ASTM D4020-00a

Standard Specification for Ultra-High-Molecular-Weight Polyethylene Molding and Extrusion Materials

SCOPE
1.1 This specification provides for the identification of virgin, unmodified ultra-high-molecular-weight polyethylene (UHMW-PE) plastics molding and extrusion materials. This identification is made in such a manner that the seller and purchaser can agree on the acceptability of different commercial lots or shipments.
1.2 It is not intended to differentiate between various molecular weight grades of ultra-high-molecular-weight polyethylene commercially available.
1.3 It is not the function of this specification to provide specific engineering data for design purposes.
1.4 Ultra-high-molecular-weight polyethylenes, as defined in this specification, are those linear polymers of ethylene which have a relative viscosity of 1.44 or greater, in accordance with the test procedures described herein.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 The following precautionary caveat pertains only to the test method portion. Section 7, of 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 and health practices and determine the applicability of regulatory limitations prior to use.
Note 1—There is no ISO equivalent specification. However, in ISO 11542-1, a range of viscosity numbers defines the viscosity of UHMW-PE grades. The viscosity numbers are determined in accordance with ISO 1628-3.

General Information

• Status: Historical
• Publication Date: 09-Nov-2001
• ICS: 83.140.99 - Other rubber and plastics products
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.15 - Thermoplastic Materials

Relations

• Replaced By: ASTM D4020-01 - Standard Specification for Ultra-High-Molecular-Weight Polyethylene Molding and Extrusion Materials
• Effective Date: 10-Nov-2001
• Referred By: ASTM F2759-19 - Standard Guide for Assessment of the Ultra-High Molecular Weight Polyethylene (UHMWPE) Used in Orthopedic and Spinal Devices
• Effective Date: 10-Nov-2001
• Referred By: ASTM D7611/D7611M-21 - Standard Practice for Coding Plastic Manufactured Articles for Resin Identification
• Effective Date: 10-Nov-2001
• Referred By: ASTM D4000-23 - Standard Classification System for Specifying Plastic Materials
• Effective Date: 10-Nov-2001
• Referred By: ASTM D1601-18 - Standard Test Method for Dilute Solution Viscosity of Ethylene Polymers
• Effective Date: 10-Nov-2001
• Referred By: ASTM F648-21 - Standard Specification for Ultra-High-Molecular-Weight Polyethylene Powder and Fabricated Form for Surgical Implants
• Effective Date: 10-Nov-2001
• Referred By: ASTM F2193-20 - Standard Specifications and Test Methods for Components Used in the Surgical Fixation of the Spinal Skeletal System
• Effective Date: 10-Nov-2001
• Referred By: ASTM D6712-17 - Standard Specification for Ultra-High-Molecular-Weight Polyethylene (UHMW-PE) Solid Plastic Shapes
• Effective Date: 10-Nov-2001
• Referred By: ASTM F2695-12(2020) - Standard Specification for Ultra-High Molecular Weight Polyethylene Powder Blended With Alpha-Tocopherol (Vitamin E) and Fabricated Forms for Surgical Implant Applications
• Effective Date: 10-Nov-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 4020 – 00a
Standard Specification for
Ultra-High-Molecular-Weight Polyethylene Molding and
Extrusion Materials
This standard is issued under the fixed designation D 4020; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope * D 1601 Test Method for Dilute Solution Viscosity of Eth-
ylene Polymers
1.1 This specification provides for the identification of
D 1898 Practice for Sampling of Plastics
virgin, unmodified ultra-high-molecular-weight polyethylene
2.2 ISO Standards:
(UHMW-PE) plastics molding and extrusion materials. This
ISO 11542-1 Plastics—Ultra High Molecular-Weight Poly-
identification is made in such a manner that the seller and
ethylene (PE-UHMW) Moulding and Extrusion
purchaser can agree on the acceptability of different commer-
Materials—Part 1: Designation System and Basis for
cial lots or shipments.
Specification
1.2 It is not intended to differentiate between various
ISO 1628-3 Plastics—Determination of Viscosity Number
molecular weight grades of ultra-high-molecular-weight poly-
and Limiting Viscosity Number—Part 3: Polyethylenes
ethylene commercially available.
and Polypropylenes
1.3 It is not the function of this specification to provide
specific engineering data for design purposes.
3. Terminology
1.4 Ultra-high-molecular-weight polyethylenes, as defined
3.1 Definitions—Definitions of terms used in this specifica-
in this specification, are those linear polymers of ethylene
tion are in accordance with Terminology D 883.
which have a relative viscosity of 1.44 or greater, in accor-
3.2 Definitions of Terms Specific to This Standard:
dance with the test procedures described herein.
3.2.1 ultra-high-molecular-weight polyethylene molding
1.5 The values stated in SI units are to be regarded as the
and extrusion materials—as defined by this specification, those
standard. The values given in parentheses are for information
substantially linear polyethylenes which have a relative viscos-
only.
ity of 1.44 or greater, at a concentration of 0.02 %, at 135°C, in
1.6 The following precautionary caveat pertains only to the
decahydronaphthalene.
test method portion. Section 7, of this specification: This
3.2.1.1 Discussion—It has been common practice to refer to
standard does not purport to address all of the safety concerns,
the “molecular weight” of UHMW-PE resins. The following
if any, associated with its use. It is the responsibility of the user
calculations shall be used to approximate the specific viscosity
of this standard to establish appropriate safety and health
(h ), reduced viscosity (hred or R.S.V.), intrinsic viscosity (h
sp
practices and determine the applicability of regulatory limita-
or I.V.), and the approximate viscosity average molecular
tions prior to use.
weight of virgin resin. The solution viscosity test on thermally
NOTE 1—There is no ISO equivalent specification. However, in ISO
processed material is invalid due to inadequate solubility and
11542-1, a range of viscosity numbers defines the viscosity of UHMW-PE
possible crosslinking.
grades. The viscosity numbers are determined in accordance with ISO
k
1628-3.
t 2
s
t
s
Relative viscosity5h 5 (1)
r
2. Referenced Documents
k
t 2
o
t
2.1 ASTM Standards: o
D 883 Terminology Relating to Plastics Specific viscosity5h 5h 2 1
sp r
h
sp
Reduced viscosity5h 5
red
C
1/2
This specification is under the jurisdiction of ASTM Committee D20 on
Intrinsic viscosity = [h]=(2hsp−2ln hrel) 4 c
Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic
Materials.
Current edition approved Nov. 10, 2000. Published January 2001. Originally Discontinued; see 1997 Annual Book of ASTM Standards, Vol 08.01.
published as D 4020 – 81. Last previous edition D 4020 – 00. Available from American National Standards Institute, 11 W. 42nd St., 13th
Annual Book of ASTM Standards, Vol 08.01. Floor, New York, NY 10036.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 4020
limiting viscosity number at 0 % concentration
in this specification, the color and translucence of molded or
4 1.37
Nominal viscosity molecular weight = 5.37 3 10 [h]
extruded pieces, formed under conditions recommended by the
manufacturer of the material, will be comparable within
where:
commercial match tolerances to the color and translucence of
k = kinetic energy correction constant for the particular
standard molded or extruded samples of the same thickness
viscometer used,
supplied in advance by the manufacturer of the material.
t = flow time of solution at 135°C, s,
s
t = flow time of pure solvent at 135°C, s, and
o
C = concentration.
6. Sampling
NOTE 2—There are other equations being used in industry to calculate
6.1 A batch or lot shall be considered as a unit of manufac-
the viscosity average molecular weights. Refer to Appendix X3 for the
ture and may consist of a blend of two or more production runs
other equations and their relationship to the viscosity average molecular
of the same material.
weight equation in 3.2.1.1. The equation in 3.2.1.1 is the only equation
that shall be used for reporting of viscosity average molecular weight. 6.2 Unless otherwise agreed upon between the seller and the
purchaser, the material shall be sampled in accordance with the
4. Classification
procedure described in the general and specific sampling
4.1 It is recognized that dilute solution viscosity measure-
procedures of Practice D 1898. Adequate statistical sampling
ments can only be made on virgin resin. Therefore, the
prior to packaging shall be considered an acceptable alterna-
following test and limits shall be used to determine the
tive.
properties of virgin polymer only.
5. Materials and Manufacture
7. Test Method
5.1 The molding and extrusion material shall be UHMW
7.1 Dilute Solution Viscosity—Use Test Method D 1601, as
polyethylene in the form of powder, granules, or pellets.
modified in Annex A1.
5.2 The molding and extrusion materials shall be as uniform
in composition and size and as free of contamination as can be
8. Keywords
achieved by good manufacturing practice. If necessary, the
level of contamination may be agreed upon between the seller
8.1 extrusion materials; molding materials; plastics; poly-
and the purchaser.
ethylene; ultra-high-molecular-weight; UHMW-PE; viscosity
5.3 Unless controlled by requirements specified elsewhere
ANNEX
(Mandatory Information)
A1. DILUTE SOLUTION VISCOSITY
A1.1 General Description A1.3 Reagents
A1.1.1 The test sequence consists of dissolving UHMW-PE A1.3.1 Decahydronaphthalene, freshly distilled.
in decahydronaphthalene (0.02 g/100 mL) at 150°C and then A1.3.2 Tetrakis [methylene 3-(38,58-di-tert-butyl-48-
measuring the relative viscosity at 135°C in an Ubbelohde No. hydroxyphenyl) propionate] methane.
1 viscometer. The relative solution viscosity may be calculated A1.3.3 Xylene, industrial-grade.
from these experimental data. A1.3.4 Sulfuric Acid-Potassium Dichromate Cleaning
Solution—To 35 mL of a saturated solution of potassium
A1.2 Apparatus
dichromate (K Cr O ), carefully add 1 L of concentrated
2 2 7
A1.2.1 Analytical Balance.
sulfuric acid (H SO ).
2 4
A1.2.2 Microscope Slide Cover Slip.
A1.3.5 Acetone, reagent grade.
A1.2.3 Hot Plate, with magnetic stirrer.
A1.2.4 Erlenmeyer Flask, 250-mL, with glass stopper. A1.4 Procedure
A1.2.5 Vacuum Drying Oven.
A1.4.1 Decahydronaphthalene Preparation—Distill in ac-
A1.2.6 Vacuum Aspirator.
cordance with Test Method D 1061 and add 0.2 % tetrakis
A1.2.7 Viscometer, Ubbelohde No. 1.
[methylene 3-(38,58-di-tert-butyl-48-hydroxyphenyl) propi-
A1.2.8 Constant-Temperature Bath, 135 6 0.1°C, with a
onate] methane.
305-mm diameter by 460 mm (12 by 18-in.) tall glass jar as a
A1.4.2 Cleaning the Viscometer—Clean the viscometer
container, and having a suitable support for the viscometer.
thoroughly with the cleaning solution, wash several times with
A1.2.9 Buret, 100-mL capacity, 0.1-mL subdivisions.
distilled water, rinse with acetone, and purge with dry nitrogen.
A1.2.10 Stopwatch, 0.2-s reading.
A1.2.11 Still, for decahydronaphthalene.
A1.2.12 Glass Funnel, with heating mantle. The anitioxidant (Irganoxt 1010) is available from Ciba-Geigy, Ardsley, NY.
D 4020
A1.4.3 Solution Preparation—Dry the UHMW-PE in a sufficient solution to fill the viscometer to the mark (see Note
vacuum oven for2hat 60°C. Weigh 14 to 17 mg of the dry A1.1) and determine the viscosity of the solution.
UHMW-PE onto a slide cover slip. Use the buret to transfer the A1.4.4.3 Between uses, clean the viscometer as described in
decahydronaphthalene at room temperature into the Erlenm- A1.4.2. Prolonged waits between uses (overnight, etc.) will
eyer flask, measuring, in millilitres, a volume equal to 4.5 times require the use of the H SO –K Cr O cleaning solution.
2 4 2 2 7
the UHMW-PE weight in milligrams, for example, 15 mg of
NOTE A1.1—Filling of the viscometer is made easier by the use of a
UHMW-PE and 67.5 mL of decahydronaphthalene. Heat the
glass funnel warmed with a heating mantle. This helps to prevent the
decahydronaphthalene, with stirring, to 150°C, and drop in the
UHMW-PE from precipitating.
UHMW-PE and its slide cover slip. Continue stirring at 150°C
A1.5 Calculation
for 1 h, with the flask lightly stoppered.
A1.4.4 Viscosity Measurement: A1.5.1 Calculate the relative solution viscosity as follows:
A1.4.4.1 Place the clean viscometer into the constant-
k
t –
temperature bath, fill with decahydronaphthalene, and allow s
t
s
h 5 (A1.1)
the viscometer and solvent to come to thermal equilibrium at r
k
t –
o
135 6 0.1°C. Determine the viscosity of the solvent. Remove
t
o
the decahydronaphthalene with vacuum and wash the viscom-
where:
eter with 200 mL of warm (110 to 120°C) xylene. Remove with
k = kinectic energy correction constant for the particular
vacuum and aspirate dry air or nitrogen to dry the viscometer
viscometer used,
(2 or 3 min). It is essential that the whole viscometer be dry.
t = flow time of solution at 135°C, and
s
A1.4.4.2 Meanwhile, place the flask of polymer solution
t = flow time of pure solvent at 135°C.
o
into the 135°C bath and allow it to equilibrate. Transfer
APPENDIXES
(Nonmandatory Information)
X1. IMPACT TEST METHOD FOR ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE
X1.1 Scope X1.2.2 ISO Standards:
ISO 180-1982 (E) Determination of Izod Impact Strength of
X1.1.1 This test method covers determination of the impact
Rigid Materials
strength of UHMW-PE, which is extremely impact resistant.
ISO/CD 11542-2 Plastics—Ultra-High Molecular Weight
When tested in accordance with Test Method D 256, Method
Polyethylene (PE-UHMW) Moulding and Extrusion
A, UHMW-PE generally gives the NBF type of failure,
Materials—Part 2: Preparation of Test Specimens and
rendering the test result invalid. This test method specifies the
Determination of Properties
same type of pendulum impact test machine as that given in
Test Method D 256 but introduces a much higher degree of
X1.3 Apparatus
stress concentration into the specimen by double notching with
X1.3.1 The Izod-type impact machine that conforms to the
a razor blade. Application of this test method shall be limited
requirements of Test Method D 256, including the calibration
to the characterization of virgin, unmodified UHMW-PE res-
and checking methods, shall be used.
ins, not commercially processed products. It is advised that the
user be familiar with Test Method D 256 before attempting to
X1.4 Test Specimen
use this test method.
X1.4.1 The geometry and dimensions of the specimen are
X1.1.2 The values stated in SI units are to be regarded as the
given in Fig. X1.1.
standard.
X1.4.2 The specimens shall be cut from a sheet compression
X1.1.3 This standard does not purport to address all of the
molded under the following conditions:
safety concerns, if any, associated with its use. It is the
Molding pressure 6.9 to 10.3 MPa
responsibility of the user of this standard to establish appro-
Platen temperature 196 to 210°C
priate safety and health practices and determine the applica-
Heating time 20 min at 196 to 210°C
bility of regulatory limitations prior to use.
Platen cooling rate 15 6 2°C/min from 150 to 90°C
Platen temperature for demolding <30°C
NOTE X1.1—There is currently no ISO standard that duplicates this test
X1.4.3 The width of the specimen shall be the thickness of
method. The impact strength of UHMW-PE is measured by a double-
the sheet if the sheet thickness is within 6.00 to 6.75 mm. Sheet
notched Charpy impact test in the pending ISO/CD 11542-2.
material thicker than 6.75 mm shall be machined down to 6.35
X1.2 Referenced Documents
6 0.25 mm. Sheet material thicker than 7.65 mm shall not be
X1.2.1 ASTM Standards: used.
D 256 Test Method for Determining the Pendulum Impact X1.4.4 Each specimen shall be free of twist and shall be
Resistance of Notched Specimens of Plastics bounded by mutually perpendicular pairs of plane parallel
D 4020
X1.7.4.1 With the excess energy indicating pointer in its
normal starting position, but without a specimen in the vise,
release the pendulum from its normal starting position and note
the position that the pointer attains after the swing as one
reading of Factor A.
X1.7.4.2 Without resetting the pointer, raise the pendulum
and release again. The pointer should move up the scale an
additional amount. Repeat this procedure until a swing causes
no additional movement of the pointer, and note the final
A = 6.7/6.0 Q 90 6 2°
reading as one reading of Factor B.
B = 12.8/12.6
X1.7.4.3 Repeat the above two operations several times,
C = 32.0/31.5
and calculate and record the average A and B readings.
D = 64.0/63.0
E = 4.60/4.50
X1.7.5 Position the specimen precisely and rigidly but not
F= 60.10
clamped too tightly in the vise. The relationship of the vise,
FIG. X1.1 Dimensions of Double-Notched Izod Test Specimens
specimen, and striking edge of the pendulum to one another is
given in Fig. X1.2. Note that the top plane of the vise shall be
surfaces, free from scratches, pits, and sink marks.
0.13 6 0.13 mm below the notches.
X1.7.6 Release the pendulum and note and record the
X1.5 Notching of Specimens
excess energy remaining in the pendulum after breaking the
X1.5.1 Notching shall be performed on the side parallel to
specimen.
the direction of the a
...