1、 FORD LABORATORY TEST METHOD BV 153-12 Date Action Revisions 2001 04 10 Revised Editorial no technical change A. Cockman 1998 05 28 Printed copies are uncontrolled Page 1 of 4 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF YELLOWING OF PVC HEAT CURING SEALERS ON ELECTROCOAT Applicat
2、ion This method is used to determine the yellowing of PVC heat curing sealers when applied on production electrocoat. Apparatus Required Test Panels Procedure A: Steel body skin panels, dimensions 105 x 190 x 0.89 mm or similar. Prepared in accordance with FLTM BI 120-01, except 20 mm of one side wi
3、thout electrocoat. Procedure B: Steel body skin panels, dimensions 100 x 300 x 0.8 mm CRLC. The panel shall be phosphate coated to meet the requirements of WSS-M3P1- D or equivalent. Mechanical Convection Oven/(Gas Fired preferred for Procedure B) Capable of maintaining a temperature of 200 +/- 2 C.
4、 Jar with Cover Suitable to take up prepared samples. Four 1 liter Containers The containers shall be capable of withstanding a temperature of 200 +/-2 C for a min of 1 h. Colorimeter The colorimeter used shall be capable of measuring color change per SAE J1545, CIELAB color space, D65 illuminate/10
5、 observer, 0 / 45 geometry spectrophotometer. Conditioning 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 unl
6、ess otherwise specified. FORD LABORATORY TEST METHOD BV 153-12 Page 2 of 4 Copyright 2001, Ford Global Technologies, Inc. Procedure A 1. Wrap up with aluminum foil two electrocoated panels, one upon the other and separated by a heat resistant spacer of 1 mm thickness. 2. Place the panels into the ov
7、en and bake according to the relevant Material Specification. 3. Remove the panels from the oven and after conditioning for 1 h at 23 +/- 2 C remove the aluminum foil. 4. Apply on each panel a bead of the sealer, 20 mm wide and 3 mm thick, across the coated and uncoated surface. 5. Place the specime
8、ns in the oven and bake according to FLTM BV 150-05, Table 2, or according to the relevant Material Specification. 6. Remove the specimens from the oven and condition at 23 +/- 2 C. 7. Coat the specimens by spraying with the currently approved white production enamel to a thickness 20 - 30 micromete
9、r. 8. Allow specimens to stand for a flash time of 10 minutes and then cure in the oven according to FLTM BV 150-05, Table 3, or according to the relevant Engineering Material Specification. 9. Condition at 23 +/- 2 C and hang the specimens in the jar filled with water to a level of 10 mm without co
10、ntacting the water. 10. Expose the jar with specimens for 14 days at 40 +/- 2 C. Procedure A Evaluation Examine specimens for yellowing as required by the relevant Engineering Material Specification. Procedure B 1. PANEL PREPARATION a) Ecoat a 300 x 100 x 0.8 mm phosphated CRLC steel panel with cand
11、idate ecoat. Prepare per FLTM BI 120-01 unless otherwise specified. b) Bake the panels for 23 minutes at 200 C metal temperature (MT) in a humidified* oven; gas fired. Cool for 10 minutes at 38 C and 95 - 100 % RH. Blow-off excess moisture. Note: If electric fired oven is used it shall be noted in t
12、he test report. FORD LABORATORY TEST METHOD BV 153-12 Page 3 of 4 Copyright 2001, Ford Global Technologies, Inc. c) Apply sealer to the panel as shown in Figure 1 (attached). Condition for 10 minutes at 38 C and 95 - 100 % RH. Blow-off excess moisture. d) Bake the panels for 8 minutes at 135 C metal
13、 temperature (or as specified by the material specification) in a humidified* oven; gas fired. Cool the panels for 10 minutes at 38 C and 95 - 100 %RH. Blow-off excess moisture. e) Apply 13/10 micrometer white basecoat/clearcoat to the sealer. Use paints specified by the responsible Engineering acti
14、vity. f) Allow paint to flash off for 5 minutes at 23 C. g) Bake the panels for 10 minutes at 130 C MT in a humidified* oven; gas fired. *Humidification is achieved by placing a 1 liter container of deionized water in each corner of the oven. 2. YELLOWING EVALUATION - Determine the “b“ readings for
15、each of the test areas (Test areas are defined as areas where readings are taken; over the painted sealer or over the painted metal). Take 3 readings for each test area. Measurements shall be taken in the center portion of the test area. Readings shall be taken 24 - 48 h after painting. Measure the
16、yellowness of each sample per SAE J1545, using a colorimeter. 3. ENVIRONMENTAL EXPOSURE - Expose the panels for 2 weeks at 80 +/- 2 C. Repeat the measurements taken in step 2. Procedure B Evaluation 1. EVALUATIONS - Determine the degree of paint yellowing when comparing paint over sealer to paint no
17、t over sealer, initially and after 2 weeks at 82 +/- 2 C dry heat. 2. REPORT - Report initial Delta b and final Delta b. Record all raw data (individual values and averages) for each measurement. Report any deviations from the test procedure. Calculate average change in Delta b readings. (Delta b fi
18、nal minus Delta b initial.) Chemicals, materials, parts, and equipme nt 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 BV 153-12 Page 4 of 4 Copyright 2001, Ford Global Technologies, Inc.
