ASTM C1303-2008 Standard Test Method for Predicting Long-Term Thermal Resistance of Closed-Cell Foam Insulation.pdf

1、Designation: C 1303 08Standard Test Method forPredicting Long-Term Thermal Resistance of Closed-CellFoam Insulation1This standard is issued under the fixed designation C 1303; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea

2、r 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.1. Scope1.1 This test method covers a procedure for predicting thelong-term thermal resistance (LTTR) of unfaced or permeably

3、faced rigid gas-filled closed-cell foam insulations by reducingthe specimen thickness to accelerate aging under controlledlaboratory conditions (1-5) .21.2 Rigid gas-filled closed-cell foam insulation includes allcellular plastic insulations manufactured with the intent toretain a blowing agent othe

4、r than air.1.3 This test method is limited to unfaced or permeablyfaced, homogeneous materials. This method is applied to awide range of rigid closed-cell foam insulation types, includingbut not limited to: extruded polystyrene, polyurethane, poly-isocyanurate, and phenolic. This test method does no

5、t apply toimpermeably faced rigid closed-cell foams or to rigid closed-cell bun stock foams.NOTE 1See Note 7 for more details regarding the applicability of thistest method to rigid closed-cell bun stock foams.1.4 This test method utilizes referenced standard test proce-dures for measuring thermal r

6、esistance. Periodic measurementsare performed on specimens to observe the effects of aging.Specimens of reduced thickness (that is, thin slices) are used toshorten the time required for these observations. The results ofthese measurements are used to predict the long-term thermalresistance of the ma

7、terial.1.5 The test method is given in two parts. The PrescriptiveMethod in Part A provides long-term thermal resistance valueson a consistent basis that can be used for a variety of purposes,including product evaluation, specifications, or product com-parisons. The Research Method in part B provide

8、s a generalrelationship between thermal conductivity, age, and productthickness.1.5.1 To use the Prescriptive Method, the date of manufac-ture must be known, which usually involves the cooperation ofthe manufacturer.1.6 The values stated in SI units are to be regarded as thestandard. The inch-pound

9、values given in parentheses are forinformation only.1.7 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 safety and health practices and determine the applica-bility of

10、 regulatory limitations prior to use.1.8 Table of Contents:SectionScope 1Reference Documents 2Terminology 3Summary of Test Method 4Significance and Use 5Part A: The Prescriptive Method 6Applicability 6.1Qualification Requirements 6.1.1Facing Permeability 6.1.2Apparatus 6.2Sampling 6.3Schedule 6.3.1R

11、epresentative Replicate Product Sheets 6.3.2Replicate Test Specimen Sets 6.3.3Specimen Preparation 6.4Goal 6.4.1Schedule 6.4.2Specimen Extraction 6.4.3Slice Flatness 6.4.4Slice Thickness 6.4.5Stack Composition 6.4.6Storage Conditioning 6.5Test Procedure 6.6Thermal Resistance Measurement Schedule 6.6

12、.1Thermal Resistance Measurements 6.6.2Product Density 6.6.3Calculations 6.7Part B: The Research Method 7Background 7.1TDSL Apparatus 7.2Sampling Schedule 7.3Specimen Preparation 7.4Storage Conditioning 7.5Test Procedure 7.6Calculations 7.7Reporting 8Reporting for Part A, the Prescriptive Method 8.1

13、Reporting for Part B, the Research Method 8.2Precision and Bias 9Keywords 10Mandatory Information Qualification Annex A1Specimen Preparation A1.1Homogeneity Qualification A1.21This test method is under the jurisdiction ofASTM Committee C16 on ThermalInsulation and is the direct responsibility of Sub

14、committee C16.30 on ThermalMeasurement.Current edition approved Sept. 15, 2008. Published October 2008. Originallyapproved in 1995. Last previous edition approved in 2007 as C 1303 07.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.1Copyright ASTM Inte

15、rnational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Aging Equivalence Test Procedure A1.3Alternate Product Thickness Qualification A1.4Example Calculations A1.5Mandatory Information-Preparation of TestSpecimens for Spray-Foam ProductsAnnex A2Effect Of TDSL

16、AppendixX1History of the Standard AppendixX2Theory of Foam Aging AppendixX3References2. Referenced Documents2.1 ASTM Standards:3C 168 Terminology Relating to Thermal InsulationC 177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Pl

17、ate ApparatusC 518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC 578 Specification for Rigid, Cellular Polystyrene ThermalInsulationC 591 Specification for Unfaced Preformed Rigid CellularPolyisocyanurate Thermal InsulationC 1029 Specification

18、 for Spray-Applied Rigid CellularPolyurethane Thermal InsulationC 1045 Practice for Calculating Thermal TransmissionProperties Under Steady-State ConditionsC 1126 Specification for Faced or Unfaced Rigid CellularPhenolic Thermal InsulationC 1289 Specification for Faced Rigid Cellular Polyisocya-nura

19、te Thermal Insulation BoardD 1622 Test Method for Apparent Density of Rigid CellularPlasticsD 2856 Test Method for Open-Cell Content of Rigid Cel-lular Plastics by the Air Pycnometer4D 6226 Test Method for Open Cell Content of Rigid Cel-lular PlasticsE 122 Practice for Calculating Sample Size to Est

20、imate,With Specified Precision, the Average for a Characteristicof a Lot or Process2.2 Other Standards:CAN/ULC S770 Standard Test Method for Determinationof Long-Term Thermal Resistance of Closed-Cell Ther-mal Insulation Foams52.3 ASTM Adjuncts:Test Method for Predicting Long-Term Thermal Resistance

21、of Closed-Cell Foam Insulation63. Terminology3.1 DefinitionsFor definitions of terms and symbols usedin this test method, refer to Terminology C 168.3.2 Definitions of Terms Specific to This Standard:3.2.1 aging, vthe change in thermophysical properties ofrigid closedcell plastic foam with time, pri

22、marily due tochanges in the composition of the gas contained within theclosed cells.3.2.2 core slice, na thin-slice foam specimen that wastaken at least 5 mm (0.2 in.) or 25 % of the product thickness,whichever is greater, away from the surface of the full-thickness product.3.2.3 effective diffusion

23、 thickness, n one-half of the geo-metric thickness minus the total thickness of damaged surfacelayer(s) (TDSL).3.2.4 facing, na material adhered to the surface of foaminsulation, including any foam product that has been suffusedinto the facing material, but not inclusive of any skin formedby the foa

24、m insulation itself.3.2.5 homogeneous material, nsufficiently uniform instructure and composition to meet the requirements of this testmethod (see A1.2).3.2.6 long-term, adjfor the purposes of the PrescriptiveMethod, long term refers to five years.3.2.7 normalized service life, nproduct service life

25、 di-vided by the square of the full product thickness, units oftime/length2.3.2.8 scaled time, ntime divided by the square of thespecimen thickness.3.2.9 scaled service life, ntime necessary for a thinspecimen to reach the same thermal conductivity that a fullthickness specimen would reach at the en

26、d of its service life,equals the product service life multiplied by the square of theratio of the average slice thickness to the full product thickness,value has units of time.3.2.10 service life, nthe anticipated period of time that thematerial is expected to maintain claimed thermophysical prop-er

27、ties, may be dependent on the specific end-use application.3.2.11 surface slice, na thin-slice foam specimen that wasoriginally adjacent to the surface of the full-thickness productand that includes any facing that was adhered to the surface ofthe original full-thickness product.3.2.12 thickness of

28、damaged surface layer (TDSL), ntheaverage thickness of surface cells, on one surface, that areeither destroyed (ruptured or opened) during the preparation oftest specimens or were originally open due to the manufactur-ing process.3.3 Symbols:i = counter used in a summationk = thermal conductivity, W

29、/(mK)n = counter used in a summationN = number of cut planar surfacesnSL= counter in a time series that corresponds to the servicelife.R = thermal resistance, (m2K)/WTDSL = average thickness of damaged surface layer, mDXeff= effective diffusion thickness of thermal resistancespecimen, m3For referenc

30、ed 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.4Withdrawn. The last approved version of this historical standard is refer

31、encedon www.astm.org.5Underwriters Laboratory of Canada, 333 Pfingsten Road, Northbrook, IL60062-2096 USA,www.ulc.ca6Available from ASTM International Headquarters. Order Adjunct No.ADJC1303.C13030824. Summary of Test Method4.1 Rigid gas-filled closed-cell foam insulation is thin-slicedto reduce the

32、 gas diffusion path length which accelerates theaging process. The resulting temporal acceleration is propor-tional to the square of the ratio of the product use thickness tothe slice thickness.4.2 Careful and precise slice preparation is necessary andthe process is described in detail in 6.4.4.3 In

33、 PartA, the Prescriptive Method, specific test dates arecalculated and the thermal resistance of the thin slices ismeasured on those dates.4.3.1 Qualification tests are included to determine whetherthis method is applicable to a given material.4.4 In Part B, the Research Method, thermal conductivity

34、 ismeasured for a series of time periods and extensive dataanalysis is possible.5. Significance and Use5.1 Rigid gas-filled closed-cell foam insulations include allcellular plastic insulations which rely on a blowing agent (orgas), other than air, for thermal resistance values.At the time ofmanufact

35、ure, the cells of the foam usually contain their highestpercentage of blowing agent and the lowest percentage ofatmospheric gases. As time passes, the relative concentrationsof these gases change due primarily to diffusion. This results ina general reduction of the thermal resistance of the foam due

36、 toan increase in the thermal conductivity of the resultant cell gasmixture. These phenomena are typically referred to as foamaging.5.1.1 For some rigid gas-filled closed-cell foam insulationproducts produced using blowing agent gases that diffuse veryrapidly out of the full-thickness foam product,

37、such as ex-panded polystyrene, there is no need to accelerate the agingprocess.5.1.2 Physical gas diffusion phenomena occur in threedimensions. The one-dimensional form of the diffusion equa-tions used in the development of this practice are valid only forplanar geometries, that is, for specimens th

38、at have parallelfaces and where the thickness is much smaller than the widthand much smaller than the length.NOTE 2Please see Appendix X3 for a discussion of the theory ofaccelerated aging via thin slicing.NOTE 3Theoretical and experimental evaluations of the aging ofinsulation in radial forms, such

39、 as pipe insulation, have been made. (6)However, these practices have not evolved to the point of inclusion in thetest standard.5.2 The change in thermal resistance due to the phenomenadescribed in 5.1 usually occurs over an extended period oftime. Information regarding changes in the thermal resist

40、anceof these materials as a function of time is required in a shorterperiod of time so that decisions regarding formulations, pro-duction, and comparisons with other materials can be made.5.3 Specifications C 578, C 591, C 1029, C 1126 andC 1289 on rigid closed-cell foams measure thermal resistancea

41、fter conditioning at 23 6 1C (73 6 2F) for 180 6 5 daysfrom the time of manufacture or at 60 6 1C (140 6 2F) for90 days. This conditioning can be used for comparativepurposes, but is not sufficient to describe long-term thermalresistance. This requirement demonstrates the importance ofthe aging phen

42、omena within this class of products.5.4 The Prescriptive Method in Part A provides long-termthermal resistance values on a consistent basis for a variety ofpurposes, including product evaluation, specifications, or prod-uct comparisons. The consistent basis for these purposes isprovided by a series

43、of specific procedural constraints, whichare not required in the Research Method described in Part B.The values produced by the Prescriptive Method correspond tothe thermal resistance at an age of five years, which corre-sponds closely to the average thermal resistance over a 15-yearservice life (7,

44、 8).5.4.1 It is recommended that any material standard thatrefers to C 1303 to provide a product rating for long-termthermal resistance specify the Part A Test Method of C 1303.5.5 The Research Method in Part B provides a relationshipbetween thermal conductivity, age, and product thickness. Thecalcu

45、lation methods given in Part B can be used to predict theresistance at any specific point in time as well as the averageresistance over a specific time period.NOTE 4The 5-year aged values produced in Part A can be derivedfrom the Part B data only if all other Part A requirements are met.5.6 This tes

46、t method addresses three separate elementsrelating to the aging of rigid closed-cell plastic foams.5.6.1 Specimen PreparationTechniques for the prepara-tion of thin flat specimens, including their extraction from the“as manufactured” product, and the measurement of specimenthickness are discussed.5.

47、6.2 Measurement of the Thermal ResistanceThermalresistance measurements, taken at scheduled times, are anintegral part of the test method.5.6.3 Interpretation of DataProcedures are included toproperly apply the theory and techniques to achieve the desiredgoals.6. Part A: The Prescriptive Method6.1 A

48、pplicability:6.1.1 Qualification RequirementsBefore reporting the re-sults from a C 1303 Part A aging test, the material must bequalified using the procedures given in Annex A1.6.1.1.1 The qualification requirement tests must be per-formed whenever a significant change that would affect thethermal r

49、esistance properties is made to the product.6.1.1.2 The qualification is valid for a period not to exceedtwo years.NOTE 5This test method is founded upon gas diffusion physical lawsthat apply to homogeneous materials with free surface exposure to theatmosphere as discussed more fully in Appendix X3 (2-4 and 9-11).Although rigid closed-cell foam insulation may not rigorously meet thesehomogeneity and exposure criteria, this test method has been shown toprovide useful information for a wide range of products. Recognizing thatnone of the foam insulation pr