ASTM D3104-99(2005)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D3104–99 (Reapproved 2005)
Standard Test Method for
Softening Point of Pitches (Mettler Softening Point Method)
This standard is issued under the fixed designation D3104; 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 less viscous. For this reason, the determination of the softening
pointmustbemadebyanarbitrary,butcloselydefined,method
1.1 This test method covers the determination of the soft-
if the test values are to be reproducible.
eningpointofpitcheshavingsofteningpointsintherangefrom
4.2 This test method is useful in determining the consis-
50 to 180°C by this test method, and gives results comparable
tency of pitches as one element in establishing the uniformity
to those obtained by Test Method D2319 above 176°F (80°C).
of shipments or sources of supply.
1.2 The values stated in SI units are to be regarded as the
standard.
5. Apparatus
1.3 This standard does not purport to address all of the
5.1 A Mettler dropping point cell shall be used to deter-
safety concerns, if any, associated with its use. It is the
mine pitch softening points by this test method. These com-
responsibility of the user of this standard to establish appro-
mercially available instruments consist of a control unit with a
priate safety and health practices and determine the applica-
digital temperature indicator, matched furnace, sample car-
bility of regulatory limitations prior to use.
tridges, and accessories. The control unit automatically regu-
2. Referenced Documents lates the heating rate of the furnace. The softening point is
indicated on the readout, and the heating program stopped,
2.1 ASTM Standards:
when the sample flow triggers a photocell detector. A general
A314 Specification for Stainless Steel Billets and Bars for
view of the contents of the Mettler is shown in Fig. 1.
Forging
5.1.1 Control Unit—This unit shall provide a continuous,
D2319 Test Method for Softening Point of Pitch (Cube-in-
linear temperature increase from 25 to 250°C at a rate of
Air Method)
2°C/min. A digital readout shall indicate the temperature to
D4296 Practice for Sampling Pitch
0.1°C throughout.
3. Summary of Test Method 5.1.2 Furnace Unit—This unit shall be capable of heating a
sample cup assembly, as described in 5.1.3, at a linear rate of
3.1 In this test method, the softening point is defined as the
2 6 0.3°C/min. It shall include a sensing system capable of
temperatureatwhichpitch,suspendedinacylindricalcupwith
detecting the softening point with a precision of 0.1°C.
a 6.35-mm hole in the bottom, flows downward a distance of
5.1.3 Sample Cup Assembly—A cup of chromium-plated
19 mm to interrupt a light beam, as the sample is heated at a
brass, or of stainless steel conforming to the requirements for
linear rate in air.
Type 303 (UNS S30300) as prescribed in Specification A314,
4. Significance and Use
with the dimensions shown in Fig. 2. It shall be placed in the
assembly so that the pitch sample will flow downward a
4.1 Pitch does not go through a solid-liquid phase change
distance of 19 mm before interrupting a light beam and
when heated, and therefore does not have a true melting point.
stopping the heating program as the softening point is reached.
Asthetemperatureisraisedpitchgraduallysoftensorbecomes
6. Reagents
6.1 Xylene, industrial grade.
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
6.2 Benzoic Acid.
D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.
Current edition approved March 1, 2005. Published March 2005. Originally
approved in 1972. Last previous edition approved in 1999 as D3104 – 99. DOI: The sole source of supply of the apparatus known to the committee at this time
10.1520/D3104-99R05. is available from the Mettler Toledo, Inc., Balances and Instruments, 69 Princeton-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Hightstown Rd., Hightstown, NJ 08520-0071. If you are aware of alternative
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D3104–99 (2005)
FIG. 1 General View of the Mettler FP-5/53
7. Calibration of the Mettler Apparatus down with a rod (approximately 4.5 mm in diameter). Check
thatthebottomorificeiscompletelyfilled.Refillandrepeatthe
7.1 This step, required only occasionally, is designed to
pressing step until the cup is filled with benzoic acid. Remove
establish that the temperature indicated by the instrument is in
any crystals from the exterior of the cup.
agreement with a known standard.Aspecial cup with a bottom
7.3.2 Heating— Preheat the Mettler furnace to 121°C, and
orifice of 2.8 mm is used instead of the one prescribed for the
testing of pitch. maintain it at that temperature. Place the cartridge assembly
containing the benzoic acid in position in the furnace, taking
7.2 Reagent—Use either analytical reagent or primary stan-
dard grade benzoic acid for the calibration. As this material is care that the slits for the light beam are properly positioned.
Wait for temperature equilibration, that is, the furnace and the
hygroscopic it must be stored in a tightly sealed container, and
replaced with fresh material from a newly opened supply if sampleareinequilibriumatthepresettemperature,butnotless
hydration or other contamination is suspected. than the 30 s after inserting the cartridge, start the automatic
7.3 Procedure: heating cycle at 0.2°C/min. The temperature will rise steadily
7.3.1 Filling the Sample Cup—Place the cup on a clean, flat at the correct rate until the drop point is reached, and then
surface.Add a small amount of benzoic acid crystals and press remain steady on the readout.
D3104–99 (2005)
molten pitch should not exceed the expected softening point by
more than 50°C. Any foam that forms must be skimmed off.
8.4.2 Prepare the sample by slightly overfilling the sample
cup, which rests on a brass plate. Keep the lip of the container
close to the top of the cup to minimize entrainment of air
bubbles. Underpouring past the blade of a spatula is helpful in
this respect. Cool the pitch in the cup until firm, under cold
water if necessary. Trim the sample flush with the top of the
cup by pressing with a heated knife or spatula while drawing it
toward you. Do not trim by cutting across the top with a
forward or sideward motion as this tends to lift the sample out
of the mold, thus creating an internal void which is not easily
detected, and which significantly alters the result.
8.4.3 An alternative method which avoids possible loss of
volatiles in remelting, is to press the cold, solid sample into the
sample cup. Select clean, dry, dust-free lumps from the
representative portion of the sample and crush to a size of less
than 2 mm. Place a sample cup in the mold (see Figs. 3-5).
Place the
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