1、Designation:E87410a Designation: E874 11Standard Practice forAdhesive Bonding of Aluminum Facings to NonmetallicHoneycomb Core for Shelter Panels1This standard is issued under the fixed designation E874; the number immediately following the designation indicates the year oforiginal adoption or, in t
2、he 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This
3、 practice describes the materials, processes, and quality controls to be used in the manufacture of adhesive-bonded,aluminum-faced, nonmetallic-honeycomb-core sandwich panels for tactical shelters.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parenthes
4、es are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of theuser of this standard to establish appropriate safety a
5、nd health practices and determine the applicability of regulatory limitationsprior to use.2. Referenced Documents2.1 ASTM Standards:2B209 Specification for Aluminum and Aluminum-Alloy Sheet and PlateC297/C297M Test Method for Flatwise Tensile Strength of Sandwich ConstructionsD1781 Test Method for C
6、limbing Drum Peel for AdhesivesE864 Practice for Surface Preparation of Aluminum Alloys to Be Adhesively Bonded in Honeycomb Shelter PanelsE865 Specification for Structural Film Adhesives for Honeycomb Sandwich PanelsE866 Specification for Corrosion-Inhibiting Adhesive Primer for Aluminum Alloys to
7、Be Adhesively Bonded in HoneycombShelter PanelsE990 Specification for Core-Splice Adhesive for Honeycomb Sandwich Structural PanelsE1091 Specification for Nonmetallic Honeycomb Core for Use in Shelter PanelsE1826 Specification for Low Volatile Organic Compound (VOC) Corrosion-Inhibiting Adhesive Pri
8、mer for Aluminum Alloysto Be Adhesively Bonded Specification for Low Volatile Organic Compound (VOC) Corrosion-Inhibiting Adhesive Primer forAluminum Alloys to Be Adhesively BondedE2004 Test Method for Facing Cleavage of Sandwich Panels2.2 Military Standards:3MIL-STD-105 Sampling Procedures and Tabl
9、es for Inspection by Attributes2.3 Federal Standards:3Fed. Std. No. 209 Clean Room and Work Station Requirements, Controlled Environment3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 excessive corrosion, nsurface corrosion that is not removed by cleaning as described in Pract
10、ice E864.3.1.2 gouge, na surface defect in which material has been removed and that causes a decrease in strength in a highly stressedarea.3.1.3 nominal pressure, nthe intended operating pressure.3.1.4 nominal temperature, nthe intended operating temperature.1This practice is under the jurisdiction
11、of ASTM Committee E06 on Performance of Buildings and is the direct responsibility of Subcommittee E06.53 on Materials andProcesses for Durable Rigidwall Relocatable Structures.Current edition approved Nov.Sept. 1, 2010.2011. Published December 2010.October 2011. Originally approved in 1982. Last pr
12、evious edition approved in 2010 asE874 10a. DOI: 10.1520/E0874-10A.10.1520/E0874-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary
13、page on the ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of wha
14、t 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 the
15、 official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.5 tapping test, na nondestructive evaluation procedure for detecting panel delamination in which the outer skin of thepanels is tapped with a hammer or coin.3.1.5.
16、1 DiscussionChanges in acoustic emissions resulting from tapping can be associated with delamination andnondelaminated sections of panel.4. Significance and Use4.1 The formation of reproducible, durable-adhesive bonds in structural units requires great care in the selection of materials,the preparat
17、ion of the surfaces of the parts to be bonded, and the performance of the steps in the bonding process. Experience hasshown that adhesive bonding carried out in accordance with this practice produces relatively reproducible bonds.5. Facilities5.1 Panel-Assembly-Layup AreaThe panel-assembly-lay-up ar
18、ea is an enclosed, environmentally controlled area that iscontinuously controlled for temperature, relative humidity, and concentration of airborne particles. The environmentally controlledarea shall be maintained at a temperature of 75 6 10F (24 6 6C) and not more than 50 % relative humidity. The t
19、emperatureand relative humidity shall be recorded continuously.All incoming and recirculated air shall be filtered to control airborne particles.The air handling equipment shall provide at least five air changes per hour in the environmentally controlled area. The filters shallensure that the partic
20、le count within the environmentally controlled area will not exceed 200 000 particles/ft3(7 3 106particles/m3) of size 1 m and larger. The air pressure differential between the environmentally controlled area and adjacent areasshall be monitored continuously and recorded at least twice weekly. The a
21、ir pressure in the environmentally controlled area shallbe maintained above that of adjacent areas by a minimum of 0.015 in. H2O (3.7 Pa). The particle count shall be monitored inaccordance with Fed. Std. No. 209. The recorders shall be calibrated every six months. The environmentally controlled are
22、a shallbe conspicuously identified at all entrances as limited access. Unnecessary traffic within the environmentally controlled area shallnot be permitted. Eating and smoking within the environmentally controlled area shall not be permitted and the environmentallycontrolled area shall be so posted.
23、 All materials, tools, and equipment used in the environmentally controlled area shall be clean,low shed, and free of lint, oil, and grease. The application of oil, grease, mold release agents, or other possible contaminants withinthe environmentally controlled area shall be prohibited. The interior
24、, exposed surfaces of the environmentally controlled area shallbe nonshedding and easily cleaned. The floor shall be sealed and cleaned daily to minimize dust generation. No preparations suchas insertion of foam into honeycomb core, or cleaning other than by filtered vacuum, shall take place in the
25、environmentallycontrolled area. No core cutting shall be allowed in the environmentally controlled area other than that required for integral-panelcutouts involving total thickness of the core to precut skin openings, core repair, or minor trimming.5.2 Primer Application AreaThe primer-application a
26、rea shall be separated from the cleaning tanks, manufacturing area, andother areas of potential contamination. All air furnished to this area shall be filtered, and compressed air used shall be oil-free.6. Apparatus6.1 Pressure EquipmentPressure equipment for bonding of shelter panels shall be large
27、 enough to permit the bonding of thetotal panel in one step. The manufacturer shall provide calibration and test data demonstrating that the temperature on the twofacings of press platens during lamination will be equal and uniform within 4 % of their nominal temperature. The pressureequipment used
28、for curing the panels shall be capable of applying greater than 20 psi (138 kPa) and 300F (150C) over the entirepanel surface. Platens shall be flat to within 0.002 in./ft (0.17 mm/m). The pressure equipment shall be equipped with temperatureand pressure recorders and controls that accurately contro
29、l heat-up rate, pressure application, dwell time, cool down (whenrequired), and pressure removal. The pressure equipment shall also be equipped with suitable devices (for example, caul sheets)that facilitate moving the panel layup into the press without misaligning the layup.6.1.1 Calibrations, Temp
30、erature and Pressure Requirements, and ControlsGages shall be calibrated every six months by anaccredited independent laboratory or by the manufacturer if approved by the purchaser. The latest calibration certificate shall beattached to the equipment near each gage. It shall be demonstrated that the
31、 actual bonding pressure is within 10 % of the nominalpressure. It shall also be demonstrated that the average temperatures of the top and bottom panel facings during the bonding processare equal and uniform to within 4 % of the nominal temperature. Thermocouples placed at each corner and at the cen
32、ter of eachfacing shall be used to demonstrate the uniformity of the temperature. Compliance of the equipment with these requirements shallbe verified at intervals not exceeding six months. A permanent record of the pressure, time, and temperature measurements duringbonding shall be maintained. All
33、calibrations must be traceable to the National Institute of Standards and Technology (NIST).46.2 Testing EquipmentThe supplier shall have available sufficient testing equipment to ensure that all process-controlspecimen preparation and testing required by this practice can be accomplished without un
34、necessarily delaying production. Allcalibrations of test equipment required by this practice shall be traceable to NIST.7. Materials7.1 Materials shall be as specified herein or as specified in the contract.All materials shall be stored and handled in such manneras to provide adequate protection aga
35、inst degrading environments and mechanical damage.4Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.E874 1127.2 Aluminum:7.2.1 FacingsThe facings shall be aluminum alloy conforming to Specification B209 a
36、nd shall be certified as complying withthe alloy, temper, and thickness requirements of the shelter specification. Facings shall be free of excessive corrosion, oil canning(snap-buckling), dents, gouges, or other defects that may adversely affect the structural integrity of a bonded panel. Themanufa
37、cturers certification or reports of tests for mechanical properties and chemical composition shall be included with eachshipment.7.2.2 Preparation of Aluminum-Alloy Parts for BondingThe aluminum-alloy parts used in the manufacture of honeycombpanels shall be prepared for bonding in accordance with P
38、ractice E864.7.3 Honeycomb CoreThe honeycomb-core material shall be as specified in the shelter specification and shall meet therequirements of Specification E1091. It shall be stored in its shipping container in a segregated area away from traffic congestionuntil processing for panel layup.7.4 Adhe
39、sivesThe structural film and core splice adhesives shall conform to Specifications E865 and E990, respectively. Theyshall be stored in accordance with the manufacturers recommendation.7.4.1 Qualification of Adhesive SystemThe panel manufacturer is responsible for ensuring that the adhesive system us
40、ed inthe manufacture of panels under this practice is qualified to meet Specifications E865 and E990.7.5 PrimerThe adhesive primer shall conform to Specification E866.7.6 Thermal BarriersThermal barriers shall conform to the purchasers requirements.NOTE 1Thermal barriers are bonded between the skin
41、and metal-edge members to prevent a thermal short between exterior and interior skins.8. Panel Construction8.1 The alloy, temper, and thickness of the facings, edge closure details, core type, and the weights and sizes of the panels shallbe as specified in the design specification. Panels shall not
42、have any defects, bulges, depressions, or dents with an area greater than8 in.2(5200 mm2) or deeper than 0.040 in. (1.0 mm). The total allowable area of defects per panel shall not exceed 0.1 % of panelarea per side. Panels exceeding 0.1 % defect area may be subjected to rework procedure agreed upon
43、 between the manufacturerand the customer. Panels shall not be bowed or warped nor shall there be any deviation from total flatness of the panel greater than0.016 in./ft (1.3 mm/m). The allowable deviation from flatness (warpage) shall be determined by applying a straight-edge, asspecified in 10.6.1
44、, against the concave side of the panel with the opposite side lying on a flat surface and measuring the maximumgap between the straightedge and the panel.8.2 Edge Closures and Framing MembersThese shall be as specified in the shelter-design specification. On pre-existingdesigns, process the materia
45、l in accordance with pre-existing design configuration/specification requirements unless otherwisedirected by the procuring activity. When the aluminum edge closures are to be bonded, they shall be treated in accordance withPractice E864. When the shelter design requires the edge closures and framin
46、g members to be bonded simultaneously with panelsbonding, the edge closures and framing members shall be bonded to the facings with the structural film adhesive specified in 7.4.8.3 Preparation of Aluminum Facings and Edge ClosuresAll cutting, trimming, and sizing of the facings and edge closuressha
47、ll be made prior to surface preparation or on the panel following completion of the bonding operation. The faying surfaces ofall aluminum parts which are to be bonded shall be prepared in accordance with Practice E864 and Specification E866 orSpecification E1826. All aluminum for bonded panels shall
48、 be placed in primer application area within12 h after completion ofthe cleaning process.8.4 Preparation of Honeycomb CoreHoneycomb that is not to be filled with plastic foam shall be cleaned of dust with dry,oil-free, filtered, compressed air or vacuumed prior to delivery to the panel-assembly-lay-
49、up area. When the cells of the honeycombcore are filled with plastic foam, the surface of the installed foam shall be at least116 in. (1.5 mm) below the surface of thehoneycomb on both surfaces, and all bonding surfaces shall be freed from foam dust and contaminants by vacuuming. When apanel requires more than one sheet of core, the seam between pieces shall be spliced so that uniformity of thickness is maintainedacross the seam. The core-splicing material shall conform to Specification E990 and must be impermeable to water and serve asa barrier to
