1、Designation: D5824 98 (Reapproved 2017)Standard Test Method forDetermining Resistance to Delamination of Adhesive Bondsin Overlay-Wood Core Laminates Exposed to Heat andWater1This standard is issued under the fixed designation D5824; the number immediately following the designation indicates the yea
2、r 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.1. Scope1.1 This test method provides a procedure to determine theq
3、uality of bond between an overlay and a wood core in anadhesively bonded laminate. The quality of bond is determinedby measuring the resistance to delamination of the adhesivelybonded laminate when tested under specific conditions ofpreparation, conditioning, and testing. Such products include,but a
4、re not limited to, window and door components, such asstiles and rails, and other overlaid panels. Typical wood-basedcores are finger-jointed lumber, particleboard, oriented strandboard, and hardboard. Typical overlays would be veneer,high-pressure laminate, high-density polyethylene, andfiberglass-
5、reinforced plastic.1.2 Adhesive bond performance as measured by resistanceto delamination in this test method is suitable for use inadhesive product development, manufacturing quality control,and monitoring bonding processes.1.3 This test method does not provide guidance for deter-mining bond line p
6、erformance for plywood products.1.4 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This standard does not purport to address all of
7、thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in acco
8、r-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 AST
9、M Standards:2D907 Terminology of AdhesivesD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Based MaterialsD5266 Practice for Estimating the Percentage of WoodFailure in Adhesive Bonded JointsE6 Terminology Relating to Methods of Mechanical TestingE41 Terminology Relating
10、To ConditioningE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 Certain terms in this test method are defined inTerminologies D907, E6, and E41.
11、3.1.2 delamination, nthe separation of layers in a laminatebecause of failure of the adhesive, either in the adhesive itselfor at the interface between the adhesive and the adherend. (SeeTerminology D907.)3.1.3 overlay, na uniform layer of material, usually in theform of a sheet, adhesively bonded t
12、o an adherend with thepurpose of improving the appearance or physical properties ofthe laminate.3.2 Definitions of Terms Specific to This Standard:3.2.1 edge, nin an adhesively bonded laminate, the di-mension along its length and parallel to the grain where theoverlay is bonded to the core.3.2.2 end
13、, nin an adhesively bonded laminate, the dimen-sion which is perpendicular to the length of the laminate wherethe overlay is bonded to the core.1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.30 on WoodAdhesives.Curre
14、nt edition approved Aug. 1, 2017. Published August 2017. Originallyapproved in 1995. Last previous edition approved in 2011 as D5824 98 (2011).DOI: 10.1520/D5824-98R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
15、 Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally rec
16、ognized 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.14. Significance and Use4.1 This test method measures quantitat
17、ively the effects ofwater soaking and drying, and their associated swelling andshrinking stresses on adhesive bonds in overlay-laminatedassemblies.4.2 Adhesive bond performance is based on the ability ofthe adhesive and adhesive bonds to resist delamination duringaccelerated exposure to water and he
18、at.4.3 Resistance to delamination when subjected to environ-mental factors is critical to the performance of the laminatedassembly in service.4.4 This test method is to be used to determine the quality ofadhesive bonds in overlay-wood core laminates after theadhesive has been certified by a specific
19、ation appropriate forthe product, class, and end use.5. Apparatus5.1 Oven(s)Forced-air oven capable of maintaining 170 65F (77 6 3C), with sufficient air circulation to ensure that theprescribed drying temperature is uniformly maintained whenthe oven is fully loaded and the air flow is parallel to t
20、he facesof the specimens. A mechanism is to be provided for moistureto be removed from the chamber during drying of the speci-mens.5.1.1 Use an oven to accommodate a sufficient number oftest specimens and to provide for at least 3-in. (76-mm)separation between the test specimens so that the dryingte
21、mperature is uniformly maintained.5.2 Vacuum-Pressure VesselAutoclave or similar vesselcapable of withstanding 80-psi (562-kPa) pressure, equippedwith a pump or similar device capable of drawing a vacuum of25 in. Hg (84.4 kPa). Provide a system so that pressure ismaintained at 75 psi (517 kPa).5.2.1
22、 Use a vessel so that all the specimens are at least 2 in.(51 mm) below the water level during the complete cycle.6. Test Specimens6.1 Cut laboratory specimens from prepared test panels (seeFig. 1) as described in Sections 7 and 8 to the form anddimensions shown in Fig. 2 and Table 1.6.2 Cut field s
23、pecimens from test panels (see Fig. 3)totheform and dimensions shown in Fig. 2 and Table 1. When thenominal width of the panel is used, the edges are to be preparedas the product would exist in service.6.3 Test ten specimens, representing at least four differentpanels.7. Preparation and Conditioning
24、 of Laboratory TestPanels7.1 Select veneer, either rotary cut or sliced, 0.063 in. (1.6mm) in thickness, and wood-based core, a minimum of 0.5 in.(13 mm) in thickness, so that they are free from defects such asknots, cracks, rough surfaces, or any unusual amount ofdiscoloration. The species and type
25、 of veneer and compositionof the wood core are to be agreed upon between the purchaserand the manufacturer of the adhesive. As an alternative toveneer, specific overlays can be used as agreed upon betweenthe purchaser and the adhesive manufacturer. Surface the coreto a thickness tolerance of 60.005
26、in. (0.13 mm) (see Table 1).If finger-jointed/edge-bonded core stock is used, it must remainintact without delamination during the test cycle. Both theveneer and the wood-based core are to be 61 % of themoisture content recommended by the manufacture of theadhesive. In the absence of such a recommen
27、dation, themoisture content is to be from 10 to 12 %, based on oven-dryweight as determined on representative samples in accordancewith Method A of Test Methods D4442. Cut the veneer andwood core to a suitable size and grain orientation in order tobuild a panel with the grain of the veneer parallel
28、to the grainof the wood core. A size that has been found to be convenientis shown in Fig. 1.7.2 Follow the adhesive manufacturers instructions forconditions and procedures for preparing the adhesive andapplying it to the wood core, as well as for assembling,pressing, and curing the panel.7.3 After a
29、ssembly, condition the panels for a period ofseven days (or until the panels reach equilibrium) at a relativehumidity of 50 6 2 % and a temperature of 73.4 6 2F (23 61C), or condition them in accordance with a specific recom-mendation by the adhesive manufacturer.FIG. 1 Laboratory Test PanelD5824 98
30、 (2017)28. Preparation of Specimens8.1 Laboratory Specimens:8.1.1 Prepare the test panels as described in Section 7.8.1.2 Prepare the test panels on the sides to a uniform widthof 5 in. (127 mm). Using a sharp saw, trim 1 in. (25 mm) offboth ends of each panel by cutting perpendicular to the grain o
31、fthe veneer. Discard the trim. Prepare each test specimen bycutting 3 in. (76 mm) in length along the grain as shown in Fig.1 and Fig. 2. Cut the panel across the grain into 3-in. (76-mm)sections to obtain a total of ten specimens from a minimum offour test panels.8.2 Field Specimens:8.2.1 Select th
32、e test panels so that they are representative ofproduction.8.2.2 Cut the specimens to the nominal width or a maximumof 5 in. (127 mm). Using a sharp saw, trim 1 in. (25 mm) offboth ends of each panel. Discard the trim. Cut the panel acrossthe grain into 3-in. (76-mm) sections, as shown in Fig. 3,too
33、btain a total of ten specimens from a minimum of four panels.8.3 The number of specimens taken from each panel and thenumber of panels selected may be varied, depending on thenumber of panels selected for the test and the purpose of thetesting.8.4 Retain the specimens in the conditioning environment
34、described in 7.3 until tested.9. Procedure9.1 Place the specimens in the pressure vessel described in5.2.1, weight down, and admit water at a temperature of 65 to80F (18 to 27C) so that all specimens are immersed at least2 in. below the water surface. Separate the test specimens withstickers, wire s
35、creens, or other means to ensure that allend-grain surfaces are freely exposed to the water. Draw andmaintain a vacuum of 25 in. Hg (84.4 kPa) for 30 min andfollow immediately with pressure application of 75 6 5 psi(517 6 35 kPa) for 30 min. Remove the specimens from thepressure vessel and place the
36、m in the oven described in 5.1.1at a temperature of 170 6 5F (77 6 3C) for 4 h. Place thespecimens in the oven vertically with the faces parallel,end-grain surfaces perpendicular to the air flow, and spaced atleast 3 in. (76 mm) apart. If necessary, place the specimens onstickers to minimize contact
37、 with the oven shelves and toensure that all edges are freely exposed to the air flow.9.2 At the end of the drying period specified in 9.1, removethe specimens from the drying oven. Immediately measure andrecord the length of the overlay-wood core laminate bondlineson the ends as well as on the edge
38、s of the specimen. Measureto the nearest 0.05 in. (1.27 mm), the total length of visabledelamination on the end-grain surfaces as well as on the edgesof the specimen. The use of a probe, such as a machine feelergage, has been found to be a useful aid. Do not regard failurein the wood due to checking
39、 or other causes as delamination.When the separation occurs in the wood, even though veryclose to the bond line, the separation is termed wood failure.Magnification is often necessary to determine whether thefailure is in the bond or in the wood. Ignore isolated delami-nation less than 0.1 in. (2.5
40、mm) long and more than 0.2 in. (5.1mm) away from the nearest delamination. Determine the totallength of delamination on the end-grain dimension of thespecimens, and separately determine the total length of delami-nation on the edge-grain dimension. Use these numbers tocalculate the percent delaminat
41、ion as described in 10.1 10.4.FIG. 2 Form and Dimensions of Test SpecimensTABLE 1 Test Specimen Dimensions, and TolerancesDimensionMeasurement,in. (mm)Tolerance,in. (mm)Specimen widthA5 (127) 0.031 (0.79)Specimen length 3 (76) 0.031 (0.79)Specimen thickness, minB0.625 (15.9) 0.031 (0.79)Wood core th
42、ickness, minB0.5 (12.7) 0.031 (0.79)Overlay thickness, minB0.063 (1.6) 0.005 (0.13)AThe specimen width is nominal or cut to a maximum of 5 in.BFor field-prepared specimens, the minimum overlay thickness is 0.050 in. (1.3mm). Alternative thickness is permitted as agreed upon between the purchaserand
43、the adhesive manufacturer.D5824 98 (2017)310. Calculation10.1 Calculate the percent of end delamination of thespecimen by dividing the length of delamination on theend-grain surface by the total length of exposed bond line, andmultiplying by 100.10.2 Calculate the percent of edge delamination of the
44、specimen by dividing the length of delamination on theedge-grain surface by the total length of exposed bond line, andmultiplying by 100.10.3 Calculate the percent of total delamination of thespecimen by dividing the sum of the length of delamination onthe end- and edge-grain surfaces by the total l
45、ength on exposedend- and edge-bond lines, and multiplying by 100.10.4 Calculate the average end delamination, average edgedelamination, and average total delamination.11. Report11.1 Report the following for each testing condition:11.1.1 Identification of the adhesive tested, including type,manufactu
46、rer, and code numbers,11.1.2 Type and thickness of overlay, type of wood coreused, and their respective moisture contents,11.1.3 Application and bonding conditions used in prepar-ing the specimens, including temperature and relativehumidity,11.1.4 Conditioning procedure for the specimens,11.1.5 Numb
47、er of panels represented,FIG. 3 Field Test Panel Showing Cutting Test SpecimensD5824 98 (2017)411.1.6 Number of specimens tested,11.1.7 Individual test results identified in terms of specimennumber,11.1.8 Maximum and minimum delamination for end andedge surfaces. The standard deviations of all test
48、means forend, edge, and total delamination may be included in the reportat the option of either the purchaser or the manufacturer of theadhesive.11.1.9 The mean end, edge, and total delamination.12. Precision and Bias312.1 Round-robin studies were conducted to determine theprecision of this test met
49、hod and the data analyzed usingPractice E691. Factors controlled were species of veneer andwood core, adhesive, bonding conditions, and preparation oftest specimens.12.1.1 The round-robin studies were conducted on field-produced panels to determine repeatability and reproducibility.The repeatability and reproducibility standard deviations werelarge for all the tests, thus indicating a low level of precision.The within-laboratory, single-operator, standard deviation (re-peatability) for determining the percent delamination was11.20 %. This was determined
