1、Designation: D 5440 93 (Reapproved 2003)Standard Test Method forDetermining the Melting Point of Fats and Oils1This standard is issued under the fixed designation D 5440; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. 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 is intended to determine the meltingpoint of all normal animal and vegetable fats and oils. This tes
3、tmethod was derived from ALCA H-16.1.2 This standard does not purport to address 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 limit
4、ations prior to use.2. Referenced Documents2.1 American Leather Chemists Association Standard:ALCA H-16 Melting Point23. Significance and Use3.1 This test method is intended to determine the meltingpoint of all normal animal and vegetable fats.3.2 The natural fats and oils, that is, those of animal
5、andvegetable origin, are mixtures of glycerides and other sub-stances and consist of a number of components. They do notexhibit either a definite or sharp melting point. Fats passthrough a stage of gradual softening before they becomecompletely liquid. The melting point then shall be defined bythe s
6、pecific conditions of the method by which it is determinedand, in this case, it shall be the temperature at which the samplebecomes perfectly clear and liquid.4. Apparatus4.1 Melting Point Tubes, capillary globe tubing, with aninside diameter of 1 mm and an outside diameter of 2 mm,max. A convenient
7、 length is 50 to 80 mm.4.2 Thermometer, 2 to 68C with 0.2C divisions.4.3 Glass Beaker, 600 mL.4.4 Heat Source, gas burner or electric hot plate.5. Procedure5.1 The sample shall be melted and filtered through filterpaper to remove any impurities and the last traces of moisture.The sample shall be abs
8、olutely dry. At least three cleancapillary tubes shall be dipped in the completely liquid sampleso that the fat stands approximately 10 mm high in each tube.One end of the tube (where the sample is located) shall befused in a small flame, taking care not to burn the fat.5.2 The tubes shall be placed
9、 in a beaker and held in arefrigerator at 4 to 10C (40 to 50F) overnight (16 h).5.2.1 The samples shall be completely liquid when the tubesare placed in the refrigerator. It is good practice to pass theends of the tubes containing the sample momentarily throughthe flame, just before they are taken t
10、o the refrigerator.5.3 After removing the tubes from the refrigerator, theyshall be attached to the thermometer, using a rubber band orany suitable means, so that the lower ends of the melting pointtubes shall be even with the bottom of the mercury bulb of thethermometer. The thermometer shall be su
11、spended in a 600 mLbeaker, which is about half full of clear distilled water and thebottom of the thermometer immersed approximately 30 mm.5.4 The starting bath temperature shall be adjusted to 8 to10C below the melting point of the sample at the beginning ofthe test. Agitation of the water bath sha
12、ll be made with a smallstream of air or other suitable means, and heat shall be appliedso the batch temperature is increased at the rate of approxi-mately 0.5C (1F) per min.5.5 Fats usually pass through an opalescent stage beforemelting completely. The heating shall be continued until thetubes are c
13、ompletely clear throughout. The temperature shallbe observed at which each tube becomes clear.5.6 The average of the melting point of all the tubes shall betaken and this average shall be reported as the melting point.6. Report6.1 Report the temperature recorded in 5.6 as the meltingpoint in this te
14、st method.7. Precision and Bias7.1 This test method is adopted from the procedure of theAmerican Leather Chemists Association where it has long beenin use, and where it was approved for publication before theinclusion of precision and bias statements was mandated. Theoriginal interlaboratory test da
15、ta is no longer available. Theuser is cautioned to verify by the use of reference materials, ifavailable, that the precision and bias (or reproducibility) of thistest method is adequate for the contemplated use.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the di
16、rect responsibility of Subcommittee D31.08 on Fats and Oils.Current edition approved May 10, 2003. Published June 2003. Originallyapproved in 1993. Last previous edition approved in 1997 as D 5440 93 (1997).2Available from American Leather Chemists Assn., Texas Tech University, P.O.Box 45300, Lubboc
17、k, TX 79409.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8. Keywords8.1 fats and oils; leather; melting pointASTM International takes no position respecting the validity of any patent rights asserted in connection with any item me
18、ntionedin 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 responsibility.This standard is subject to revision at any time by the responsible technical committe
19、e 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 addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeti
20、ng 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 address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO
21、 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 5440 93 (2003)2
