1、Designation: D1171 99 (Reapproved 2007)D1171 15Standard Test Method forRubber DeteriorationSurface Ozone Cracking Outdoors orChamber (Triangular Specimens)1This standard is issued under the fixed designation D1171; the number immediately following the designation indicates the year oforiginal adopti
2、on or, in the case of revision, 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.This standard has been approved for use by agencies of the U.S. Department of Defense.
3、1. Scope1.1 This test method permits the estimation of the relative ability of rubber compounds used for applications requiring resistanceto outdoor weathering or ozone chamber testing.weathering.1.2 This test method is not applicable to materials ordinarily classed as hard rubber, but is adaptable
4、to molded or extruded softrubber materials and sponge rubber for use in window weatherstripping as well as similar automotive applications.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard t
5、o establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For a specific hazard statement, see Note 1 and 8.1.NOTE 1WarningOzone is a hazardous chemical.2. Referenced Documents2.1 ASTM Standards:2D518 Test Method for Rubber Deteriorati
6、onSurface Cracking (Withdrawn 2007)3NOTE 2The procedures in Test Method D518 have been incorporated as Procedures B1, B2, and B3 in Test Methods D1149.D1149 Test Methods for Rubber DeteriorationCracking in an Ozone Controlled EnvironmentD4575 Test Methods for Rubber DeteriorationReference and Altern
7、ative Method(s) for Determining Ozone Level inLaboratory Test Chambers3. Summary of Test Method3.1 Procedures are given for preparing triangular cross-section specimens, for mounting them in strained condition aroundspecified circular mandrels, and for rating the effect of exposure as evidenced by t
8、he appearance of surface cracks. The type, time,temperature, and other conditions of exposure are not given but shall be agreed upon by the purchaser and the seller and shall becompletely described in the test reports.3.2 Two techniques are described, the exposure rating and the quality-retention ra
9、ting.3.3 Refer to Test Methods D4575 for the reference and optional alternative methods for the measurement of the ozone partialpressure in laboratory test chambers.4. Significance and Use4.1 Molded or extruded rubber products must withstand the effects of ozone cracking and outdoor weathering for s
10、atisfactoryuse. This test enables a simple comparison of performance to be made under specified test conditions, either in a laboratory testchamber or in conditions in an outdoor test. No direct correlation between test performance and service performance can beclaimed due to the wide range of servi
11、ce conditions.1 This test method is under the jurisdiction of ASTM Committee D11 on Rubber and is the direct responsibility of Subcommittee D11.15 on Degradation Tests.Current edition approved Nov. 1, 2007July 1, 2015. Published January 2008September 2015. Originally approved in 1951. Last previous
12、edition approved in 19992007as D1171 99.D1171 99 (2007). DOI: 10.1520/D1171-99R07.10.1520/D1171-15.2 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 Docu
13、ment Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.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. Because
14、it may not be technically possible 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.Copyright ASTM International, 100 Barr
15、 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Apparatus5.1 Mounting MandrelAwood mandrel 50 mm (2 in.) in outside diameter, suitably coated with spar varnish or a clear lacquer.The mandrel may be supported by any convenient method.5.2 Fastening Wire Enameled copper w
16、ire.5.3 Test Chamber An ozone chamber as described in Test Methods D1149.6. Test Specimen6.1 The triangular cross-section test specimen shall be a molded, extruded, or sponge section with a continuous skin or surfacelayer, 250 mm (10 in.) long, and cured in a straight position. The cross-sectional d
17、imensions shall be as shown in Fig. 1. Duplicatespecimens shall be tested.6.2 It is recommended that the manufacturer observe a minimum rest period of 24 h between compound mixing and compoundpreparation, and a minimum rest period of 12 h between compound preparation and curing when preparing specim
18、ens. The finishof the specimens shall be as smooth as possible.METHOD AEXPOSURE RATING7. Procedure7.1 Mounting of SpecimensPlace bench marks on each specimen with a crayon, 190 mm (7.5 in.) apart and 32 mm (1.25 in.)from the ends. Form the specimens into a loop by placing the 19-mm (0.75-in.) sides
19、together and tying securely with wire at thebench marks. Slip the complete loop over the mandrel. Place as many specimens on the mandrels as length of mandrel will permit.7.2 Exposure of Specimens:7.2.1 Conditioning Period:7.2.1.1 Outdoor ExposureAfter the specimens are mounted allow them to conditi
20、on for 70 to 72 h at room temperature in anozone free atmosphere. Do not touch the looped part after mounting until the test is completed.7.2.1.2 Ozone Chamber ExposureAfter the specimens are mounted allow them to condition for 70 to 72 h at 40 6 C (1046 2F) either in a temperature controlled cabine
21、t or preferably in the ozone cabinet itself. After this conditioning period transferto the ozone chamber or, if already conditioning in this apparatus, switch on the ozone so that it rises to a level of 50 6 5 mPapartial ozone pressure.7.2.2 Angle and Direction and Positioning of Exposures:7.2.2.1 I
22、ncline specimens exposed outdoors so that the portion of the loop diametrically opposite the tied ends shall face southat an angle of 45 with the horizontal as shown in Fig. 2.7.2.2.2 Ozone Chamber ExposurePosition in the chamber in which ozone is controlled as described in Test Methods D4575.The po
23、sition of mounted specimens exposed in the ozone test chamber shall be such that there is complete circulation of air aroundthe specimens and the specimens do not touch anything during the necessary handling.7.2.3 Test Conditions:7.2.3.1 Outdoor ExposureThe type, time, temperature, and other essenti
24、al conditions of exposure shall be agreed upon by thepurchaser and the seller.7.2.3.2 Ozone-Chamber Exposure Method AExpose specimens for 72 h at 40 6 1C (104 6 2F) at an ozone level of 50 65 mPa partial ozone pressure, unless otherwise specified by agreement between the purchaser and the seller. Th
25、e specimens maybe removed from the test chamber after 24, 48 and 72-h exposure for rating.7.2.3.3 Ozone-Chamber Exposure Method BOn materials known to be substantially resistant to ozone, test specimens andfixtures as described under Procedure B in Test Method D518 may be used. Expose specimens for
26、70 h at 406 1C (104 6 2F)at an ozone level of 50 6 5 mPa partial ozone pressure, unless otherwise specified by agreement between the purchaser and seller.The specimens may be removed from the test chamber after 22, 46, and 70-h exposure, for examination.7.3 Rating of Exposed SpecimensWhen the specif
27、ied exposure period is completed, examine the specimens before removalfrom the mandrel, and evaluate the degree of cracking by comparison with the reference standards shown in Fig. 3 using a 2-powerheadgear binocular magnifier or equivalent. If the size of the cracks at 2 magnification is less than
28、those shown on one photographbut greater than those shown on the next lower rating picture, give the lower rating.FIG. 1 Cross-Sectional Dimension of Test SpecimensD1171 1527.4 In ozone chamber exposure Method B, no rating is intended, rather, there shall be no cracks permitted under 2magnification.
29、8. Hazards8.1 WarningOzone is a hazardous substance. Consult and follow all applicable laws, rules, and regulations regardingexposure to ozone.9. Report9.1 Report the following information:9.1.1 Description of the specimen, giving the identification number of compound and vulcanization data, if know
30、n, includingdate,9.1.2 Date of start of exposure, and complete information describing conditions of exposure,9.1.3 Rating number of exposed specimens, and9.1.4 If desired, a photograph at 2 magnification.METHOD BQUALITY-RETENTION RATING10. Procedure10.1 If it is desired to apply a quality-retention
31、rating value based on three observations of crack rating taken at three successivetime intervals of exposure, use the following procedure: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 that thetime of exposure shall be six weeks.
32、Other periods of outdoor exposure may be used if agreed upon by producer and consumer.Make the crack rating as described in 7.3 every second week or at three equal intervals. This will give three ratings.10.1.2 The three crack-growth ratings shall be put together to give a three-digit number and Tab
33、le 1 then used to find the percentquality retention. The three-digit crack-growth number in the crack-growth column corresponds to the quality retention in theright-hand column.11. Report11.1 Report the following information:11.1.1 Description of the specimen, giving the identification number of the
34、 compound and date of vulcanization,11.1.2 Date of start of exposure and complete information describing condition of exposure,11.1.3 Crack rating number composed of three digits representing three readings taken each two weeks for six weeks or takenat three equal intervals, and11.1.4 Quality-retent
35、ion value in percent.12. Precision and Bias12.1 Both the exposure rating and the quality-retention rating are essentially rank order or qualitative comparison methods.Precision as normally expressed for quantitative-measurement test methods is not directly applicable.13. Keywords13.1 crack growth; c
36、racking; ozone; ozone cracking; surface crack; triangular; weatheringFIG. 2 Outdoor Exposure of Test SpecimenD1171 153ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly
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40、ividual 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
41、 from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 0 Rating 1 Rating 2 Rating 3FIG. 3 Ratings for Weathering Tests of Rubber Compounds (Specimens mounted on mandrel.)mandrel) (2)TABLE 1 Quality Retention RatingCrack Growth Quality Retention, %000 100001 95011 90111 85002 80012 75112 70022 65122 60222 55003 45013 40113 35023 30123 25223 20033 15133 10233 5333 0D1171 154
