ASTM D1004-94a(2003)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 1004 – 94a (Reapproved 2003)
Standard Test Method for
Initial Tear Resistance of Plastic Film and Sheeting
This standard is issued under the fixed designation D 1004; 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 E 691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This test method covers the determination of the tear
resistance of flexible plastic film and sheeting at very low rates
3. Significance and Use
of loading, 51 mm [2 in.]/min. This test method is designed to
3.1 Tear resistance of plastic film or sheeting is a complex
measure the force to initiate tearing. The specimen geometry of
function of its ultimate resistance to rupture. The specimen
this test method produces a stress concentration in a small area
geometry and speed of testing in this test method are controlled
of the specimen. The maximum stress, usually found near the
to produce tearing in a small area of stress concentration at
outset of tearing, is recorded as the tear resistance in newtons
rates far below those usually encountered in service.
(or pounds-force).
3.2 The data of this test method furnish comparative infor-
1.2 The values stated in SI units are to be regarded as the
mation for ranking the tearing resistance of plastic specimens
standard. The values given in parentheses are for information
of similar composition. Actual use performance in tearing of
only.
some plastics may not necessarily correlate with data from this
1.3 This standard does not purport to address all of the
test method.
safety concerns, if any, associated with its use. It is the
3.3 The resistance to tear of plastic film and sheeting, while
responsibility of the user of this standard to establish appro-
partly dependent upon thickness, has no simple correlation
priate safety and health practices and determine the applica-
with specimen thickness. Hence, tearing forces measured in
bility of regulatory limitations prior to use. Specific cautionary
newtons (or pounds-force) cannot be normalized over a wide
statements are given in Note 2.
range of specimen thickness without producing misleading
NOTE 1—There is no similar or equivalent ISO standard.
data as to the actual tearing resistance of the material. Data
from this test method are comparable only from specimens
2. Referenced Documents
which vary by no more than 610 % from the nominal or
2.1 ASTM Standards:
average thickness of all specimens tested. Therefore, the
D 374 Test Methods for Thickness of Solid Electrical Insu-
tearing resistance is expressed in maximum newtons (or
lation
pounds-force) of force to tear the specimen.
D 618 Practice for Conditioning Plastics for Testing
3.4 For many materials, there may be a specification that
D 882 Test Methods for Tensile Properties of Thin Plastic
requires the use of this test method, but with some procedural
Sheeting
modifications that take precedence when adhering to the
D 4000 Classification System for Specifying Plastic Mate-
specification. Therefore, it is advisable to refer to that material
rials
specification before using this test method. Table 1 of Classi-
E 4 Practices for Force Verification of Testing Machines
fication System D 4000 lists the ASTM materials standards that
currently exist.
4. Apparatus
This test method is under the jurisdiction of ASTM Committee D20 on Plastics
4.1 Testing Machines—A power-driven machine of either of
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.
Current edition approved January 10, 2003. Published March 2003. Originally
the two following types shall be used:
approved in 1949. Last previous edition approved in 1994 as D 1004 – 94a.
4.1.1 Static Weighing—Constant Rate of Grip Separation
An ISO equivalency statement has been added since the prior version of this test
Type—Negligible movement of the upper jaw.
method.
The following reference may be of interest in connection with this test method: 4.1.2 Pendulum Weighing—Constant Rate of Powered-Grip
Graves, F. L., “The Evaluation of Tear Resistance in Elastomers,” India Rubber
Motion Type—Constant rate of lower jaw movement, variable
World, Vol 111, No. 3, December 1944, pp. 305–308.
upper jaw movement (Note 2). The machine shall conform to
Annual Book of ASTM Standards, Vol 10.01.
Annual Book of ASTM Standards, Vol 08.01.
Annual Book of ASTM Standards, Vol 08.02.
6 7
Annual Book of ASTM Standards, Vol 03.01. Annual Book of ASTM Standards, Vol 14.02.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 1004 – 94a (2003)
requirements given in the appropriate Method A or B of Test shall be used to cut all specimens. The 90° angle should be
Methods D 882, except that cross-head rates of other than 51 honed sharp with no radius or have a minimum practical
mm [2 in.]/min are not required. Either maximum load radius. The cutting edge of the die shall have a 5° negative
indicating devices or recorders are permissible in the testing rake, and shall be kept sharp and free from nicks to avoid
machine. The accuracy of the testing machine shall be verified leaving ragged edges on the specimen. Cutting may be facili-
in accordance with Practices E 4 (Note 3). The applied load, as tated by wetting the surface of the sample and the cutting edges
indicated by a recorder, dial, or scale, shall be accurate to of the die with water. The sample shall rest on the smooth,
within 62 %. If an indicating device is used, the indicator shall slightly yielding surface that will not injure the die blade.
remain at the point of maximum load after rupture of the test Light-weight cardboard or a piece of leather belting is suitable.
specimen. Care should be taken that the cut edges of the specimen are
perpendicular to its other surfaces and that the edges have a
NOTE 2—If both jaws of the machine are power activated, the rate of
minimum of concavity.
jaw separation shall be nominally 51 mm [2 in.]/min.
4.5 Conditioning Apparatus—Apparatus for maintaining
NOTE 3—Experience has shown that many testing machines now in use
laboratory atmospheric conditions of 23 6 1°C [73.4 6 1.8°F]
are incapable of maintaining accuracy for as long as the periods between
inspection recommended in Practices E 4. Hence, it is recommended that
and 50 6 2 % relative humidity for conditioning prior to and
each machine be studied individually and verified as often as may be
during testing shall be used in accordance with Procedure A of
found necessary. It will frequently be necessary to perform this function
Practice D 618, unless otherwise specified.
daily.
4.2 Grips—A gripping system that minimizes both slippage
5. Test Specimens
and uneven stress distribution on the specimen shall be used.
5.1 The test specimens shall conform to the dimensions
NOTE 4—Grips lined with thin rubber. No. 80 emery cloth, or crocus
shown in Fig. 1 and shall not vary by more than 0.5 % from
cloth, have been successfully used. Grips may be of the self-tightening
these dimensions.
type. In cases where specimens frequently fail at the edge of the grips, the
5.2 Single specimens shall be used. Where orientation
radius of curvature of the edges of the grips may be increased slightly at
effects are significant and are to be evaluated, duplicate sets of
the point where they come in contact with the specimen.
specimens shall be prepared so that their direction of tear is
4.3 Thickness Measuring Devices—Suitable micrometers,
respectively parallel with and normal to the direction of
or thickness gages, reading to 0.0025 mm [0.0001 in.] or less,
maximum orientation. The direction of maximum orientation
shall be used for measuring the thickness of the specimens. The
may be established for transparent materials by examination of
pressure exerted by the gage on the specimen being measured
the film or sheeting between crossed Polaroids.
shall be between 0.159 and 0.186 MPa [23 and 27 psi] in
5.3 At least 10 specimens shall be tested for each sample, in
accordance with Method C of Test Methods D 374.
the case of isotropic materials.
4.4 Die —A die having the dimensions shown in Fig. 1
5.4 Twenty specimens, 10 parallel with and 10 normal to the
principal axis of anisotropic or maximum orientation, shall be
tested for each sample, in the case of anisotropic material.
5.5 Data from specimens which break at some obvious flaw
or which break in or at the edges of the grips shall be discarded
and retests made, unless such failures constitute a variable
whose effect is being studied.
5.6 Data from specimens which deviate markedly from the
mean value of all tests shall be rejected if the deviation of the
TABLE 1 Initial Tear Resistance (Graves Tear) Machine Direction
Tolerance 6 0.002°
Tolerance 6 0.5° Values Expressed in Units of Grams-Force
Material
Table of Metric Equivalents
A B C D
Average S S r R
r R
in. mm
LDPE—LD 104 314.6 31.98 55.79 89.53 156.2
4.0 101.60 LLDPE 384.9 7.80 41.73 21.84 116.8
0.750 19.05 Polystyrene 459.8 98.06 261.6 274.6 732.3
1.061 26.95
...