1、Designation: D5551 95 (Reapproved 2012)Standard Test Method forDetermination of the Cloud Point of Oil1This standard is issued under the fixed designation D5551; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 man
3、ufacture of fat liquors and other softening and stuffingcompounds. This test method was derived from Test MethodsD97 and D2500.1.2 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 address al
4、l 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 for
5、Pour Point of Petroleum ProductsD2500 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 test jar
6、 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 for t
7、he 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 and con-
8、forming to the requirements prescribed in Specification E1 forthermometers: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-sionally
9、 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.5.4 Jacket, metal or glass, watertight, cylindrical, flat bot-
10、tom, 115 mm in depth, 42- to 50-mm inside diameter. It must1This test method is under the jurisdiction ofASTM Committee 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
11、 H 18-1957).Current edition approved April 1, 2012. Published April 2012. Originallyapproved in 1994. Last previous edition approved in 2006 as D5551 95(2006).DOI: 10.1520/D5551-95R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm
12、.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.NOTE 1All dimensions in millimetres.FIG. 1 Apparatus for Cloud Point Test1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Uni
13、ted States.be supported 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.
14、 The gasket may be 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
15、 vertical. The requiredbath 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 12CCrus
16、hed ice and calcium 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
17、 advantageous in the 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 mus
18、t be reported that 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
19、 The following solvents 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
20、 Dioxide.(WarningExtremelycold 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
21、 such filtration at 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 i
22、s above 38C (36F) and 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 sep
23、aration of the mercury 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 diffe
24、ring from 0C (32F) 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 t
25、est jar in the jacket.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 r
26、eading that is a multiple 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
27、 jar to another jacket 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). Fo
28、r the determination 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
29、place the cold test 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
30、 where the temperature 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 interf
31、erence, filtration 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 d
32、rylintless filter paper. 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 inex
33、cess of 49C (120F).8. Report8.1 Report the temperature recorded in 7.7 as the cloudpoint.D5551 95 (2012)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 o
34、pera-tor should be 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 (
35、8F), in the case of 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 I
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39、Standards, at the 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D5551 95 (2012)3
