ASTM D7735-11
(Test Method)Standard Test Method for Type A Durometer Hardness Testing of Road Marking Thermoplastic at Elevated Temperatures
Standard Test Method for Type A Durometer Hardness Testing of Road Marking Thermoplastic at Elevated Temperatures
SIGNIFICANCE AND USE
This method is based on the penetration of a specific type of indentor when forced into the material under specified conditions. The indentation hardness is inversely related to the penetration and is dependent on the elastic modulus, viscoelastic behavior of the material, geometry of the indentor, the applied force and temperature at test. This test method is empirical and therefore primarily for control purposes. No simple relationship exists between indentation hardness determined by this test method and any fundamental property of the material tested.
SCOPE
1.1 This test method covers Type A Durometer hardness of road marking thermoplastic material at elevated temperatures.
1.2 This test method is similar to Test Method D2240 for hardness with special attention given to keeping the temperature of the test sample and instrument constant. Within the highway materials community, it is sometimes known as “indentation resistance.”
1.3 All materials, instruments or equipment used for the determination of temperature, hardness and time shall be traceable to National Institute of Standards and Technology or other internationally recognized organizations parallel in nature.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.5 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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Standards Content (Sample)
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Designation: D7735 − 11
StandardTest Method for
Type A Durometer Hardness Testing of Road Marking
Thermoplastic at Elevated Temperatures
This standard is issued under the fixed designation D7735; 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 E177 Practice for Use of the Terms Precision and Bias in
ASTM Test Methods
1.1 This test method covers Type A Durometer hardness of
E691 Practice for Conducting an Interlaboratory Study to
road marking thermoplastic material at elevated temperatures.
Determine the Precision of a Test Method
1.2 This test method is similar to Test Method D2240 for
hardness with special attention given to keeping the tempera-
3. Terminology
ture of the test sample and instrument constant. Within the
3.1 Definitions:
highway materials community, it is sometimes known as
3.1.1 The terms and definitions in Terminology D16 apply
“indentation resistance.”
to this method.
1.3 All materials, instruments or equipment used for the
3.1.2 hardness, adv—the value of resistance of a small
determination of temperature, hardness and time shall be
penetrating device. In the case of the Type A Durometer in
traceable to National Institute of Standards and Technology or
accordance with Test Method D2240, the presser foot/indentor
other internationally recognized organizations parallel in na-
(spherical to 0.79 6 0.03 mm or 0.03 6 0.001 in.) is connected
ture.
to a spring loaded to a total of 0.075 N/Durometer units at full
1.4 The values stated in SI units are to be regarded as
deflection. For reading of Type A hardness the instruments
standard. The values given in parentheses are for information
scale reads from 0 to 100. Minimal deflection is 0 (softest) and
only.
maximum is 100 (hardest).
1.5 This standard does not purport to address all of the
3.1.3 thermoplastic, n—traffic marking (same as 3.1.4).
safety concerns, if any, associated with its use. It is the
3.1.4 thermoplastic traffıc marking—a highly filled 100 %
responsibility of the user of this standard to establish appro-
total solids highway marking system that when heated to a
priate safety and health practices and determine the applica-
moltenstatecanbeextrudedorsprayedontoaroadsurfaceand
bility of regulatory limitations prior to use.
when cooled forms a solid durable delineator or road marking
thermoplastic usually melted to 220°C (425°F).
2. Referenced Documents
2.1 ASTM Standards:
4. Summary of Test Method
D16 TerminologyforPaint,RelatedCoatings,Materials,and
4.1 This method was developed to enable the testing of
Applications
hardness or indentation resistance of road marking thermoplas-
D2240 Test Method for Rubber Property—Durometer Hard-
tic material at ambient roadway/highway temperatures. Due to
ness
the speed at which basic road marking thermoplastic cools,
D7307 PracticeforSamplingofThermoplasticTrafficMark-
testing its hardness at elevated temperatures is difficult, even at
ing Materials
a relatively low 46°C (115°F). Existing non-standard methods
D7308 Practice for Sample Preparation of Thermoplastic
are not consistent because they allow the samples to change
Traffic Marking Materials
temperature during testing. By keeping both the test samples
and the hardness tester in a regulated environment before and
during testing, the results are much more repeatable within a
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
laboratory. The goal for this method is to allow results from
Subcommittee D01.44 on Traffic Coatings.
this test to be more reproducible from laboratory to laboratory.
Current edition approved Nov. 1, 2011. Published December 2011. DOI:
10.1520/7735-11.
4.2 The methodology involves measuring the hardness of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
roadmarking thermoplastic by keeping the test sample in the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
elevated temperature environment (a water bath) during the
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. testing process and using a Durometer that can be placed in the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7735 − 11
water bath and function. This method could be performed in a 9.4 Turn on oven set to 46 6 1.0°C (115 6 3.0°F) or as
glove box/oven if the door was not opened before or during the mutually agreed upon by the involved parties and place the
testing. Type A Durometer inside
NOTE 1—A bath or oven operated outside the recommended tempera-
5. Significance and Use
ture control may result in greater result variability.
5.1 This method is based on the penetration of a specific
9.4.1 Other temperatures can be used when agreed upon
type of indentor when forced into the material under specified
between the parties involved.
conditions. The indentation hardness is inversely related to the
9.5 Place cooled hardness sample in water bath and turn on
penetration and is dependent on the elastic modulus, viscoelas-
oscillator or stirrer.
tic behavior of the material, geometry of the indentor, the
applied force and temperature at test. This test method is
9.6 Samples should be allowed to equilibrate to the required
empirical and therefore primarily for control purposes. No
temperature for at least one hour before being tested. Samples
simple relationship exists between indentation hardness deter-
should be tested within three hours of being in the water.When
mined by this test method and any fundamental property of the
all samples and testing equipment have stabilized to the set
material tested.
temperature, testing can begin.
6. Apparatus 9.7 Before testing sample, remove lid from water bath and
turn off oscillator or stirrer. Quickly place hardness tester from
6.1 Safety Glasses.
oven in water bath making sure that the needle point and
6.2 Aluminum Pans(20mL)oradequatesizefortesterbase.
bottom of weight is below the waterline. This will ensure that
6.3 A Hardness Tester Type A Needle-type Durometer in tester is exactly the same temperature as sample. If the tester is
removed from the water during the testing process, its tem-
accordance with Test Method D2240.
perature will change and cause variations in results. Sample(s)
6.4 Constant 100 g Load Weight for Type A Durometer.
can be tested multiple times as long as sample and tester
6.5 Optional—Test Block Kit containing Type A Durometer
bottom are not removed from water during testing.
samples with values traceable to an accredited calibration
9.8 To test sample, set timer so that a fifteen second
laboratory.
countdown will begin. Place hardness tester over sample
6.6 Oven controllable to 46 6 1.0°C (115 6 3.0°F) (or
keeping both under water at all times.
within 2.5 % of set point).
9.9 Lower the hardness tester over the center of the test
6.7 Water Bathcontrollableto46 61.0°C(115 63.0°F)(or
sample. As soon as contact is made, start timer and release
within 2.5 %
...
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