1、Designation: D 5824 98 (Reapproved 2003)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 D 5824; the number immediately following the designation indicates the y
2、ear 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provides a procedure to determine t
3、hequality 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,bu
4、t are 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, andfibergla
5、ss-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 lin
6、e performance for plywood products.1.4 The values stated in inch-pound units are to be regardedas standard.1.5 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 a
7、nd health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 907 Terminology of Adhesives2D 4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Based Materials3D 5266 Practice for Estimating the Percen
8、tage of WoodFailure in Adhesive Bonded Joints2E 6 Terminology Relating to Methods of Mechanical Test-ing4E 41 Terminology Relating to Conditioning5E 177 Practice for Use of the Terms Precision and Bias inASTM Test Methods6E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precisi
9、on of a Test Method63. Terminology3.1 DefinitionsCertain terms in this test method are de-fined in Terminologies D 907, E 6, and E 41.3.1.1 delamination, nthe separation of layers in a lami-nate because of failure of the adhesive, either in the adhesiveitself or at the interface between the adhesive
10、 and the adherend.(See Terminology D 907.)3.1.2 overlay, na uniform layer of material, usually in theform of a sheet, adhesively bonded to 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
11、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, nin an adhesively bonded laminate, the dimen-sion which is perpendicular to the length of the laminate wherethe overlay is bonded to the core.4. Significance and
12、 Use4.1 This test method measures quantitatively 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
13、 duringaccelerated exposure to water and heat.4.3 Resistance to delamination when subjected to environ-mental factors is critical to the performance of the laminatedassembly in service.1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of S
14、ubcommittee D14.30 on WoodAdhesives.Current edition approved April 10, 2003. Published April 2003. Originallyapproved in 1995. Last previous edition approved in 1998 as D 5824 98.2Annual Book of ASTM Standards, Vol 15.06.3Annual Book of ASTM Standards, Vol 04.10.4Annual Book of ASTM Standards, Vol 0
15、3.01.5Annual Book of ASTM Standards, Vol 14.04.6Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.4 This test method is to be used to determine the quality ofadhesive bonds in overlay-wood cor
16、e laminates after theadhesive has been certified by a specification appropriate forthe product, class, and end use.5. Apparatus5.1 Oven(s)Forced-air oven capable of maintaining 1706 5F (77 6 3C), with sufficient air circulation to ensure thatthe prescribed drying temperature is uniformly maintainedw
17、hen the oven is fully loaded and the air flow is parallel to thefaces of the specimens. A mechanism is to be provided formoisture to be removed from the chamber during drying of thespecimens.5.1.1 Use an oven to accommodate a sufficient number oftest specimens and to provide for at least 3-in. (76-m
18、m)separation between the test specimens so that the dryingtemperature 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 sy
19、stem so that pressure ismaintained at 75 psi (517 kPa).5.2.1 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 fo
20、rm anddimensions shown in Fig. 2 and Table 1.6.2 Cut field specimens from test panels (see Fig. 3) to theform 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
21、 at least four differentpanels.7. Preparation and Conditioning 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 surface
22、s, or any unusual amount ofdiscoloration. The species and type 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 man
23、ufacturer. Surface the coreto a thickness tolerance of 60.005 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
24、 manufacture of theadhesive. In the absence of such a recommendation, 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 D 4442. Cut the veneer andwood core to a suitable size and grain orientation
25、in order tobuild a panel with the grain of the veneer parallel 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 we
26、ll as for assembling,pressing, and curing the panel.7.3 After assembly, 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
27、 the adhesive manufacturer.8. 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 perpendic
28、ular to the grain ofthe 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 Specim
29、ens:8.2.1 Select the test panels so that they are representative ofproduction.FIG. 1 Laboratory Test PanelD 5824 98 (2003)28.2.2 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 acr
30、ossthe grain into 3-in. (76-mm) sections, as shown in Fig. 3, toobtain 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 th
31、etesting.8.4 Retain the specimens in the conditioning environmentdescribed 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 th
32、e water surface. Separate the test specimens withstickers, wire screens, 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 3
33、0 min. Remove the specimens from thepressure vessel and place them 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.
34、 If necessary, place the specimens onstickers to minimize contact 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 overl
35、ay-wood core laminate bondlineson the ends as well as on the edges 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
36、be a useful aid. Do not regard failurein the wood due to checking 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 i
37、n the wood. Ignore isolated delami-nation less than 0.1 in. (2.5 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-gra
38、in dimension. Use these numbers tocalculate the percent delamination as described in 10.1-10.4.10. 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 100.1
39、0.2 Calculate the percent of edge delamination of thespecimen 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 delaminat
40、ion onthe end- and edge-grain surfaces by the total length 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 Identifica
41、tion of the adhesive tested, including type,manufacturer, 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 relative humid-ity,FIG.
42、 2 Form and Dimensions of Test SpecimensTABLE 1 Test Specimen Dimensions, and TolerancesDimensionMeasurement,in. (mm)Tolerance,in. (mm)Specimen widthA5 (127) 60.031 (0.79)Specimen length 3 (76) 60.031 (0.79)Specimen thickness, minB0.625 (15.9) 60.031 (0.79)Wood core thickness, minB0.5 (12.7) 60.031
43、(0.79)Overlay thickness, minB0.063 (1.6) 60.005 (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 the adhesive manufacturer.D 5
44、824 98 (2003)311.1.4 Conditioning procedure for the specimens,11.1.5 Number of panels represented,11.1.6 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 te
45、st 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 Bias712.1 Round-robin studies were conducted to determine theprecision of this test
46、method and the data analyzed usingPractice E 691. 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.7Supporting d
47、ata are available from ASTM International Headquarters. RequestRR:D14-1006.FIG. 3 Field Test Panel Showing Cutting Test SpecimensD 5824 98 (2003)4The repeatability and reproducibility standard deviations werelarge for all the tests, thus indicating a low level of precision.The within-laboratory, sin
48、gle-operator, standard deviation (re-peatability) for determining the percent delamination was#11.20 %. This was determined for different drying rateswhere the mean percent delamination was less than or equal to6.59 %. The between-laboratory standard deviation (reproduc-ibility) was #12.24 %. Since
49、the reproducibility standarddeviation (between-laboratories) was not much larger than therepeatability standard deviation (within a laboratory), it mayindicate that the largest variability was due to a factor whichwould affect all laboratories.12.2 The procedure in this test method has no measure ofbias, since percent delamination is defined in terms of the testmethod.13. Keywords13.1 bonded; delamination; overlay; veneerASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.
