ASTM D5628-96
(Test Method)Standard Test Method for Impact Resistance of Flat, Rigid Plastic Specimens by Means of a Falling Dart (Tup or Falling Mass)
Standard Test Method for Impact Resistance of Flat, Rigid Plastic Specimens by Means of a Falling Dart (Tup or Falling Mass)
SCOPE
1.1 This test method covers the determination of the relative ranking of materials according to the energy required to crack or break flat, rigid plastic specimens under various specified conditions of impact of a free-falling dart (tup).
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 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. Specific hazard statements are given in Section 8.
Note 1—This test method and ISO 6603-1-1985 are technically equivalent only when the test conditions and specimen geometry required for Geometry FE and the Bruceton Staircase method of calculation are used.
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Designation: D 5628 – 96 An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Impact Resistance of Flat, Rigid Plastic Specimens by
Means of a Falling Dart (Tup or Falling Mass)
This standard is issued under the fixed designation D 5628; 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.
1. Scope D 3763 Test Method for High-Speed Puncture Properties of
Plastics Using Load and Displacement Sensors
1.1 This test method covers the determination of the relative
D 4066 Specification for Nylon Injection and Extrusion
ranking of materials according to the energy required to crack
Materials
or break flat, rigid plastic specimens under various specified
E 171 Specification for Standard Atmospheres for Condi-
conditions of impact of a free-falling dart (tup).
tioning and Testing Materials
1.2 The values stated in SI units are to be regarded as the
E 177 Practice for Use of the Terms Precision and Bias in
standard. The values in parentheses are for information only.
ASTM Test Methods
1.3 This standard does not purport to address all of the
E 691 Practice for Conducting an Interlaboratory Study to
safety concerns, if any, associated with its use. It is the
Determine the Precision of a Test Method
responsibility of the user of this standard to establish appro-
2.2 ISO Standards:
priate safety and health practices and determine the applica-
ISO 291 Standard Atmospheres for Conditioning and Test-
bility of regulatory limitations prior to use. Specific hazard
ing
statements are given in Section 8.
ISO 6603-1 Plastics-Determination of Multiaxial Impact
NOTE 1—This test method and ISO 6603-1-1985 are technically 9
Behavior of Rigid Plastics—Part 1: Falling Dart Method
equivalent only when the test conditions and specimen geometry required
for Geometry FE and the Bruceton Staircase method of calculation are
3. Terminology
used.
3.1 Definitions:
2. Referenced Documents 3.1.1 For definitions of plastic terms used in this test
method, see Terminologies D 883 and D 1600.
2.1 ASTM Standards:
3.2 Definitions of Terms Specific to This Standard:
D 374 Test Methods for Thickness of Solid Electrical Insu-
3.2.1 failure (of test specimen)—the presence of any crack
lation
or split, created by the impact of the falling tup, that can be
D 618 Practice for Conditioning Plastics and Electrical
seen by the naked eye under normal laboratory lighting
Insulating Materials for Testing
conditions.
D 638 Test Method for Tensile Properties of Plastics
3.2.2 mean-failure energy (mean-impact resistance)—the
D 883 Terminology Relating to Plastics
energy required to produce 50 % failures, equal to the product
D 1600 Terminology for Abbreviated Terms Relating to
of the drop height and the mean-failure mass or the product of
Plastics
the constant mass and mean-failure height.
D 1709 Test Method for Impact Resistance of Plastic Film
2 3.2.3 mean-failure height (impact-failure height)—the
by the Free Falling Dart Method
height at which a standard mass when dropped on test
D 1898 Practice for Sampling of Plastics
specimens, will cause 50 % failures.
D 2188 Practice for Statistical Design in Interlaboratory
Testing of Plastics
NOTE 2—Cracks usually start at the surface opposite the one that is
D 2444 Test Method for Impact Resistance of Thermo-
struck. Occasionally incipient cracking in glass-reinforced products, for
example, may be difficult to differentiate from the reinforcing fibers. In
plastic Pipe and Fittings by Means of a Tup (Falling
such cases, a penetrating dye may be used to confirm the onset of crack
Weight)
formation.
3.2.4 mean-failure mass (impact-failure mass)—the mass of
This test method is under the jurisdiction of ASTM Committee D-20 on Plastics
the dart (tup) that, when dropped on the test specimens from a
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.
Current edition approved March 10, 1996. Published July 1996. Originally
published as D 5628 – 94. Last previous edition D 5628 – 95. Annual Book of ASTM Standards, Vol 08.02.
2 7
Annual Book of ASTM Standards, Vol 08.01. Annual Book of ASTM Standards, Vol 08.03.
3 8
Annual Book of ASTM Standards, Vol 10.01. Annual Book of ASTM Standards, Vol 14.02.
4 9
Discontinued; see 1982 Annual Book of ASTM Standards, Vol 08.02. Available from American National Standards Institute, 11 W. 42nd St., 13th
Annual Book of ASTM Standards, Vol 08.04. Floor, New York, NY 10036.
D 5628
standard height, will cause 50 % of them to fail. been used in specifications for extruded sheeting. A limitation
3.2.5 tup—a dart with a hemispherical nose. See 7.2 and of this geometry is that considerable material is required.
Fig. 1. 5.5 The test conditions of Geometry FD are the same as for
Test Method D 3763.
4. Summary of Test Method
5.6 The test conditions of Geometry FE are the same as for
4.1 A free-falling dart (tup) is allowed to strike a supported ISO 6603-1.
5.7 Because of the nature of impact testing, the selection of
specimen directly. Either a dart having a fixed mass may be
dropped from various heights, or a dart having an adjustable a test method and tup must be somewhat arbitrary. While any
one of the tup geometries may be selected, knowledge of the
mass may be dropped from a fixed height. (See Fig. 2).
4.2 The procedure determines the energy (mass 3 height) final or intended end-use application should be considered.
5.8 Clamping of the test specimen will improve the preci-
that will cause 50 % of the specimens tested to fail (mean
failure energy). sion of the data. Therefore, clamping is recommended. How-
ever, with rigid specimens, valid determinations can be made
4.3 The technique used to determine mean failure energy is
commonly called the Bruceton Staircase Method or the Up- without clamping. Unclamped specimens tend to exhibit some-
what greater impact resistance.
and-Down Method (1). Testing is concentrated near the
mean, reducing the number of specimens required to obtain a
6. Interferences
reasonably precise estimate of the impact resistance.
6.1 Falling-mass-impact-test results are dependent on the
4.4 Each test method permits the use of different tup and test
geometry of both the falling mass and the support. Thus,
specimen geometries to obtain different modes of failure,
impact tests should be used only to obtain relative rankings of
permit easier sampling, or test limited amounts of material.
materials. Impact values cannot be considered absolute unless
There is no known means for correlating the results of tests
the geometry of the test equipment and specimen conform to
made by different methods or procedures.
the end-use requirement. Data obtained by different procedures
5. Significance and Use
within this test method, or with different geometries, cannot, in
general, be compared directly with each other. However, the
5.1 Plastics are viscoelastic and therefore may be sensitive
relative ranking of materials may be expected to be the same
to changes in velocity of the mass falling on their surfaces.
between two test methods if the mode of failure and the impact
However, the velocity of a free-falling object is a function of
velocities are the same.
the square root of the drop height. A change of a factor of two
6.1.1 Falling-mass-impact types of tests are not suitable for
in the drop height will cause a change of only 1.4 in velocity.
predicting the relative ranking of materials at impact velocities
Hagan et al (2) found that the mean-failure energy of sheeting
differing greatly from those imposed by these test methods.
was constant at drop heights between 0.30 and 1.4 m. This
6.2 As cracks usually start at the surface opposite the one
suggests that a constant mass-variable height method will give
that is struck, the results can be greatly influenced by the
the same results as the constant height-variable mass tech-
quality of the surface of test specimens. Therefore, the com-
nique. On the other hand, different materials respond differ-
position of this surface layer, its smoothness or texture, levels
ently to changes in the velocity of impact. Equivalence of these
of and type of texture, and the degree of orientation introduced
methods should not be taken for granted. While both constant-
during the formation of the specimen (such as may occur
mass and constant-height techniques are permitted by these
during injection molding) are very important variables. Flaws
methods, the constant-height method should be used for those
in this surface will also affect results.
materials that are found to be rate-sensitive in the range of
6.3 Impact properties of plastic materials can be very
velocities encountered in falling-weight types of impact tests.
sensitive to temperature. This test can be carried out at any
5.2 The test geometry FA causes a moderate level of stress
reasonable temperature and humidity, thus representing actual
concentration and can be used for most plastics.
use environments. However, this test method is intended
5.3 Geometry FB causes a greater stress concentration and
primarily for rating materials under specific impact conditions.
results in failure of tough or thick specimens that do not fail
with Geometry FA (3). This approach may produce a punch
7. Apparatus
shear failure on thick sheet. If that type of failure is undesir-
7.1 Testing Machine—The apparatus shall be constructed
able, Geometry FC may be used. Geometry FB is suitable for
essentially as is shown in Fig. 2. The apparatus is similar in
research and development because of the smaller test area
design to that used in Test Method D 1709 and Test Method
required.
D 2444. The geometry of the specimen clamp and tup shall
5.3.1 The conical configuration of the 12.7-mm diameter
conform to the dimensions given in 7.1.1 and 7.2.
tup used in Geometry FB minimizes problems with tup
7.1.1 Specimen Clamp—For flat specimens, a two-piece
penetration and sticking in failed specimens of some ductile
annular specimen clamp similar to that shown in Fig. 3 is
materials.
recommended. For Geometries FA and FD, the inside diameter
5.4 The test conditions of Geometry FC are the same as
should be 76.06 3.0 mm (3.00 6 0.12 in.). For Geometry FB,
those of Test Method A of Test Method D 1709. They have
the inside diameter should be 38.1 6 0.80 mm (1.5 6 0.03 in.).
For Geometry FC, the inside diameter should be 127.0 6 2.5
mm (5.00 6 0.10 in.). For Geometry FE an annular specimen
The boldface numbers in parentheses refer to a list of references at the end of
the text. clamp similar to that shown in Fig. 4 is required. The inside
D 5628
Dimensions of Conical Dart—Fig. 1(b)
NOTE 1—Unless specified, the tolerance on all dimensions shall be 62%.
Position Dimension, mm Dimension, in.
A 27.2 1.07
B 15 0.59
C 12.2 0.48
D 6.4 0.25
E 25.4 1
F 12.7 0.5
R 6.356 0.05 0.2506 0.002
(nose radius)
r (radius) 0.8 0.03
A
S (diameter) 6.4 0.25
u 25 6 1° 25 6 1°
A
Larger diameter shafts may be used.
FIG. 1 Tup Geometries for Geometries FA (1a), FB (1b), FC (1c), FD (1d), and FE (1e)
D 5628
FIG. 2 One Type of Falling Mass Impact Tester
FIG. 3 Support Plate/Specimen/Clamp Configuration for Geometries FA, FB, FC, and FD
diameter should be 40 6 2 mm (1.57 6 0.08 in.) (see Table 1). 7.1.1.1 Contoured specimens shall be firmly held in a jig so
For Geometries FA, FB, FC, and FD, the inside edge of the
that the point of impact will be the same for each specimen.
upper or supporting surface of the lower clamp should be
7.1.2 Tup Support, capable of supporting a 13.5-kg (30-lb)
rounded slightly; a radius of 0.8 mm (0.03 in.) has been found
mass, with a release mechanism and a centering device to
to be satisfactory. For Geometry FE this radius should be 1 mm
ensure uniform, reproducible drops.
(0.04 in.).
D 5628
FIG. 4 Test-Specimen Support for Geometry FE
TABLE 1 Tup and Support Ring Dimensions
enough to accommodate the maximum mass (see Fig. 1(c) and
Dimensions, mm (in.) Table 1).
Geometry
7.2.4 The tup used in Geometry FD shall have a 12.706
Tup Diameter Inside Diameter Support Ring
0.25-mm (0.500 6 0.010-in.) diameter hemispherical head of
FA 15.86 6 0.10 76.0 6 3.0
(0.625 6 0.004) (3.00 6 0.12) tool steel hardened to 54 HRC or harder. A steel shaft about 8
FB 12.7 6 0.1 38.1 6 0.8
mm (0.31 in.) in diameter shall be attached to the center of the
(0.500 6 0.003) (1.5 6 0.03)
flat surface of the head with its longitudinal axis at 90° to the
FC 38.1 6 0.4 127.0 6 2.5
(1.5 6 0.010) (5.00 6 0.10) surface. The length of the shaft shall be great enough to
FD 12.70 6 0.25 76.0 6 3.0
accommodate the maximum mass required (see Fig. 1(d) and
(0.500 6 0.010) (3.00 6 0.12)
Table 1).
FE 20.0 6 0.2 40.0 6 2.0
(0.787 6 0.008) (1.57 6 0.08) 7.2.5 The tup used in Geometry FE shall have a 20.0 6
0.2-mm (0.787 6 0.008-in.) diameter hemispherical head of
NOTE 3—Reproducible drops may be ensured through the use of a tube tool steel hardened to 54 HRC or harder. A steel shaft about 13
or cage within which the tup falls. In this event, care should be exercised
mm (0.5 in.) in diameter shall be attached to the center of the
so that any friction that develops will not reduce the velocity of the tup
flat surface of the head with its longitudinal axis at 90° to the
appreciably.
surface. The length of the shaft shall be great enough to
7.1.3 Positioning Device—Means shall be provided for
accommodate the maximum mass required (see Fig. 1(e) and
positioning the tup so that the distance from the impinging Table 1).
surface of the tup head to the test specimen is as specified. 7.2.6 The tup head shall be free of nicks, scratches, or other
7.2 Tup: surface irregularities.
7.2.1 The tup used in Geometry FA shall have a 15.866 7.3 Masses—Cylindrical steel masses are required that have
0.10-mm (0.625 6 0.004-in.) diameter hemispherical head of a center hole into which the tup shaft will fit. A variety of
tool steel hardened to 54 HRC or harder. A steel shaft about 13 masses are needed if different materials or thicknesses are to be
mm (0.5 in.) in diameter shall be attached to the center of the tested. For a material of low impact resistance, the tup mass
flat surface of the head with its longitudinal axis at 90° to that may need to be adjusted by increments of 10
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