1、Designation: D3104 99 (Reapproved 2010)D3104 14Standard 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 rev
2、ision, the year of 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 Scope*1.1 This test method covers the determination of the softening point of pitches having softening
3、 points in the range from 50 to180C by this test method, and gives results comparable to those obtained by Test Method D2319 above 176F (80C).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, associa
4、ted 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 For
5、gingD2319 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 hole in the bottom, flows downward
6、a distance of 19 mm to interrupt a light beam, as the sample is heated at a linearrate 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 softens or becomes
7、 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 uniformity ofshipmen
8、ts or sources of supply.5. Apparatus5.1 A Mettler dropping point cell3 shall be used to determine pitch softening points by this test method. These commerciallyavailable instruments consist of a control unit with a digital temperature indicator, matched furnace, sample cartridges, andaccessories. Th
9、e control unit automatically regulates the heating rate of the furnace. The softening point is indicated on the readout,and the heating program stopped, when the sample flow triggers a photocell detector.Ageneral view of the contents of the Mettleris shown in Fig. 1.5.1.1 Control UnitThis unit shall
10、 provide a continuous, linear temperature increase from 25 to 250C at a rate of 2C/min.A digital readout shall indicate the temperature to 0.1C throughout.1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricantsand is the direct
11、responsibility ofSubcommittee D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved May 1, 2010June 1, 2014. Published May 2010July 2014. Originally approved in 1972. Last previous edition approved in 20052010 asD3104 99 (2010). (2005). DOI: 10.1520/D3104-99R10.1
12、0.1520/D3104-14.2 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
13、known to the committee at this time is available from the Mettler Toledo, Inc., Balances and Instruments, 69Princeton-Hightstown Rd., Hightstown, NJ 08520-0071. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Yourcomments will receive ca
14、reful consideration at a meeting of the responsible technical committee,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 previous version. Becauseit may not be technically pos
15、sible 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 Changes section appears at the end of this standardCo
16、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.1 Control and Furnace UnitThis unit shall shall provide a continuous, linear temperature increase from 25 to 250C ata rate of 2C/min. A digital readout shall indicate the temperature t
17、o 0.1C throughout. This shall be capable of heating a one ortwo sample cup assembly,assemblies, as described in 5.1.35.1.2, at a linear rate of 2 6 0.3C/min. It shall include a sensing systemcapable of detecting the softening point with a precision of 0.1C.5.1.2 Sample Cup AssemblyA cup of chromium-
18、plated brass, or of stainless steel steel, or of aluminum, conforming to therequirements for Type 303 (UNS S30300) as prescribed in Specification A314, with the dimensions shown in Fig. 2. It shall beplaced in the assembly so that the pitch sample will flow downward a distance of 19 mm before interr
19、upting a light beam andstopping the heating program as the softening point is reached.softening point will be detected when it has flowed down a distanceof 19 mm.6. Reagents6.1 Xylene, industrial grade.6.2 Benzoic Acid.FIG. 1 General View of the Mettler FP-5/53D3104 1427. Calibration of the Mettler
20、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 analytic
21、al 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:7.3.1 Filling the Sample Cu
22、pPlace 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 benzoic acid. Remove any crystals from
23、 the exterior of the cup.7.3.2 Heating Preheat the Mettler furnace to 121C, 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 positioned. Waitfor temperature equilibratio
24、n, 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. The temperature will rise steadily at the correctrate until the drop point is reached, and then remain steady o
25、n 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 suspected, the entire procedure must be repeated. Inspect the apparatuscarefully to ensure that no residu
26、e 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 suitable solvent, to remove thelast traces of the residue.7.3.4 InterpretationIf the result is not 123.5 6 0
27、.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 recalibrationor repair. Consult the manufacturers instruction manual.NOTE 1Users of older instruments such as FP
28、90/83 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.8. Sampling8.1 Samples from shipments shall be taken in accordance with Practice D4296, and shall be free of foreign sub
29、stances.Thoroughly mix the sample before removing a representative portion for 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.8.3 If the sample is liquid, check for any surface foam which may indicat
30、e the presence of water. If foam is found, maintainthe sample at a temperature of about 125C 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:FIG. 2
31、Sample CupD3104 1438.4.1 Crush air-dry lumps of pitch to a size of 6 to 12 mm.Add the material to a container, having a height equal to or exceedingits width, and having a volume of not less than 50 mL, 50 mL, until it is about half full. Place the container on a hot plate, or inan oven or a bath. D
32、o not use an open flame to melt pitch. After melting is complete, stir gently but thoroughly, avoidingincorporation of air bubbles. The maximum temperature of the molten pitch should not exceed the expected softening point bymore than 50C. Any foam that forms must be skimmed off.8.4.2 Prepare the sa
33、mple by slightly overfilling the sample cup, which rests on a brass plate. Keep the lip of the container closeto 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 ne
34、cessary. Trim the sample flush with the top of the cup by pressing witha heated knife or spatula while drawing it toward you. Do not trim by cutting across the top with a forward or sideward motionas this tends to lift the sample out of the mold, thus creating an internal void which is not easily de
35、tected, and which significantlyalters 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
36、2 mm.Place a sample cup in the mold (see Figs. 3-5). Place the assembled mold, with the knockout pin in position, on the bottom plateof a hydraulic press. Pour about 2 g of the crushed pitch into the top of the mold and insert the top ram. Compress the pitch intothe cup with a total force on the ram
37、 of 22.24 kN (5000 lbf). Hold this pressure for a minimum of 15 s. 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
38、 horizontally at 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 a
39、voidNOTE 1Diameters are concentric. These two parts will be hardened tool steel and then ground to final dimensions.All dimensions are in millimetres.FIG. 3 Upper Half of Mold Assembly for Pressure Molding Pitch into a Sample CupD3104 144misalignment or binding during subsequent use. This procedure
40、does not work well for pitches having softening points below 80Cunless 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 instrument hasbeen developed to duplicate the results obta
41、ined by Test Method D2319.9.2 Preset the temperature of the furnace to 20 to 25C below the expected softening point of the sample and maintain thistemperature for a few minutes (see Note 12). Place the sample cup in the cartridge and the cartridge assembly in the furnace, takingcare that the slits f
42、or the light beam are properly positioned. Wait for temperature equilibration, that is, the furnace and the sampleare in equilibrium at the preset temperature, but not less than the 30 s after inserting the cartridge, start the automatic heating cycleat 2.0C/min. Heating will be maintained at this r
43、ate until the drop point is reached, after which a steady temperature will bedisplayed on the digital readout. Record this temperature as the softening point of the sample.NOTE 2In the event of a dispute, the purchaser and supplier shall agree on the exact starting temperature to be used.9.3 Immedia
44、tely remove the cartridge assembly upon completion of the test. Check to ensure that the sample has passed the lightbeam and no pre-triggering has occurred. If a malfunction is suspected, reject the result and repeat the test. Inspect the apparatusclosely to ensure that no particles of residue remai
45、n.9.4 Clean the sample cups by placing them upside down on a hard surface and punching out any residual material. Use a spatula,shaped to the contour of the cup, with a swirling motion to remove any remaining particles. Washing with xylene, or other suitablesolvent, may be necessary to get the appar
46、atus completely clean.10. Report10.1 Report the softening point, as indicated by the digital readout, to the nearest 0.1C. If converting to degrees Fahrenheit,report to the nearest 0.2F. Experience indicates that duplicate determinations are unnecessary. If any error occurs, or is suspected,in carry
47、ing out the details of this procedure, discard the results and make a second run.NOTE 1Diameters are concentric. These two parts will be made of Type 303 stainless steel. All dimensions are in millimetres.FIG. 4 Lower Half of Mold Assembly for Pressure Molding Pitch into a Sample CupD3104 14511. Pre
48、cision and Bias11.1 The following criteria shall be used for judging the acceptability of any result (95 % confidence level):11.1.1 RepeatabilityDuplicate values by the same operator shall not be considered suspect unless they differ by more than0.5C.11.1.2 ReproducibilityThe values reported by each
49、 of two laboratories shall not be considered suspect unless they differ bymore than 1.5C.11.1.3 BiasThis test method has no bias because the value of softening point is defined in terms of this test method.12. Keywords12.1 Mettler; pitch; softening pointFIG. 5 Assembly of Mold for Pressure Molding Pitch into a Sample CupD3104 146SUMMARY OF CHANGESSubcommittee D02.05 has identified the location of selected changes to this standard since the last issue(D3104 99 (2010) that may impact the use of this standard. (Approved June 1, 20
