US 5,330,783 A · Method and apparatus for forming and dispensing single and multiple phase coating material containing fluid diluent

Abstract

A method and apparatus for forming and dispensing a coating material formulation or solution containing a liquid coating composition and a fluid diluent such as a supercritical fluid comprises a supply for the liquid coating composition, a supply for the fluid diluent, a mixer for combining the two components to form the coating material solution or formulation, and a control system for monitoring a parameter of the formulation which can be correlated to the fluid diluent content and/or liquid coating composition content of the formulation, and for monitoring the pressure of the formulation at selected locations within the system. The control system is effective to open or close the supply of fluid diluent and/or liquid coating composition in accordance with variations in the formulation parameter which is being sensed, and in response to pressure changes within the system, to maintain single or multiple phase coating material formulations, to account for changes in a parameter of the liquid coating composition and to ensure that the desired ratio of fluid diluent to liquid coating composition is maintained in the formulation which is supplied to coating dispensers for deposition onto a substrate.

Claims30

Dependent claims

The method of applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent with a flow of liquid coating composition to form a coating material formulation;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing a parameter of said coating material formulation which is correlated to at least one of the supercritical fluid diluent content and the liquid coating composition content of said coating material formulation;
producing an output dependent on said sensed parameter;
controlling the flow of at least one of the supercritical fluid diluent and liquid coating composition which are combined with one another dependent on said output so that a selected ratio of supercritical fluid diluent to liquid coating composition is substantially maintained in said coating material formulation within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and
applying the coating material formulation onto a substrate.

5 more elements

The method of applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent with a flow of liquid coating composition to form a coating material formulation;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing a parameter of said coating material formulation which is correlated to at least one of the supercritical fluid diluent content and the liquid coating composition content of aid coating material formulation, and producing an output depending on said sensed parameter;
determining the variability of said output over time to produce a calculated output;
controlling the flow of at least one of the supercritical fluid diluent and liquid coating composition which are combined with one another dependent on a comparison between said calculated output and a selected set point or range so that a desired ratio of supercritical fluid diluent to liquid coating composition is substantially maintained in said coating material within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and
applying the coating material formulation onto a substrate.

5 more elements

The method of applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent and a flow of liquid coating composition to form a coating material formulation;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing the capacitance of said coating material formulation with a capacitor electrically connected to a source of AC voltage to produce a current output from said capacitor which is correlated to at least one of the supercritical fluid diluent content and liquid coating composition content of said coating material formulation, said current output from said capacitor having a resistive component which is in phase with said AC voltage, and a capacitive component which is 90.degree. out of phase with said AC voltage;
filtering out said resistive component or said capacitive component of said current output to produce a filtered output which reflects either the capacitive component or the resistive component of said current output;
controlling the flow of at least one of said supercritical fluid diluent and said liquid coating composition dependent on said filtered output so that a selected ratio of supercritical fluid diluent to liquid coating composition is substantially maintained in said coating material formulation within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and
applying the coating material formulation onto a substrate.

5 more elements

The method of applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent and a flow of liquid coating composition to form a coating material formulation;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing the capacitance of said coating material formulation with a first capacitor which is electrically connected to an electrical power source to produce an output from said first capacitor correlated to at least one of the supercritical fluid diluent content and liquid coating composition content of said coating material formulation;
measuring the capacitance of said liquid coating composition, prior to combining said liquid coating composition with said supercritical fluid diluent, to produce a liquid coating composition capacitance value;
subtracting said liquid coating composition capacitance value from said output of said first capacitor to produce a corrected capacitance output;
controlling the flow of at least one of said supercritical fluid diluent and said liquid coating composition dependent on said corrected capacitance output so that a selected ratio of supercritical fluid diluent liquid coating composition is substantially maintained in the coating material formulation within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and
applying the coating material formulation onto a substrate.

6 more elements

A method of applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent and a flow of liquid coating composition to form a coating material formulation;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing a parameter of said formulation which is correlated to at least one of the supercritical fluid diluent content and the liquid coating composition content of said formulation, and producing a first output dependent on said sensed parameter;
comparing said first output with a selected value to produce a second output which is dependent on said comparison;
and
controlling the flow of at least one of the supercritical fluid diluent and the liquid coating material dependent on said second output to substantially maintain a selected ratio of supercritical fluid diluent to liquid coating composition in said coating material formulation within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and
applying the coating material formulation onto a substrate.

6 more elements

A method applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent with a flow of liquid coating composition to form a coating material formulation;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing a parameter of said formulation which is correlated to at least one of the supercritical fluid diluent content and the liquid coating composition content of said formulation, and producing a first output dependent on said sensed parameter;
comparing said first output with a selected range of values to produce a second output which is dependent on said comparison;
controlling the flow of at least one of the supercritical fluid diluent and the liquid coating material dependent on said second output to substantially maintain a selected ratio of supercritical fluid diluent to liquid coating composition in said coating material formulation within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and applying the coating material formulation onto a substrate.

4 more elements

The method applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent with a flow of liquid coating composition to form a multiple phase coating material formulation including at least a first phase and a second phase appearing as dispersed forms in said first phase;
directing the multiple phase coating material formulation through a means to control the size of said dispersed forms;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing a parameter of said coating material formulation which is correlated to at least one of the supercritical fluid diluent content and the liquid coating composition content of said coating material formulation, and producing a first output representative of said sensed parameter;
comparing said first output with a selected value to produce a second output which is dependent upon said comparison;
controlling the flow of at least one of the supercritical fluid diluent and liquid coating composition which are combined with one another, dependent on said second output, to substantially maintain a selected ratio of supercritical fluid diluent to liquid coating composition in said coating material formulation within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and
applying the coating material formulation onto a substrate.

6 more elements

The method of applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent with a flow of liquid coating composition in a combining means to form a coating material formulation;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing a parameter of said coating material formulation which is correlated to at least one of the supercritical fluid diluent content and liquid coating composition content of said liquid coating material formulation;
producing an output dependent on said sensed parameter;
controlling the flow of at least one of the supercritical fluid diluent and the liquid coating composition which are combined with one another dependent on said output;
sensing the pressure differential across a pump located within the recirculation loop which circulates said coating material formulation through said combining means;
producing a second output dependent on the sensed pressure differential across said pump;
controlling the flow of at least one of the liquid coating composition and the supercritical fluid diluent which are combined with one another, dependent on said second output, to substantially maintain a selected ratio of supercritical fluid diluent to liquid coating composition in the coating material formulation within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and
applying the coating material formulation onto a substrate.

8 more elements

The method of applying a coating material formulation onto a substrate, comprising:

combining a flow of supercritical fluid diluent with a flow of liquid coating composition in a combining means to form a coating material formulation;
circulating the coating material formulation within a recirculation loop at a selected minimum temperature and minimum pressure sufficient to substantially maintain the supercritical fluid diluent in solution in the coating material formulation;
sensing a parameter of the coating material formulation which is correlated to at least one of the supercritical fluid diluent content and the liquid coating composition content of the coating material formulation over a selected time period, and producing a first output dependent on said sensed parameter over said selected time period;
comparing said first output with a selected maximum value or range of values to produce a second output which is dependent upon said comparison;
controlling the flow of at least one of the supercritical fluid diluent and liquid coating composition which are combined with one another dependent on said second output to maintain a selected ratio of supercritical fluid diluent liquid coating material within said coating material formulation;
sensing the pressure differential across a pump which circulates said coating material formulation through said combining means;
producing third output dependent on the sensed pressure differential across said pump;
controlling the flow of at least one of the liquid coating composition and the supercritical fluid diluent which are combined with one another dependent on said third output to substantially maintain a selected ratio of supercritical fluid diluent to liquid coating composition in the coating material formulation within the recirculation loop;
transmitting the coating material formulation from the recirculation loop to one or more coating dispensers;
and
applying the coating material formulation onto a substrate.

8 more elements

Dependencies are inferred from the claim text.

Method and apparatus for forming and dispensing single and multiple phase coating material containing fluid diluent

Life of this patent

Method and apparatus for forming and dispensing single and multiple phase coating material containing fluid diluent

Life of this patent

Abstract

Claims30