ASTM F736-95

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.

General Information

• Status: Historical
• Publication Date: 31-Dec-2000
• Technical Committee: F07 - Aerospace and Aircraft
• Drafting Committee: F07.08 - Transparent Enclosures and Materials

Relations

• Replaced By: ASTM F736-95(2001) - Standard Test Method for Impact Resistance of Monolithic Polycarbonate Sheet by Means of a Falling Weight
• Effective Date: 01-Jan-2001
• Referred By: ASTM F790-23 - Standard Guide for Testing Materials for Aerospace Plastic Transparent Enclosures
• Effective Date: 01-Jan-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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.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: F 736 – 95
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 4. Summary of Test Method
1.1 This test method covers the determination of the energy 4.1 The test procedure to cause failure covers a range of
required to initiate failure in monolithic polycarbonate sheet impact energies and differs with respect to geometry and
material under specified conditions of impact using a free support of test specimen Type A and test specimen Type B.
falling weight. Guidelines are established to control drop heights, impact
1.2 Two specimen types are defined as follows: velocity, drop weights, impactor heads, impactor release,
1.2.1 Type A consists of a flat plate test specimen and impactor rebound, impact location, and specimen configuration
employs a clamped ring support. which are applicable to a falling weight impact tester designed
1.2.2 Type B consists of a simply supported three-point to accommodate Type A or Type B test specimens, or both,
loaded beam specimen (Fig. 1) and is recommended for use fabricated from monolithic polycarbonate sheet material.
with material which can not be failed using the Type A
5. Significance and Use
specimen. For a maximum drop height of 6.096 m (20 ft) and
5.1 This practice is applicable for qualitatively evaluating
a maximum drop weight of 22.68 kg (50 lb), virgin polycar-
bonate greater than 12.70 mm ( ⁄2 in.) thick will probably coated and uncoated monolithic polycarbonate sheet material,
for monitoring process control, for screening studies, and as an
require use of the Type B specimen.
aid in the prediction of hardware performance when exposed to
NOTE 1—See also ASTM Methods: D 1709, D 2444 and D 3029.
impact service conditions.
1.3 This standard does not purport to address all of the
5.2 A limitation of Type A specimen testing is that a thick
safety concerns, if any, associated with its use. It is the
sheet may not fail since the available impact energy is limited
responsibility of the user of this standard to establish appro-
by the maximum drop height and falling weight capacity of the
priate safety and health practices and determine the applica-
test apparatus. Use Specimen Type A for material less than 12.7
bility of regulatory limitations prior to use. For specific hazard
mm (0.50 in.) thick.
statement, See Section 7.
5.3 Within the range of drop heights of this system, tests
employing different velocities are not expected to produce
2. Referenced Documents
different results. However, for a given series of tests, it is
2.1 ASTM Standards:
recommended that the drop height be held approximately
D 618 Practice for Conditioning Plastics and Electrical
constant so that velocity of impact (strain rate) will not be a
Insulating Materials for Testing
variable.
D 790 Test Methods for Flexural Properties of Unreinforced
5.4 As the polycarbonate specimen undergoes large plastic
and Reinforced Plastics and Electrical Insulating Materi-
deformation under impact, the down (opposite impact) side is
als
under tensile loading and most influential in initiating failure.
Polycarbonate sheet coated on one side may yield significantly
3. Terminology
different test results when tested with the coated side down
3.1 Definitions of Terms Specific to This Standard:
versus the coated side up.
3.1.1 failure (of test specimen)—failure is signified by the
5.5 Direct comparison of specimen Type A and specimen
presence of any crack or split in the impact-deformed area that
Type B test results should not be attempted. For test programs
was created by the impact of the falling weight and that can be
that will require the comparison of interlaboratory test results
seen by the naked eye.
the specimen type and the approximate drop height must be
specified.
5.6 Monolithic polycarbonate sheet is notch sensitive. Data
This test method is under the jurisdiction of ASTM Committee F-7 on
obtained from other test methods, particularly notched Izod/
Aerospace and Aircraft and is the direct responsibility of Subcommittee F07.08 on
Transport Enclosures and Materials. Charpy test results, and extremely high- or low-strain rate test
Current edition approved Aug. 15, 1995. Published October 1995. Originally
results, should not be compared directly to data obtained from
e1
published as F736 – 81. Last previous edition F736 – 81 (1987) .
this method. It is noted that Type A specimens, free of flaws,
Annual Book of ASTM Standards, Vol 08.01.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
F 736
FIG. 1 Type B Specimen Geometry and Loading
have not experienced the characteristic ductile-to-brittle tran- specimens. Adjustable D 790–Test Method 1 supports will be
sition between thin, less than 3.18 mm ( ⁄8 in.), and thick, used to accommodate the Type B simply supported beam
greater than 7.94 mm ( ⁄16 in.), sheet as reflected by other test specimens of 6 + 1 span-to-depth ratio. Specimens shall be
methods. supported so that the surface to be impacted is horizontal and
at an angle of 90 (6 1)° (p/2 radians) with respect to the falling
6. Apparatus
weight guides.
6.1 Impact Tester—The apparatus shall be constructed es-
sentially as shown in Fig. 2. Although not specified, materials
TABLE 1 Plate Support Ring Geometry
called out have been found to be satisfactory.
6.1.1 Drop Height—A lifting carrier shall be provided to NOTE 1—Reference Fig. 5 for definition of “A” and “C.”
raise or lower the falling weight impactor that will be adjust-
Ring Size “A”“C” Span
able within the range of 0.305 m (1 ft) to maximum drop height
mm (in.) mm (in.) mm (in.)
and measurable to the nearest 25.40 mm (1 in.).
1 88.9 (3.50) 127.0 (5.00) 101.6 (4.00)
6.1.2 Drop Weight—The falling weights shall be detach-
2 114.3 (4.50) 157.5 (6.20) 127.0 (5.00)
3 190.5 (7.50) 254.0 (10.00) 203.2 (8.00)
able, interchangeable, and variable in small known increments
4 292.1 (11.50) 381.0 (15.00) 304.8 (12.00)
from a total of 0.45 kg (1 lb) to a maximum drop weight of 50
kg (110 lb).
6.1.3 Impactor—The loading nose to be used with Type A
6.1.6 Release—An electromagnetic or mechanical releasing
specimens is shown in Fig. 3; with Type B specimens as shown
mechanism, capable of supporting the maximum falling
in Fig. 4. The impactor surface shall be free of nicks or other
weight, will be provided to assure uniform and reproducible
surface irregularities. The impactor geometry for Type B
drops.
specimens corresponds to Test Method D 790.
6.1.7 Rebound Catcher—Means must be provided to catch
6.1.4 Impact Location—The center of mass of the falling
the weight if it rebounds to prevent restriking the specimen and
weight shall be guided by a two cable system or other suitable
causing further damage.
means to repeatedly strike within 2.54 mm (0.10 in.) of the
6.1.8 Energy Absorber—An energy absorbent material must
center of the specimen support fixture as measured in the plane
be provided beneath the specimen to prevent damage to the
of the specimen, in order to assure uniform, reproducible
fixture when the impactor penetrates the speci
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