ASTM E28-99(2009)
(Test Method)Standard Test Methods for Softening Point of Resins Derived from Naval Stores by Ring-and-Ball Apparatus
Standard Test Methods for Softening Point of Resins Derived from Naval Stores by Ring-and-Ball Apparatus
SIGNIFICANCE AND USE
In general, with materials of these types, softening does not take place at a definite temperature. As the temperature rises, these materials gradually change from brittle or exceedingly thick and slow-flowing materials to softer and less viscous liquids. For this reason, the determination of the softening point must be made by a fixed, arbitrary, and closely defined method if the results obtained are to be comparable.
In these test methods, the softening point is defined as the temperature at which a disk of the sample held within a horizontal ring is forced downward a distance of 25.4 mm (1 in.) under the weight of a steel ball as the sample is heated at 5°C/min in a water, glycerin, silicone oil, ethylene glycol/water or glycerin/water bath.
SCOPE
1.1 These test methods are intended for determining the softening point of resins (including rosin and terpene resins) and similar materials by means of the ring-and-ball apparatus.
Note 1—For testing asphalts, tars, and pitches, see Test Method D 36.
1.1.1 Test method using the manual ring and ball softening point apparatus, and
1.1.2 Test method using an automated ring and ball softening point apparatus.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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.
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Standards Content (Sample)
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Designation: E28 − 99 (Reapproved2009)
Standard Test Methods for
Softening Point of Resins Derived from Naval Stores by
Ring-and-Ball Apparatus
ThisstandardisissuedunderthefixeddesignationE28;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope rises, these materials gradually change from brittle or exceed-
ingly thick and slow-flowing materials to softer and less
1.1 These test methods are intended for determining the
viscous liquids. For this reason, the determination of the
softening point of resins (including rosin and terpene resins)
softening point must be made by a fixed, arbitrary, and closely
and similar materials by means of the ring-and-ball apparatus.
defined method if the results obtained are to be comparable.
NOTE 1—For testing asphalts, tars, and pitches, see Test Method D36.
3.2 In these test methods, the softening point is defined as
1.1.1 Test method using the manual ring and ball softening
the temperature at which a disk of the sample held within a
point apparatus, and
horizontal ring is forced downward a distance of 25.4 mm(1
1.1.2 Test method using an automated ring and ball soften-
in.) under the weight of a steel ball as the sample is heated at
ing point apparatus.
5°C/mininawater,glycerin,siliconeoil,ethyleneglycol/water
1.2 The values stated in SI units are to be regarded as the
or glycerin/water bath.
standard. The values given in parentheses are for information
4. Sample Preparation
only.
1.3 This standard does not purport to address all of the 4.1 Preparation of Sample by the Pour Method:
safety concerns, if any, associated with its use. It is the
4.1.1 This procedure is suitable for materials that can be
responsibility of the user of this standard to establish appro- heated and poured without adverse effects on the softening
priate safety and health practices and determine the applica-
point.
bility of regulatory limitations prior to use. 4.1.2 Select a sample representative of the material to be
tested.Thesampleshouldconsistofflakes,pastilles,orfreshly
2. Referenced Documents
broken lumps free of oxidized surfaces. Avoid inclusion of
2.1 ASTM Standards:
finely divided material or dust.
D36TestMethodforSofteningPointofBitumen(Ring-and-
4.1.3 Selectaquantityatleasttwicethatnecessarytofillthe
Ball Apparatus)
desired number of rings, and melt it immediately in a clean
E1Specification for ASTM Liquid-in-Glass Thermometers
container, using an oven, hot plate, sand bath or oil bath to
E177Practice for Use of the Terms Precision and Bias in
prevent local overheating. Take care to avoid incorporating air
ASTM Test Methods
bubbles in the sample. Melt the sample completely, but do not
E691Practice for Conducting an Interlaboratory Study to
heat it above a temperature necessary to pour the material
Determine the Precision of a Test Method
readily. The time from the beginning of heating to the pouring
of the sample should not exceed 15 min.
3. Significance and Use
NOTE 2—For materials that may be heat sensitive, continuously inert
3.1 In general, with materials of these types, softening does
the flask containing the test specimen with nitrogen (N ) during the
not take place at a definite temperature. As the temperature 2
remelting procedure.
1 4.1.4 Formaterialsthattendtocrackorshrinkintheringon
These test methods are under the jurisdiction of ASTM Committee D01 on
Paint and Related Coatings, Materials, and Applications and are the direct
cooling, immediately before filling the ring, preheat the ring to
responsibility of Subcommittee D01.34 on Pine Chemicals and Hydrocarbon
approximately the temperature at which the material is to be
Resins.
poured. The ring, while being filled, should rest bottom down
Current edition approved June 1, 2009. Published June 2009. Originally
on a suitable metal surface. Pour the sample into the ring so as
approvedin1936.Lastpreviouseditionapprovedin2004asE28–99(2004).DOI:
10.1520/E0028-99R09.
to leave an excess on cooling.After cooling a minimum of 30
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
min, trim off the excess resin on the periphery of the ring. To
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
remove excess resin from the top, cut the excess material off
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. cleanlywithaslightlyheatedknifeorspatula,orgraspthering
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E28 − 99 (2009)
in a pair of tongs and draw the top surface quickly and firmly MANUAL RING AND BALL SOFTENING POINT
over the surface of a heated metal plate. In case the test is METHOD
repeated, use a clean container and fresh sample.
6. Apparatus
4.2 Preparation of Sample by the Molding Method:
6.1 Ring and Ball Apparatus, consisting of the following:
4.2.1 See Appendix X1, Alternate Sample Preparation Pro-
cedures. 6.1.1 Ring—A brass, shouldered ring conforming to the
dimensions shown in Fig. 1(a).
4.3 Preparation of Samples Having a Low Softening Point
6.1.2 Ball—Asteelball,9.53 60.1mm( ⁄8in.)indiameter,
(up to 35°C (95°F)):
weighing between 3.45 and 3.55 g.
4.3.1 Place a ring on a piece of aluminum foil. Pour the
6.1.3 Ball-CenteringGuide—Abrassguideforcenteringthe
material to be tested into the ring, then place the foil and filled
ball conforming to the general shape and dimensions shown in
ring on dry ice or in a freezer to cool. The material in the ring
Fig. 1(c), the use of which is optional.
must be free of bubbles.
6.2 Support for Ring and Thermometer—Any convenient
4.3.2 After cooling, cut and scrape off any excess material
method for supporting the ring and thermometer may be used,
using a slightly heated spatula, then slide the ring gently from
provided it meets the following requirements:
the foil. Place the ring in the supporting apparatus, and
immediately perform the softening point analysis according to 6.2.1 The ring must be supported in a substantially horizon-
Section 11.
tal position.
6.2.2 When using the apparatus shown in Fig. 1(d): The
5. Reagents and Materials
bottom of the ring must be 25.4 6 0.2 mm (1.0 in.) above the
horizontal plate below it; the bottom surface of the horizontal
5.1 Bath Liquids:
plate must be 12.7 to 19.05 mm (0.5 to 0.75 in.) above the
5.1.1 Distilled or Deionized Water, Freshly Boiled—For
bottom of the beaker.
softening points between 35°C (95°F) and 80°C (176°F).
6.2.3 Suspend a thermometer so that the bottom of the bulb
5.1.1.1 Usedistilledordeionizedwaterthathasbeencooled
is level with the bottom of ring and within 12.7 mm (0.5 in.)
to at least 27°C (81°F) below the anticipated softening point,
but not touching the ring or the ring holder.
but in no case lower than 5°C (41°F).
6.3 Bath—A heat-resistant glass beaker, at least 85 mm
5.1.2 USP Glycerin—For softening points between 80°C
(3.34 in.) in diameter and 127 mm (5 in.) in depth from the
(176°F) and 150°C (302°F). Repeated use of glycerin will
bottom of the flare, for example, an 800-mL low-form Griffin
increase the moisture content over time and may affect results.
beaker.
Replace with fresh glycerin if any change in appearance is
noted.
6.4 TemperatureMeasuringDevice—Athermometerhaving
a range described below and conforming to the requirements
NOTE 3—Glycerin should not be used for softening points greater than
prescribed in Specification E1, or an electronic temperature
150°C (302°F) due to the 160°C (320°F) flash point of glycerin.
measuring device, such as a resistance thermometer or ther-
5.1.3 Silicone Oil (Polydimethylsiloxane)—For softening
mocouple. The device must exhibit the same temperature
points above 80°C (176°F). The silicone oil must have a
responseasthethermometersspecifiedinSpecificationE1and
temperature range of 200°C+(392°F), remain clear within the
must be accurately calibrated.
temperature range, have no apparent reactivity with the test
6.4.1 An ASTM Thermometer, having a range from−38 to
specimen, have a high water repellency, and maintain a
+50°C (−36 to+120°F), ASTM 5C, 5F, or equivalent.
uniform viscosity and stirring rate within the temperature
3 6.4.2 AnASTMLow-Softening-PointThermometer,having
range.
a range from−2 to 80°C (30 to 180°F), ASTM 15C, 15F or
NOTE 4—Replace with fresh silicone oil if any change in appearance is
equivalent.
noted. Do not use silicone oil that contains any gels; gels are an indicator
6.4.3 An ASTM Medium-Softening Point Thermometer,
that degradation has occurred.
having a range from 30 to 200°C (85 to 392°F), ASTM 16C,
5.1.4 Ethylene Glycol—For softening points up to 35°C
16F or equivalent.
(95°F).
6.4.4 An ASTM High-Softening-Point Thermometer, hav-
5.1.4.1 Prepareafresh50/50(v/v)mixtureofdistilledwater ing a range from−2 to 300°C (30 to 580°F),ASTM 7C, 7F or
and ethylene glycol prior to sample analysis. For softening
equivalent.
pointsbetween0°Cand35°C,a50/50(v/v)mixtureofglycerin
6.5 Stirrer—The heating bath must be stirred at a speed
and water may be used.
sufficient to ensure uniform heat distribution without causing
significant sideways displacement of the resin as it softens in
the ring. A stirring rate of 500 to 700 r/min is typical. A
The sole source of supply of silicone oil, 200 fluid, 50 cSt viscosity known to
mechanical motor-driven stirrer, mounted so that any vibra-
the committee at this time is Dow Corning Corp., Midland, MI 48686. If you are
tions created by its rotation are not conveyed directly to the
aware of alternative suppliers, please provide this information to ASTM Interna-
samplesupport,oramagneticstirrerplacedunderthebathmay
tional Headquarters.Your comments will receive careful consideration at a meeting
of the responsible technical committee, which you may attend. be used.
E28 − 99 (2009)
FIG. 1 Shouldered Ring, Ring Holder, Ball-Centering Guide, and Assembly of Apparatus Showing Two Rings
6.6 Heat Source—Aheat source capable of maintaining the the water for 15 min. Start stirring, and continue stirring until
proper heating rate, such as a temperature controller with completion of the determination.
immersion heating coil, an electric heater or a bunsen burner.
7.2 Heating—Heat the bath so that the temperature of the
water is raised uniformly at a rate of 5°C (10°F)/min. Protect
7. Procedure for Materials Having a Softening Point
thebathfromdrafts,usingshieldsifnecessary.Donotaverage
Between 35 and <80°C (95 and 176°F)
the rate of rise over the test period. The maximum permissible
7.1 Assembly of Apparatus—Fill the bath with distilled or
variation for any 1-min period after the first three minutes is
deionized water, conforming to the requirements in 5.1.1,so
60.5°C (61°F). Reject any test in which the rate of tempera-
that the level will be 105 6 3 mm (4.13 6 0.12 in.). If a
ture rise does not fall within these limits.
mechanicalmotor-drivenstirrerisused,positiontheaxisofthe
stirrer shaft near the back wall of the beaker, with the blades NOTE5—Rigidadherencetotheprescribedrateofheatingisabsolutely
essential for reproducibility of results.
clearing the wall and with the bottom of the blades approxi-
mately 19.0 mm (0.75 in.) above the top of the ring. If the
7.3 Softening Point—Record as the softening point the
ball-centering guide is not used, make a slight indentation in
temperature of the thermometer at the instant the material
the center of the sample by pressing the ball or a rounded rod,
touches the lower horizontal plate (Fig. 1(d)). Make no
slightlyheatedforhardmaterials,intothematerialatthispoint.
correction for the emergent stem of the thermometer.
Suspend the ring containing the sample in the water in the
NOTE 6—When the ball drops through the ring, it should be completely
manner described in 6.2.2 or 25.4 6 0.2 mm (1 in.) above the
surrounded by softening resin and should drop straight down to the lower
bottom of the beaker when using the apparatus in Fig. 2(e).
horizontal plate.
Center the ball on the surface of the test specimen in the ring.
Suspend an ASTM low-softening-point thermometer in the 7.4 Thoroughly clean the ring holder, ball, and ring in a
bath as prescribed in 6.2.3. Maintain the initial temperature of suitable solvent.
E28 − 99 (2009)
FIG. 2 Assembly of Apparatus Showing Stirrer and Single Shouldered Ring
8. Calibration 11. Procedure for Materials Having Softening Points
Below 35°C (95°F)
8.1 Acalibration check of any temperature controllers used
in the manual ring and ball softening point apparatus must be
11.1 Apparatus:
performedonaregularbasissinceaccuratetemperaturecontrol
11.1.1 Isopropyl Alcohol Dry-Ice Bath.
is required.
11.2 Procedure:
9. Procedure for Materials Having Softening Points
11.2.1 Coolthebath,describedin5.1.4.1,to−25°C(−13°F)
Between 80°C (176°F) and 150°C (302°F)
in an isopropyl alcohol dry-ice bath.
11.2.2 UsethesameprocedureasinSection9exceptforthe
9.1 Use the same procedure as described in Section 8,
bathliquid,andimmediatelybeginheatingasdirectedoncethe
except fill the bath with glycerin or silicone oil (Note 3) and
test specimen in the ring has been placed in the bath.
use an ASTM medium-softening-point thermometer. The
maximum allowable starting temperature of the bath is the
AUTOMATED RING AND BALL SOFTENING POINT
lower of: (a) 27°C (81°F) below the anticipated softening
METHOD
point, or (b) 32°C (90°F).
NOTE 7—For materials softening around 80°C (176°F) report the bath
12. Apparatus
liquidsinceaglycerinorsiliconeoilbathwillyieldaslightlyhigherresult
than a water bath.
12.1 Automated Ring and Ball-Softening Point Instrument
NOTE 8—Repeated use of glycerin will increase the moisture content
with Control Unit, test units, and test inserts.
overtimeandmayaffectresults.Replacewithfreshglycerinifanychange
in appearance is noted. 12.2 Ring—A brass, shouldered ring conforming to the
dimensions shown in Fig. 1(a).
10. Procedure for Materials Having Softening Points
12.3 Ball—Asteel ball, 9.53 6 0.1 mm ( ⁄8 in.) in diameter,
Above 150°C (302°F)
weighing between 3.45 and 3.55 g.
10.1 Use the same procedure as described in Section 9,
exceptfillthebathwithsiliconeoil(Note4)anduseanASTM 12.4 Beaker, 600 mL. Ensure that the dimensions will
high-softening-point thermometer. properly fit the heating unit.
E28 − 99 (2009)
12.5 Stir Bar—The dimensions must be such that
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