1、Designation: C 765 97 (Reapproved 2007)Standard Test Method forLow-Temperature Flexibility of Preformed Tape Sealants1This standard is issued under the fixed designation C 765; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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.1. Scope1.1 This test method covers a laboratory procedure fortesting the low-temperature flexibility of preformed tape sea
3、l-ants.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.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 a
4、ppro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 717 Terminology of Building Seals and SealantsE 145 Specification for Gravity-Convection and Forced-Ventilation Ovens3. Terminology3.1 Definiti
5、onsThe definitions of the following terms usedin this test method are found in Terminology C 717: preformedtape sealant, sealant.4. Summary of Test Method4.1 The preformed tape sealant to be tested is applied to analuminum panel. The assembly is heat aged, then placed in thefreezer where the panel i
6、s quickly bent over a mandrel. Thespecimen is examined for cracking and loss of adhesion.5. Significance and Use5.1 Preformed tape sealants are tacky, deformable solidsthat are used under compression between two substrates in avariety of sealing applications. This procedure is not intendedto simulat
7、e an actual use condition, but it will give someindication of the flexibility and adhesion of a tape at lowtemperature. It can serve to differentiate between flexible tapesthat can take some movement and those that tend to harden orembrittle on aging and crack or lose adhesion when flexed atlow temp
8、erature. It will also aid in identifying sealants thathave poor flexibility because they are overextended andcontain a low level of binder as well as those sealants havingbinders that will embrittle at low temperature.6. Apparatus6.1 Freezer Unit, capable of maintaining a temperatureof236 2C (10 6 3
9、.6F).6.2 Aluminum Panel (unpolished), approximately 0.635mm (0.025 in.) thick, 76 mm (3 in.) wide, and 152 mm (6 in.)long.6.3 Steel Mandrel, 25.4 mm (1 in.) in diameter, withsupporting holder or rack.6.4 Vented Air Circulating Oven, that complies with Speci-fication E 145 and is capable of maintaini
10、ng a temperature of70 6 2C (158 6 3.6F).7. Sampling7.1 Samples to be tested shall be taken from a fresh roll oftape sealant after first removing and discarding approximatelythe first 0.61 m (2 ft) of the roll.8. Test Specimen8.1 Prepare the test specimen as follows:8.1.1 Clean the 76-mm by 152-mm (3
11、-in by 6-in.) alumi-num panel with methyl ethyl ketone or similar solvent.8.1.2 Place a 102-mm (4-in.) length of tape in the center ofthe panel with its length paralleling that of the panel, leavingthe release paper in place on the preformed tape sealant.8.1.3 Apply light finger pressure to ensure i
12、ntimate contactof the preformed tape sealant with the panel.8.1.4 Remove the release paper from the test specimen.9. Conditioning9.1 Place the specimen in a horizontal position in a forced-draft oven and condition for 14 days at 70 6 2C (158 63.6F).9.2 Remove the test specimen from the oven and imme
13、di-ately place it in a horizontal position in a freezer unitmaintained at 236 2C (10 6 3.6F) for 4 h.1This test method is under the jurisdiction ofASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of Subcommittee C24.20 onGeneral Test Methods.Current edition approved
14、June 1, 2007. Published July 2007. Originally approvedin 1973. Last previous edition approved in 2001 as C 765 97(2001)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, ref
15、er 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.9.3 Condition the steel mandrel with its holder or rack in thefreezer in the same manner.10. Procedure10.1 After the specime
16、n and mandrel have been conditionedfor 4 h and while they are still in the freezer at 236 2C (106 3.6F), bend the test specimen 180 around the mandrel,with the aluminum panel next to the mandrel, using no morethan2stomake the bend.10.2 Visually examine the specimen for cracking or loss ofadhesion of
17、 tape to panel, or both, and estimate the area of suchadhesion loss to the nearest 64.5 mm2(0.1 in.2).11. Report11.1 Report the following information:11.1.1 Identification of the preformed tape sealant, that is,the name, lot number, and any other identifying characteristics.11.1.2 Amount of adhesion
18、 loss on the specimen in terms ofpercentage of the total tape area.11.1.3 Description of any cracking. Indicate the degree,depth, extent, and location of cracks.12. Precision and Bias12.1 No statement can be made on the repeatability andreproducibility of the procedure in this test method for rating
19、adhesion loss and cracking because all four laboratories testingthree materials obtained the same result, none, for all samplestested.13. Keywords13.1 flexibility; low-temperature flexibility; preformed tapesealants; tapes; tape sealantsASTM International takes no position respecting the validity of
20、 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.This standard is subject to
21、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 International Headquarters. Y
22、our 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 shown below.This standard is co
23、pyrighted 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).C 765 97 (2007)2
