1、Designation: F904 98 (Reapproved 2008)F904 16Standard Test Method forComparison of Bond Strength or Ply Adhesion of SimilarLaminates Made from Flexible Materials1This standard is issued under the fixed designation F904; the number immediately following the designation indicates the year of originala
2、doption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () 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 when
4、 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.1.
5、 Scope1.1 This test method covers a procedure for comparing the bond strength or ply adhesion of similar laminates made from flexiblematerials such as cellulose, paper, plastic film, and foil. This includes laminates made by various processes: adhesive laminates,extrusion coatings, extrusion laminat
6、es, and coextrusion.1.2 Because of the impact of the bending force, direct comparisons between different materials or even between the samematerials of different thickness cannot be made.1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are provide
7、d for informationpurposes only.1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations
8、 prior to use. Specific precautionary statements are given in 7.1.1.2. Referenced Documents2.1 ASTM Standards:2D882 Test Method for Tensile Properties of Thin Plastic SheetingD1898 Practice for Sampling of Plastics (Withdrawn 1998)3E691 Practice for Conducting an Interlaboratory Study to Determine t
9、he Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 adhesive failurefailure at the interface of two adjacent layers.3.1.2 cohesive failurefailure within one of the two adjacent layers comprising the bonded area under test.3.1.3 bond strengthamount of force or energy required to separate
10、 plies of material or materials plus the force to bend theplies.1 This test method is under the jurisdiction of ASTM Committee F02 on Flexible Barrier Packaging and is the direct responsibility of Subcommittee F02.20 on PhysicalProperties.Current edition approved April 1, 2008April 1, 2016. Publishe
11、d May 2008June 2016. Originally approved in 1984. Last previous edition approved in 20032008 asF904 98 (2008). (2003). DOI: 10.1520/F0904-98R08.10.1520/F0904-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. ForAnnual Book ofA
12、STM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of
13、what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered
14、the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.4 neckinglocalized reduction in cross section which may occur in a material under tensile stress.3.1.5 webrefers to roll stock after it has been unwound from th
15、e roll.4. Summary of Test Method4.1 Ply separation is initially started mechanically by the application of heat or by using a solvent. The separated plies of thetest specimen are placed into the grips of a tensile testing machine. The grips are then separated and the force required to furtherseparat
16、e the plies is defined as bond strength. Alternatively, the energy may be used.NOTE 1The force to bend the separated plies is included.5. Significance and Use5.1 Laminates are made by bonding together two or more layers of material or materials. Their performance is often dependenton the ability of
17、the laminate to function as a single unit. If the plies have not been properly bonded together, the performance maybe adversely affected. Laminates may maintain adequate bond strength under standard test conditions, but under conditions of usemay exhibit an increase or decrease in bond strength. App
18、lying heat, such as in boilable pouch applications, may adversely affectbond strength, as may cold temperatures, such as those encountered in freezer storage of foods. Fats and oils may also influencebond strength as well as the softness or moduli of the plies. This test method can be used to compar
19、e bond strength of similarmaterials and to study changes under these and other conditions of end use, providing caution is used with respect to the effectsof the included force to bend the separated plies.6. Apparatus6.1 GripsA gripping system that minimizes both slippage and uneven stress distribut
20、ion is required. Grips lined with thinrubber, crocus cloth or pressure sensitive tape, as well as file-faced or serrated grips have been successfully used for manymaterials. Air-actuated grips have been found advantageous, particularly in the case of materials that tend to “neck” in the grips,since
21、pressure is maintained at all times.6.2 Testing MachineA tensile testing machine conforming to the requirements for Method A of Test Method D882.6.3 Specimen CutterIn accordance with Test Method D882.7. Reagents and Materials7.1 SolventsToluene, ethyl acetate, MEK (2-Butanone) THF (tetrahydrofuran)
22、or other suitable solvent to weaken the bondbetween layers sufficiently so that delamination may be started.7.1.1 WarningUse of these solvents requires that appropriate safeguards be used to avoid hazards of skin contact, inhalation,and flammability.8. Sampling, Test Specimens, and Test Units8.1 Sam
23、pling must be performed in a manner that will provide the desired information. No single procedure can be given forall situations. Therefore, Practice D1898 should be used as a guide in planning sampling procedures.8.2 Test SpecimensCut strips exactly 25.4 mm (1.0 in.) wide and about 250 mm (10 in.)
24、1.0 in. (25 mm.) wide65% and about10 in. (250 mm) long. It is important that the test specimens are cut with clean, uniform edges so as not to affect the test results.8.3 Test UnitTest five specimens in the longitudinal (machine) direction. It may be desirable to test specimens in the transverse(cro
25、ss-machine) direction for special purposes.9. Preparation of Apparatus and Calibration9.1 Equip the tensile testing machine according to manufacturers instructions for tensile testing thin films.9.2 Set full-scale load so that most test specimen scans fall in the center two thirds of the chart, and
26、draw speed at 28.0 cm/min6 10 % (10 or 12 in./min are included). A few trial runs may be required. Other draw speeds may be used if it can be shown thatthey yield the same results as those specified.10. Conditioning10.1 Specimen Conditioning:10.1.1 Store specimens at 23 6 2C (73.4 6 3.6F) and 50 6 5
27、 % relative humidity for not less than 40 h.10.2 End-Use Specimen Conditioning :10.2.1 Store specimens at the specific end-use temperature and humidity for not less than 40 h.10.2.2 Accelerated testing conditions for “wet” materials packaging may be accomplished by placing the test specimensbetween
28、paper towels saturated with distilled water, sealing in a moisture proof pouch and storing at 23 6 2C (73.4 6 3.6F) for40 h.F904 16210.2.3 Conditioning to simulate other conditions of end use shall be determined by specific application. Normally theconditioning period will be 40 to 96 h.10.2.4 In so
29、me cases, conditioning will consist of treatment of test specimen prior to actual conditioning. Example: Boilablepouch applications. Test specimens may be immersed in boiling water for a period of time equal to normal end use and thenconditioned for testing as specified in 10.1.1 (or perhaps tested
30、shortly after boiling treatment if desired to simulate performancein use).NOTE 2At these conditions pouch and contents should be aged to allow time for contents to migrate into seal area.10.3 Test Conditions:10.3.1 Conduct tests in the standard laboratory atmosphere of 23 6 2C (73.4 6 3.6F) and 50 6
31、 5 % relative humidity.11. Procedure11.1 Initiate separation of the plies of the test specimens mechanically if possible. That is, crinkle roughly or apply adhesivetape to both sides, or both, and pull apart. If not, initiate the separation by making a heat seal and pulling it apart. If both the abo
32、vefail, determine which solvent seems best by trial and error and initiate the separation by immersion of the end of the strip in thesolvent for as little time as possible to initiate the separation. Heat the solvent solution only if absolutely necessary. Dry well inroom air without heat.11.2 Clamp
33、the separated ends of the test specimen in the jaws of the tensile testing machine using an original jaw distance of25.4 mm (1.0 in.) and make certain the jaws are aligned vertically.11.3 The unseparated portion of each test specimen shall be treated in one of the following ways:11.3.1 Left loose to
34、 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 of draw.11.4 Activate the tensile testing machine and record the force to separate 3 in. of the test specimen at 280 mm/min6 10 % (10 or 12 in./min). Repeat for each te
35、st specimen in the test unit.12. Calculation of Results12.1 Disregarding the initial peak, determine the average force to separate the next 2 in. of each test specimen. Express innewtons/metre, g/25.4 mm, or pounds force/inch.12.2 Alternatively, determine the energy to separate this 2-in. segment of
36、 each test specimen. Express in joules/metre or footpound-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.13.1.4 Method of supporting unseparated portion of te
37、st specimen.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 each test specimen.13.1.9 Average force or energy, standard deviation, and confidence limits for each test unit.13.1.1
38、0 Type of failureadhesive or cohesive failure.TABLE 1 Bond StrengthNOTE 1 Values expressed in units of g/25.4 mmMaterial Thickness or other Condition Average SrA SRB2 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 Nylo
39、n/PVdC/4.0 mil Poly-olefin805.7 274.9 743.0ASr is the within-laboratory standard deviation.BSR is the between-laboratories standard deviation.F904 16314. Precision and Bias14.1 PrecisionTable 1 is based on a round robin conducted in 1989 in accordance with Practice E691, involving threematerials tes
40、ted by seven laboratories.4 For each material, all the samples were prepared at one source, but the individual specimenswere prepared at the laboratories which tested them. Each test result is an individual determination. Each laboratory obtained tentest results for each material.14.2 BiasThere are
41、no recognized standards by which to estimate bias of this 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 t
42、o cause tensile breaks of the plies before delamination occurs. When this isexperienced backing either the samples or test specimens with cellophane tape will often allow measurement of a value for bondstrength. This technique is sometimes helpful when studying particular materials. However, it must
43、 be used with caution and thefull knowledge that the force to bend the tape including any variations in both the thickness of the tape and its adhesion to the testspecimen will be reflected in the bond strength values obtained.X1.2 Until this technique is better established, it should be used for sp
44、ecial studies only and not for establishing values betweenlaboratories.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
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