ASTM D1623-17

Designation: D1623 − 17Standard Test Method forTensile and Tensile Adhesion Properties of Rigid CellularPlastics1This standard is issued under the fixed designation D1623; the number immediately following the designation indicates the year oforiginal adoption 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.1. Scope*1.1 This test method covers the determination of the tensileand tensile adhesion properties of rigid cellular materials in theform of test specimens of standard shape under definedconditions of temperature, humidity, and testing machinespeed.1.2 Tensile properties shall be measured using any of threetypes of specimens:1.2.1 Type A shall be the preferred specimen in those caseswhere enough sample material exists to form the necessaryspecimen.1.2.2 Type B shall be the preferred specimen when onlysmaller specimens are available, as in sandwich panels, etc.1.2.3 Type C shall be the preferred specimen for the deter-mination of tensile adhesive properties of a cellular plastic to asubstrate as in a sandwich panel (top and bottom substrate) orthe bonding strength of a cellular plastic to a single substrate.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.NOTE 1—There is no known ISO equivalent to this test method.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D638 Test Method for Tensile Properties of PlasticsD883 Terminology Relating to PlasticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions of terms applying to this test method appearin Test Method D638, Annex A2.4. Apparatus4.1 Testing Machine—A testing machine that is capable ofapplying a constant rate of crosshead movement, comprisingessentially the following:4.1.1 Grips—Grips for holding the test specimen shall bethe self-aligning type; that is, they must be attached to the fixedand movable members of the testing machine in such a waythat they will move freely into alignment as soon as any loadis applied, so that the long axis of the test specimen willcoincide with the direction of the applied pull through thecenter line of the grip assembly. Universal-type joints imme-diately above and below the specimen grips are recommended.The test specimen shall be held in such a way that slippagerelative to the grips is prevented, insofar as possible. For TypeA specimens, use a grip assembly like the one shown in Fig. 1and Fig. 2. For Type B specimens, one suitable grip assemblyis shown in Fig. 3 and Fig. 4. For Type C specimen, a suitablegrip assembly is shown in Fig. 5.4.1.2 Load Indicator—A load cell or suitable load-indicating mechanism, capable of showing the total tensile load1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.22 on Cellular Materials -Plastics and Elastomers.Current edition approved May 1, 2017. Published June 2017. Originallyapproved in 1959. Last previous edition approved in 2009 as D1623 – 09. DOI:10.1520/D1623-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1exerted on the test specimen when held in the grips, shall beused. Choose an indicator that will permit precision to within61%.4.1.3 Extension Indicator—If measurement of the extensionis desired, use a suitable instrument for determining thedistance between two fixed points on the test specimen, orMetric Equivalentsin.1⁄81⁄41⁄29⁄1611⁄16 1 1.130 11⁄2 221⁄4 21⁄2 335⁄16mm 3.18 6.35 12.7 14.3 17.5 25.4 28.7 38.1 50.8 57.2 63.5 76.2 84.1FIG. 1 Details of Grips for Tension Test on Type A SpecimenFIG. 2 Grip Assembly for Type A SpecimenD1623 − 172similarly by grip separation or extensometer, at any time duringthe test, shall be used.4.2 Specimen Cutter—For Type A specimens, use a suitablelathe cutter (see Fig. 6).5. Test Specimen5.1 All surfaces of the specimen shall be free of large visibleflaws or imperfections. If it is necessary to place gauge markson the specimen, do this in such a way as not to affect theMetric Equivalentsin.3⁄161⁄41⁄25⁄163⁄4 111⁄2 19⁄16 23mm 4.76 6.35 12.7 7.9 19.1 25.4 38.1 39.7 50.8 76.2FIG. 3 Details of Grips for Tension on Type B SpecimenD1623 − 173surfaces of the test specimen. Gauge marks shall not bescratched, punched, or impressed on the specimen.5.2 When testing materials that are suspected to beanisotropic, prepare duplicate sets of specimens having theirlong axes parallel and perpendicular to the direction of the cellorientation.5.3 Preparation of Type A Specimens—The recommendedType A test specimen shall conform to the dimensions given inFig. 7. It shall be prepared by normal molding procedureswherever possible, but the “skin” effect which results cannot beeliminated and will cause a variance in the final result. Anothermethod of preparation of the specimen, which would eliminatethe “skin effect” variable, is to machine the desired geometryon a small lathe, using a cutter like the one shown in Fig. 6.Insert a 50 by 50 by 150-mm (2 by 2 by 6-in.) block of theFIG. 4 Grip Assembly for Type B SpecimenFIG. 5 Grip Assembly for Type C SpecimenMetric Equivalentsin.1⁄415⁄323⁄4 11⁄2 21⁄8 41⁄4mm 6.35 11.9 19.1 38.1 54.0 108.0FIG. 6 Cutter for Preparing Type A SpecimenD1623 − 174material to be tested into the four-jaw chuck, which had beenpreviously centered. Prepare the other end of the block toreceive the 60° tapered end of the tailstock center. Set the latheat its highest speed. The appropriate rate of entry of the cutterblade will depend on the density of the foam. Advance thecutter until it reaches a stop, at which time the diameter of thespecimen test section shall be 28.7 mm (1.130 in.), giving a645 mm2(1 in.2) cross sectional area. Using a band saw, cut offthe excess sample end (up to the taper). The lathe assembly andcompleted specimen are shown in Fig. 6 and Fig. 7. Therecommended gauge length shall be 25.4 mm (1 in.) with aradius of curvature of 11.9 mm (15⁄32 in.) at each end joining itto the grip surface, which is at an angle of 18° to the center line.However, in no case shall the gauge length be less than 12.7mm (1⁄2 in.).NOTE 2—If specimens exhibit excessive slippage in the jaws, a lowerthan actual tensile strength could possibly be obtained. Where this occurs,it is recommended that a 6.35-mm (1⁄4-in.) shoulder be left on thespecimen ends next to the tapered area, or the specimen ends be dippedmomentarily in a molten paraffin wax prior to test (temperature not inexcess of 80°C (176°F), or both.5.4 Preparation of Type B Specimens—Type B test speci-mens shall be rectangular, round or square and shall have aminimum cross-sectional area of 645 mm2(1 in.2). Specimentop and bottom surfaces shall be parallel. Bond the specimenmounting (or grip assembly) blocks to the top and bottomsurfaces of the test specimens by a suitable method, which doesnot affect the material under test, taking care to assure that thebonding pressure is not great enough to cause compression ofthe specimen. The adhesive curing temperature shall be lowenough to cause no effect on the specimen to be tested.5.5 Preparation of Type C Specimens:5.5.1 Type C test specimens shall be square or rectangular,with a minimum length and width dimension equal to, orgreater than, the thickness.5.5.2 Care and caution shall be exercised in preparing thespecimen so that the bond between the cellular plastic and thesubstrate is not affected. The speed of the saw blade, thenumber of teeth per inch, and other cutting variables shall beconsidered in specimen preparation, in order to avoid excessvibrations or heat buildup, which could weaken the bondbetween the cellular plastic and the substrate.5.5.3 When adhesion test involves only one surface, theother side shall be trimmed to provide a smooth, parallelbonding surface.5.5.4 Bond the specimen mounting (or grip assembly)blocks to the top and bottom of the test specimen by a suitablemethod that does not affect the material being tested.6. Conditioning6.1 Conditioning—Condition the test specimens at 23 62°C (73.4 6 3.6°F) and 50 6 10 % relative humidity for notless than 24 h prior to testing.6.2 Test Conditions—Conduct tests in the standard labora-tory atmosphere of 23 6 2°C (73.4 6 3.6°F) and 50 6 10 %relative humidity, unless otherwise specified.7. Number of Test Specimens7.1 A minimum of three specimens shall be tested. Speci-mens that break at some obvious flaw shall be discarded andretests made, unless such flaws constitute a variable that is tobe studied.8. Speed of Testing8.1 The standard speed of testing shall be such that ruptureoccurs in 3 to 6 min. A suggested rate of crosshead movementis 1.3 mm (0.05 in.)/min for each 25.4 mm (1 in.) of test sectiongauge length.9. Procedure9.1 Measure the cross-sectional dimensions of the testspecimen to the nearest 0.025 mm (0.001 in.) at several points,and record the minimum value. Calculate the specimen’scross-sectional area from these dimensions.9.2 Zero the load indicator with all of the upper hardware inplace, but no specimen attached. If Type B or C specimens areused, zero the load indicator with all of the upper hardware inplace, including the specimen with top and bottom mountingblocks attached.9.3 Place the specimen into the grip assembly as defined in4.1.1, and adjust the entire assembly to align it with the centralaxis of the specimen and the testing machine. (If a Type Aspecimen is used, tighten the1⁄4 in. set screws in the sides of theholders so that the split collars are held firmly together and arein axial alignment with the specimen and testing machine.)9.4 Determine and record the load at the moment ofspecimen breaking. If an extensometer is used, a completestress-strain curve may be obtained thereby. Also determineand record the extension at the moment of rupture of thespecimen.10. Calculation10.1 Tensile Strength—Calculate the tensile strength bydividing the breaking load in kilonewtons (or pounds-force) bythe original minimum cross-sectional area of the specimen insquare metres (or square inches). Express the result in kilopas-cals (kilonewtons per square metre) (or pounds-force persquare inch) to two significant figures.10.2 Elongation—Calculate the percent elongation, whendetermined, by dividing the extension at the moment ofspecimen breaking by the original distance between gaugeMetric Equivalentsin. 1.12915⁄32 15⁄8 41⁄4mm 28.7 11.9 41.3 108.0FIG. 7 Dimensions of Type A SpecimenD1623 − 175marks, or similarly by grip separation, and multiplying by 100.Report the percent elongation to two significant figures.10.3 Calculate the standard deviation (estimated) as followsand report it to two significant figures:s 5 =~(X22 nX¯ 2!/~n 2 1! (1)where:s = estimated standard deviation,X = value of a single observation,n = number of observations, andX¯= arithmetic mean of the set of observations.11. Report11.1 The report shall include the following:11.1.1 Complete identification of the material tested, includ-ing type, source, code numbers, form, principal dimensions,previous history, etc.11.1.2 Type of specimen used: Type A, Type B, or Type C.11.1.3 Conditioning procedure used, if different from thatspecified in 6.1.11.1.4 Atmospheric conditions in test room, if differentfrom those specified in 6.2.11.1.5 Number of specimens tested, if different from thatspecified in Section 7.11.1.6 Rate of crosshead movement.11.1.7 Tensile or tensile adhesion strength of eachspecimen, average value and standard deviation.11.1.8 Percent elongation of each specimen, average valueand standard deviation. Indicate method used to measureextension (either gauge marks, grip separation or extensom-eter).11.1.9 Date of test.12. Precision and Bias12.1 Tables 1 and 2 are based on a round robin conducted in2000 using Type B specimens in accordance with PracticeE691, involving three materials tested by six laboratories. Foreach material, all of the samples were prepared at one source,but the individual Type B specimens were prepared at thelaboratories that tested them. Each laboratory obtained six testresults for each material. Precision, characterized by repeat-ability (Srand r) and reproducibility (SRand R), have beendetermined as shown in Tables 1 and 2.(Warning—Theexplanation of r and R are only intended to present a mean-ingful way of considering the approximate precision of this testmethod. The data in Tables 1 and 2 should not be applied toacceptance or rejection of materials, as these data apply only tothe materials tested in the round robin and are unlikely to berigorously representative of other lots, formulations,conditions, materials, or laboratories. Users of this test methodshould apply the principles outlined in Practice E691 togenerate data specific to their materials and laboratory.)NOTE 3—The precision data presented in Tables 1 and 2 were obtainedusing the test conditions defined in this test method in 2000. The testconditions in 2000 were 23 6 2°C and 50 % 6 5 % relative humidity. Ifa material specification defines other test conditions, this precision datashall not be assumed to apply.12.2 Bias—There are no recognized standards by which toestimate bias for this test method.13. Keywords13.1 rigid cellular plastics; tensile adhesion; tensile strengthTABLE 1 Tensile, kPa Type B Specimens(Six Laboratories)Material Avg. SrASRBrCRDA 184.8 22.8 43.1 63.8 120.9B 340.6 57.8 141.5 161.9 396.3C 188.9 25.4 53.0 71.2 148.3ASr= within-laboratory standard deviation for the indicated material. It is obtainedby pooling the within-laboratory standard deviations of the test results from all ofthe participating laboratories.BSR= between-laboratory reproducibility, expressed