1、Designation: D 5551 95 (Reapproved 2006)Standard Test Method forDetermination of the Cloud Point of Oil1This standard is issued under the fixed designation D 5551; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the cloudpoint of oils used in the softening and stuffing of leather and inthe
3、manufacture of fat liquors and other softening and stuffingcompounds. This test method was derived from Test MethodsD 97 and D 2500.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to addre
4、ss all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D97 Test Method
5、 for Pour Point of Petroleum ProductsD 2500 Test Method for Cloud Point of Petroleum ProductsE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 cloud pointthat temperature, expressed as a multipleof 1C (2F), at which a cloud or haze of wax crystals appearsat the bottom of the te
6、st jar when the oil is cooled underprescribed conditions.4. Significance and Use4.1 This test method is intended to determine the cloudpoint of oils used in the softening and stuffing of leather, aswell as those used in the manufacture of products for suchpurpose. The cloud point of oils is measured
7、 for the purpose ofquality assurance.5. Apparatus5.1 Test Jar, clear cylindrical glass, flat bottom, 30- to33.5-mm inside diameter, and 115- to 125-mm height. Toindicate sample height the jar should be marked with a line 546 3 mm above the inside bottom.5.2 Thermometers, having ranges shown below an
8、d con-forming to the requirements prescribed in Specification E1forthermometers:ThermometerTemperature NumberThermometer Range ASTM IPHigh cloud and pour 38 to +50C 5C 1CLow cloud and pour 80 to +20C 6C 2CMelting point +32 to +127C 61C 63C5.2.1 Since separation of liquid column thermometers occa-sio
9、nally occurs and may escape detection, thermometersshould be checked immediately prior to the test and used onlyif they prove accurate within 6 1C (for example, ice point).5.3 Cork, to fit the test jar, bored centrally for the testthermometer.1This test method is under the jurisdiction ofASTM Commit
10、tee D31 on Leatherand is the direct responsibility of Subcommittee D31.08 on Fats and Oils. This testmethod was developed in cooperation with the American Leather Chemists Assn.(Method H 18-1957).Current edition approved April 1, 2006. Published April 2006. Originallyapproved in 1994. Last previous
11、edition approved in 2001 as D 5551 95(2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.NOTE 1All dimensi
12、ons in millimetres.FIG. 1 Apparatus for Cloud Point Test1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 Jacket, metal or glass, watertight, cylindrical, flat bot-tom, 115 mm in depth, 42- to 50-mm inside diameter. It mustbe suppo
13、rted firmly in a vertical position in the cooling bath of5.7 so that not more than 25 mm projects out of the coolingmedium.5.5 Disk, cork or felt, 6 mm thick, to fit loosely inside thejacket.5.6 Gasket, to fit snugly around the outside of the test jarand loosely inside the jacket. The gasket may be
14、made ofrubber, leather, or other material that is elastic enough to clingto the test jar and hard enough to hold its shape. Its purpose isto prevent the test jar from touching the jacket.5.7 Bath or Baths, maintained at prescribed temperatureswith a firm support to hold the jacket vertical. The requ
15、iredbath temperatures may be obtained by refrigeration if avail-able, otherwise by suitable freezing mixtures. Freezing mix-tures commonly used for temperatures down to those shownare as follows:For Tempera-tures DownIce and water 9CCrushed ice and sodium chloride crystals 12CCrushed ice and calcium
16、 chloride crystals 27CAcetone or petroleum naphtha (see Section 6) chilled in acovered metal beaker with an ice-salt mixture to 12C thenwith enough solid carbon dioxide to give the desired temper-ature.57CNOTE 1There are automatic pour point testers available and in usethat may be advantageous in th
17、e saving of test time, permit the use ofsmaller samples, and have other factors that may merit their use. Ifautomatic testers are used, the user must ensure that all of the manufac-turers instructions for calibration, adjustment, and operation of theinstrument are followed. It must be reported that
18、the pour point wasdetermined by an automatic instrument. Precision of automatic pour pointtesters has not been determined. In any case of dispute, the pour point, asdetermined by the manual method described herein, shall be consideredthe reference test.6. Reagents and Materials6.1 The following solv
19、ents of technical grade are appropri-ate for low-temperature bath media.6.2 Acetone.(WarningExtremely flammable.)6.3 Alcohol, Ethanol.(WarningFlammable.)6.4 Alcohol, Methanol.(WarningFlammable. Vaporharmful.)6.5 Petroleum Naphtha.(WarningCombustible. Vaporharmful.)6.6 Solid Carbon Dioxide.(WarningEx
20、tremelycold 78.5C.)7. Procedure7.1 Bring the oil to be tested to a temperature at least 14C(25F) above the approximate cloud point. Remove any mois-ture present by any suitable method, such as by filtrationthrough dry lintless filter paper until the oil is perfectly clear,but make such filtration at
21、 a temperature of at least 14C (25F)above the approximate cloud point.7.2 Pour the clear oil into the test jar to the level mark.7.3 Close the test jar tightly by the cork carrying the testthermometer (Note 2). Use the high cloud and pour thermom-eter if the expected cloud point is above 38C (36F) a
22、nd thelow cloud and pour thermometer if the expected cloud point isbelow 38C (36F). Adjust the position of the cork and thethermometer so that the cork fits tightly, the thermometer andthe jar are coaxial, and the thermometer bulb is resting on thebottom of the jar.NOTE 2Since separation of the merc
23、ury or toluene thread of cloudand pour thermometers occasionally occurs, and since such separationmay otherwise escape immediate detection, it is suggested that the icepoints of the thermometers be checked immediately prior to the test. Anythermometer that shows as ice point differing from 0C (32F)
24、by morethan 1C (2F) should be further examined or recalibrated, or both, beforeuse.7.4 Place the disk in the bottom of the jacket. Place the ringgasket around the test jar, 25 mm (1 in.) from the bottom. Thedisk, gasket, and inside of the jacket shall be clean and dry.Insert the test jar in the jack
25、et.7.5 Maintain the temperature of the cooling bath at 1to +2C (30 to 35F). Support the jacket containing the test jarfirmly in a vertical position in the cooling bath so that not morethan 25 mm (1 in.) of the jacket projects out of the coolingmedium.7.6 At each test thermometer reading that is a mu
26、ltiple of1C (2F), remove the test jar from the jacket quickly butwithout disturbing the oil, inspect for cloud, and replace in thejacket. This complete operation shall require not more than 3 s.If the oil does not show a cloud when it has been cooled to10C (50F), transfer the test jar to another jac
27、ket in a secondbath maintained at a temperature of 18 to 15C (0 to +5F).(Do not transfer the jacket.) If the oil does not show a cloudwhen it has been cooled to 7C (20F), transfer the test jar toanother jacket in a third bath maintained at a temperatureof 34 to 32C (30 to 25F). For the determination
28、 of verylow cloud points, additional baths are required, each bath to bemaintained at 17C (30F) below the temperature of thepreceding bath. In each case transfer the test jar when thetemperature of the oil reaches a point 28C (50F) above thetemperature of the new bath. At no time place the cold test
29、 jardirectly in the cooling medium.7.7 When such inspection first reveals a distinct cloudinessor haze in the oil at the bottom of the test jar, record the readingof the test thermometer as the cloud point.NOTE 3Awax cloud or haze is always noted first at the bottom of thetest jar where the temperat
30、ure is lowest.Aslight haze throughout the entiresample, which slowly becomes more apparent as the temperature islowered, is usually due to traces of water in the oil. Generally, this waterhaze will not interfere with the determination of the wax cloud point. Inmost cases of interference, filtration
31、through dry lintless filter papers suchas described in 7.1 is sufficient.In the case of diesel fuels, however, if the haze is very dense, a freshportion of the sample should be dried by shaking 100 mL with5gofanhydrous sodium sulfate for at least 5 min and then filtering through drylintless filter p
32、aper. Given sufficient contact time, this procedure willremove or sufficiently reduce the water haze so that the wax cloud can bereadily discerned.Drying and filtering should be done always at a temperature at least14C (25F) above the approximate cloud point but otherwise not inexcess of 49C (120F).
33、8. Report8.1 Report the temperature recorded in 7.7 as the cloudpoint.D 5551 95 (2006)29. Precision and Bias9.1 Precision:9.1.1 OilsThe following criteria should be used for judg-ing the acceptability of results (95 % confidence):9.1.1.1 RepeatabilityDuplicate results by the same opera-tor should be
34、 considered suspect if they differ by more than2C (4F), in the case of distillate oils, and by more than 6C(10F) in the case of other oils.9.1.1.2 ReproducibilityThe results submitted by each oftwo laboratories should be considered suspect if the two resultsdiffer by more than 4C (8F), in the case o
35、f distillate oils, andby more than 6C (10F) in the case of other oils.9.2 BiasThere being no criteria for measuring bias inthese test-product combinations, no statement of bias can bemade.10. Keywords10.1 cloud point; fat liquors; leather; oil; softening andstuffing compoundsASTM International takes
36、 no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own resp
37、onsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addresse
38、d to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the
39、address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 5551 95 (2006)3
