 11357-3 g/cm
MPa, MPa, 1eA, kJ/m , 1.82 MPa,
G/10 min °C, min
min min min °C, min
01 Homopolymer 1 general purpose 1 <4 170 1.39 to 1.44 65 2400 7.0 80
and 2 4 to 10 170 1.39 to 1.44 65 2500 6.0 80
high flow
3 8 to 19 170 1.39 to 1.44 65 2700 4.5 80
4 19 to 30 170 1.39 to 1.44 65 2700 4.5 85
5 30 to 55 170 1.39 to 1.44 65 2700 4.0 85
G10 10 % glass 170 1.45 to 1.53 80 3500 3.0 150
G25 25 % glass 170 1.55 to 1.63 125 7000 6.0 160
0 other
3 UV stabilized 1 <8 170 1.39 to 1.44 65 2400 7.0 75
2 8 to 19 170 1.39 to 1.44 65 2700 4.5 75
3 19 to 30 170 1.39 to 1.44 65 2700 4.5 75
4 30 to 55 170 1.39 to 1.44 65 2700 4.5 75
0 other
4 impact modified 1 <4 170 1.31 to 1.37 35 800 50.0 50
2 8 to 17 170 1.36 to 1.42 45 1800 8.0 65
3 170 1.32 to 1.38 35 1100 12.0 55
0 other 0 other
02 Copolymer 1 general purpose 1 <4 160 1.38 to 1.43 58 2000 4.0 80
and 2 4 to 7 160 1.38 to 1.43 58 2200 3.5 80
high flow
3 7 to 11 160 1.38 to 1.43 58 2200 3.5 80
4 11 to 16 160 1.38 to 1.43 58 2000 3.0 80
5 16 to 35 160 1.38 to 1.43 60 2300 3.0 80
6 35 to 60 160 1.38 to 1.43 60 2500 2.5 80
7 60+ 160 1.38 to 1.43 60 2500 2.0 80
G10 10 % glass 160 1.40 to 1.52 70 4000 3.0 150
G15 15 % glass 160 1.45 to 1.55 80 5500 3.0 150
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
D6778 − 20
A,B,C
TABLE POM Polyoxymethylene Materials, Detail Requirements (Natural and Black Color Only)
Tensile Tensile Charpy Deflection
Flow Melting
Strength, Modulus, Impact Temperature,
Density,
Rate Point,
ISO ISO Resistance, ISO 75/
Group Description Class Description Grade Description ISO ISO ISO 1183,
G H I J
D
3 527, 527 ISO 179 / Method A
, E F
f
g/cm
1133, 11357-3
MPa, MPa, 1eA, kJ/m , 1.82 MPa,
G/10 min °C, min
min min min °C, min
G20 20 % glass 160 1.50 to 1.60 80 6500 3.0 150
G25 25 % glass 160 1.54 to 1.65 80 7300 3.0 150
GE25 25 % glass beads 160 1.50 to 1.70 36 3000 1.0 80
M30 30 % Mineral 160 1.55 to 1.65 40 3500 2.5 80
0 other
2 UV stabilized 1 <4 160 1.38 to 1.43 56 2000 4.0 80
2 4 to 7 160 1.38 to 1.43 56 2000 3.5 80
3 7 to 11 160 1.38 to 1.43 57 2000 3.5 80
4 11 to 16 160 1.38 to 1.43 57 2000 3.0 80
5 16 to 35 160 1.38 to 1.43 58 2100 3.0 80
6 35 to 60 160 1.38 to 1.43 58 2100 2.5 80
7 60+ 160 1.38 to 1.43 58 2100 2.0 80
0 other
3 impact modified 1 11 to 28 155 1.34 to 1.40 46 1800 4.5 70
2 11 to 28 155 1.30 to 1.38 40 1400 4.5 60
3 12 max 155 1.34 to 1.40 44 1500 5.0 70
4 12 max 155 1.30 to 1.40 35 1300 5.0 60
0 other
4 high modulus 1 <4 165 1.38 to 1.43 62 2400 5.0 80
4 11 to 16 165 1.38 to 1.43 64 2700 4.0 80
0 other
03 Terpolymer 1 high melt strength 1 <2 160 1.38 to 1.43 56 2250 3.5 80
0 other
00 Other 0 other 0 other
A
No descriptions are listed unless needed to describe a special grade under the class. All other grades are listed by requirements.
B
Refer to 9.1 under Specimen Preparation for source of test pieces.
C
Data on 4 mm test specimens may be limited and the minimum values may be changed in a later revision after a statistical database of sufficient size is generated.
D
Flow rate: 190/2.16 (T/M).
E
Flow rate, g/10 min (MFR) can be converted to flow rate, cc/10 min (MVR) by the relationship MVR = (MFR/density of the melt at 190°C).
F
Melting point rate 10°C/min. T second melting curve.
M
G
Crosshead speed shall be 50 mm/min ± 10 % unless the specimen exhibits brittle failure (no yield point) and strain at break of <10 % in which case crosshead speed
shall be 5 mm/min ± 25 %.
H
Crosshead speed shall be 1 mm/min.
I
Notched specimen tested edgewise (method 1eA).
J
Deflection temperature shall be determined with the specimen in the flatwise position (Method A ).
f
A,B
TABLE A Detail Requirements: Filled or Reinforced Polyoxymethylene
Designation
Order Property 0 1 2 3 4 5 6 7 8 9
Number
D
1 Tensile strength, ISO 527, unspecified 20 35 50 65 90 110 130 150 specify value
C
min, MPa
D
2 Tensile modulus, ISO 527, unspecified 1500 2500 3500 4500 5500 6500 7500 8500 specify value
E
min, MPa
D
3 Charpy impact, ISO 179/1eA, unspecified 1.0 2.0 3.0 4.0 6.0 10.0 20.0 40.0 specify value
min, kJ/m
D
4 Deflection temperature, unspecified 50 70 90 110 120 130 140 150 specify value
ISO 75, Method A ,
f
F
1.82 MPa, min, °C
5 To be determined unspecified . . . . . . . . . . . . . . . . . . . . . . . . . . .
A
It is recognized that detailed test values, particularly Charpy impact, may not predict nor even correlate with the performance of parts molded of these materials.
B
Refer to 9.1 under Specimen Preparation for source of test specimens.
C
Crosshead speed shall be 50 mm/min ± 10 % unless the specimen exhibits brittle failure (no yield point) and a strain at break of <10 % in which case crosshead speed
shall be 5 mm/min ± 25 %.
D
If specific value is required, it must appear on the drawing or contract, or both.
E
Crosshead speed shall be 1 mm/min.
F
Deflection temperature shall be determined with the specimen in the flatwise position (Method A ).
f
A,B
TABLE B Detail Requirements: Special Polyoxymethylene
Designation
Order Property 0 1 2 3 4 5 6 7 8 9
Number
D
1 Tensile strength, ISO 527, unspecified 10 20 30 40 50 60 70 80 specify value
C
min, MPa
D
2 Tensile modulus, ISO 527 unspecified 200 600 1000 1400 1800 2200 2600 3000 specify value
E
min, MPa
D
3 Charpy impact, ISO 179/1eA, unspecified 1.0 2.0 3.0 4.0 6.0 10.0 20.0 50.0 specify value
D6778 − 20
A,B
TABLE B Detail Requirements: Special Polyoxymethylene
Designation
Order Property 0 1 2 3 4 5 6 7 8 9
Number
min, kJ/m
D
4 Deflection temperature, unspecified 40 55 70 80 90 100 110 120 specify value
ISO 75, Method A ,
f
F
1.82 MPa, min, °C
5 To be determined unspecified . . . . . . . . . . . . . . . . . . . . . . . . . . .
A
It is recognized that detailed test values, particularly Charpy impact, may not predict nor even correlate with the performance of parts molded of these materials.
B
Refer to 9.1 under Specimen Preparation for source of test specimens.
C
Crosshead speed shall be 50 mm/min ± 10 % unless the specimen exhibits brittle failure (no yield point) and a strain at break of <10 % in which case crosshead speed
shall be 5 mm/min ± 25 %.
D
If specific value is required, it must appear on the drawing or contract, or both.
E
Crosshead speed shall be 1 mm/min.
F
Deflection temperature shall be determined with the specimen in the flatwise position (Method A ).
f
NOTE 2—An example of this classification system for unreinforced polyoxymethylene is given as follows. The designation POM0112 indicates the
following:
POM = polyoxymethylene (acetal) as found in Terminology D1600,
01 = homopolymer (group),
1 = general purpose and high flow (class), and
2 = requirements given in Table POM (grade).
4.1.1 Reinforced, filled, and lubricated versions of polyoxymethylene materials that are found in Table POM are classified
according to the reinforcement used and the nominal level, by weight percent, of the reinforcement. The grade is identified by a
single letter that indicates the filler or reinforcement used and two digits, in multiples of 5, which indicate the nominal quantity
in percent by weight. Thus, a grade containing 25 % glass reinforcement would be indicated by POM021G25. This specification
indicates:
POM = polyoxymethylene (acetal) as found in Terminology D1600,
02 = copolymer (group),
1 = general purpose and high flow (class), and
G25 = 25 % glass reinforcement and requirements given in Table POM (grade).
The reinforcement letter designations and associated tolerance levels are shown in Table 1.
A B
TABLE 1 Reinforcement-Filler Symbols and Tolerances
Symbol Material Tolerance
C carbon and graphite ±2 %
fiber-reinforced
G glass-reinforced ±2 %
L lubri
...