ASTM F736-95(2001)
(Test Method)Standard Test Method for Impact Resistance of Monolithic Polycarbonate Sheet by Means of a Falling Weight
Standard Test Method for Impact Resistance of Monolithic Polycarbonate Sheet by Means of a Falling Weight
SCOPE
1.1 This test method covers the determination of the energy required to initiate failure in monolithic polycarbonate sheet material under specified conditions of impact using a free falling weight.
1.2 Two specimen types are defined as follows:
1.2.1 Type A consists of a flat plate test specimen and employs a clamped ring support.
1.2.2 Type Bconsists of a simply supported three-point loaded beam specimen (Fig. 1) and is recommended for use with material which can not be failed using the Type A specimen. For a maximum drop height of 6.096 m (20 ft) and a maximum drop weight of 22.68 kg (50 lb), virgin polycarbonate greater than 12.70 mm (1/2 in.) thick will probably require use of the Type B specimen.
Note 1--See also ASTM Methods: D1709, D2444 and D3029.
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. For specific hazard statement, See Section 7.
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Designation:F736–95 (Reapproved 2001)
Standard Test Method for
Impact Resistance of Monolithic Polycarbonate Sheet by
Means of a Falling Weight
This standard is issued under the fixed designation F 736; 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 was created by the impact of the falling weight and that can be
seen by the naked eye.
1.1 This test method covers the determination of the energy
required to initiate failure in monolithic polycarbonate sheet
4. Summary of Test Method
material under specified conditions of impact using a free
4.1 The test procedure to cause failure covers a range of
falling weight.
impact energies and differs with respect to geometry and
1.2 Two specimen types are defined as follows:
support of test specimen Type A and test specimen Type B.
1.2.1 Type A consists of a flat plate test specimen and
Guidelines are established to control drop heights, impact
employs a clamped ring support.
velocity, drop weights, impactor heads, impactor release,
1.2.2 Type B consists of a simply supported three-point
impactorrebound,impactlocation,andspecimenconfiguration
loaded beam specimen (Fig. 1) and is recommended for use
which are applicable to a falling weight impact tester designed
with material which can not be failed using the Type A
to accommodate Type A or Type B test specimens, or both,
specimen. For a maximum drop height of 6.096 m (20 ft) and
fabricated from monolithic polycarbonate sheet material.
a maximum drop weight of 22.68 kg (50 lb), virgin polycar-
bonate greater than 12.70 mm ( ⁄2 in.) thick will probably
5. Significance and Use
require use of the Type B specimen.
5.1 This practice is applicable for qualitatively evaluating
NOTE 1—See also ASTM Methods: D 1709, D 2444 and D 3029.
coated and uncoated monolithic polycarbonate sheet material,
for monitoring process control, for screening studies, and as an
1.3 This standard does not purport to address all of the
aidinthepredictionofhardwareperformancewhenexposedto
safety concerns, if any, associated with its use. It is the
impact service conditions.
responsibility of the user of this standard to establish appro-
5.2 A limitation of Type A specimen testing is that a thick
priate safety and health practices and determine the applica-
sheet may not fail since the available impact energy is limited
bility of regulatory limitations prior to use. For specific hazard
by the maximum drop height and falling weight capacity of the
statement, See Section 7.
testapparatus.UseSpecimenTypeAformateriallessthan12.7
2. Referenced Documents
mm (0.50 in.) thick.
2.1 ASTM Standards: 5.3 Within the range of drop heights of this system, tests
employing different velocities are not expected to produce
D 618 Practice for Conditioning Plastics for Testing
D 790 TestMethodsforFlexuralPropertiesofUnreinforced different results. However, for a given series of tests, it is
recommended that the drop height be held approximately
and Reinforced Plastics and Electrical Insulating Materi-
als constant so that velocity of impact (strain rate) will not be a
variable.
3. Terminology
5.4 As the polycarbonate specimen undergoes large plastic
3.1 Definitions of Terms Specific to This Standard: deformation under impact, the down (opposite impact) side is
3.1.1 failure (of test specimen)—failure is signified by the under tensile loading and most influential in initiating failure.
presence of any crack or split in the impact-deformed area that Polycarbonate sheet coated on one side may yield significantly
different test results when tested with the coated side down
versus the coated side up.
5.5 Direct comparison of specimen Type A and specimen
This test method is under the jurisdiction of ASTM Committee F7 on
Aerospace and Aircraft and is the direct responsibility of Subcommittee F07.08 on
Type B test results should not be attempted. For test programs
Transport Enclosures and Materials.
that will require the comparison of interlaboratory test results
Current edition approved Aug. 15, 1995. Published October 1995. Originally
e1
the specimen type and the approximate drop height must be
published as F736 – 81. Last previous edition F736 – 81 (1987) .
Annual Book of ASTM Standards, Vol 08.01. specified.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F736
FIG. 1 Type B Specimen Geometry and Loading
5.6 Monolithic polycarbonate sheet is notch sensitive. Data
=2gh
obtained from other test methods, particularly notched Izod/
where:
Charpy test results, and extremely high- or low-strain rate test
g = acceleration of gravity, and
results, should not be compared directly to data obtained from
h = drop height.
this method. It is noted that Type A specimens, free of flaws,
6.1.5 Supports—Clamp and support rings as shown in Fig.
have not experienced the characteristic ductile-to-brittle tran-
5 and Table 1 will be used to accommodate Type A plate
sition between thin, less than 3.18 mm ( ⁄8 in.), and thick,
specimens. Adjustable D 790–Test Method 1 supports will be
greater than 7.94 mm ( ⁄16 in.), sheet as reflected by other test
used to accommodate the Type B simply supported beam
methods.
specimens of 6 + 1 span-to-depth ratio. Specimens shall be
supported so that the surface to be impacted is horizontal and
6. Apparatus
atanangleof90(61)°(p/2radians)withrespecttothefalling
6.1 Impact Tester—The apparatus shall be constructed es-
weight guides.
sentially as shown in Fig. 2. Although not specified, materials
called out have been found to be satisfactory.
TABLE 1 Plate Support Ring Geometry
6.1.1 Drop Height—A lifting carrier shall be provided to
raise or lower the falling weight impactor that will be adjust-
NOTE 1—Reference Fig. 5 for definition of “A” and “C.”
ablewithintherangeof0.305m(1ft)tomaximumdropheight
Ring Size “A”“C” Span
and measurable to the nearest 25.40 mm (1 in.).
mm (in.) mm (in.) mm (in.)
6.1.2 Drop Weight—The falling weights shall be detach-
1 88.9 (3.50) 127.0 (5.00) 101.6 (4.00)
able, interchangeable, and variable in small known increments
2 114.3 (4.50) 157.5 (6.20) 127.0 (5.00)
from a total of 0.45 kg (1 lb) to a maximum drop weight of 50 3 190.5 (7.50) 254.0 (10.00) 203.2 (8.00)
4 292.1 (11.50) 381.0 (15.00) 304.8 (12.00)
kg (110 lb).
6.1.3 Impactor—The loading nose to be used with Type A
specimens is shown in Fig. 3; withType B specimens as shown
in Fig. 4. The impactor surface shall be free of nicks or other 6.1.6 Release—An electromagnetic or mechanical releasing
surface irregularities. The impactor geometry for Type B mechanism, capable of supporting the maximum falling
specimens corresponds to Test Method D 790. weight, will be provided to assure uniform and reproducible
6.1.4 Impact Location—The center of mass of the falling drops.
weight shall be guided by a two cable system or other suitable 6.1.7 Rebound Catcher—Means must be provided to catch
means to repeatedly strike within 2.54 mm (0.10 in.) of the the weight if it rebounds to prevent restriking the specimen and
center of the specimen support fixture as measured in the plane causing further damage.
of the specimen, in orde
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