GB1466044A - Electrophoretic coating apparatus - Google Patents

Abstract

1466044 Electro-phoretic coating apparatus HAJTOMUVEK ES FESTOBERENDEZESEK GYARA 14 Oct 1975 [8 May 1975] 28037/75 Heading C7B Electro-phoretic coating, e.g. painting or dyeing, apparatus of the kind wherein articles are conveyed through a coating bath and then a rinsing station comprises a coating tank 1 to which is connected a paint supply 7 via a metering valve 8 automatically controlled by a coulometer-integrator 6, and having a recirculation duct 12, including an ultra-filter 14 connected via valve 17 with a filtrate tank 18. A rinsing device 20 downstream of the tank 1 is connected with the filtrate tank directly and/or indirectly, by way of a de-ionizer, and the discharge from the filtrate tank passes via the rinser back to tank 1. A second rinsing device 22, further downstream, is connected with the output from a de-ionized liquid store 10, the latter being connected via a valve 32 with the filtrate tank. A detector 29 in the filtrate pipe responds to changes in viscosity and/or conductivity of the filtrate and upon detection of excess contamination closes valve 17 and opens valve 32. Valve 17 may be in two parts which act in opposite senses, the part 31 being open when 17 is closed, whereby contaminated filtrate may be fed to an electrolytic coagulator 35 for solids recovery and liquid waste discharge. The valves 17, 31, 32 may be reset automatically after a pre-set time lag. A further detector 36, responsive to coating material concentration, may control valve 8 in the event of failure of device 6. A heater may be included in line 12. The rinser 22 may be supplied from and discharge back into a tank 24 whose overflow feeds a tank 25 intermediate store 10 and filtrate tank 18. The de-ionizer (not shown) may be in the line containing pump 26. Store 10 may also feed supply 7 in response to the control of device 6. A stabilized constant voltage supply may provide all power requirements. Pumps 13, 15, 16, 19, 26, 27 may be provided.