1、Designation: F 904 98 (Reapproved 2008)Standard Test Method forComparison of Bond Strength or Ply Adhesion of SimilarLaminates Made from Flexible Materials1This standard is issued under the fixed designation F 904; the number immediately following the designation indicates the year oforiginal adopti
2、on or, in the 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.INTRODUCTIONIt has been widely discussed in the literature that bond strength of flex
3、ible multi-ply materials isimpossible to measure with current technology. The above is recognized and accepted, since all knownmethods of measurement include the force required to bend the separated layers, in addition to thatrequired to separate them. However, useful information can be obtained whe
4、n one realizes that thebending force is included and that direct comparisons between different materials, or even between thesame materials of different thicknesses, cannot be made. Also, conditioning that affects the softness ormoduli of the plies will be reflected in the bond strength measurement.
5、1. Scope1.1 This test method covers a procedure for comparing thebond strength or ply adhesion of similar laminates made fromflexible materials such as cellulose, paper, plastic film, and foil.This includes laminates made by various processes: adhesivelaminates, extrusion coatings, extrusion laminat
6、es, and coex-trusion.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are provided forinformation purposes only.1.3 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the
7、 user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in 7.1.1.2. Referenced Documents2.1 ASTM Standards:2D 882 Test Method for Tensile Properties of Thin Plas
8、ticSheetingD 1898 Practice for Sampling of Plastics3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 adhesive failurefailure at the interface of two adja-cent layers.3.1.2 cohesive failurefailure within one of the tw
9、o adja-cent layers comprising the bonded area under test.3.1.3 bond strengthamount of force or energy required toseparate plies of material or materials plus the force to bend theplies.3.1.4 neckinglocalized reduction in cross section whichmay occur in a material under tensile stress.3.1.5 webrefers
10、 to roll stock after it has been unwoundfrom the roll.4. Summary of Test Method4.1 Ply separation is initially started mechanically by theapplication of heat or by using a solvent. The separated plies ofthe test specimen are placed into the grips of a tensile testingmachine. The grips are then separ
11、ated and the force required to1This test method is under the jurisdiction of ASTM Committee F02 on FlexibleBarrier Packaging and is the direct responsibility of Subcommittee F02.20 onPhysical Properties.Current edition approved April 1, 2008. Published May 2008. Originallyapproved in 1984. Last prev
12、ious edition approved in 2003 as F 904 98 (2003).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, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1
13、Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.further separate the plies is defined as bond strength. Alterna-tively, the energy may be used.NOTE 1The force to bend the separated plies is included.5. Significance and Use5.1 Laminate
14、s are made by bonding together two or morelayers of material or materials. Their performance is oftendependent on the ability of the laminate to function as a singleunit. If the plies have not been properly bonded together, theperformance may be adversely affected. Laminates may main-tain adequate b
15、ond strength under standard test conditions, butunder conditions of use may exhibit an increase or decrease inbond strength. Applying heat, such as in boilable pouchapplications, may adversely affect bond strength, as may coldtemperatures, such as those encountered in freezer storage offoods. Fats a
16、nd oils may also influence bond strength as well asthe softness or moduli of the plies. This test method can beused to compare bond strength of similar materials and to studychanges under these and other conditions of end use, providingcaution is used with respect to the effects of the included forc
17、eto bend the separated plies.6. Apparatus6.1 GripsA gripping system that minimizes both slippageand uneven stress distribution is required. Grips lined with thinrubber, crocus cloth or pressure sensitive tape, as well asfile-faced or serrated grips have been successfully used formany materials. Air-
18、actuated grips have been found advanta-geous, particularly in the case of materials that tend to “neck”in the grips, since pressure is maintained at all times.6.2 Testing MachineAtensile testing machine conformingto the requirements for Method A of Test Method D 882.6.3 Specimen CutterIn accordance
19、with Test MethodD 882.7. Reagents and Materials7.1 SolventsToluene, ethyl acetate, MEK (2-Butanone)THF (tetrahydrofuran) or other suitable solvent to weaken thebond between layers sufficiently so that delamination may bestarted.7.1.1 WarningUse of these solvents requires that appro-priate safeguards
20、 be used to avoid hazards of skin contact,inhalation, and flammability.8. Sampling, Test Specimens, and Test Units8.1 Sampling must be performed in a manner that willprovide the desired information. No single procedure can begiven for all situations. Therefore, Practice D 1898 should beused as a gui
21、de in planning sampling procedures.8.2 Test SpecimensCut strips exactly 25.4 mm (1.0 in.)wide and about 250 mm (10 in.) long. It is important that thetest specimens are cut with clean, uniform edges so as not toaffect the test results.8.3 Test UnitTest five specimens in the longitudinal (ma-chine) d
22、irection. It may be desirable to test specimens in thetransverse (cross-machine) direction for special purposes.9. Preparation of Apparatus and Calibration9.1 Equip the tensile testing machine according to manufac-turers instructions for tensile testing thin films.9.2 Set full-scale load so that mos
23、t test specimen scans fallin the center two thirds of the chart, and draw speed at 28.0cm/min6 10 % (10 or 12 in./min are included).Afew trial runsmay be required. Other draw speeds may be used if it can beshown that they yield the same results as those specified.10. Conditioning10.1 Specimen Condit
24、ioning:10.1.1 Store specimens at 23 6 2C (73.4 6 3.6F) and 506 5 % relative humidity for not less than 40 h.10.2 End-Use Specimen Conditioning:10.2.1 Store specimens at the specific end-use temperatureand humidity for not less than 40 h.10.2.2 Accelerated testing conditions for “wet” materialspackag
25、ing may be accomplished by placing the test specimensbetween paper towels saturated with distilled water, sealing ina moisture proof pouch and storing at 23 6 2C (73.4 6 3.6F)for 40 h.10.2.3 Conditioning to simulate other conditions of end useshall be determined by specific application. Normally the
26、conditioning period will be 40 to 96 h.10.2.4 In some cases, conditioning will consist of treatmentof test specimen prior to actual conditioning. Example: Boil-able pouch applications. Test specimens may be immersed inboiling water for a period of time equal to normal end use andthen conditioned for
27、 testing as specified in 10.1.1 (or perhapstested shortly after boiling treatment if desired to simulateperformance in use).NOTE 2At these conditions pouch and contents should be aged toallow time for contents to migrate into seal area.10.3 Test Conditions:10.3.1 Conduct tests in the standard labora
28、tory atmosphereof 23 6 2C (73.4 6 3.6F) and 50 6 5 % relative humidity.11. Procedure11.1 Initiate separation of the plies of the test specimensmechanically if possible. That is, crinkle roughly or applyadhesive tape to both sides, or both, and pull apart. If not,initiate the separation by making a h
29、eat seal and pulling itapart. If both the above fail, determine which solvent seemsbest by trial and error and initiate the separation by immersionof the end of the strip in the solvent for as little time as possibleto initiate the separation. Heat the solvent solution only ifabsolutely necessary. D
30、ry well in room air without heat.11.2 Clamp the separated ends of the test specimen in thejaws of the tensile testing machine using an original jawdistance of 25.4 mm (1.0 in.) and make certain the jaws arealigned vertically.11.3 The unseparated portion of each test specimen shall betreated in one o
31、f the following ways:11.3.1 Left loose to move around freely,11.3.2 Supported at 90 to the direction of draw by hand, or11.3.3 Mechanically supported at 90 to the direction ofdraw.F 904 98 (2008)211.4 Activate the tensile testing machine and record theforce to separate 3 in. of the test specimen at
32、280 mm/min6 10 % (10 or 12 in./min). Repeat for each test specimen in thetest unit.12. Calculation of Results12.1 Disregarding the initial peak, determine the averageforce to separate the next 2 in. of each test specimen. Expressin newtons/metre, g/25.4 mm, or pounds force/inch.12.2 Alternatively, d
33、etermine the energy to separate this2-in. segment of each test specimen. Express in joules/metre orfoot pound-force/inch.13. Report13.1 The report shall include the following:13.1.1 Complete sample identification.13.1.2 Statement of conditioning.13.1.3 Name and model number of tensile machine used.1
34、3.1.4 Method of supporting unseparated portion of testspecimen.13.1.5 Film direction if different than longitudinal.13.1.6 Method of separation.13.1.7 Number of specimens tested.13.1.8 Average force or energy to separate each ply of eachtest specimen.13.1.9 Average force or energy, standard deviatio
35、n, andconfidence limits for each test unit.13.1.10 Type of failureadhesive or cohesive failure.14. Precision and Bias14.1 PrecisionTable 1 is based on a round robin con-ducted in 1989 in accordance with Practice E 691, involvingthree materials tested by seven laboratories.4For each material,all the
36、samples were prepared at one source, but the individualspecimens were prepared at the laboratories which tested them.Each test result is an individual determination. Each laboratoryobtained ten test results for each material.14.2 BiasThere are no recognized standards by which toestimate bias of this
37、 test method.15. Keywords15.1 adhesion; bond strength; flexible barrier materials;laminatesAPPENDIX(Nonmandatory Information)X1. BACKING SAMPLES WITH CELLOPHANE TAPE BEFORE MEASURING BOND STRENGTHX1.1 Sometimes bond strengths are sufficient to causetensile breaks of the plies before delamination occ
38、urs. Whenthis is experienced backing either the samples or test specimenswith cellophane tape will often allow measurement of a valuefor bond strength. This technique is sometimes helpful whenstudying particular materials. However, it must be used withcaution and the full knowledge that the force to
39、 bend the tapeincluding any variations in both the thickness of the tape and itsadhesion to the test specimen will be reflected in the bondstrength values obtained.X1.2 Until this technique is better established, it should beused for special studies only and not for establishing valuesbetween labora
40、tories.ASTM International takes no position 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 righ
41、ts, 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 revision of this standard or for additional
42、standardsand should be addressed to ASTM International 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
43、Committee on Standards, at the address shown 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 abovea
44、ddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: F021008.TABLE 1 Bond StrengthNOTE 1 Values expressed
45、in units of g/25.4 mmMaterial Thickness or other Condition Average SrASRB2 0.5 mil Oriented Polyester/metallization/2.5 mil Polyolefin258.4 12.6 79.41 5.0 mil PVC/2.0 mil Ionomer 409.1 20.0 77.63 1.5 mil Nylon/PVdC/4.0 mil Poly-olefin805.7 274.9 743.0ASr is the within-laboratory standard deviation.BSR is the between-laboratories standard deviation.F 904 98 (2008)3
