1、 FORD LABORATORY TEST METHOD BI 022-01 Date Action Revisions 2000 08 31 Revised Editorial no technical change A. Cockman 1992 06 29 Printed copies are uncontrolled Pag e 1 of 6 Copyright 2000, Ford Global Technologies, Inc. DETERMINATION OF ENAMEL SAG RESISTANCE Application This test method describe
2、s the procedure to determine the relative sag resistance of exterior body enamel. Apparatus Required Automatic Paint Spray Machine Spraymation or equivalent Source: Sprayma tion Inc. Little Falls, New Jersey 07424 Oven Shall be capable of maintaining 130 +/ - 2 C. No. 2 Ford Cup Paint Film Thickness
3、 Tester Any reliable electromagnetic thickness gauge such as Autotest, Type MS. Source: Twin Cities International, Inc. 175 Pineview Drive Amherst, N.Y. 14150 (716) 691 - 8855 Materials Required Test Panels 300 x 450 mm Bonderite 40 Parker Test Panel (or equivalent). Source: Parker Division O.M.I. C
4、orp. 322 Main Street Morenci, MI 48256 (517) 458 - 2221 FORD LABORATORY TEST METHOD BI 022-01 Page 2 of 6 Copyright 2000, Ford Global Te chnologies, Inc. OR Formed Sag Test Panels Source: Advanced Coatings Technologies P.O. Box 310 273 Industrial Drive Hillsdale, MI 48242 (517) 439 - 1492 Control En
5、amel The enamel shall have been shown to exhibit sag resistance that is acceptable for production. Enamel Solvent Xylol or equiva lent. Caution: Low flash point; refer to Industrial Hygiene for health and safety comments. Conditioning and Test Conditions All test values indicated herein are based on
6、 material conditioned in a controlled atmosphere of 23 +/ - 2 C and 50 +/ - 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure 1. Prepare sag test panels (refer to Figure 2). . Drill a 6 mm hole as shown in Figure
7、2. . Form the simulated ch aracter line by back bending the middle angle to 90 degrees and back bending the two side angles to 135 degrees. (The distance from the base of the triangle to the apex is approximately 35 mm.) Note: Refer to the “Materials Required“ section for preform ed sag test panels.
8、 12. Reduce both the control enamel and the test enamel to 38 +/ - 2 s using a No. 2 Ford Cup (unless otherwise specified by the applicable Manufacturing Process Standard or Engineering Material Specification). The control enamel should be taken from a previous batch of the same color known to be sa
9、tisfactory. 12. Apply the control and the test enamels with an automatic spray machine to separate sag test panels at 23 +/ - 2 C. FORD LABORATORY TEST METHOD BI 022-01 Page 3 of 6 Copyright 2000, Ford Global Te chnologies, Inc. 12. Set the Spraymation as follows: . “A“ position (i.e. approximatel y
10、 230 mm from gun tip to the face of the panel). . Five coats. . 520 +/ - 15 kPa. . No flash between coats. . The fluid flow should be 405 +/ - 15 cm /minute. 3 . The air fan valve should be open to give a full spray fan. . The gun traverse speed shoul d be 34 traverses/minute. 12. Position a 300 x 4
11、50 mm sag test panel with the character line in vertical position in the center of the Spraymation rack. 12. Create a film thickness wedge by applying five coats as follows: . First coat uniform even coat over the entire panel. . Second coat uniform even coat over the entire panel. . Third coat coat
12、 the lower 3/4 of the panel. . Fourth coat coat the lower 1/2 of the panel. . Fifth coat coat the lower 1/4 of the panel. Note: Allow no flash time betw een coats (other than the time it takes the Spraymation to recycle automatically). 12. Immediately hang the panel with the sag/character line in th
13、e horizontal position. 12. Allow the panel to flash for 120 s after the final coat. 12. Place the panel (with the sag/ character line in the horizontal position) in an oven that is up to temperature (130 +/ - 3 C) and bake for 17 minutes. 12. If there is no evidence of sag, repeat steps 3 8. Respray
14、 both the test and control enamel on fresh test panels; increase the fluid flow through the gun to achieve the thicker paint films and then bake as in step 9. FORD LABORATORY TEST METHOD BI 022-01 Page 4 of 6 Copyright 2000, Ford Global Te chnologies, Inc. Evaluation 12. Determine the paint thicknes
15、s at the sag line. Measure the film thickness at approximately 3.2 mm downfield from the first evidence of sag. Refer to Figure 1. Rating System: No. 1 Sag Starts to sag at 1.5 mils No. 2 Sag Starts to sag at 1.8 mils No. 3 Sag Starts to sag at 2.0 mils No. 4 Sag Starts to Sag at 2.3 mils No. 5 Sag
16、Starts to sag at 2.5 mils No. 6 Sag Starts to sag at 2.6 mils No. 7 Sa g Starts to sag at 2.8 mils No. 8 Sag Starts to sag at 3.0 mils It should be noted the above sag ratings are merely a general guideline. Due to variances in atmospheric conditions, sag readings may change (i.e., a No. 8 Sag one d
17、ay can give a 3.0 mil reading; the same paint at a later point in time could give an entirely different reading). This is why a control sample is vital in accurately determining the acceptability of a given test sample. 12. Compare the sag level rating for the material under tes t to the known satis
18、factory control sample. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD BI 022-01 Page 5 of 6 Copyright 2000, Ford Global Te chnologies, Inc. DETERMINATION OF ENAMEL SAG RESISTANCE Figure 1 FORD LABORATORY TEST METHOD BI 022-01 Page 6 of 6 Copyright 2000, Ford Global Te chnologies, Inc. DETERMINATION OF ENAMEL SAG RESISTANCE Sage Test Panel Figure 2
