1、 ENGINEERING MATERIAL SPECIFICATIONMaterial Name Specification NumberDate Para No. Revisions1983 12 19 Released C901-DR522849WP 3948-a Page 1 of 9SEALER, EXTRUDED POLYOLEFIN - HEAT EXPANDING - HIGH ESB-M4G254-ATEMPERATURE CURE1. SCOPE:The material defined by this specification is an extruded uncured
2、ethylene vinyl acetate base sealer which expands when exposed to heat. Itcan be used only in plants with electrocoat paint systems. This materialis produced in extruded profiles or die cut sheet form.2. APPLICATION:This specification was released originally for material used to isolatebody side stra
3、iners and roof bows from exterior sheet metal panels. Thematerial is normally stapled or heat staked in position, and is used onoily galvanized and CRLC steel surfaces. Recommended cure schedules are8 min at 171 C metal temperature minimum, and 30 min at 205 C metaltemperature maximum.Compliance wit
4、h the performance requirements of this specification doesnot guarantee the expandable sealer will function for all potentialapplications on a vehicle. The specific design condition should beevaluated by a plant trial or laboratory simulation prior to release ofthe material.3. REQUIREMENTS:3.1 CONDIT
5、IONINGAll test values indicated herein are based on material conditionedin a controlled atmosphere of 23 +/- 2 C and 50 +/- 5% relativehumidity for 24 h prior to testing and tested under the samecontrolled conditions.3.2 INFRARED SPECTROPHOTOMETRYFord Motor Company, at its option, may conduct infrar
6、ed analysis ofmaterial/parts supplied to this specification. The spectraestablished for initial approval shall constitute the referencestandard and shall be kept on file at the designated materiallaboratory. All samples shall produce spectra that correspond tothe reference standard when tested under
7、 the same conditions asthose specified on the master spectrum.3.3 DIMENSIONS As specified on engineering drawings3.4 SPECIFIC GRAVITY (uncured material) 0.90 - 1.20(ASTM D 297, Water Displacement Method)3.5 HARDNESS, DUROMETER “D“ 25-50(ASTM D 2240, Reading after 15 s, uncured state)ENGINEERING MATE
8、RIAL SPECIFICATIONESB-M4G254-AWP 3948-b Page 2 of 93.6 EXPANSION 225 - 375%Test Method:. Prepare six test assemblies as shown in Fig 1. Use 1.0 - 1.1 mmCRLC steel- oiled. Cure three samples at each of the bake schedules indicated inpara 5.5. Allow samples to cool to 23 +/- 2 C for 1 h minimum. Calcu
9、late the percent expansion as the relationship between themaximum expanded thickness of the cured material (dimension “X“- Fig 1) and the uncured thickness of the original sample (“T“).X - TPercent Expansion = - x 100T. Using a hot knife disassemble test samples by cutting the curedsealer along the
10、surface of panel “A“ - Fig 1. The cured sealershall be resilient to the touch and exhibit a uniform cellstructure.3.7 SHEAR ADHESION STRENGTH, kPa, minThe minimum adhesion values indicated shall be obtained by allcoupons in each exposure group when subjected to the followingenvironments.3.7.1 Normal
11、 - 24 h at 23 +/- 2 C 6203.7.2 14 days at 83 +/- 2 C 6203.7.3 14 days at 38 +/- 1 C and 95-100% R.H. 6203.7.4 Salt Spray, 240 h 100(ASTM B 117)3.7.5 Thermal Cycle (5 times) 620. 4 h at 83 +/- 2 C. 4 h at 38 +/- 1 C and 95-100% R.H. 16 h at -29 +/- 1 C. 4 h at 38 +/- 1 C and 95-100% R.H. 4 h at 83 +/
12、- 2 C. 16 h at -29 +/- 1 CSample Preparation: Reference FLTM BV 1-6; uncuredmaterial thickness per para 5.4 (machine direction ofsample material to be parallel to long sides of lap shearcoupon), bondline thickness after cure 1.8 - 3.3 mm,substrates per para 5.3, material cure temperature per para5.5
13、.ENGINEERING MATERIAL SPECIFICATIONESB-M4G254-AWP 3948-b Page 3 of 9Prepare five samples per exposure per bake schedule. Aftercuring, condition coupons for 24 h at 23 +/- 2 C. Prior tobeginning exposure tests, trim all material that expandedout of bond joint during cure.Test Method: Subject test ass
14、emblies to exposures noted.After completing exposure the test specimens shall beconditioned at a 23 +/- 2 C for a minimum of 2 h and amaximum of 3 h prior to testing on a tensile machine at ajaw separation rate of 25 mm/min.3.8 CORROSION RESISTANCE, min 240 h(ASTM B 117)3.8.1 CRLC Steel - OiledSurfa
15、ce rust within 7.0 mm of the perimeter of the curedsealer is permissible after disassembly of test assemblies.Test Method:. Prepare four test assemblies as shown in Fig 2A. Cure two samples at each of the bake schedules indicatedin para 5.5. Condition samples 24 h at 23 +/- 2 C. Remove clamps and su
16、bject the four cured assemblies to240 h salt spray per ASTM B 117. After exposure disassemble panels and examine metalsurfaces under sealer for evidence of corrosion. Surfacecorrosion shall not extend more than 7.0 mm inside ofsealer perimeter.3.8.2 CRLC Steel - ElectrocoatedThere shall be no eviden
17、ce of corrosion under the sealer oneither panel surface.Test Method:. Prepare four test assemblies as shown in Fig 2B. Electrocoat four assemblies in a production paint systemor equivalent laboratory batch tank. Electrocoating tobe conducted with the assistance of qualified Ford paintpersonnel.NOTE:
18、 When electrocoating in a production facility,oiled CRLC steel test assemblies are to be processedthrough the phosphate system. If samples areelectrocoated in a batch tank, Parker 40 panels shouldbe used to construct the test assemblies. Cure two samples at each of the bake schedules indicatedin par
19、a 5.5. Electrocoated assemblies to be cured in avertical position with the 150 mm long side parallel tobottom of oven.ENGINEERING MATERIAL SPECIFICATIONESB-M4G254-AWP 3948-b Page 4 of 9. After curing remove clamps and condition 24 h at 23 +/-2 C. Subject cured assemblies to 240 h salt spray perASTM
20、B 117. After exposure disassemble panels and examine metalsurfaces under sealer for corrosion. There shall be noevidence of corrosion beneath the sealer on either steelpanel.3.9 LOW TEMPERATURE RESISTANCEThere shall be no evidence of adhesive or cohesive failure afterthe test assemblies have accumul
21、ated 100 cold slams at -29 +/- 1 C.Test Method:. Prepare two test samples as shown in Fig 3. Cure one sample at each of the bake schedules indicated in para5.5. Cure samples in a horizontal position. Condition samples at 23 +/- 2 C for a minimum of 24 h. Place two test assemblies and cold slam appar
22、atus described inFLTM BV 1-2 in a cold box and condition at -29 +/- 1 C for aminimum of 4 h. Individually mount panels on the cold slam apparatus with bonded100 x 300 mm panel at bottom side facing away from fixture. Slam10 times per FLTM BV 1-2 at -29 +/- 1 C. Remove two test panels from cold box a
23、nd condition at 23 +/- 2 ha minimum of 1 h. Return two panels to cold box and condition 4h minimum at -29 +/- 1 C and slam 10 times. Repeat this sequenceuntil 100 cold slams have accumulated. Condition at 23 +/- 2 C for 1 h minimum and disassemble samples.Examination of samples shall iindicate no ad
24、hesive or cohesivefailure of the sealer.3.10 SAG RESISTANCE, max 3.0 mmTest Method:. Provide a 12.7 mm diameter hole in the center of four oily CRLCsteel panels with nominal dimensions of 100 x 150 x 0.8-0.9 mm. Place a 50 x 50 x 2.3 - 2.8 mm piece of uncured sealer materialon each panel with sealer
25、 centered over hole. Support the panels on opposite sides and bake in a horizontalposition. Cure two samples at each of the bake schedulesindicated in para 5.5. Remove from oven and condition 1 h minimum at 23 +/- 2 C. Fromthe under surface of the panel measure the distance the materialhas sagged th
26、rough the hole.ENGINEERING MATERIAL SPECIFICATIONESB-M4G254-AWP 3948-b Page 5 of 93.11 FUEL RESISTANCEAfter a controlled immersion in ASTM Type “B“ fuel or diesel fueland recovery at 23 +/- 2 C, the minimum adhesion value for overlapshear samples shall be 275 kPa.Test Method:. Prepare overlap shear
27、test samples as described in 3.7.4. Testfive samples from each cure schedule in ASTM type “B“ fuel, andfive from each schedule in diesel fuel. Immerse total bonded area of all samples in each type of fuel.NOTE: Because of precise time constraints for immersion,recovery and tensile testing, it is rec
28、ommended each fuel typebe tested separately.Vessels containing fuel should be maintained at 23 +/- 2 C. Allfuel work should be conducted in a laboratory hood. Samples tobe immersed for 2 h +5 min., -0 min. Remove samples from fuel immersion and condition 4 h at 23 +/-2 C. During conditioning period,
29、 store samples in a panel rackin a closed area to minimize evaporative action. After conditioning period, test samples immediately on a tensiletest machine at a jaw separation rate of 25 mm/min. The 10samples should be tested within 15 minutes of completingconditioning.3.12 STORAGE STABILITYThe mate
30、rial shall be stored at temperatures below 41 C, away fromall sources of heat. Heat greatly accelerates aging. Under theseconditions the minimum shelf life of the material shall be sixmonths. When this material is stored at temperatures below 23 C,it shall be conditioned at room temperature prior to
31、 application.3.13 FUNCTIONAL APPROVALMaterials being evaluated for initial approval to thisspecification shall be subjected to a functional trial at arepresentative production facility. The material used for thetrial must be manufactured using production equipment andprocessing methods. Function tri
32、al results should be available toDesign and Materials Engineering prior to material approval andrelease.3.14 SUPPLIERS RESPONSIBILITYMaterial supplied to this specification must be equivalent to thatoriginally approved. Changes in formulation or processing shallnot be made without prior approval as
33、described in SupplierProcedure I-A.ENGINEERING MATERIAL SPECIFICATIONESB-M4G254-AWP 3948-b Page 6 of 94. APPROVAL OF SUPPLIERS:Suppliers to this specification must be approved by the affected productengineering office. Procedure for gaining approval of a specificmaterial to a new/existing ES-M speci
34、fication is contained in SupplierProcedure I-A. Approved new suppliers will be added to the EngineeringMaterials Approved Source List.5. GENERAL INFORMATION:The material data and information included herein is for information onlyand is not a requirement for the supplier.5.1 SPECIFICATION USAGEThis
35、specification was developed for the following purposes:. To enable approved supplier(s) to verify that productionmaterial is being manufactured in compliance with specifiedperformance requirements. To evaluate materials that are submitted as candidates foralternate source approval.The specification
36、cannot be used for quality control purposes tocheck production parts, unless the part being evaluated is ofsufficient size and thickness (2.3 - 2.8 mm) to permit preparationof the various test samples.5.2 MECHANICAL CONVECTION OVENThe mechanical oven(s) used to cure the material shall be capableof a
37、chieving 205 C metal temperature on body steel (0.8 - 0.9 mmthickness) within 8 - 10 min.5.3 SUBSTRATESNominal panel thickness 0.8 - 0.9 mm, surface precoated withM-99C47-A mineral oil at an application of approximately 2.2 cm 3 /m 25.3.1 CRLC steel - plain.5.3.2 Galvanized steel (ESB-M1A250-A3).5.4
38、 TEST MATERIAL THICKNESSSample material submitted for evaluation to this specificationshall be 2.3 - 2.8 mm thickness.5.5 MATERIAL CURE SCHEDULES5.5.1 Minimum: 8 min at 171 +/- 3 C metal temperature.5.5.2 Maximum: 30 min at 205 +/- 3 C metal temperature.ENGINEERING MATERIAL SPECIFICATIONESB-M4G254-A
39、WP 3948-b Page 7 of 9FIG 1 EXPANSION TESTA. TEST ASSEMBLY BEFORE CURE (1.0-1.1 mm CRLC STEEL-OILED)B. TEST ASSEMBLY AFTER CUREENGINEERING MATERIAL SPECIFICATIONESB-M4G254-AWP 3948-b Page 8 of 9FIGURE 2 CORROSION RESISTANCEA. CRLC STEEL-OILEDB. CRLC STEEL-PHOSPHATE AND ELECTROCOATEDENGINEERING MATERIAL SPECIFICATIONESB-M4G254-AWP 3948-b Page 9 of 9FIGURE 3 LOW TEMPERATURE RESISTANCE
