ASTM E28-99(2004)
(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(Reapproved2004)
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 (e) 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 ingly thick and slow-flowing materials to softer and less
viscous liquids. For this reason, the determination of the
1.1 These test methods are intended for determining the
softening point must be made by a fixed, arbitrary, and closely
softening point of resins (including rosin and terpene resins)
defined method if the results obtained are to be comparable.
and similar materials by means of the ring-and-ball apparatus.
3.2 In these test methods, the softening point is defined as
NOTE 1—For testing asphalts, tars, and pitches, see Test Method D36.
the temperature at which a disk of the sample held within a
1.1.1 Test method using the manual ring and ball softening horizontal ring is forced downward a distance of 25.4 mm (1
point apparatus, and in.) under the weight of a steel ball as the sample is heated at
1.1.2 Test method using an automated ring and ball soften- 5°C/mininawater,glycerin,siliconeoil,ethyleneglycol/water
ing point apparatus. or glycerin/water bath.
1.2 The values stated in SI units are to be regarded as the
4. Sample Preparation
standard. The values given in parentheses are for information
4.1 Preparation of Sample by the Pour Method:
only.
1.3 This standard does not purport to address all of the 4.1.1 This procedure is suitable for materials that can be
heated and poured without adverse effects on the softening
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- point.
4.1.2 Select a sample representative of the material to be
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. tested.Thesampleshouldconsistofflakes,pastilles,orfreshly
broken lumps free of oxidized surfaces. Avoid inclusion of
2. Referenced Documents
finely divided material or dust.
2.1 ASTM Standards: 4.1.3 Selectaquantityatleasttwicethatnecessarytofillthe
D36 Test Method for Softening Point of Bitumen (Ring- desired number of rings, and melt it immediately in a clean
and-Ball Apparatus) container, using an oven, hot plate, sand bath or oil bath to
E1 Specification forASTM Liquid-in-GlassThermometers prevent local overheating. Take care to avoid incorporating air
E177 Practice for Use of Terms Precision and Bias in bubbles in the sample. Melt the sample completely, but do not
ASTM Test Methods heat it above a temperature necessary to pour the material
E691 Practice for Conducting an Interlaboratory Study to readily. The time from the beginning of heating to the pouring
Determine the Precision of a Test Method of the sample should not exceed 15 min.
NOTE 2—For materials that may be heat sensitive, continuously inert
3. Significance and Use
the flask containing the test specimen with nitrogen (N ) during the
3.1 In general, with materials of these types, softening does
remelting procedure.
not take place at a definite temperature. As the temperature
4.1.4 Formaterialsthattendtocrackorshrinkintheringon
rises, these materials gradually change from brittle or exceed-
cooling, immediately before filling the ring, preheat the ring to
approximately the temperature at which the material is to be
These test methods are under the jurisdiction of ASTM Committee D01 on poured. The ring, while being filled, should rest bottom down
Paint and Related Coatings, Materials, andApplications and is the direct responsi-
on a suitable metal surface. Pour the sample into the ring so as
bility of Subcommittee D01.34 on Naval Stores.
to leave an excess on cooling.After cooling a minimum of 30
Current edition approved June 1, 2004. Published June 2004. Originally
min, trim off the excess resin on the periphery of the ring. To
approved in 1936. Last previous edition approved in 1999 as E28–99.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
remove excess resin from the top, cut the excess material off
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
cleanlywithaslightlyheatedknifeorspatula,orgraspthering
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E28–99 (2004)
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:
4.2.1 See Appendix X1, Alternate Sample Preparation Pro- 6.1 Ring and Ball Apparatus, consisting of the following:
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-Centering Guide—A brass guide for centering
material to be tested into the ring, then place the foil and filled
theballconformingtothegeneralshapeanddimensionsshown
ring on dry ice or in a freezer to cool. The material in the ring
in 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
6.2.1 The ring must be supported in a substantially horizon-
immediately perform the softening point analysis according to
tal position.
Section 11.
6.2.2 When using the apparatus shown in Fig. 1(d): The
bottom of the ring must be 25.4 6 0.2 mm (1.0 in.) above the
5. Reagents and Materials
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
bottom of the beaker.
5.1.1 Distilled or Deionized Water, Freshly Boiled—For
6.2.3 Suspend a thermometer so that the bottom of the bulb
softening points between 35°C (95°F) and 80°C (176°F).
is level with the bottom of ring and within 12.7 mm (0.5 in.)
5.1.1.1 Usedistilledordeionizedwaterthathasbeencooled
but not touching the ring or the ring holder.
to at least 27°C (81°F) below the anticipated softening point,
6.3 Bath—A heat-resistant glass beaker, at least 85 mm
but in no case lower than 5°C (41°F).
(3.34 in.) in diameter and 127 mm (5 in.) in depth from the
5.1.2 USP Glycerin—For softening points between 80°C
bottom of the flare, for example, an 800-mL low-form Griffin
(176°F) and 150°C (302°F). Repeated use of glycerin will
beaker.
increase the moisture content over time and may affect results.
6.4 Temperature Measuring Device—A thermometer hav-
Replace with fresh glycerin if any change in appearance is
ing a range described below and conforming to the require-
noted.
ments prescribed in Specification E1, or an electronic tem-
NOTE 3—Glycerin should not be used for softening points greater than peraturemeasuringdevice,suchasaresistancethermometeror
150°C (302°F) due to the 160°C (320°F) flash point of glycerin.
thermocouple. The device must exhibit the same temperature
responseasthethermometersspecifiedinSpecificationE1and
5.1.3 Silicone Oil (Polydimethylsiloxane)—For softening
must be accurately calibrated.
points above 80°C (176°F). The silicone oil must have a
6.4.1 An ASTM Thermometer, having a range from−38
temperature range of 200°C+(392°F), remain clear within the
to+50°C (−36 to+120°F), ASTM 5C, 5F, or equivalent.
temperature range, have no apparent reactivity with the test
6.4.2 AnASTMLow-Softening-PointThermometer,having
specimen, have a high water repellency, and maintain a
a range from−2 to 80°C (30 to 180°F), ASTM 15C, 15F or
uniform viscosity and stirring rate within the temperature
3 equivalent.
range.
6.4.3 An ASTM Medium-Softening Point Thermometer,
NOTE 4—Replace with fresh silicone oil if any change in appearance is
having a range from 30 to 200°C (85 to 392°F), ASTM 16C,
noted. Do not use silicone oil that contains any gels; gels are an indicator
16F or equivalent.
that degradation has occurred.
6.4.4 An ASTM High-Softening-Point Thermometer, hav-
5.1.4 Ethylene Glycol—For softening points up to 35°C ing a range from−2 to 300°C (30 to 580°F),ASTM 7C, 7F or
(95°F). equivalent.
6.5 Stirrer—The heating bath must be stirred at a speed
5.1.4.1 Prepareafresh50/50(v/v)mixtureofdistilledwater
sufficient to ensure uniform heat distribution without causing
and ethylene glycol prior to sample analysis. For softening
significant sideways displacement of the resin as it softens in
pointsbetween0°Cand35°C,a50/50(v/v)mixtureofglycerin
the ring. A stirring rate of 500 to 700 r/min is typical. A
and water may be used.
mechanical motor-driven stirrer, mounted so that any vibra-
tions created by its rotation are not conveyed directly to the
samplesupport,oramagneticstirrerplacedunderthebathmay
The sole source of supply of silicone oil, 200 fluid, 50 cSt viscosity known to
be used.
the committee at this time is Dow Corning Corp., Midland, MI 48686. If you are
6.6 Heat Source—Aheat source capable of maintaining the
aware of alternative suppliers, please provide this information to ASTM Interna-
proper heating rate, such as a temperature controller with
tional Headquarters.Your comments will receive careful consideration at a meeting
of the responsible technical committee, which you may attend. immersion heating coil, an electric heater or a bunsen burner.
E28–99 (2004)
FIG. 1 Shouldered Ring, Ring Holder, Ball-Centering Guide, and Assembly of Apparatus Showing Two Rings
7. Procedure for Materials Having a Softening Point 7.2 Heating—Heat the bath so that the temperature of the
Between 35 and< 80°C (95 and 176°F) water is raised uniformly at a rate of 5°C (10°F)/min. Protect
thebathfromdrafts,usingshieldsifnecessary.Donotaverage
7.1 Assembly of Apparatus—Fill the bath with distilled or
the rate of rise over the test period. The maximum permissible
deionized water, conforming to the requirements in 5.1.1, so
variation for any 1-min period after the first three minutes is
that the level will be 105 6 3 mm (4.13 6 0.12 in.). If a
60.5°C (61°F). Reject any test in which the rate of tempera-
mechanicalmotor-drivenstirrerisused,positiontheaxisofthe
ture rise does not fall within these limits.
stirrer shaft near the back wall of the beaker, with the blades
clearing the wall and with the bottom of the blades approxi-
NOTE 5—Rigidadherencetotheprescribedrateofheatingisabsolutely
mately 19.0 mm (0.75 in.) above the top of the ring. If the
essential for reproducibility of results.
ball-centering guide is not used, make a slight indentation in
the center of the sample by pressing the ball or a rounded rod, 7.3 Softening Point—Record as the softening point the
slightlyheatedforhardmaterials,intothematerialatthispoint. temperature of the thermometer at the instant the material
Suspend the ring containing the sample in the water in the touches the lower horizontal plate (Fig. 1(d)). Make no
manner described in 6.2.2 or 25.4 6 0.2 mm (1 in.) above the
correction for the emergent stem of the thermometer.
bottom of the beaker when using the apparatus in Fig. 2( e).
NOTE 6—Whentheballdropsthroughthering,itshouldbecompletely
Center the ball on the surface of the test specimen in the ring.
surrounded by softening resin and should drop straight down to the lower
Suspend an ASTM low-softening-point thermometer in the
horizontal plate.
bath as prescribed in 6.2.3. Maintain the initial temperature of
the water for 15 min. Start stirring, and continue stirring until 7.4 Thoroughly clean the ring holder, ball, and ring in a
completion of the determination. suitable solvent.
E28–99 (2004)
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:
11.2.1 Coolthebath,describedin5.1.4.1,to−25°C(−13°F)
9. Procedure for Materials Having Softening Points
in an isopropyl alcohol dry-ice bath.
Between 80°C (176°F) and 150°C (302°F)
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).
12. Apparatus
NOTE 7—For materials softening around 80°C (176°F) report the bath
liquidsinceaglycerinorsiliconeoilbathwillyieldaslightlyhigherresult
12.1 Automated Ring and Ball-Softening Point Instrument
than a water bath.
with Control Unit, test units, and test inserts.
NOTE 8—Repeated use of glycerin will increase the moisture content
12.2 Ring—A brass, shouldered ring conforming to the
overtimeandmayaffectresults.Replacewithfreshglycerinifanychange
dimensions shown in Fig. 1(a).
in appearance is noted.
12.3 Ball—Asteel ball, 9.53 6 0.1 mm ( ⁄8 in.) in diameter,
10. Procedure for Materials Having Softening Points
weighing between 3.45 and 3.55 g.
Above 150°C (302°F)
12.4 Beaker, 600 mL. Ensure that the dimensions will
10.1 Use the same procedure as described in Section 9, properly fit the heating unit.
exceptfillthebathwithsiliconeoil(Note4)anduseanASTM 12.5 Stir Bar—The dimensions must be such that the bar
high-softening-point thermometer. spins freely under the test stand.
E28–99 (2004)
13. Procedure f
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