ASTM F1536-95(2005)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:F1536–95(Reapproved 2005)
Standard Test Method for
Determining Strength and Setting Time of Synthetic Water-
Activated Polyurethane Fiberglass Orthopaedic Casting
Tape
This standard is issued under the fixed designation F1536; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1 diametral compression strength—the load per unit
width in lbs/in. (Newtons/mm), calculated by dividing either
1.1 This test method covers the functional diametral com-
the peak failure load or the maximum deflection load by the
pression strength of cylindrical test specimens formed from
nominal sample length (that is, manufacturer’s stated tape
synthetic fiberglass polyurethane casting materials. The test
width).
specimens employed in this test method are similar in geom-
3.1.2 maximum deflection load—the test cylinder is com-
etry and construction to casts used in orthopaedic applications.
pressed 0.4 in. (10 mm) from the initial load position without
This test method is not intended to determine the strength of
noticeable failure or a measurable decrease in load.The load at
the base materials used for fabrication of the test specimen.
0.4 in. (10 mm) deflection shall be called the maximum
1.2 The values stated in inch-pound units are to be regarded
deflection load.
as standard. The values given in parentheses are mathematical
3.1.3 peak failure load—failure of the test cylinder with a
conversions to SI units that are provided for information only
concomitantdecreaseinloadpriorto0.4in.(10mm)diametral
and are not considered standard.
compression. The highest load attained prior to the decrease
1.3 This standard does not purport to address all of the
shall be called the peak failure load.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Summary of Test Method
priate safety and health practices and determine the applica-
4.1 Atestcylinderispreparedbyimmersingthecastingtape
bility of regulatory limitations prior to use. Specific warning
in 75 6 2°F (23.9 6 1.1°C) water, squeezing per the
statements are given in 6.7.
manufacturer’s instructions under the surface of the water, and
2. Referenced Documents thenwrappingaroundeithera2.0in.(50.8mm)or2.5in.(63.5
mm)outsidediametercylindricalmandrel.Thetapeiswrapped
2.1 ASTM Standards:
layer upon layer producing a five layer cylinder. The test
E4 Practices for Force Verification of Testing Machines
cylinder is removed from the mandrel after an initial setting
E691 Practice for Conducting an Interlaboratory Study to
period. After a specified time, the test specimen is positioned
Determine the Precision of a Test Method
on its side between two flat platens in the testing machine and
3. Terminology compressedtodetermineitsstrength.Ambienttemperatureand
humidity are specified because of their pronounced effect on
3.1 Definitions of Terms Specific to This Standard:
material properties during the curing period.
5. Significance and Use
This test method is under the jurisdiction ofASTM Committee F04 on Medical
and Surgical Materials and Devices and is the direct responsibility of Subcommittee
5.1 Diametralcompressionstrengthisanimportantmeasure
F04.15 on Material Test Methods.
of the mechanical properties of casting materials. This test
Current edition approved Apr. 1, 2005. Published April 2005. Originally
method simulates the loading pattern seen in lower extremity
approved in 1995. Last previous edition approved in 1999 as F1536 – 95 (1999).
DOI: 10.1520/F1536-95R05.
casting applications during ambulation. This test method can-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
not be used to determine cast life or measure bending or other
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
modes of cast failure.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.2 Thistestmethodmeasuresbutdoesnotprescribevalues.
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F1536–95 (2005)
6. Apparatus 6.3 Constant Tension Method—Each layer of tape shall be
wrapped on the mandrel at a constant tension of 0.25 lbs/in.
6.1 Testing Machines—Machinesusedforcompressiontest-
(4.5 g/mm) width of tape. Suggested methods for accomplish-
ing shall conform to the requirements of Practices E4. For
ing this include the use of a dead weight clamped to the free
universal machines with a common test space, calibration shall
end of the tape while the horizontally mounted mandrel is
be performed in compression.
manually rotated (see Fig. 1), or the use of an automated
6.1.1 The surfaces of the flat platens shall be perpendicular
to the loading axis and parallel at all times within 0.005 in./in. constant torque winding mechanism (see Fig. 2).
(1.3 mm/mm). Platen surfaces should be clean and free of
6.4 Water Container—A container capable of holding at
corrosion.
least 1 gal (3.78 L) of water and of sufficient depth to allow
6.1.2 The testing machine shall be capable of producing a
complete immersion of the casting tape.
constant compression rate between 1 to 10 in./min (25.4 to 254
6.5 Release Liner—Asheetformlinerofnominalthickness,
mm/min).
such as waxed paper, shall be used to cover the mandrel and
6.1.3 The testing machine shall be capable of measuring the
prevent adhesion of the resin to the mandrel. This liner must
compressive load within 60.5 lbs (2.2 N).
allow release of the cured specimen from the mandrel with
6.2 Test Specimen Preparation Mandrel—A solid, cylindri-
minimal force, and must be easily removable from the speci-
cal aluminum mandrel of sufficient length to accommodate
men inner diameter prior to compression testing.
three test specimens without end contact shall be mounted in a
horizontal position (see Fig. 1). Either of two mandrel diam- 6.6 Timer—A timing device accurate to 61s.
eters may be used: Type I—2.00 in. (50.8 mm) diameter, or
6.7 Gloves—Gloves capable of protecting the hands from
Type II—2.50 in. (63.5 mm) diameter.
contact with the resin, for example, latex surgical gloves.
6.2.1 Option—Three individual mandrels, either Type I or
(Warning—Contact with uncured or curing resins should be
Type II, each capable of holding one test specimen, may be
avoided.These resins may adhere to the skin and be difficult to
substituted for a single, solid mandrel.
FIG. 1 Manual Preparation Method
F1536–95 (2005)
FIG. 2 Automated Constant Torque Preparation Method
remove. In addition, most polyurethane resins contain isocy- 9.5 Remove roll from water and allow excess water to drain
anate to which some individuals are or may become sensitized. fornotmorethanfiveseconds.DONOTSQUEEZEtoremove
Gloves should be worn at all times when handling uncured or excess water.
curing casting tape.) 9.6 Wrap a five-ply cylinder on mandrel as rapidly as
6.8 Thermometer— A device capable of measuring tem- possible using constant tension (see Fig. 1 or Fig. 2). Each
peratures within 61°F (0.5°C) in the 70 to 80°F (21.1 to succeeding layer shall be aligned directly over the preceding
26.7°C) range. layer with complete overlap. Cut the tape at the end of the fifth
ply within 6 ⁄4 in. (6.4 mm) relative to the starting end of the
7. Reagents and Materials first ply.
9.7 Immediately wrap a second five-ply cylinder as rapidly
7.1 Atleastthreerollsofthecastingtapeshallbetested;one
as possible by repeating 9.6.
roll for each of the three specified time periods. Three test
9.8 Immediately wrap a third five-ply cylinder as rapidly as
cylinders shall be prepared from each roll without the use of
possible by repeating 9.6. Cut off excess tape.
manual molding techniques.
9.9 Molding—Primary test samples should be prepared
NOTE 1—If testing of cylinders with the use of manual molding is
without the use of manual molding. If testing of samples with
desired, a secondary group of samples should be prepared using the
the use of manual molding is desired, a secondary group of
desired molding technique.
samples should be prepared using the desired molding tech-
7.2 Water for initiation of the curing process shall be
nique. Record the molding time and degree of manipulation
maintained at 75 6 2°F (23.9 6 1.1°C).
used.
7.2.1 The water shall be changed after three rolls have been
9.10 Setting Time—This is determined by a manual inden-
prepared.
tation test, that is, the time elapsed from the initial immersion
until the test cylinder cannot be indented by moderate finger-
8. Sample Conditioning
nail pressure. Begin indentation testing for material setting
8.1 Store each package flat, with each roll on its side, at 70 after all three samples from a single roll are wrapped. Repeat
6 5°F (21.1 6 2.8°C) for at least 24 h before use. the test
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