1、 FORD LABORATORY TEST METHOD BI 155-01 Date Action Revisions 2001 03 20 Revised Editorial no technical change A. Cockman 1999 01 19 Printed copies are uncontrolled Page 1 of 5 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF THE BEHAVIOR OF ELECTROSTATIC PAINT UNDER HIGH VOLTAGE CONDI
2、TIONS Application This method is used to determine the behavior of electrostatic paint in a pumped circulating system. It may also be used to determine the spray application properties of electrostatic paint under laboratory conditions. Apparatus Required Electrostatic Testing Equipment Voltage rang
3、e up to 100 kV dc. Source: M.W. Test Equipment Faraday House 10, Lind Road Sutton Surrey SM1 4PG England Phone: 44-181-661-9963 Fax: 44-181-642-4801 XYT Recorder Input sensitivity 0.05 - 25 mV/cm, or other suitable instrument for measuring current and voltage. Pump For an enamel flow of 500 +/- 10 m
4、L/minute with an electromagnetic valve. Infinitely Variable Speed Transm ission - for the pump Enamel Container - 1.5 L with stirrer Electrostatic Spray Gun Manual and automatic operation with special nozzle. Ransburg REA Super (Type 301/14299) manual operation. Conventional Hand Spray Gun - DeVilbi
5、ss Type JG A 502, or equivalent FORD LABORATORY TEST METHOD BI 155-01 Page 2 of 5 Copyright 2001, Ford Global Technologies, Inc. Paint Mixer - according to FLTM BI 103-02 Laboratory Forced Air Oven - according to FLTM BI 103-02 Thickness Gauge - according to FLTM BI 117-01 Test Panels Steel body ski
6、n panels ground to a surface of 0.457 - 0.508 mm Ra, or otherwise specified in the relevant Engineering Material Specification. Panel size 500 x 500 mm, or otherwise specified in the relevant Engineering Material Specification. Spray Booth - according to FLTM BI 103-02 Nozzle - for electrostatic spr
7、aying Behr System - Model No. TOS1/2A12/12K. 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 unle
8、ss otherwise specified. Procedure A. Determination of the behavior of electrostatic paint (under high voltage conditions) in a pumped circulatory system (see sketch on Page 4). 1. Transfer 1 liter of an adequately mixed paint, reduced to the operating spraying viscosity, into the enamel container an
9、d pump at a flow of 500 +/- 10 mL/minute through the measuring section tube. Mixing: The can of test material must be mixed for ten minutes. After mixing, the paint is stirred with a spatula ensuring that the tip is in contact with the bottom of the can. Mixing is adequate if no evidence of settling
10、 is indicated when the spatula is withdrawn and examined. Spraying Viscosity : The paint must be reduced to the proper spraying viscosity with the appropriate thinner as specified by the relevant Engineering Material Specification. Measurement of viscosity is in accordance with FLTM BI 111-01. FORD
11、LABORATORY TEST METHOD BI 155-01 Page 3 of 5 Copyright 2001, Ford Global Technologies, Inc. 2. After the paint has been circulating for five minutes, raise the voltage at a rate of 20 kV/minute until a maximum current of ten microamperes (mA), or a voltage of 100 kV is reached (minimum voltage shoul
12、d be 40 kV). 3. Run the pump for five minutes at maximum flow rate without high voltage. 4. Decrease the flow rate to 500 mL/minute. Then switch on high voltage and increase the voltage until a maximum current of 10 microamperes (mA) or a voltage of 100 kV is reached (minimum voltage should be 40 kV
13、). 5. Reset voltage to give 40 kV (flow rate 500 mL/minute). The maximum permitted current is 10 microamperes (mA). 6. Switch off the pump. 7. After ten seconds, switch off the voltage. 8. If during the ten second period from Steps 6 - 7 above, voltage varies or current increases to more than ten mi
14、croamperes (mA), then the material is rejected. Note: The test must be performed at 23 +/- 2 C. 9. Report the following items: a. Maximum voltage obtained in Step 2 and 4. b. Voltage variation or current increase in Step 8. B. Electrostatic spray application of enamel Prepare two panels side by side
15、. 1. Apply electrocoat and spray primer to panels in accordance with FLTM BI 103-02. Bake in accordance with the relevant Engineering Specification, and then spray enamel as follows: 2. For each spray system (automatic or hand), apply 1 - 2 coats with one minute minimum flash-off time between coats
16、to a dry film thickness of 25 - 30 micrometers. The distance between panel and gun must be 250 - 300 mm. 3. Finish all panels in one coat to a total dry film thickness of 40 micrometers with a conventional hand gun. Allow to flash off for three minutes and bake as specified in the relevant Engineeri
17、ng Material Specification. FORD LABORATORY TEST METHOD BI 155-01 Page 4 of 5 Copyright 2001, Ford Global Technologies, Inc. 4. Report the following: a. Applied voltage b. Enamel flow without voltage - mL/minute c. Enamel pressure d. Air pressure e. Number of coats to reach 40 micrometers dry film th
18、ickness by each application method (i.e. automatic or hand electrostatic spray). 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. FORD LABORATORY TEST METHOD
19、BI 155-01 Page 5 of 5 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF THE BEHAVIOR OF ELECTROSTATIC PAINT UNDER HIGH VOLTAGE CONDITIONS 1. High Voltage Generator (negative polarity on test object - 100 kV) 2. High voltage measuring equipment 3. Micro Ampere meter 4. Pump with electromagnetic valve 5. Stirrer 6. Enamel container (1 liter) (Connect tube end to earth) 7. Condenser 8. Isolator 9. Tube connection 10. Tube for electrostatic spraying, 6 mm I.D. as used in Ford electrostatic spray equipment 11. Faraday-screen Figure 1
