1、Designation: D 1171 99 (Reapproved 2007)Standard Test Method forRubber DeteriorationSurface Ozone Cracking Outdoors orChamber (Triangular Specimens)1This standard is issued under the fixed designation D 1171; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case of revision, the year of 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.
3、1 This test method permits the estimation of the relativeability of rubber compounds used for applications requiringresistance to outdoor weathering or ozone chamber testing.1.2 This test method is not applicable to materials ordinarilyclassed as hard rubber, but is adaptable to molded or extrudedso
4、ft rubber materials and sponge rubber for use in windowweatherstripping as well as similar automotive applications.1.3 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
5、safety and health practices and determine the applica-bility of regulatory limitations prior to use. For a specifichazard statement, see Note 1 and 8.1.NOTE 1WarningOzone is a hazardous chemical.2. Referenced Documents2.1 ASTM Standards:2D 518 Test Method for Rubber DeteriorationSurfaceCrackingD 114
6、9 Test Methods for Rubber DeteriorationCrackingin an Ozone Controlled EnvironmentD 4575 Test Methods for Rubber DeteriorationReferenceandAlternative Method(s) for Determining Ozone Level inLaboratory Test Chambers3. Summary of Test Method3.1 Procedures are given for preparing triangular cross-sectio
7、n specimens, for mounting them in strained conditionaround specified circular mandrels, and for rating the effect ofexposure as evidenced by the appearance of surface cracks.The type, time, temperature, and other conditions of exposureare not given but shall be agreed upon by the purchaser and these
8、ller and shall be completely described in the test reports.3.2 Two techniques are described, the exposure rating andthe quality-retention rating.3.3 Refer to Test Methods D 4575 for the reference andoptional alternative methods for the measurement of the ozonepartial pressure in laboratory test cham
9、bers.4. Significance and Use4.1 Molded or extruded rubber products must withstand theeffects of ozone cracking and outdoor weathering for satisfac-tory use. This test enables a simple comparison of performanceto be made under specified test conditions, either in a labora-tory test chamber or in an o
10、utdoor test. No direct correlationbetween test performance and service performance can beclaimed due to the wide range of service conditions.5. Apparatus5.1 Mounting Mandrel A wood mandrel 50 mm (2 in.) inoutside diameter, suitably coated with spar varnish or a clearlacquer. The mandrel may be suppo
11、rted by any convenientmethod.5.2 Fastening Wire Enameled copper wire.5.3 Test Chamber An ozone chamber as described in TestMethods D 1149.6. Test Specimen6.1 The triangular cross-section test specimen shall be amolded, extruded, or sponge section with a continuous skin orsurface layer, 250 mm (10 in
12、.) long, and cured in a straightposition. The cross-sectional dimensions shall be as shown inFig. 1. Duplicate specimens shall be tested.6.2 It is recommended that the manufacturer observe aminimum rest period of 24 h between compound mixing andcompound preparation, and a minimum rest period of12 h1
13、This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.15 on Degradation Tests.Current edition approved Nov. 1, 2007. Published January 2008. Originallyapproved in 1951. Last previous edition approved in 1999 as D 1171 99.2For r
14、eferenced 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700,
15、West Conshohocken, PA 19428-2959, United States.Copyright by ASTM Intl (all rights reserved); Mon Oct 13 02:30:52 EDT 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.between compound preparation and curing when preparingspecimens. The fini
16、sh of the specimens shall be as smooth aspossible.METHOD AEXPOSURE RATING7. Procedure7.1 Mounting of SpecimensPlace bench marks on eachspecimen with a crayon, 190 mm (7.5 in.) apart and 32 mm(1.25 in.) from the ends. Form the specimens into a loop byplacing the 19-mm (0.75-in.) sides together and ty
17、ing securelywith wire at the bench marks. Slip the complete loop over themandrel. Place as many specimens on the mandrels as length ofmandrel will permit.7.2 Exposure of Specimens:7.2.1 Conditioning Period:7.2.1.1 Outdoor Exposure After the specimens aremounted allow them to condition for 70 to 72 h
18、 at roomtemperature in an ozone free atmosphere. Do not touch thelooped part after mounting until the test is completed.7.2.1.2 Ozone Chamber ExposureAfter the specimens aremounted allow them to condition for 70 to 72 h at 40 6 C(104 6 2F) either in a temperature controlled cabinet orpreferably in t
19、he ozone cabinet itself. After this conditioningperiod transfer to the ozone chamber or, if already conditioningin this apparatus, switch on the ozone so that it rises to a levelof 50 6 5 mPa partial ozone pressure.7.2.2 Angle and Direction and Positioning of Exposures:7.2.2.1 Incline specimens expo
20、sed outdoors so that theportion of the loop diametrically opposite the tied ends shallface south at an angle of 45 with the horizontal as shown inFig. 2.7.2.2.2 Ozone Chamber ExposurePosition in the chamberin which ozone is controlled as described in Test MethodsD 4575. The position of mounted speci
21、mens exposed in theozone test chamber shall be such that there is completecirculation of air around the specimens and the specimens donot touch anything during the necessary handling.7.2.3 Test Conditions:7.2.3.1 Outdoor Exposure The type, time, temperature,and other essential conditions of exposure
22、 shall be agreed uponby the purchaser and the seller.7.2.3.2 Ozone-Chamber Exposure Method AExposespecimens for 72 h at 40 6 1C (104 6 2F) at an ozone levelof 50 6 5 mPa partial ozone pressure, unless otherwisespecified by agreement between the purchaser and the seller.The specimens may be removed f
23、rom the test chamber after 24,48 and 72-h exposure for rating.7.2.3.3 Ozone-Chamber Exposure Method BOn materialsknown to be substantially resistant to ozone, test specimensand fixtures as described under Procedure B in Test MethodD 518 may be used. Expose specimens for 70 h at 406 1C(104 6 2F) at a
24、n ozone level of 50 6 5 mPa partial ozonepressure, unless otherwise specified by agreement between thepurchaser and seller. The specimens may be removed from thetest chamber after 22, 46, and 70-h exposure, for examination.7.3 Rating of Exposed SpecimensWhen the specifiedexposure period is completed
25、, examine the specimens beforeremoval from the mandrel, and evaluate the degree of crackingby comparison with the reference standards shown in Fig. 3using a 2-power headgear binocular magnifier or equivalent. Ifthe size of the cracks at 23 magnification is less than thoseshown on one photograph but
26、greater than those shown on thenext lower rating picture, give the lower rating.7.4 In ozone chamber exposure Method B, no rating isintended, rather, there shall be no cracks permitted under 23magnification.8. Hazards8.1 WarningOzone is a hazardous substance. Consultand follow all applicable laws, r
27、ules, and regulations re-garding exposure to ozone.9. Report9.1 Report the following information:9.1.1 Description of the specimen, giving the identificationnumber of compound and vulcanization data, if known, includ-ing date,9.1.2 Date of start of exposure, and complete informationdescribing condit
28、ions of exposure,9.1.3 Rating number of exposed specimens, and9.1.4 If desired, a photograph at 23 magnification.FIG. 1 Cross-Sectional Dimension of Test SpecimensFIG. 2 Outdoor Exposure of Test SpecimenD 1171 99 (2007)2Copyright by ASTM Intl (all rights reserved); Mon Oct 13 02:30:52 EDT 2008Downlo
29、aded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.METHOD BQUALITY-RETENTION RATING10. Procedure10.1 If it is desired to apply a quality-retention rating valuebased on three observations of crack rating taken at threesuccessive time intervals of exposu
30、re, use the followingprocedure:10.1.1 Prepare the test specimens as described in Section 6,and mount and expose as described in 7.1 and 7.2 except thatthe time of exposure shall be six weeks. Other periods ofoutdoor exposure may be used if agreed upon by producer andconsumer. Make the crack rating a
31、s described in 7.3 everysecond week or at three equal intervals. This will give threeratings.10.1.2 The three crack-growth ratings shall be put togetherto give a three-digit number and Table 1 then used to find thepercent quality retention. The three-digit crack-growth numberin the crack-growth colu
32、mn corresponds to the quality reten-tion in the right-hand column.11. Report11.1 Report the following information:11.1.1 Description of the specimen, giving the identificationnumber of the compound and date of vulcanization,11.1.2 Date of start of exposure and complete informationdescribing conditio
33、n of exposure,11.1.3 Crack rating number composed of three digits repre-senting three readings taken each two weeks for six weeks ortaken at three equal intervals, and11.1.4 Quality-retention value in percent.12. Precision and Bias12.1 Both the exposure rating and the quality-retentionrating are ess
34、entially rank order or qualitative comparisonRating 0 Rating 1 Rating 2 Rating 3FIG. 3 Ratings for Weathering Tests of Rubber Compounds (Specimens mounted on mandrel.) (23)TABLE 1 Quality Retention RatingCrack Growth Quality Retention, %000 100001 95011 90111 85002 80012 75112 70022 65122 60222 5500
35、3 45013 40113 35023 30123 25223 20033 15133 10233 5333 0D 1171 99 (2007)3Copyright by ASTM Intl (all rights reserved); Mon Oct 13 02:30:52 EDT 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.methods. Precision as normally expressed for qua
36、ntitative-measurement test methods is not directly applicable.13. Keywords13.1 crack growth; cracking; ozone; ozone cracking; surfacecrack; triangular; weatheringASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this st
37、andard. 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 committee and must be rev
38、iewed 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 meeting of theresponsi
39、ble 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 Box C700, West C
40、onshohocken, 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 1171 99 (2007)4Copyright by ASTM Intl (all rights reserved); Mon Oct 13 02:30:52 EDT 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.
