1、 FORD LABORATORY TEST METHOD BI 158-01 Date Action Revisions 2000 08 31 Revised Editorial no technical change A. Cockman 1995 01 11 Printed copies are uncontrolled Page 1 of 4 Copyright 2000, Ford Global Technologies, Inc. MEASUREMENT OF DRY HIDING POWER OF PAINTS Application This method is used to
2、determine the dry hiding power of paints by measuring the film thickness required to completely hide black and gray stripes of a standard hiding chart. Apparatus and Materials Required Straight Line Hiding Chart Black and gray hiding chart. This is made up of standard color lines, the gray to match
3、Munsell neutral color value N/6 medium gray. Source: Erichsen GmbH Munsell Color Co. 587 Hemer Sundwig 2441 N. Calvert S t. W. Germany Baltimore, MD 21218 Masking Tape High temperature masking tape, 25 mm nominal width. Test Panels Body skin steel panels, dimensions 100 x 300 mm. Surface roughness 0
4、.9 - 1.8 micrometre Ra, or as otherwise specified in the relevant Engi neering Materials Specification. Color Matching Device Macbeth Color Matching Booth, or equivalent with North Sky Daylight according to FLTM BI 109 - 01. Film Thickness Measuring Device According to FLTM BI 117 - 01. Source: Fisc
5、her Instruments Fischer Instrumentation (G.B.), Ltd. Stuttgart Arnhem Industrial Estate W. Germany Arnhem Road, Newbury, Berkshire FORD LABORATORY TEST METHOD BI 158-01 Page 2 of 4 Copyright 2000, Ford Global T echnologies, Inc. Conditioning and Test Conditions All test values indicated herein are b
6、ased 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. Position the chart on the panel (see Page 4) even with the left edge and abou
7、t 15 mm i nboard from the upper and lower edge. Tape the cardboard to the panel using high temperature masking tape. The tape should cover only about 10 mm of the chart at the top and bottom ends. 2. The paint should be thinned to the viscosity required by the re levant Engineering Materials Specifi
8、cation with the solvent specified. Viscosity to be determined in accordance with FLTM BI 111 - 01. 3. Spray the entire panel and chart with a uniform, wet coating of the test color approximately 12 micrometre thick. 4. Allow 1 minute flash - off, then spray the lower 3/4 of the panel with an additio
9、nal 12 micrometer coat of paint. 5. Allowing 1 minute flash - off between coats, progressively spray the remaining lower areas of the panel until complete hiding of black and gra y stripes is obtained at the lower end of the panel. Note: Some practice may be required to accomplish the object of this
10、 test. A gradual increase in film thickness from the top to the bottom of the panel is desired with a dry film thickness gradient of 12 - 60 micrometres. A wedge type film thickness with complete hiding of the lower chart stripes is obtained when the panel is sprayed in increments with successive co
11、ats of paint. 6. Flash -off for 3 minutes after final coat, then bake the panel at one o f the standard cycles designated by the relevant Engineering Materials Specification. Remove the baked panel from the oven and cool to room temperature. FORD LABORATORY TEST METHOD BI 158-01 Page 3 of 4 Copyrigh
12、t 2000, Ford Global T echnologies, Inc. Evaluation 1. Examine the painted chart under the North Sky Daylight of the Macbeth unit. The pane l should be viewed at various angles in order to determine the point where complete hiding of the black and gray stripes on the chart begins. 3. Remove the panel
13、 from the Macbeth unit and according to FLTM BI 117 - 01 measure the paint thickness on the stee l panel adjacent to the area of the chart marked as having complete hiding. Record this measurement and report as the dry hiding (black and gray straight line chart) thickness of the paint. Chemicals, materials, parts, and equipment referenced in this doc ument must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD BI 158-01 Page 4 of 4 Copyright 2000, Ford Global T echnologies, Inc.
