1、Designation: D3104 14D3104 14aStandard Test Method forSoftening Point of Pitches (Mettler Softening Point Method)1This standard is issued under the fixed designation D3104; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the softening point of pitches having softening points in the range fr
3、om 50 Cto 180C 180 C by this test method, and gives results comparable to those obtained by Test Method D2319 above 176F (80C).80 C (176 F).1.2 The values stated in SI units are to be regarded as the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associate
4、d with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A314 Specification for Stainless Steel Billets and Bars for Forgi
5、ngD2319 Test Method for Softening Point of Pitch (Cube-in-Air Method)D4296 Practice for Sampling Pitch3. Summary of Test Method3.1 In this test method, the softening point is defined as the temperature at which pitch, suspended in a cylindrical cup with a6.35-mm 6.35 mm hole in the bottom, flows dow
6、nward a distance of 19 mm 19 mm to interrupt a light beam, as the sample isheated at a linear rate in air.4. Significance and Use4.1 Pitch does not go through a solid-liquid phase change when heated, and therefore does not have a true melting point. Asthe temperature is raised pitch gradually soften
7、s or becomes less viscous. For this reason, the determination of the softening pointmust be made by an arbitrary, but closely defined, method if the test values are to be reproducible.4.2 This test method is useful in determining the consistency of pitches as one element in establishing the uniformi
8、ty ofshipments or sources of supply.5. Apparatus5.1 A Mettler METTLER TOLEDO dropping point cell3 shall be used to determine pitch softening points by this test method.These commercially available instruments consist of a control unit with a digital temperature indicator, matched furnace, withfurnac
9、e built in or attached, sample cartridges, and accessories. The control unit automatically regulates the heating rate of thefurnace. The softening point is indicated on the readout, and the heating program stopped, when the sample flow triggers aphotocell detector. the softening point detection. A g
10、eneral view of the contents of the Mettler a METTLER TOLEDO droppingpoint instrument is shown in Fig. 1. (old instrument) and Fig. 2 (new instrument).1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility
11、of SubcommitteeD02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved June 1, 2014Oct. 1, 2014. Published July 2014November 2014. Originally approved in 1972. Last previous edition approved in 20102014 asD3104 99 (2010).D3104 14. DOI: 10.1520/D3104-14.10.1520/D310
12、4-14A.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.3 The sole source of supply of the apparatus known to t
13、he committee at this time is available from the Mettler Toledo, Inc., Balances and Instruments, 69Princeton-Hightstown Rd., Hightstown, NJ 08520-0071. Mettler-Toledo, LLC., 1900 Polaris Pkwy, Columbus, OH 43240, . If you are aware of alternativesuppliers, please provide this information to ASTM Inte
14、rnational Headquarters. Your comments will receive careful consideration at a meeting of the responsible technicalcommittee,1 which you may attend.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the pr
15、evious 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 the standard as published by ASTM is to be considered the official document.*A Summary of C
16、hanges section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.1 Integrated or Separate Control UnitThe control unit shall provide a continuous, linear temperature increase from 25 Cto 250 C at a
17、 rate of 2 C/min. A digital readout shall indicate the temperature to 0.1 C throughout.5.1.2 Control and Integrated or Separate Furnace UnitThis shall provide a continuous, linear temperature increase from 25to 250C at a rate of 2C/min.Adigital readout shall indicate the temperature to 0.1C througho
18、ut. This shall The furnace unit shallbe capable of heating one or two sample cup assemblies, as described in 5.1.25.1.3, at a linear rate of 2 C 60.3C/min.0.3 Cmin. It shall include a sensing system capable of detecting the softening point with a precision of 0.1C.0.1 C.5.1.3 Sample Cup AssemblyA cu
19、p of chromium-plated brass, or of stainless steel, aluminum, or of aluminum, stainless steelconforming to the requirements for Type 303 (UNS S30300) stainless steel as prescribed in Specification A314, with thedimensions shown in Fig. 23. It shall be placed in the assembly so that the pitch sample s
20、oftening point will be detected when ithas flowed down a distance of 19 mm.19 mm.6. Reagents6.1 Xylene, Xylene,industrial grade.6.2 Benzoic Acid.Benzoic Acid.FIG. 1 General View of the Mettler FP-5/53METTLER TOLEDO FP90 Control Unit with Heater FP83HTD3104 14a27. Calibration of the Mettler METTLER T
21、OLEDO Apparatus7.1 This step, required only occasionally, is designed to establish that the temperature indicated by the instrument is inagreement with a known standard.Aspecial cup with a bottom orifice of 2.8 mm is used instead of the one prescribed for the testingof pitch.7.2 ReagentUse either an
22、alytical reagent or primary standard grade benzoic acid for the calibration. As this material ishygroscopic it must be stored in a tightly sealed container, and replaced with fresh material from a newly opened supply ifhydration or other contamination is suspected.7.3 Procedure: ProcedureOld Instrum
23、ents:7.3.1 Filling the Sample CupPlace the cup on a clean, flat surface. Add a small amount of benzoic acid crystals and pressdown with a rod (approximately 4.5 mm in diameter). Check that the bottom orifice is completely filled. Refill and repeat thepressing step until the cup is filled with benzoi
24、c acid. Remove any crystals from the exterior of the cup.7.3.2 HeatingPreheat the Mettler furnace to 121C, 121 C, and maintain it at that temperature. Place the cartridge assemblycontaining the benzoic acid in position in the furnace, taking care that the slits for the light beam are properly positi
25、oned. WaitFIG. 2 General View of the METTLER TOLEDO DP70D3104 14a3for temperature equilibration, that is, the furnace and the sample are in equilibrium at the preset temperature, but not less than the30 s after inserting the cartridge, start the automatic heating cycle at 0.2C/min. 0.2 C/min. The te
26、mperature will rise steadily atthe correct rate until the drop point is reached, and then remain steady on the readout.7.3.3 CleaningImmediately remove the cartridge assembly. Check to determine that the sample has passed through the lightbeam and no pre-triggering has occurred. If a malfunction is
27、suspected, the entire procedure must be repeated. Inspect the apparatuscarefully to ensure that no residue remains. Use a spatula shaped to the contour of the cup to remove most of the remaining acidfrom the cup and from the bottom of the cartridge. Wash the cup and cartridge in xylene, or other sui
28、table solvent, to remove thelast traces of the residue.7.3.4 InterpretationIf the result is not 123.5 6 0.5C, repeat the test. If the second value is 0.6 above or below 123.5C,measure the dropping point of a fresh sample of benzoic acid. If the deviation exceeds 0.6C, the instrument requires recalib
29、rationor repair. Consult the manufacturers instruction manual.NOTE 1Users of older instruments such as FP90/83 may refer to earlier versions of this method for the sample insertion procedure for thoseinstruments. The procedure differs in that the cup holder and receiver are different.7.4 Interpretat
30、ionSee 7.6.7.5 ProcedureNew Instruments:7.5.1 Filling the Sample CupPlace the cup on a clean, flat surface. Optionally, the sample preparation tool may be used. SeeFig. 2. Add a small amount of benzoic acid crystals and press down with a rod (approximately 4.5 mm in diameter). Check thatthe bottom o
31、rifice is completely filled. Refill and repeat the pressing step until the cup is filled with benzoic acid. Remove anycrystals from the exterior of the cup. Place a glass collector below the cup and a cup cap on top, and place in the sample carrier.Two cup assemblies may be placed in the sample carr
32、ier.7.5.2 HeatingPreheat the furnace to 121 C, and maintain it at that temperature. Place the sample carrier containing thebenzoic acid in position in the furnace. Wait for temperature equilibration, that is, the furnace and the sample are in equilibriumat the preset temperature, but not less than t
33、he 30 s after inserting the cartridge, start the automatic heating cycle at 0.2 C/min.The temperature will rise steadily at the correct rate until the drop point is reached, and then remain steady on the readout. If thereare two samples, heating will continue until both have dropped.7.5.3 CleaningIm
34、mediately remove the cartridge assembly. Check to determine that the sample has dropped and nopre-triggering has occurred. The video may be viewed to make sure the drop was detected correctly. If a malfunction is suspected,the entire procedure must be repeated. Inspect the apparatus carefully to ens
35、ure that no residue remains. Use a spatula shaped tothe contour of the cup to remove most of the remaining acid from the cup. Wash the cup and glass collector in xylene, or othersuitable solvent, to remove the last traces of the residue. Glass collectors may be treated as disposable items.Aluminum c
36、ups maybe used which may also be considered to be disposable.7.6 InterpretationIf the result is not 123.5 C 6 0.5 C, repeat the test. If the second value is 0.6 C above or below 123.5C, measure the dropping point of a fresh sample of benzoic acid. If the deviation exceeds 0.6 C, the instrument requi
37、resrecalibration or repair. Consult the manufacturers instruction manual.FIG. 23 Sample CupD3104 14a48. Sampling8.1 Samples from shipments shall be taken in accordance with Practice D4296, and shall be free of foreign substances.Thoroughly mix the sample before removing a representative portion for
38、the determination or for dehydration.8.2 If a solid bulk sample contains free water, air-dry a representative portion in a forced draft oven at 50C.50 C.8.3 If the sample is liquid, check for any surface foam which may indicate the presence of water. If foam is found, maintainthe sample at a tempera
39、ture of about 125C 125 C in an open container until the surface is free of foam. Take care not to overheat.Remove from the heat source as soon as the foam has subsided. Proceed as directed in 8.4.2.8.4 Filling the Sample Cup:8.4.1 Crush air-dry lumps of pitch to a size of 6 mm to 12 mm. 12 mm. Add t
40、he material to a container, having a height equalto or exceeding its width, and having a volume of not less than 50 mL, until it is about half full. Place the container on a hot plate,or in an oven or a bath. Do not use an open flame to melt pitch. After melting is complete, stir gently but thorough
41、ly, avoidingincorporation of air bubbles. The maximum temperature of the molten pitch should not exceed the expected softening point bymore than 50C. 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. Optionall
42、y, the sample preparationtool may be used (see Fig. 2). 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 s
43、ample flush with the top of the cup by pressing with a heated knife or spatula while drawing it toward you. Do not trimby cutting across the top with a forward or sideward motion as this tends to lift the sample out of the mold, thus creating an internalvoid which is not easily detected, and which s
44、ignificantly 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 thesample 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 sampl
45、e cup in the mold (see Figs. 3-4-56). Place the assembled mold, with the knockout pin in position, on the bottomplate of a hydraulic press. Pour about 2 g of the crushed pitch into the top of the mold and insert the top ram. Compress the pitchinto the cup with a total force on the ram of 22.24 kN (5
46、000 lbf).lb). Hold this pressure for a minimum of 15 s. Excessive moldingpressure can cause the sample cup to fail by shearing. Remove the mold assembly from the press and rotate the upper half whilekeeping the lower half of the mold stationary. This action causes the pitch to shear horizontally at
47、the top of the cup. Separate thetwo parts of the mold and remove the sample cup from the lower half. It may be necessary to dislodge it by pressing against theknockout pin. A small-diameter rod mounted in the base plate may be used for this. Clean the mold of all residual pitch to avoidmisalignment
48、or binding during subsequent use. This procedure does not work well for pitches having softening points below 80C80 C unless the mold is precooled below room temperature.9. Procedure9.1 The procedure described in this test method for measuring the softening point of pitches using either Mettler METT
49、LERTOLEDO instrument has been developed to duplicate the results obtained by Test Method D2319.9.2 Old InstrumentsPreset the temperature of the furnace to 20 C to 25C 25 C below the expected softening point of thesample and maintain this temperature for a few minutes (see Note 21). Place the sample cup in the cartridge and the cartridgeassembly in the furnace, taking care that the slits for the light beam are properly positioned. Wait for temperature equilibration,that is, the furnace and the sample a
