ASTM F1536-95(2010)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: F1536 − 95(Reapproved 2010)
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 the peak failure load or the maximum deflection load by the
nominal sample length (that is, manufacturer’s stated tape
1.1 This test method covers the functional diametral com-
width).
pression strength of cylindrical test specimens formed from
3.1.2 maximum deflection load—the test cylinder is com-
synthetic fiberglass polyurethane casting materials. The test
pressed 0.4 in. (10 mm) from the initial load position without
specimens employed in this test method are similar in geom-
noticeable failure or a measurable decrease in load.The load at
etry and construction to casts used in orthopaedic applications.
0.4 in. (10 mm) deflection shall be called the maximum
This test method is not intended to determine the strength of
deflection load.
the base materials used for fabrication of the test specimen.
3.1.3 peak failure load—failure of the test cylinder with a
1.2 The values stated in inch-pound units are to be regarded
concomitantdecreaseinloadpriorto0.4in.(10mm)diametral
as standard. The values given in parentheses are mathematical
compression. The highest load attained prior to the decrease
conversions to SI units that are provided for information only
shall be called the peak failure load.
and are not considered standard.
4. Summary of Test Method
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.1 Atestcylinderispreparedbyimmersingthecastingtape
responsibility of the user of this standard to establish appro-
in 75 6 2°F (23.9 6 1.1°C) water, squeezing per the
priate safety and health practices and determine the applica-
manufacturer’s instructions under the surface of the water, and
bility of regulatory limitations prior to use. Specific warning
thenwrappingaroundeithera2.0in.(50.8mm)or2.5in.(63.5
statements are given in 6.7.
mm)outsidediametercylindricalmandrel.Thetapeiswrapped
layer upon layer producing a five layer cylinder. The test
2. Referenced Documents
cylinder is removed from the mandrel after an initial setting
period. After a specified time, the test specimen is positioned
2.1 ASTM Standards:
on its side between two flat platens in the testing machine and
E4 Practices for Force Verification of Testing Machines
compressedtodetermineitsstrength.Ambienttemperatureand
E691 Practice for Conducting an Interlaboratory Study to
humidity are specified because of their pronounced effect on
Determine the Precision of a Test Method
material properties during the curing period.
3. Terminology
5. Significance and Use
3.1 Definitions of Terms Specific to This Standard:
5.1 Diametralcompressionstrengthisanimportantmeasure
3.1.1 diametral compression strength—the load per unit
of the mechanical properties of casting materials. This test
width in lbs/in. (Newtons/mm), calculated by dividing either
method simulates the loading pattern seen in lower extremity
casting applications during ambulation. This test method can-
not be used to determine cast life or measure bending or other
1 modes of cast failure.
This test method is under the jurisdiction ofASTM Committee F04 on Medical
and Surgical Materials and Devices and is the direct responsibility of Subcommittee
5.2 Thistestmethodmeasuresbutdoesnotprescribevalues.
F04.15 on Material Test Methods.
Current edition approved March 1, 2010. Published April 2010. Originally
6. Apparatus
approved in 1995. Last previous edition approved in 2005 as F1536 – 95 (2005).
DOI: 10.1520/F1536-95R10.
6.1 Testing Machines—Machines used for compression test-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ing shall conform to the requirements of Practices E4. For
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
universal machines with a common test space, calibration shall
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. be performed in compression.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1536 − 95 (2010)
6.1.1 The surfaces of the flat platens shall be perpendicular end of the tape while the horizontally mounted mandrel is
to the loading axis and parallel at all times within 0.005 in./in. manually rotated (see Fig. 1), or the use of an automated
(1.3 mm/mm). Platen surfaces should be clean and free of constant torque winding mechanism (see Fig. 2).
corrosion.
6.4 Water Container—A container capable of holding at
6.1.2 The testing machine shall be capable of producing a
least 1 gal (3.78 L) of water and of sufficient depth to allow
constant compression rate between 1 to 10 in./min (25.4 to 254
complete immersion of the casting tape.
mm/min).
6.5 Release Liner—Asheet form liner of nominal thickness,
6.1.3 The testing machine shall be capable of measuring the
such as waxed paper, shall be used to cover the mandrel and
compressive load within 60.5 lbs (2.2 N).
prevent adhesion of the resin to the mandrel. This liner must
6.2 Test Specimen Preparation Mandrel—A solid, cylindri-
allow release of the cured specimen from the mandrel with
cal aluminum mandrel of sufficient length to accommodate
minimal force, and must be easily removable from the speci-
three test specimens without end contact shall be mounted in a
men inner diameter prior to compression testing.
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
Type II—2.50 in. (63.5 mm) diameter.
6.7 Gloves—Gloves capable of protecting the hands from
6.2.1 Option—Three individual mandrels, either Type I or
contact with the resin, for example, latex surgical gloves.
Type II, each capable of holding one test specimen, may be
(Warning—Contact with uncured or curing resins should be
substituted for a single, solid mandrel.
avoided.These resins may adhere to the skin and be difficult to
6.3 Constant Tension Method—Each layer of tape shall be remove. In addition, most polyurethane resins contain isocya-
wrapped on the mandrel at a constant tension of 0.25 lbs/in. nate to which some individuals are or may become sensitized.
(4.5 g/mm) width of tape. Suggested methods for accomplish- Gloves should be worn at all times when handling uncured or
ing this include the use of a dead weight clamped to the free curing casting tape.)
FIG. 1 Manual Preparation Method
F1536 − 95 (2010)
FIG. 2 Automated Constant Torque Preparation Method
6.8 Thermometer—Adevicecapableofmeasuringtempera- 9.6 Wrap a five-ply cylinder on mandrel as rapidly as
tures within 61°F (0.5°C) in the 70 to 80°F (21.1 to 26.7°C) possible using constant tension (see Fig. 1 or Fig. 2). Each
range. succeeding layer shall be aligned directly over the preceding
layer with complete overlap. Cut the tape at the end of the fifth
7. Reagents and Materials 1
ply within 6 ⁄4 in. (6.4 mm) relative to the starting end of the
first ply.
7.1 Atleastthreerollsofthecastingtapeshallbetested;one
roll for each of the three specified time periods. Three test
9.7 Immediately wrap a second five-ply cylinder as rapidly
cylinders shall be prepared from each roll without the use of
as possible by repeating 9.6.
manual molding techniques.
9.8 Immediately wrap a third five-ply cylinder as rapidly as
NOTE 1—If testing of cylinders with the use of manual molding is
possible by repeating 9.6. Cut off excess tape.
desired, a secondary group of samples should be prepared using the
9.9 Molding—Primary test samples should be prepared
desired molding technique.
without the use of manual molding. If testing of samples with
7.2 Water for initiation of the curing process shall be
the use of manual molding is desired, a secondary group of
maintained at 75 6 2°F (23.9 6 1.1°C).
samples should be prepared using the desired molding tech-
7.2.1 The water shall be changed after three rolls have been
nique. Record the molding time and degree of manipulation
prepared.
used.
8. Sample Conditioning
9.10 Setting Time—This is determined by a manual inden-
tation test, that is, the time elapsed from the initial immersion
8.1 Store each package flat, with each roll on its side, at 70
until the test cylinder cannot be indented by moderate finger-
6 5°F (21.1 6 2.8°C) for at least 24 h before use.
nail pressure. Begin indentation testing for material setting
8.2 Open each package immediately prior to use.
after all three samples from a single roll are wrapped. Repeat
the test every 15 s until all samples are set. Record the three
9. Specimen Preparation
times and report the average as the setting time.
9.1 Beforeopeningeachpackage,reco
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