1、Designation: D 1781 98 (Reapproved 2004)Standard Test Method forClimbing Drum Peel for Adhesives1This standard is issued under the fixed designation D 1781; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers the determination of the p
3、eelresistance of adhesive bonds between: a relatively flexibleadherend and a rigid adherend; and the relatively flexiblefacing of a sandwich structure and its core, when tested underspecified conditions.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parenthe
4、ses are for informationonly.1.3 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 regulatory limitations
5、prior to use.2. Referenced Documents2.1 ASTM Standards:2B 209 Specification for Aluminum and Aluminum-AlloySheet and PlateD 907 Terminology of AdhesivesE 4 Practices for Force Verification of Testing Machines2.2 ASTM Adjuncts:Climbing Drum Peel Tester33. Terminology3.1 DefinitionsMany of the terms u
6、sed in this test methodare defined in Terminology D 907.4. Summary of Test Method4.1 Determine the peeling force of a conditioned adhesivebonded sandwich assembly by peeling a face skin around acircular drum. This is done by clamping the assembly in auniversal test machine. The average peeling load
7、is determinedusing a standard formula.5. Significance and Use5.1 This test method may be used to determine comparativerather than fundamental measurements of adhesion and isparticularly suitable for process control, some examples ofwhich are listed.5.1.1 This test method is particularly sensitive to
8、 adherendsurface preparation and is of value where the adhesive is usedin conjunction with a primer.5.1.2 When a relatively brittle adhesive is used, the peelresistance can often give an indication of the degree of cure,that is, higher values than normally realized may indicate anincomplete cure. Di
9、rect comparison of different adhesives orprocesses can only be made when specimen design and testconditions are identical.6. Apparatus6.1 Peeling Apparatus, consisting of a flanged drum, flex-ible loading straps or cables, and suitable clamps for holdingthe test specimen. The apparatus illustrated i
10、n Fig. 1 has beenfound to be satisfactory.6.1.1 The outside radius of the drum is 51.00 6 0.13 mm(2.000 6 0.005 in.), and the radius of the flange, including onehalf of the thickness of the loading straps or cables, is 12.70 60.13 mm (0.500 6 0.005 in.) larger than the radius of the drum.This 12.70
11、6 0.13 mm (0.500 6 0.005 in.) less half thethickness of the adherend to be peeled, is the effective torquearm of the apparatus.6.1.2 Use a suitable top clamp (Fig. 2) for supporting thespecimen, and a drum clamp (Fig. 3) to hold the adherendagainst the face of the drum.6.1.3 Balance the drum about t
12、he axis by the use ofcounterweights (as shown in Fig. 1) placed diametricallyopposite the drum clamp to compensate for the weight of thisclamp.6.1.4 The drum and flanges with the drum clamp and itscompensating weight weighs # 3.6 kg (8 lb), a lighter weightbeing preferable to facilitate handling of
13、the apparatus.4,31This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is under the jurisdiction of Subcommittee D14.80 on Metal BondingAdhesives.Current edition approved April 1, 2004. Published April 2004. Originallyapproved in 1960. Last previous edition approved in 19
14、98 as D 1781 98.2For 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.3Detailed working drawings for the apparatus
15、illustrated are available fromASTM International, 100 Barr Harbor Drive, West Conshohocken PA 19428-2959.Request ADJD1781.4A suitable climbing drum peel apparatus is available from Custom ScientificInstruments, Inc., 13 Wing Drive, Whippany, NJ, 07981.1Copyright ASTM International, 100 Barr Harbor D
16、rive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Testing Machine, capable of applying tensile loadsunder the conditions prescribed in Section 11 and with thefollowing further requirements:6.2.1 The rate of movement between heads of the testingmachine remains essentially constan
17、t under fluctuating loads(Note 1).6.2.2 The testing machine weighs the load to within 1 %.The testing machine and range are selected such that themaximum load on the specimen falls between 15 and 85 % ofthe full-scale capacity.6.2.3 The use of autographic equipment to record loadversus head movement
18、 is recommended.6.2.4 Verification of the testing machine is made in accor-dance with the recommendations of Practices E 4.NOTE 1It is difficult to meet this requirement when loads aremeasured with a spring-type or pendulum-type weighing device.7. Test Specimen7.1 For evaluation of adhesives in lami
19、nated assemblies, aspecimen of the type shown in Fig. 4 has been found to besatisfactory. The specimen is 25 mm (1 in.) wide between sawkerfs and at least 254 mm (10 in.) long. The specimen may becut from larger bonded panels if desired.7.2 For evaluation of adhesives in sandwich constructions,make
20、the test specimens in conformance to the general form ofthe specimen shown in Fig. 1. The specimen is 76 mm (3 in.)wide by at least 305 mm (12 in.) long, including about a25-mm (1-in.) overhang of one facing at each end. Thicknessof the core is not important, except in the sense that thesandwich spe
21、cimen does not bend while the facing is beingpeeled. For comparative evaluation of adhesives in bondingmetal-faced sandwich constructions, a facing of clad aluminumalloy meeting the requirements of Specification B 209, Alloy2024-T3, 0.51 mm (0.020 in.) thick with a core 12.7 mm (0.5in.) thick, has b
22、een found to be suitable. Other metal facings ofcomparable flexibility may also be used. The specimens maybe cut from larger bonded panels if desired.NOTE 2Direct comparisons of different adhesives can be made onlywhen specimen design and test conditions are identical.7.3 Test at least six specimens
23、, for example, two or morefrom each of three bonded panels, for each adhesive sample.7.4 For sandwich constructions based on orthotropic cores,peel half of the specimens parallel to the length direction of thecore and half parallel to the width direction, as determinedfrom the configuration of the c
24、ell structure.8. Preparation of Test Specimen8.1 Do all preconditioning or special preparation of theadherends in accordance with the recommendations of themanufacturer of the adhesive.8.2 Bond in accordance with the procedure and recommen-dations prescribed by the manufacturer of the adhesive.NOTE
25、3Other preconditioning, preparation, and bonding conditionsmay be used if agreeable to the supplier and the purchaser of the adhesive.8.3 Cut specimens from the sandwich panels or laminatedpanels in such a way as to avoid overheating or mechanicaldamage to the bond.NOTE 4A metal-cutting bandsaw has
26、been found suitable forFIG. 1 Assembly of Peeling ApparatusFIG. 2 Top ClampFIG. 3 Drum ClampD 1781 98 (2004)2aluminum-alloy specimens of the types illustrated. The kerfs in laminateassemblies may be cut with a metal-cutting circular saw or milling cutter.8.4 Attach laminated assemblies to the backin
27、g plate in sucha manner that the surface to be peeled has no projections. Thisis done by drilling and tapping the specimen and attaching it bymeans of No. 6 machine screws inserted from the back side asshown in Fig. 4. Alternatively, with thick assemblies, holes inthe specimen are counterbored, and
28、flathead machine screwsare then inserted through the specimen and backing plate andheld with nuts on the back surface. This permits the use ofslotted holes in the backing plate to accommodate less accu-rately spaced holes in the specimen. In some cases, it ispossible to bond the specimen to the back
29、ing plate.9. Calibration of Test Apparatus9.1 Determine the load to overcome the resisting torque, F0(12.2), of drum, clamp, and counterweight, by one of thefollowing methods:9.1.1 For peel resistance of adhesive with no compensationfor bending of adherend, insert a strip of fabric 0.20 to 0.28mm (0
30、.008 to 0.011 in.) thick and having negligible stiffness inplace of the specimen, and apply a load sufficient to roll thedrum upward on the fabric. With the drum dimensions given in6.1 this measured load is about four times the weight of thedrum, clamp, and counterweight, if the weighing apparatus i
31、sbalanced to zero at the start.9.1.2 For peel resistance of the adhesive with compensationfor bending of the adherend, substitute a piece of material ofthe same composition, properties, and dimensions as theadherend to be peeled in place of the thin fabric, and apply aload sufficient to roll the dru
32、m upward on the material. Thismethod largely offsets the torque required to bend the adherendin the peel test. The forces imposed on the adherend during thepeel test usually result in greater bending than is obtained inbending the unbonded adherend around the drum. More torqueis required, therefore,
33、 to bend a bonded than an unbondedmaterial; hence, this compensation is only approximate.10. Conditioning10.1 Condition specimens for 7 days at a relative humidityof 50 6 2 % and a temperature of 23 6 1C (73.4 6 1.8F),except when the adhesive manufacturer specifies that thisconditioning period is un
34、necessary and that a shorter period isadequate. The manufacturer may also specify that a longerperiod is necessary.10.2 Conditioning is not required for laminated assembliescontaining only metal adherends, unless specified by theadhesive manufacturer as part of the bonding procedure.11. Procedure11.
35、1 Clamp the test specimen securely to the drum by meansof the drum clamp as shown in Fig. 3, and attach the other endof the specimen in the top clamp as shown in Fig. 1 and Fig.2. Attach a suitable rigid backing plate to each laminatespecimen. See 8.4 for suggested methods of attachment.Suspend the
36、top clamp from the upper head of the testingmachine. Balance the weighing apparatus to zero. Then pin theloading bar to the appropriate fittings on the lower head of thetesting machine as shown in Fig. 1.11.2 Apply an initial load, equal to that obtained in thecalibration of the apparatus for load t
37、o overcome the resistingtorque of the drum assembly, by loading the apparatus intension. Determine the peel resistance over at least 152 mm (6in.) of the bond by loading the apparatus in tension at acrosshead speed of 25.40 6 2.54 mm/min (1.00 6 0.10in./min).NOTE 5A crosshead speed of 25 mm/min (1 i
38、n./min) peels the flexiblemember from the assembly at a rate of 102 mm/min (4 in./min), using thespecified drum dimensions.11.3 It is preferred that an autographic recording of the loadversus head movement or load versus distance peeled be madeduring the peel test. If autographic equipment is not us
39、ed,average loads are obtained by recording the load at fixedincrements of time (or of head motion) after the initial peak.For example, operating at a crosshead speed of 25 mm (1in.)/min, the load is recorded 15 s after the start of the test andat each 5-s interval thereafter until approximately 152
40、mm (6in.) of the specimen have been peeled. This permits calculatingan average load over 127 mm (5 in.) of peeling, as described in12.2.Metric Equivalentsin.116316mm 1.5 4.5FIG. 4 Test Specimen for Laminated AssembliesD 1781 98 (2004)312. Calculation12.1 Determine the average peeling load required t
41、o peel theadherend from the autographic curve for the 127 mm (5 in.) ofpeeling of the specimen between 25 and 152 mm (1 and 6 in.),corresponding to 0.25 to 1.5 in. of head travel. It is preferredthat the average be determined from the curve with the use ofa planimeter. In case a planimeter is not us
42、ed, calculate theaverage as the average of load readings taken at fixed incre-ments of time or crosshead motion as indicated in 11.3.12.2 Calculate the average peel torque, T, as follows:T5 ro2 ri!Fp2 Fo!#/W (1)where:T= average peel torque, mmkg/mm (in.lb/in.) of width,ro= radius of flange, includin
43、g one half the thickness ofthe loading straps, mm (in.),ri= radius of drum plus one half the thickness of theadherend being peeled, mm (in.),Fp= average load required to bend and peel adherend plusthe load required to overcome the resisting torque, kg(lb),Fo= load required to overcome the resisting
44、torque, inpounds (use load correction determined in 9.1.1 or9.1.2, andW = width of specimen, in mm (in.).13. Report13.1 Report the following:13.1.1 Complete identification of the adhesive tested, in-cluding type, source, manufacturers code number, form, etc.,13.1.2 Complete description of the adhere
45、nds, their orien-tation and thicknesses, the method used for preparing theirsurfaces for bonding, and dimensions and construction of thetest specimen used,13.1.3 Application and bonding conditions used in prepar-ing the test specimens and conditions used for cutting indi-vidual test specimens,13.1.4
46、 Conditioning procedure used for specimens prior totesting,13.1.5 Test machine and machine head speed used withmethod of recording load and determining average load,13.1.6 Number of specimens tested and number of testpanels represented,13.1.7 Method of calibration of test apparatus and loadrequired
47、to overcome the resisting torque of the particular drumassembly used, in accordance with 9.1.1 or 9.1.2,13.1.8 Average, maximum, and minimum peeling load val-ues for each individual specimen,13.1.9 Average peel torque in millimetre-kilograms permillimetre (inch-pounds per inch) of specimen width for
48、 eachspecimen, and average values for each group of similarspecimens, and13.1.10 Type of failure, that is, cohesive failure within theadhesive, adhesion to the facing, adhesion to the core, failurewithin the core, or combinations thereof for each individualspecimen.14. Precision and Bias14.1 A preci
49、sion and bias statement does not exist for thistest method because resources necessary for round-robin test-ing have not been forthcoming.15. Keywords15.1 adhesives; climbing drum; peel strength; peel tests;sandwich panelASTM 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 rights, are entirely their own responsibility.This standard
