1、 FORD LABORATORY TEST METHOD BI 122-02 Date Action Revisions 2001 03 20 Revised Editorial no technical change A. Cockman 1998 08 12 Printed copies are uncontrolled Page 1 of 5 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF ENAMEL SAG RESISTANCE Application This test method describes
2、 the procedure to determine the relative sag resistance of exterior body enamel. Apparatus Required Automatic Paint Spray Machine Spraymation or equivalent application equipment. Source: Spraymation Inc. Little Falls, NJ 07424 Oven Shall be capable of maintaining 130 +/- 2 C. No. 4 Ford Cup Paint Fi
3、lm Thickness Tester Any reliable electromagnetic thickness gauge such as Autotest, Type MS. Source: Twin Cities International, Inc. 175 Pineview Drive Amherst, NY 14150 (716) 691-8855 Materials Required Sag Test Panels 300 x 450 mm Flat Cold Rolled Steel, unpolished, 17 holes (holes: 6 mm in diamete
4、r, spaced 25 mm apart, 100 mm from the bottom edge), current production zinc phosphate, deionized water rinse. Source: Advanced Coatings Technologies P.O. Box 310 273 Industrial Drive Hillsdale, MI 48242 (517) 439-1492 FORD LABORATORY TEST METHOD BI 122-02 Page 2 of 5 Copyright 2001, Ford Global Tec
5、hnologies, Inc. Control Enamel A control enamel shall be used. This must be of similar technology to the test enamel, and to have exhibited satisfactory sag resistance in production. Enamel Solvent Solvent should be the same as recommended for production for both control and test material. Condition
6、ing and Test Conditions All test values indicated herein are based on 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. Reduce both the c
7、ontrol enamel and the test enamel to 32 +/- 2 s using a No. 4 Ford Cup (unless otherwise specified by the applicable Engineering Material Specification or supplier recommendation). The control enamel should be taken from a previous batch of the same color known to be satisfactory. 2. Apply the contr
8、ol and the test enamels with an automatic spray machine to separate sag test panels at 23 +/- 2 C. 3. If a Spraymation is used, suggested setting are as follows: . “A“ position (i.e. approximately 230 mm from gun tip to the face of the panel). . Five coats. . Spray Pressure (at the gun) 485 +/- 35 k
9、Pa. . No flash between coats. . The fluid flow should be 405 +/- 15 cm3/minute. . The air fan valve should be open to give a full spray fan. . The gun traverse speed should be 34 traverses/minute. 4. Position a 300 x 450 mm sag test panel in vertical position, with the holes running top to bottom to
10、wards the right, in the center of the application equipment rack (Figure 1). FORD LABORATORY TEST METHOD BI 122-02 Page 3 of 5 Copyright 2001, Ford Global Technologies, Inc. 5. Create a film thickness wedge by applying five coats as follows: . First coat - uniform even coat over the entire panel. .
11、Second coat - uniform even coat over the entire panel. . Third coat - coat 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 between coats (other than the time it takes the application equipment to r
12、ecycle automatically). 6. Immediately hang the panel in the horizontal position, with the holes left to right and towards the bottom (see Figure 2). 7. Allow the panel to flash for 120 s after the final coat. 8. Place the panel (with the holes in the horizontal position) in an oven that is up to tem
13、perature (130 +/- 3 C) and bake for 17 minutes. Evaluation 1. Using a fine line pen, draw a straight line along the bottom of the holes, then draw a line along the bottom of the sags. The sag is measured at the point where the distance between the two lines is 5 mm. 2. Measure the film thickness 5 m
14、m above line at the bottom of holes at the 5 mm point determined in the above step. The value is reported as the sag point film thickness. Refer to Figure 2. 3. If there is no evidence of sag or if the 5 mm sag reading is not between holes # 3 and # 14, the test is invalid. Repeat steps 2 - 7. Respr
15、ay 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 8. 4. Compare the sag point film thickness for the material under test to the known satisfactory control sample. Chemicals, materials, parts,
16、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 122-02 Page 4 of 5 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF ENAMEL SAG RESISTANCE Figure 1 FORD LABORATORY TEST METHOD BI 122-02 Page 5 of 5 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF ENAMEL SAG RESISTANCE Figure 2
