1、 FORD LABORATORY TEST METHOD BI 101-03 Date Action Revisions 2001 03 13 Revised Editorial no technical change A. Cockman 1989 09 20 Printed copies are uncontrolled Page 1 of 2 Copyright 2001, Ford Global Technologies, Inc. MEASUREMENT OF DRY HIDING POWER OF PAINTS Application This method is used to
2、measure the dry hiding power of lacquers or enamels by determining the dry film thickness required to completely hide black and white squares of a standard ASTM checkerboard. Apparatus Required Checkerboard ASTM black and white checkerboard No. 5. This cardboard is made up of black and white rectang
3、les having standard reflectance values. Source: Erichsen GmbH K.G Lenata-Morest Division 587 Hemer Sundwig P.O. Box 86 West Germany Ho-Ho-Kus, NJ 07423 U.S.A. Steel Panels Body skin steel panels, dimensions 100 x 300 mm. Surface roughness to be 1.4 +/- 0.3 microns Ra, or as specified in the relevant
4、 Engineering Materials Specification. 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 unless othe
5、rwise specified. Procedure 1. Cut a section of ASTM checkerboard 50 x 250 mm long so that there are ten alternating black and white rectangles. 2. Position the checkerboard on the panel approximately 12 mm from the edge and tape to the panel. The masking tape should cover only about 10 mm of the che
6、ckerboard at the top and bottom ends. FORD LABORATORY TEST METHOD BI 101-03 Page 2 of 2 Copyright 2001, Ford Global Technologies, Inc. 3. The paint should be thinned to the viscosity by the relevant Engineering Materials Specification with the solvent specified. Viscosity to be determined in accorda
7、nce with FLTM BI 111-01. 4. Spray the entire panel and checkerboard with a uniform wet coating of the test color approximately 12 microns thick. 5. Allow 1 minute flash-off, spray the lower three-quarters of the panel with an additional 12 microns coat of color. 6. Allowing 1 minute flash-off betwee
8、n coated, progressively spraying the remaining areas of the panel until complete hiding of the black and white rectangles is obtained at the lower end of the panel. Note: Some practice may be required to accomplish the object of this test. A gradual increase in film thickness from the top to the bot
9、tom of panel is desired with a dry film thickness of 10 to 60 microns. A wedge type film thickness with complete hiding of the lower checkerboard rectangle is obtained when the panel is sprayed in increments with successive coats of paint. 7. After 3 minutes flash-off time, bake panel at one of the
10、standard cycles designed by the relevant Engineering Materials Specification. Evaluation 1. Remove the panel from the oven and cool to 23 +/- 2 C. Examine the painted checkerboard under the North Daylight of the Macbeth Unit (FLTM BI 109-01, Color Matching with Artificial Light). The panel should be
11、 held at an angle away from the viewer and at 45 from the horizontal. The lower edge of the panel should be inboard 300 mm from the outside lower edge of the color matching booth. The viewer should stand so that his line of vision is normal (90) to the surface of the steel panel which should then be
12、 marked adjacent to the point where complete hiding of the black and white rectangles of the checkerboard is obtained. 2. Remove the panel from Macbeth Unit and measure the paint film thickness in accordance with FLTM BI 117-01 (Thickness Measurement of Paint Films) on the steel panel adjacent to th
13、e area marked as having complete hiding. Record this measurement and report as the dry hiding (checkerboard) thickness of the paint. 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.
