1、Designation: E28 14E28 18Standard Test Methods forSoftening Point of Resins Derived from Pine Chemicals andHydrocarbons, by Ring-and-Ball Apparatus1This standard is issued under the fixed designation E28; the number immediately following the designation indicates the year of originaladoption or, in
2、the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 Th
3、ese test methods are intended for determining the softening point of resins (including rosin and terpene resins) and similarmaterials by means of the ring-and-ball apparatus.NOTE 1For testing asphalts, tars, and pitches, see Test Method D36.1.1.1 Test method using the automated ring and ball softeni
4、ng point apparatus is the reference method and the test method usingthe manual ring and ball method is an alternative method.1.1.2 Test method using the manual ring and ball softening point apparatus is an alternative method.1.2 The values stated in SI units are to be regarded as the standard. The v
5、alues 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 responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and de
6、termine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendation
7、s issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D36 Test Method for Softening Point of Bitumen (Ring-and-Ball Apparatus)E1 Specification for ASTM Liquid-in-Glass ThermometersE177 Practice for Use of the Terms Precision an
8、d Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Significance and Use3.1 In general, with materials of these types, softening does not take place at a definite temperature. As the temperature rises,these materials graduall
9、y 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 resultsobtained are to be comparable.3.2 In these test methods, the
10、 softening point is defined as the temperature at which a disk of the sample held within a horizontalring is forced downward a distance of 25.4 mm (1 in.) under the weight of a steel ball as the sample is heated at 5C/min in a water,glycerin, silicone oil, ethylene glycol/water or glycerin/water bat
11、h.3.3 The automatic method was chosen to be the reference method because a round robin demonstrated that it gave more preciseresults than the manual method.1 These test methods are under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and are the dir
12、ect responsibility ofSubcommittee D01.34 on Pine Chemicals and Hydrocarbon Resins.Current edition approved July 1, 2014July 1, 2018. Published August 2014July 2018. Originally approved in 1936. Last previous edition approved in 20092014 as E28 99(2009).E28 14. DOI: 10.1520/E0028-14.10.1520/E0028-18.
13、2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to
14、 provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof
15、 the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Sample Preparation4.1 Preparation of Sample by the Pour Method:4.1.1 This procedure is suitable for materi
16、als that can be heated and poured without adverse effects on the softening point.4.1.2 Select a sample representative of the material to be tested. The sample should consist of flakes, pastilles, or freshly brokenlumps free of oxidized surfaces. Avoid inclusion of finely divided material or dust.4.1
17、.3 Select a quantity at least twice that necessary to fill the desired number of rings, and melt it immediately in a cleancontainer, using an oven, hot plate, sand bath or oil bath to prevent local overheating. Take care to avoid incorporating air bubblesin the sample. Melt the sample completely, bu
18、t do not heat it above a temperature necessary to pour the material readily. The timefrom the beginning of heating to the pouring of the sample should not exceed 15 min.E28 182NOTE 2For materials that may be heat sensitive, continuously inert the flask containing the test specimen with nitrogen (N2)
19、 during the remeltingprocedure.4.1.4 For materials that tend to crack or shrink in the ring on cooling, immediately before filling the ring, preheat the ring toapproximately the temperature at which the material is to be poured. The ring, while being filled, should rest bottom down on asuitable meta
20、l surface. Pour the sample into the ring so as to leave an excess on cooling. After cooling a minimum of 30 min, trimoff the excess resin on the periphery of the ring. To remove excess resin from the top, cut the excess material off cleanly with aslightly heated knife or spatula, or grasp the ring i
21、n a pair of tongs and draw the top surface quickly and firmly over the surfaceof a heated metal plate. In case the test is repeated, use a clean container and fresh sample.5. Reagents and Materials5.1 Bath Liquids:5.1.1 Distilled or Deionized Water, Freshly BoiledFor softening points between 35C (95
22、F) and 80C (176F).5.1.1.1 Use distilled or deionized water that has been cooled to at least 27C (81F) below the anticipated softening point, butin no case lower than 5C (41F).5.1.2 USP GlycerinFor softening points between 80C (176F) and 150C (302F). Repeated use of glycerin will increase themoisture
23、 content over time and may affect results. Replace with fresh glycerin if any change in appearance is noted.NOTE 3Glycerin should not be used for softening points greater than 150C (302F) due to the 160C (320F) flash point of glycerin.5.1.3 Silicone Oil (Polydimethylsiloxane)For softening points abo
24、ve 80C (176F). The silicone oil must have a temperaturerange of 200C + (392F), remain clear within the temperature range, have no apparent reactivity with the test specimen, have ahigh water repellency, and maintain a uniform viscosity and stirring rate within the temperature range.3NOTE 4Replace wi
25、th fresh silicone oil if any change in appearance is noted. Do not use silicone oil that contains any gels; gels are an indicator thatdegradation has occurred.5.1.4 Ethylene Glycol/WaterFor softening points up to 35C (95F).5.1.4.1 Prepare a fresh 50/50 (v/v) mixture of distilled water and ethylene g
26、lycol prior to sample analysis. For softening pointsbetween 0C and 35C, a 50/50 (v/v) mixture of glycerin and water may be used.REFERENCE METHODAUTOMATED RING AND BALL SOFTENING POINT METHOD6. Apparatus6.1 Automated Ring and Ball-Softening Point Instrument with Control Unit, test units, and test ins
27、erts.6.2 RingA brass, shouldered ring conforming to the dimensions shown in Fig. 1(a).6.3 BallA steel ball, 9.53 6 0.1 mm (38 in.) in diameter, weighing between 3.45 and 3.55 g.6.4 Beaker, 600 mL or what is recommended by the manufacturer. Ensure that the dimensions will properly fit the heating uni
28、t.6.5 Stir BarThe dimensions must be such that the bar spins freely under the test stand. It is recommended that the stirringbar supplied with the instrument be used or one that has been shown to give the same result as the one supplied.7. Procedure for Materials Having a Softening Point Between 35C
29、 (95F) and 80C (176F)7.1 Add a stir bar to the 600mL beaker and fill with approximately 500 mL of distilled or deionized water, conforming to therequirements in 5.1.1. Ensure that the beaker is properly positioned on the heater in the test unit. Place the prepared sample ringsin the test insert. Pla
30、ce the ball-centering guide and ball on top of the sample ring. Place the test insert in the beaker of water,suspending it from the support pins. Place the temperature measuring device in the test insert. Verify that the control unit is setfor the correct bath liquid.7.2 HeatingHeat the bath so that
31、 the temperature of the water is raised uniformly at a rate of 5C (10F)/min. Protect the bathfrom drafts, using shields if necessary. The maximum permissible variation for any one min. period after the first three min. is60.5C (61F). Reject any test in which the rate of temperature rise does not fal
32、l within these limits. The test is complete whenthe light beam has been interrupted by the falling ball and material.NOTE 5Rigid adherence to the prescribed rate of heating is absolutely essential for reproducibility of results.7.3 Softening PointRecord as the softening point the temperature display
33、ed on the unit after the light beam has beeninterrupted by the falling ball and material.3 The sole source of supply of silicone oil, 200 fluid, 50 cSt viscosity known to the committee at this time is Dow Corning Corp., Midland, MI 48686. If you are awareof alternative suppliers, please provide this
34、 information toASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1 which you may attend.E28 1837.4 Start the cooling process in the instrument. Remove the temperature measuring device from the test insert, then remove
35、thetest insert from the beakers. Thoroughly clean the test insert, ball, and ring in a suitable solvent.8. Calibration8.1 The calibration of any automated ring and ball-softening point apparatus must be performed on a regular basis since accuratetemperature control is required. Follow the manufactur
36、ers instructions for calibration of the instrument.9. Procedure for Materials Having Softening Points Between 80C (176F) and 150C (302F)9.1 Use the same procedure as described in Section 7, except fill the bath with glycerin or silicone oil.NOTE 6For materials softening around 80C (176F), report the
37、 bath liquid since a glycerin or silicone oil bath will yield a slightly higher result thana water bath.10. Procedure for Materials Having Softening Points Above 150C (302F)10.1 Use the same procedure as described in Section 7, except fill the bath with silicone oil (Note 3).11. Procedure for Materi
38、als Having Softening Points Below 35C (95F)11.1 Apparatus:11.1.1 Freezer or Isopropyl Alcohol Dry-Ice Bath.11.2 Procedure:11.2.1 Cool the bath, described in 5.1.4.1, to 25C (13F) in the precooled freezer or an isopropyl alcohol dry-ice bath.FIG. 1 Shouldered Ring, Ring Holder, Ball-Centering Guide,
39、and Assembly of Apparatus Showing Two RingsE28 18411.2.2 Use the same procedure as in Section 7. Take care to immediately begin heating as directed once the test specimen inthe ring has been placed in the bath.12. Report12.1 Report the softening point to the nearest 1.0C.12.2 Report the bath liquid
40、used in the test.ALTERNATE METHODMANUAL RING AND BALL SOFTENING POINT METHOD13. Apparatus13.1 Ring and Ball Apparatus, consisting of the following:13.1.1 RingA brass, shouldered ring conforming to the dimensions shown in Fig. 1(a).13.1.2 BallA steel ball, 9.53 6 0.1 mm (38 in.) in diameter, weighing
41、 between 3.45 and 3.55 g.13.1.3 Ball-Centering GuideA brass guide for centering the ball conforming to the general shape and dimensions shown inFig. 1(c), the use of which is optional.13.2 Support for Ring and ThermometerAny convenient method for supporting the ring and thermometer may be used,provi
42、ded it meets the following requirements:13.2.1 The ring must be supported in a substantially horizontal position.13.2.2 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 thehorizontal plate below it; the bottom surface of the horizontal plate m
43、ust be 12.7 to 19.05 mm (0.5 to 0.75 in.) above the bottomof the beaker.13.2.3 Suspend a thermometer so that the bottom of the bulb is level with the bottom of ring and within 12.7 mm (0.5 in.) butnot touching the ring or the ring holder.13.3 BathA heat-resistant glass beaker, at least 85 mm (3.34 i
44、n.) in diameter and 127 mm (5 in.) in depth from the bottomof the flare, for example, an 800-mL low-form Griffin beaker.13.4 Temperature Measuring DeviceA thermometer having a range described below and conforming to the requirementsprescribed in Specification E1, or an electronic temperature measuri
45、ng device, such as a resistance thermometer or thermocouple.The device must exhibit the same temperature response as the thermometers specified in Specification E1 and must be accuratelycalibrated.13.4.1 An ASTM Thermometer, having a range from 38 to +50C (36 to +120F), ASTM 5C, 5F, or any temperatu
46、remeasuring device having equivalent precision.13.4.2 An ASTM Low-Softening-Point Thermometer, having a range from 2 to 80C (30 to 180F), ASTM 15C, 15F, or anytemperature measuring device having equivalent precision.13.4.3 An ASTM Medium-Softening Point Thermometer, having a range from 30 to 200C (8
47、5 to 392F), ASTM 16C, 16F, orany temperature measuring device having equivalent precision.13.4.4 An ASTM High-Softening-Point Thermometer, having a range from 2 to 300C (30 to 580F), ASTM 7C, 7F, or anytemperature measuring device having equivalent precision.13.5 StirerThe heating bath must be stirr
48、ed at a speed sufficient to ensure uniform heat distribution without causing significantsideways displacement of the resin as it softens in the ring.Astirring rate of 500 to 700 r/min is typical.Amechanical motor-drivenstirrer, mounted so that any vibrations created by its rotation are not conveyed
49、directly to the sample support, or a magnetic stirrerplaced under the bath may be used.13.6 Heat SourceA heat source capable of maintaining the proper heating rate, such as a temperature controller withimmersion heating coil, an electric heater or a bunsen burner.14. Procedure for Materials Having a Softening Point Between 35C (95F) and 80C (176F)14.1 Assembly of ApparatusFill the bath with distilled or deionized water, conforming to the requirements in 5.1.1, so thatthe level will be
