1、Designation: C 732 06Standard Test Method forAging Effects of Artificial Weathering on Latex Sealants1This standard is issued under the fixed designation C 732; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. 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. Scope1.1 This test method covers a laboratory procedure
3、 for thedetermination of aging effects of artificial weathering on latexsealants.1.2 The values stated in metric (SI) units are to be regardedas the standard. The values given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, asso
4、ciated 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.NOTE 1Currently there is no ISO standard similar to this test method.2. Referenced Documents2.1 ASTM
5、 Standards:2C 717 Terminology of Building Seals and SealantsC 1442 Practice for Conducting Tests on Sealants UsingArtificial Weathering Apparatus3. Terminology3.1 Definitions:3.1.1 Definitions of the following terms are found in Ter-minology C 717: adhesive failure (loss of adhesion); latexsealant;
6、sealant.4. Summary of Test Method4.1 The sealant is placed in a specially constructed wood-and-aluminum fixture (referred to as a “channel panel”) andexposed for intervals of 500 h to specified alternate wet and drycycles in an accelerated weathering unit, then periodicallyexamined for evidences of
7、deterioration.5. Significance and Use5.1 Accelerated weathering exposure serves to indicatelong-term exterior durability of the sealant. In this test method,durability is tested when the sealant is used with wood oraluminum.6. Apparatus6.1 Accelerated Weathering DeviceOne of the units asdescribed in
8、 Practice C 1442. Because of differences in spectralpower distributions of the exposure sources and exposureparameters used in the different types of devices described inPractice C 1442, test results may differ with the type ofaccelerated weathering device. Choice of type of device shallbe by mutual
9、 agreement among the interested parties.6.2 Channel Panel attached to a Sample Holder as shownin Fig. 1.6.3 Knife, for tooling.7. Sampling7.1 Use the sealant to be tested directly from the containeras commercially supplied by the manufacturer.8. Test Specimens8.1 Prepare two 25 by 70 by 175-mm (1 by
10、 234 by 7-in.)wood-and-aluminum channel panels as shown in Fig. 1, usingthe following materials:8.1.1 Exterior Fir Plywood, with a water-resistant thermosetglue such as urea or melamine-formaldehyde type.8.1.2 Ponderosa Pine Sapwood, white kiln dried and free ofknots or imperfections.8.1.3 Aluminum
11、Alloy 6063-T5 or 6061-T6, clear, anodizeda minimum of 30 min over a scale-free finish.8.1.4 Polyethylene Spacer of low-density film approxi-mately 5 mils (0.13 mm) thick.1This test method is under the jurisdiction ofASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of
12、 Subcommittee C24.40 onWeathering.Current edition approved Sept. 1, 2006. Published September 2006. Originallyapproved in 1972. Last previous edition approved in 2001 as C 732 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org.
13、 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, West Conshohocken, PA 19428-2959, United States.8.1.5 Screws and Nails, zinc-coated or nonrusting type.8.2 Using a
14、gun or knife, completely fill the two 7 by13-mm (14 by12-in.) channels in both panels with sealant,striking off the excess from the top and ends so that it is flushwith the panel surfaces.NOTE 2The length dimension of the channel may be reduced asneeded to accommodate the specimen holder requirement
15、s of the artificialweathering device available for use.9. Conditioning9.1 Condition both specimens for 7 days at 23 6 1C (73.46 2F) and 50 6 5 % relative humidity.10. Procedure10.1 Secure one or more test specimen(s) in the artificialweathering unit and cycle for intervals of 500 h, beginningwith th
16、e start of the light cycle. Refer to Practice C 1442 for theartificial weathering unit operating conditions. Expose speci-mens in the xenon arc device for a minimum of 500 h at anirradiance level of 0.51 W/(m2 nm) at 340 nm. The radiantexposure for this is 918 kJ/(m2 nm) at 340 nm. To determinethe e
17、xposure time required to obtain the same radiant exposureat other irradiance levels specified in Practice C 1442, seeAnnex A1 in C 1442.10.2 Maintain an unexposed file specimen at standard con-ditions until the accelerated weathering exposure is complete.Metric Equivalents Materials:in. mm in. mm 13
18、8 by 234 by 7-in. plywood14 6.434 19.1 114 by34 by 7-in. aluminum38 9.5 234 69.9 214 by12 by 7-in. ponderosa white pine12 12.7 7 177.8 1234 by 7-in. sheet untreated polyethylene3 Screws6 Nails1 Aluminum PanelFIG. 1 Channel Panel attached to a Sample HolderC73206210.3 After the test specimen has been
19、 exposed as specifiedin 10.1, remove it, allow it to cool to 23 6 1C (73.4 6 2F).Examine it visually for wash-out, slump, cracking, loss ofadhesion to the wood or aluminum, and discoloration.11. Report11.1 Report the type and description of the laboratoryaccelerated weathering device and the length
20、of time the testspecimen(s) was/were exposed in the artificial weatheringdevice. Compare the exposed specimen with the unexposed filespecimen, and report any changes in wash-out, slump, crack-ing, loss of adhesion, or discoloration.12. Precision and Bias12.1 No statement is made about either the pre
21、cision or thebias of this test method for measuring wash-out, slump,cracking, or loss of adhesion since the result merely stateswhether there is conformance to the criteria for successspecified in the procedure.13. Keywords13.1 artificial weathering; latex sealantASTM International takes no position
22、 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 responsibility.T
23、his 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 addressed to ASTM In
24、ternational 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 address show
25、n 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).C732063
