1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.s
3、ae.orgCopyright 2002 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICEJ1918REV.JAN2002Issued 1988-05Revised 2002-01Superseding J1918 MAY1988(R) Method for the Determination of Expansion and Wa
4、ter Absorption in Automotive SealersForewordThis document describes three different methods for measuring the expansion of an automotive sealerMethod #1Gravimetric MethodMethod #2Volumetric MethodMethod #3Vertical Methodand two methods for measuring water absorptionMethod #1Uncut MethodMethod #2Cut
5、MethodThe gravimetric and volumetric methods would be used to determine the amount of compound needed tocompletely fill an enclosed or “boxed in” area to effect a moisture and/or sound resistant barrier. The gravimetricmethod, Method #1, is analytical in nature and thus is more precise in its calcul
6、ated values, and is especialy usefulwhen measuring expansions of less than 100%. The volumetric method, Method #2, is a quick way to checkexpansion where errors of 5% points are not crucial.The vertical expansion method, Method #3, measures the vertical rise that a sealer achieves and is useful inde
7、termining bead size and expansion requirements in sealing applications, such as roof bows, where the criticalfunction of the compound involves “jumping” an air gap, thereby joining two irregularly spaced surfaces.The water absorption methods measure a sealers resistance to moisture transmission when
8、 the sealers outersurface is intact and/or damaged. Generally water absorption values, after 24 h immersion, of 2% or less for intactfilms and 3% or less for cut films are acceptable.1. ScopeThis SAE Recommended Practice sets forth methods for determining total expansion gravimetricallyand volumetri
9、cally, calculating vertical expansion and measuring the water absorption of cut and uncut sealerbeads.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1918 Revised JAN2002-2-2. References2.1 Relate
10、d PublicationsThe following publications are provided for information purposes only and are not arequired part of this document.2.1.1 DAIMLERCHRYSLER PUBLICATIONSAvailable from DaimlerChrysler Corporation, ?LP-463NB-5-01 Change CVolume Change of Heat Expandable SealersDetermination of,DaimlerChrylse
11、r Corporation, Laboratory Procedure (Gravimetric Test Method)LP-463NB-33-01 Change ASealersVertical Rise Method of Determining Volume Change,DaimlerChrysler Corporation, Laboratory Procedure (Vertical Expansion Test Method)LP-463NB-07-01 Change CSealersWater AbsorptionDetermination of, DaimlerChrysl
12、erCorporation, Laboratory Procedure (Water Absorption Test Method)2.1.2 FORD PUBLICATIONSAvailable from Ford Motor Company, ?FLTM BV 108-02 1992 01 21Volume Change Test for Adhesives and Sealants, Ford Motor Company,Automotive Safety and Engineering Standards (Gravimetric Test Methods)ESB-M18P11-A 1
13、988 12 093.8 Expansion, Ford Motor Company, Engineering Material Specification(Vertical Expansion Test Method)FLTM BV 117-01 1992 02 03Water Absorption Test for Adhesives and Sealants, Ford Motor Company,Engineering Material Specification (Water Absorption Test Method)2.1.3 GENERAL M OTORS CORPORATI
14、ONAvailable from General Motors Corporation, ?GM9037P September 1988Test for Measuring Expansion of Sealers, General Motors EngineeringStandards, Materials and ProcessesProcedures (Gravimetric Test Method)GM9640P January 1992Water Absorption Test for Adhesives and Sealants, General MotorsEngineering
15、 Standards, Materials and ProcessesProcedures (Water Absorption Test Method)GM9764P October 1989Test for Measuring the Ramp Expansion of Sealers, General MotorsEngineering Standards, Materials and ProcessesProcedures (Vertical Expansion Test Method)3. EquipmentThe following materials are required:3.
16、1 Expansion3.1.1 GRAVIMETRIC TEST METHODS (METHOD #1)a. Sealer to be testedb. Mechanical Convection Ovenc. Analytical Balance (0.0001 g accuracy)d. 150 mL beakere. Three count 0.9 x 25 x 62 mm (0.035 x 1 x 2.5 in) Aluminum Coupons with 0.25 mm diameter wiref. 0.9 x 300 x 300 mm (0.035 x 12 x 12 in)
17、Cold Rolled Steel Panelg. 0.9 x 75 x 150 mm (0.035 x 3 x 6 in) Cold Rolled Steel PanelCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1918 Revised JAN2002-3-3.1.2 VOLUMETRIC TEST METHODS (METHOD #
18、2)a. Sealer to be testedb. Mechanical Convection Ovenc. 500 mL graduated cylinder (50 mm (2.0 in) diameter)d. Three count 15 mL (0.5 oz) seamless containers with 0.25 mm (0.010 in) diameter wiree. 0.9 x 300 x 300 mm (0.035 x 12 x 12 in) Cold Rolled Steel Panel3.1.3 VERTICAL E XPANSION TEST METHODS (
19、METHOD #3)a. Sealer to be testedb. Mechanical Convection Ovenc. Six count 0.9 x 100 x 300 mm (0.035 x 4 x 12 in) Cold Rolled Steel Panelsd. Six count 32 mm Wide Spring Clips3.2 Water Absorptiona. Sealer to be testedb. Mechanical Convection Ovenc. Analytical Balance (0.001 g accuracy)d. 0.9 x 25 x 62
20、 mm (0.035 x 1 x 2.5 in) Aluminum Coupons without wiree. 0.9 x 300 x 300 mm (0.035 x 12 x 12 in) Cold Rolled Steel Panel4. Gravimetric Expansion Procedure (Method #1)4.1 Fabricate a small platform, from a 75 x 150 x 0.9 mm (3 x 6 x 0.035 in) steel panel, that will support a 150 mLbeaker full of wate
21、r as shown in Figure 1 (exact dimensions will vary depending on the model of balance used).The positioning of the platform and beaker should be arranged to allow complete freedom of movement of thepan.4.2 Individually identify each of three 0.9 x 25 x 62 mm (0.035 x 1 x 2.5 in) aluminum coupon assem
22、blies, asshown in Figure 2, and determine the dry weight of each panel (W1) to the nearest milligram (0.0001).4.3 Determine the wet weight of each coupon assembly (W2) to the nearest milligram (0.0001) after suspendingeach coupon in water as in Figure 3, making sure the entire coupon is submerged.4.
23、4 The volume of each coupon (V1) in milliliters is equal to the difference between the dry and wet weights dividedby the specific gravity of water, 1 g/mL(Eq. 1)4.5 Apply a semi-circular bead of sealer, approximately 10 mm (0.39 in) in diameter, down the center of eachpanel.4.6 Trim the ends of each
24、 bead leaving a 38 mm (1.5 in) length of sealer centered on each coupon as shown inFigure 4.V1 W1 mg()W2 mg()1 g mL-=Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1918 Revised JAN2002-4-FIGURE 1
25、PLATFORM PANELCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1918 Revised JAN2002-5-FIGURE 2COUPON ASSEMBLYCopyright SAE International Provided by IHS under license with SAENot for ResaleNo repro
26、duction or networking permitted without license from IHS-,-SAE J1918 Revised JAN2002-6-FIGURE 3ANALYTICAL SCALE SET-UPCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1918 Revised JAN2002-7-FIGURE
27、4GRAVIMETRIC EXPANSION SAMPLE AND COUPON GEOMETRY4.7 Determine the unexpanded sealer volume (V2) for the three marked and sealer coated coupons by weighingthe assemblies dry (W3) and wet (W4) with weights reported in milligrams using the procedure described in 4.2through 4.3 where,(Eq. 2)4.8 Place t
28、he sealer coupons horizontally in the center of a 300 x 300 x 0.9 mm (12 x 12 x 0.035 in) panel.4.9 Place the panel, with sealer coupons, in the center of a mechanical convection oven and bake in the horizontalposition for the specified time at the specified temperature.V2 mL() W3 mg()W4 mg()1 g mL-
29、V1 mL()=Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1918 Revised JAN2002-8-4.10 Allow the coupons to cool to room temperature 23 C 2 C (73 F 4 F).4.11 Determine the expanded sealer volume (V3)
30、 for the three marked, coated, and baked coupons by weighing theexpanded sealer panels dry (W5) and wet (W6) with the weights reported in milligrams using the proceduredescribed in 4.2 through 4.3 where,(Eq. 3)4.11.1 If the sealer expansion is great enough to float the coupon assembly, a weight larg
31、e enough to overcome thebuoyancy of expansion, is added to each of a second set of uncoated coupons and the steps 4.1 through4.11 are repeated.4.12 Calculate the volume change in the cured sealer as a percentage of the original uncured volume as follows,(Eq. 4)4.13 Calculate the average expansion of
32、 the three coupons and report the results.5. Volumetric Expansion Procedure (Method #2)5.1 Fill a 500 mL graduated cylinder to the 400 mL mark (V1) with water and record the volume.5.2 Mark and individually submerge the 15 mL containers and record the graduated cylinder volume levels (V2) inmL.5.3 D
33、etermine the volume of the empty container (V3) by the following formula:(Eq. 5)5.4 Fill each container with the sealer to be tested, being careful not to create any air pockets.5.5 Fill the graduated cylinder to the 400 mL mark with water and record the volume (V1) in mL.5.6 Submerge the individual
34、ly marked sealer filled containers and record the graduated cylinder volume levels(V4) in mL.5.7 Determine the volumes of the containers and uncured sealer (V5) by the following formula:(Eq. 6)5.8 Place the sealer containers in the center of a 300 x 300 x 0.9 mm (12 x 12 x 0.035 in) panel.5.9 Place
35、the panel, with the sealer containers, in the center of a mechanical convection oven and bake in thehorizontal position for the specified time at the specified temperature.5.10 Allow the containers to cool to room temperature 23 C 2 C (73 F 4 F).5.11 Fill the graduated cylinder to the 400 mL mark wi
36、th water and record the volume (V1) in mL.V3 mL() W5 mg()W6 mg()1 g mL-V1 mL()=Percentage Volume Change V3 mL()V2 mL()-1100=V3 mL()V2 mL()V1 mL()=V5 mLV4 mL()V1 mL()=Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without licens
37、e from IHS-,-SAE J1918 Revised JAN2002-9-5.12 Submerge the individually marked, expanded sealer filled containers and record the graduated cylinder volumelevels (V6) in mL. If the expanded sealer and container float, use a straightened paper clip to force the canbeneath the water and record the leve
38、l. (See Figure 5.)FIGURE 5VOLUMETRIC EXPANSION SAMPLE EVALUATION5.13 Determine the volume of the container and expanded sealer (V7) by the following formula:(Eq. 7)NOTEAfter the V6 measurement, remove the expanded material and inspect for voids.5.14 Calculate the volume change in the sealer as a per
39、centage by the following formula:(Eq. 8)5.15 Calculate the average expansion of the three containers and report the results.V7 mL()V6 mL()V1 mL()=% Volume Change V7 mL()V5 mL()V5 mL()V3 mL()-100=Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networ
40、king permitted without license from IHS-,-SAE J1918 Revised JAN2002-10-6. Vertical Expansion Procedure (Method #3)6.1 Take three 0.9 x 100 x 300 mm (0.035 x 4 x 12 in) panels and fabricate a 90 degree bend, 25 mm long, at oneend of each panel as in Figure 6.6.2 To each fabricated panel apply a 6 x 2
41、00 mm semi-circular or, as specified, bead of sealer lengthwise downthe center of each panel as shown in Figure 7.6.3 Attach a straight 0.9 x 100 x 300 mm (0.035 x 4 x 12 in) panel to the top of the first panel securing the two atthe narrow end by means of a spring clip as in Figure 8.6.4 Record the
42、 thickness of the unexpanded sealer (T1) in millimeters.6.5 Place the three assemblies horizontally in the center of a mechanical convection oven and bake theassemblies at the specified temperature for the specified time.6.6 Allow the panels to cool to room temperature 23 C 2 C (73 F 4 F).6.7 Measur
43、e and record the maximum height of the expanded sealer (T2) in millimeters for each assembly. (SeeFigure 9.)FIGURE 6VERTICAL EXPANSION SUBSTRATE GEOMETRYFIGURE 7VERTICAL EXPANSION SAMPLE/SUBSTRATE GEOMETRYCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction
44、 or networking permitted without license from IHS-,-SAE J1918 Revised JAN2002-11-FIGURE 8VERTICAL EXPANSION PRE-BAKE SAMPLE PREPARATIONFIGURE 9VERTICAL EXPANSION AFTER-BAKE SAMPLE PREPARATION6.8 Calculate the maximum vertical expansion, as a percentage of the uncured sealer height, by means of thefo
45、llowing formula:(Eq. 9)6.9 Calculate the average vertical expansion of the three assemblies and report the results.6.10 Repeat steps 6.1 through 6.9 if the expansion characteristics perpendicular to the sealed surface of anonhorizontal assembly is desired. Bake the panels as specified rather than ho
46、rizontally.7. Water Absorption, Uncut (Method #1)7.1 Individually identify each of three 0.9 x 25 x 62 mm (0.035 x 1 x 2.5 in) aluminum coupons and determine, onan analytical balance, the dry weights of each coupon (W1) to the nearest milligram (0.0001).7.2 Apply a semi-circular bead of sealer, appr
47、oximately 10 mm (0.39 in) in diameter, down the center of eachpanel.7.3 Trim the ends of each bead leaving a 38 mm (1.5 in) length of sealer centered on each coupon.7.4 Place the sealer coupons horizontally in the center of a 0.9 x 300 x 300 mm (0.035 x 12 x 12 in) panel.7.5 Place the panel, with se
48、aler coupons, in the center of a mechanical convection oven and bake in the horizontalposition for the specified time at the specified temperature.Percentage Vertical Expansion T2 mm()T1 mm()T1 mm()-100=Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking pe
