ASTM F521-83(1997)e1
(Test Method)Standard Test Methods for Bond Integrity of Transparent Laminates
Standard Test Methods for Bond Integrity of Transparent Laminates
SCOPE
1.1 These test methods cover determination of the bond integrity of transparent laminates. The laminates are usually made of two or more glass or hard plastic sheets held together by an elastomeric material. These test methods are intended to provide a means of determining the strength of the bond between the glass or plastic and the elastomeric interlayer under various mechanical or thermal loading conditions.
1.2 The test methods appear as follows: Test Methods Sections Test Method A---Flatwise Bond Tensile Strength 5 to 11 Test Method B---Interlaminar Shear Strength 12 to 17 Test Method C---Creep Rupture 18 to 25 Test Method D---Thermal Exposure 26 to 30
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.
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Designation: F 521 – 83 (Reapproved 1997)
Standard Test Methods for
Bond Integrity of Transparent Laminates
This standard is issued under the fixed designation F 521; 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.
e NOTE—Editorial changes were made in 31.1 and Section 32 was added in April 1997.
1. Scope 3.2 Definitions of Terms Specific to This Standard:
3.2.1 number of plies—a three-ply laminate is one having
1.1 These test methods cover determination of the bond
two transparent glass or plastic plies and one interlayer ply. A
integrity of transparent laminates. The laminates are usually
five-ply laminate has three glass or plastic plies and two
made of two or more glass or hard plastic sheets held together
interlayer plies.
by an elastomeric material. These test methods are intended to
provide a means of determining the strength of the bond
4. Significance and Use
between the glass or plastic and the elastomeric interlayer
4.1 These test methods provide a means to measure quan-
under various mechanical or thermal loading conditions.
titatively the bond integrity between the outer layers of the
1.2 The test methods appear as follows:
transparency and the interlayer, or to measure the cohesive
Test Methods Sections
properties of the interlayer, under various loading conditions.
Test Method A—Flatwise Bond Tensile Strength 5-11
Test Method B—Interlaminar Shear Strength 12-17
4.2 These test methods provide empirical results useful for
Test Method C—Creep Rupture 18-25
control purposes, correlation with service results, and as
Test Method D—Thermal Exposure 26-30
quality control tests for acceptance of production parts.
1.3 This standard does not purport to address all of the
4.3 Test results obtained on small, laboratory-size samples
safety concerns, if any, associated with its use. It is the
shown herein should be considered indicative of full-size part
responsibility of the user of this standard to establish appro-
capability, but not necessarily usable for design purposes.
priate safety and health practices and determine the applica-
TEST METHOD A—FLATWISE BOND TENSILE
bility of regulatory limitations prior to use.
STRENGTH
2. Referenced Documents
5. Summary of Test Method
2.1 ASTM Standards:
D 952 Test Method for Bond or Cohesive Strength of Sheet 5.1 The bond is subjected to a mechanical load in a direction
perpendicular to the plane of the bond. The adhesive or
Plastics and Electrical Insulating Materials
2.2 ANSI Standard: cohesive strength between the interlayer and the outer layers
(flatwise tensile strength) is determined, and expressed in terms
B1.1 Standard for Unified Screw Threads
of pascals (or pounds-force per square inch).
3. Terminology
6. Apparatus
3.1 Definitions:
3.1.1 delamination—a visible separation between two lay- 6.1 Metal Blocks—A pair of 50-mm (2-in.) square metal
blocks of 24 ST aluminum alloy, each having a maximum
ers of bonded material.
3.1.2 face plies—transparent glass or plastic outer materials height of 50 mm (2 in.). Each block shall have in one end a
hole (see Fig. 1) tapped 22.2 mm ( ⁄8 in.) in accordance with
joined together with an interlayer.
3.1.3 interlayer—transparent material used as the bonding ANSI B1.1, to accommodate threaded 22.2-mm ( ⁄8-in.) studs
of convenient length (see Test Method D 952). Alternative
agent between two or more hard, transparent materials.
metal blocks may be made using an aluminum “T” section, cut
to 50 mm (2 in.) square. A hole shall be drilled in the upright
These test methods are under the jurisdiction of ASTM Committee F07 on
section of each “T” block (see Fig. 2) to accommodate a metal
Aerospace and Aircraft and are the direct responsibility of Subcommittee F07.08 for
pin or holding device compatible with the test machine used.
Transparent Enclosures and Materials.
Current edition approved Sept. 30, 1983. Published November 1983. Originally 6.2 Testing Machine—Any suitable machine of the
published as F 521 – 77. Last previous edition F 521 – 77.
constant-rate-of-crosshead movement type. The testing ma-
Annual Book of ASTM Standards, Vol 08.01.
chine shall be equipped with the necessary drive mechanism
Available from American National Standards Institute, 11 W. 42nd St., 13th
for imparting to the crosshead a uniform, controlled velocity
Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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F 521 – 83 (1997)
FIG. 1 Test Assembly for Flatwise Tensile Strength Test
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F 521 – 83 (1997)
FIG. 2 Optional Tensile Strength Test Specimen
with respect to the base. The testing machine shall also be 8. Preparation of Apparatus
equipped with a load-indicating mechanism capable of show-
8.1 Determine the cross-sectional area of the test specimen
ing the total load applied to the test specimen. This mechanism
in a plane parallel to the surface.
shall be essentially free from inertial-lag at the specified rate of
8.2 Gently abrade the bonding surfaces of the metal blocks
testing and shall indicate the load with an accuracy of 61.0 %
and the specimen (except glass—see Note 1) using 200–400
of the indicated value, or better.
grit paper or light sandblasting. Do not abrade the edges and
6.3 Adhesive—Any suitable adhesive.
corners of the specimen or the metal blocks. Do not round the
corners.
7. Test Specimen
NOTE 1—Do not abrade glass surfaces unless absolutely necessary to
7.1 The test specimen shall consist of a 50-mm (2-in.)
obtain adhesion to the thoroughly cleaned surface.
square sample of laminate prepared in such a manner as to
8.3 Clean all contact surfaces of the specimens and metal or
produce smooth edges to minimize the possibility of edge
“T” blocks with a soft cloth saturated with a suitable solvent or
chipping during testing. The thickness of the specimen shall be
clean dry air blast. Thereafter, do not touch the cleaned
the thickness of the laminate. The upper and lower surfaces
surfaces with the hands. Apply a thin coating of adhesive to
shall be parallel to each other and reasonably flat. Test five
both contact surfaces being careful to remove all air bubbles
specimens.
from the adhesive. Place the specimen between the coated
blocks, being certain the blocks are aligned, then clamp the
assembly until the adhesive is cured.
Hysol Adhesive 907, a two-part epoxy adhesive available from E. V. Roberts
Co., 9601 West Jefferson Blvd., Culver City, CA 90230, has been found satisfactory
9. Conditioning
for use in this test. The instructions in Section 8 for preparation of the test assembly
are based on the use of this material. Any adhesive that is found to perform
9.1 Condition the test specimen at 23 6 2°C (73.4 6 3.6°F)
satisfactorily under this test may be used provided that the procedure for the
and 50 6 5 % relative humidity for not less than 24 h prior to
preparation of the test assembly is suitably modified to follow the manufacturer’s
recommendation for the use of the adhesive. testing.
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F 521 – 83 (1997)
9.2 Conduct tests in the Standard Laboratory Atmosphere of Prepare the specimens in such a manner as to produce smooth
23 6 2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity edges to minimize premature edge chipping during testing.
unless otherwise specified.
14.3 Orient the samples to duplicate the actual loading
conditions in service whenever possible.
10. Procedure
14.4 Number of Test Specimens:
10.1 Unless otherwise specified, test five specimens. Insert 14.4.1 Test at least five specimens for each sample in the
the specimen assembly in the tension testing machine with case of isotropic materials.
self-aligning holders and load to failure at a rate of 1.25 mm 14.4.2 Test ten specimens, five normal to, and five parallel
(0.05 in.)/min. with the principal axis of anisotropy, for each sample of
10.2 If block adhesive failure occurs, discard the test and anisotropic material.
test another specimen.
14.4.3 Discard specimens that break at some obvious flaw
and retest, unless such flaws constitute a variable whose effect
NOTE 2—If aluminum blocks are to be reused, one method of removing
is desired for study.
the adhesive is to insert the blocks in an oven at 150°C (300°F) for 1.5 h.
When the blocks have cooled, the remaining portion of the test specimen
can be easily removed by a surface sanding wheel or sandblast. In order
15. Conditioning
to maintain a plane surface, it is recommended that the metal blocks be
15.1 Condition the specimens in accordance with Section 9.
finished on a flat emery surface.
11. Report 16. Procedure
11.1 The report shall include the following: 16.1 Measure and record the length and width of the bond
11.1.1 Complete identification of the material tested, includ- area with a suitable micrometer to the nearest 0.025 mm (0.001
ing type or grade of substrate and interlayer, thickness, in.).
manufacturing history, etc.,
16.2 Place the specimen in the test fixture, taking care to
11.1.2 The block adhesive used, align the loaded end of the specimen parallel to the loading bar.
11.1.3 The atmospheric conditions in the test room,
16.3 Set the speed of testing at 1.25 mm (0.05 in.)/min and
11.1.4 The total load, in newtons (or pounds-force), re- start the testing machine.
quired to break each specimen,
16.4 Record the maximum load carried by the specimen up
11.1.5 The unit stress, in pascals (or pounds-force per
to the point of rupture.
square inch), required for failure (calculate the unit stress by
16.5 Remove and examine the test specimen for evidence of
dividing the load by the area of the test specimen), and
premature failure due to edge chipping or slippage of the
11.1.6 Failure mode (such as within the interlayer, or at
specimen in the fixture. If premature failure has occurred,
which interface).
discard the sample and retest another sample.
16.6 Calculate the bond stress by dividing the maximum
TEST METHOD B—INTERLAMINAR SHEAR
load by the bond area. For three-ply tests, the bond area is the
STRENGTH
area of one of the bond-line surfaces; for five-ply tests, the area
is two times the area of one of the bond-line surfaces.
12. Summary of Test Met
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