1、 FORD LABORATORY TEST METHOD BI 120-01 Date Action Revisions 2001 03 19 Revised Editorial no technical change A. Cockman 1989 08 07 Printed copies are uncontrolled Page 1 of 3 Copyright 2001, Ford Global Technologies, Inc. PREPARATION OF ELECTROCOATED TEST PANELS Application This procedure describes
2、 the approved method of preparing electrocoated panels for laboratory tests of the applied coatings. Apparatus Required Power Source Having a capability of 0 to 1000 volts D.C. and 0 to 20 amperes. Note 1: The maximum peak to peak for the primary AC ripple must not exceed 10 % of the indicated coati
3、ng voltage. Note 2: Equipment having a lower voltage range may be used providing voltages higher than the maximum required by the material are available. Oven Capable of maintaining temperatures up to 200 +/- 2 C, or specified by the applicable Engineering Materials Specification, or the paint suppl
4、ier. Coating Tank Having a capacity of approximately 19 liters. Dimensions approximately 280 mm I.D. and 330 mm high - made of non-conductive, acid-resistant material or coated with an insulating material. Laboratory Stirrer Having a capacity of 0 to 700 rpm, using a 450 mm long stirrer shaft with 5
5、0 mm diameter square end single blade propeller. Electrode Holders To support two (2) test panels facing each other 50 mm apart. Electrode Stainless steel panel, 100 x 300 x 0.89 mm, to be used at the opposite polarity to the coating polarity of the test panels below. FORD LABORATORY TEST METHOD BI
6、120-01 Page 2 of 3 Copyright 2001, Ford Global Technologies, Inc. Steel Test Panels Panels required for test are to be special phosphate coated steel panels conforming to Manufacturing Specification UMA 18003, unless otherwise specified in the applicable Engineering Materials Specification. Panels w
7、hich have not been newly phosphated should be dried at 120 +/- 2 C for six (6) minutes, prior to electrocoating, to remove absorbed moisture. Thermostat Capable of controlling the bath temperature to +/- 1 C. Low Conductivity Water Conductivity must be no greater than 10 micromhos/cm at 25 C (ASTM D
8、 1125). Procedure 1. A paint sample is stirred with a spatula, allowing the tip to contact the bottom of the can. Mixing is adequate if no evidence of settling is indicated when the spatula is withdrawn and examined. 2. A suitable quantity of material is made up using the specified formulation. The
9、solids, pH and conductivity should be measured and, if necessary, adjusted to the suppliers recommendation. Note: Production tank samples are used as received without additions. Suitable stirring time after sampling and transportation is required immediately on arrival at the appropriate laboratory.
10、 3. Position the stirrer in the tank so that the propeller is at least 50 mm from the bottom. Note: Stirring speed must not exceed 700 rpm, so that in this and subsequent operations, air will not be incorporated. 4. Heat the bath to operating temperature recommended by the manufacturer. 5. Stir the
11、bath at the recommended temperature for 16 h minimum. 6. Place the test panel and electrode panel of equal size in the electrode holders so that the two (2) panels are parallel to each other and 50 mm apart. 150 mm of length of the panels must be immersed. The lower edges of the panels must be at le
12、ast 50 mm from the bottom of the tank. 7. The voltage is raised from zero to the coating voltage within 15 seconds. Maintain the voltage for 120 seconds and then reduce to zero in 2 seconds. Note 1: During the coating process the current must not exceed 1 Amp./dm2 FORD LABORATORY TEST METHOD BI 120-
13、01 Page 3 of 3 Copyright 2001, Ford Global Technologies, Inc. Note 2: The coating voltage must be chosen to reach the required coating thickness, and in addition it must be at least 10 % below the rupture voltage under test. The rupture voltage is determined by coating a series of panels at differen
14、t voltages until rupture occurs. To avoid negative influences on the bath material, this must be performed after conclusion of all tests. 8. Remove the panels from the tank and rinse with the low conductivity water. Remove surplus water with oil-free compressed air (if so desired, a water plus deter
15、gent rinse may be applied). 9. Bake the electrocoated panels in accordance with the relevant Engineering Materials Specification. Note: A prime coat may be sprayed on before the combined electrocoat-prime/spray-prime system is baked for the required time cycle. 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.
