1、Designation: C 1258 94 (Reapproved 2000)Standard Test Method forElevated Temperature and Humidity Resistance of VaporRetarders for Insulation1This standard is issued under the fixed designation C 1258; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 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.1. Scope1.1 This test method covers the determination of the agingresistance of flexible low perme
3、ance vapor retarders forthermal insulation as classified in Specification C 1136. Watervapor permeance measurement and visual inspection afterexposure at elevated temperature and humidity are used toassess vapor retarder response.1.2 Typical vapor retarders applicable to this test methodthat are int
4、ended for indoor use include foil-scrim-kraft lami-nates, metallized polyester-scrim-kraft laminates, treated fab-rics, treated papers, films, foils, or combinations of thesematerials that may comprise a vapor retarder material. This testmethod is not intended for assessment of the liquid-appliedcoa
5、tings, sealants, or mastics commonly used with insulationproducts.1.3 The values stated in inch-pound units are to be regardedas standard. The SI units given in parentheses are for informa-tion purposes only.1.4 This standard does not purport to address all of thesafety concerns, if any, associated
6、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.2. Referenced Documents2.1 ASTM Standards:C 1136 Specification for Flexible, Low Permeance VaporRetarders f
7、or Thermal Insulation2E 96 Test Methods for Water Vapor Transmission of Mate-rials23. Summary of Test Method3.1 The vapor retarders are subjected to accelerated agingvia elevated temperature and humidity at 120F (49C) and95 % relative humidity for a period of 28 days, then visuallyinspected for corr
8、osion (if applicable), delamination, or otherdegradation. Water vapor permeance in accordance with TestMethods E 96 is measured after humid aging.4. Significance and Use4.1 On sub-ambient temperature systems, humid ambientconditions cause a vapor driving force toward the insulationwhich, if not reta
9、rded, is detrimental to the insulations thermalresistance. Therefore a vapor retarder should resist degrada-tion. Degradation in this test method is induced by elevatedtemperature and humidity conditions.5. Apparatus5.1 Environmental Chamber, capable of maintaining 120 62F (49 6 1C) and 95 6 2 % rel
10、ative humidity, using distilledor deionized water as the humidity source. The chamber shallbe of the air-circulating variety.5.2 Lighted Box in a Darkened RoomA lighted box is anenclosure having five opaque sides with one transparent glassor plastic viewing side. The box is illuminated using anincan
11、descent lightbulb. The viewing area shall be slightlysmaller than the vapor retarder specimen so that holes ordegradation caused by aging are readily visible.5.3 Cotton Gloves.5.4 Cardboard Overhead Transparency Frames or Equiva-lent.5.5 Stainless Steel Staples.5.6 Glass or Stainless Steel Rods.6. T
12、est Specimens6.1 From each sample cut four specimens that are largeenough to acquire water vapor permeance test specimens afterexposure. The specimens shall be cut in a manner which bestcharacterizes the roll width. Material exhibiting extraneousdamage from mishandling in shipment or during samplepr
13、eparation shall be avoided. A fifth specimen shall be cut andretained as a control. An 1134 in. (298 mm) by 1034 in. (273mm) specimen size is recommended since this is the size of atypical overhead transparency frame, which is useful to supportspecimens in the humidity chamber. In any case, the spec
14、imensize shall be at least 6 in. by 6 in. (152 mm by 152 mm).7. Aging Procedure7.1 Use clean cotton gloves during handling to avoidsurface contamination that may be confused with corrosion onfoil or metallized laminates.7.2 Once cut to the desired size, individually sandwich and1This test method is
15、under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.33 on InsulationFinishes and Moisture.Current edition approved March 15, 1994. Published May 1994.2Annual Book of ASTM Standards, Vol 04.06.1Copyright ASTM, 100 Barr Harbor Drive, W
16、est Conshohocken, PA 19428-2959, United States.staple the retarder specimens between two transparency framesor equivalent. The frames help to minimize curl and facilitatehandling without disturbing the specimen surface area. Num-ber the specimens 1 through 4, and retain the extra framedspecimen for
17、later comparisons.7.3 Mount the four frames on a glass rod. This is easilyaccomplished by using a paper punch on one corner of theframes and sliding the frames onto the rod. Space the frames atleast 1 in. (25 mm) apart.7.4 Suspend the rod with frames in the humidity chamber.The specimens shall be or
18、iented to allow air-flow parallel to thesurface.7.4.1 Carefully follow operation instructions of the testchamber to avoid surface condensation of the test specimens.Expose the specimens for 28 days at 120 6 2F (49 6 1C)and 95 % 6 2 relative humidity.7.4.2 Alternate methods of suspending specimens ma
19、y beused, provided specimen to specimen contact, or contact withpotentially reactive materials, is avoided. Specimens must haveadequate airspace and should never be oriented horizontally inthe cabinet.8. Evaluation8.1 At the end of 28 days, evaluate the specimens for thefollowing:8.1.1 For all produ
20、cts, place the specimens on the lightedbox and inspect for pinholes, large holes, or increased trans-lucency from the retained control specimen. Lightly marknoteworthy areas with a felt-tip pen.8.1.2 For foil laminates also inspect the foil surface forevidence of corrosion in the form of crystalline
21、 deposits. Thisinspection is easily accomplished in a darkroom by viewing thespecimen using a flashlight held at an angle. Corrosion depositshave an iridescent appearance when viewed in this manner.8.1.3 For all products, cut one water vapor permeancespecimen from each aged piece. Specimens shall be
22、 cut fromany noteworthy areas identified during the light box inspection.Determine the water vapor permeance in accordance with thedesiccant method of Test Methods E 96. The water vaporpermeance test temperature shall be 73 6 2F (23 6 1C);relative humidity shall be 50 6 2%.8.1.4 After the permeance
23、specimen is cut, carefully removethe remaining portion of sample from the test frames andinspect for evidence of delamination.9. Report9.1 The report shall include the following:9.1.1 A description of the material tested including supplies,type, lot number, and production date where possible, and9.1
24、.2 Any evidence of delamination if applicable, and9.1.3 Any evidence of corrosion if applicable, and9.1.4 Any evidence of metallization loss if applicable, and9.1.5 Water vapor permeance after aging.10. Precision and Bias10.1 No statement is made concerning the precision andbias of the visual inspec
25、tion portion of the accelerated aging ofvapor retarders for insulation, since results merely compareperformance to an unexposed control.10.2 Refer to Test Methods E 96 for precision and bias ofthe water vapor permeance determination.11. Keywords11.1 corrosion; humid aging; insulation; vapor retarder
26、;water vapor permeanceThe American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any suchpatent rights
27、, and the risk of 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 reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for r
28、evision of this standard or for additional standardsand should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsibletechnical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make
29、 yourviews known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM, 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 above address or at610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website (www.astm.org).C 12582
