Apparatus and Method for Processing Coating Compositions

Abstract

A method and apparatus for processing coating compositions. The apparatus comprises: at least one liquid displacement device, such as a stirrer or dispenser pump; a motor for driving the liquid displacement device; a sensor for determining one or more motor performance parameters corresponding to resistance encountered by the motor, such as torque, motor speed or power consumption; and a control unit responsive to output signals from the sensor representing the determined parameter value.

1 . An apparatus for processing coating compositions, the apparatus comprising:
 at least one liquid displacement device;   at least one motor for driving the liquid displacement device;   at least one sensor for determining one or more motor performance parameters corresponding to resistance encountered by the motor; and   a control unit responsive to output signals from the sensor representing the determined parameter value.   
     
     
         2 . An apparatus according to  claim 1 , wherein the determined parameter includes torque exerted by the motor, motor speed and/or current consumption. 
     
     
         3 . An apparatus according to  claim 1 , wherein the sensor comprises a load cell, an encoder and/or a current measurement circuit. 
     
     
         4 . An apparatus according to  claim 1 , wherein the control unit adjusts the speed of the motor on basis of the determined torque. 
     
     
         5 . An apparatus according to  claim 1 , wherein the control unit is programmed to generate a feedback signal on basis of the change in electric current consumed by the motor resulting from the change of speed. 
     
     
         6 . An apparatus according to  claim 1 , wherein the liquid displacement device includes a pump, such as a piston pump or a rotary pump. 
     
     
         7 . An apparatus according to  claim 1 , wherein the parameter is determined during a displacement stroke by the pump, and wherein the control unit is programmed to compare the determined parameter with a set value as a function of time and/or temperature. 
     
     
         8 . An apparatus according to  claim 1 , wherein the pump is part of a dispenser, e.g., a dispenser of a paint delivery system. 
     
     
         9 . An apparatus according to  claim 1 , wherein the motor is an electromotor provided with an encoder, wherein the parameter includes motor speed determined by means of the encoder. 
     
     
         10 . An apparatus according to  claim 1  wherein the control unit is programmed to adjust power feed to the motor if the determined speed of the motor deviates from a set value. 
     
     
         11 . An apparatus according to  claim 1 , wherein the control unit is programmed to calculate a signal indicative for the condition of the coating composition on basis of the difference between the determined motor speed and the set value. 
     
     
         12 . An apparatus according to  claim 1 , wherein the one or more displacement devices include a stirrer in a container for storing the coating composition. 
     
     
         13 . An apparatus according to  claim 1 , wherein the motor for driving the stirrer comprises a DC electromotor and wherein the sensor comprises a current measurement circuit. 
     
     
         14 . An apparatus according to  claim 1 , wherein a dispensing unit is connected to an outlet of the container and wherein the control unit is programmed to stop dispensing in response to a drop of the determined torque of the motor driving the stirrer. 
     
     
         15 . An apparatus according to  claim 1 , wherein the control unit is programmed to provide user feedback when the determined parameter passes a threshold value. 
     
     
         16 . An apparatus according to  claim 1 , wherein the one or more motors include an electromotor, e.g., a stepper motor. 
     
     
         17 . A method for processing a coating composition using a liquid displacement device driven by a motor, wherein a control unit generates a signal on basis of resistance encountered by the motor. 
     
     
         18 . A method according to  claim 17 , wherein the signal is used as user feedback to indicate the condition of the coating composition. 
     
     
         19 . A method according to  claim 17 , wherein the motor is controlled on basis of the determined resistance encountered by the motor.