Adhesive dispensing system having metering system including variable frequency drive and closed-loop feedback control

Patent metadata

Field	Value
Publication number	US-9296009-B2
Application number	US-201213548543-A
Country	US
Kind code	B2
Filing date	Jul 13, 2012
Priority date	Jul 13, 2012
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

A hot melt adhesive dispensing unit includes an adhesive supply for receiving solid or semi-solid hot melt adhesive material, an adhesive supply heater associated with the adhesive supply for melting the solid or semi-solid hot melt adhesive material into a liquid hot melt adhesive material, a manifold connected to the adhesive supply and including a flow rate sensor for measuring a flow rate of the liquid hot melt adhesive material, the flow rate sensor generating flow rate information, a pump connected to the manifold for pumping liquid hot melt adhesive material from the adhesive supply into the manifold, the pump including a pump motor, and a variable frequency drive for controlling the pump motor. The variable frequency drive is in communication with the flow rate sensor for receiving the flow rate information and the pump motor for controlling the speed of the pump motor.

First claim

What is claimed is:

1. A hot melt adhesive dispensing unit, comprising:
an adhesive supply for receiving solid or semi-solid hot melt adhesive material,
an adhesive supply heater associated with said adhesive supply for melting the solid or semi-solid hot melt adhesive material into a liquid hot melt adhesive material,
a manifold connected to said adhesive supply for receiving the liquid hot melt adhesive material and splitting the liquid hot melt adhesive material into flow streams,
a flow rate sensor for measuring a flow rate of at least one of the flow streams of the liquid hot melt adhesive, said flow rate sensor generating flow rate information,
a pump connected to said manifold for pumping the liquid hot melt adhesive material from said adhesive supply into said manifold, said pump including a pump motor,
a controller configured to provide control information to a variable frequency drive, and
said variable frequency drive being in direct communication with said flow rate sensor and said controller, said variable frequency drive configured to receive said flow rate information,
wherein said variable frequency drive is further configured to adjust a speed of said pump motor using said control information and said flow rate information.

2. The hot melt adhesive dispensing unit of claim 1 , wherein the control information includes a target flow rate, and
wherein said variable frequency drive is configured to adjust the speed of said pump motor so that said flow rate of the liquid hot melt adhesive material approximates said target flow rate.

3. The hot melt adhesive dispensing unit of claim 2 , wherein said flow rate sensor includes an encoder.

4. The hot melt adhesive dispensing unit of claim 2 , wherein said variable frequency drive controls said pump motor by controlling at least one of a frequency and voltage of electrical power supplied to said pump motor.

5. The hot melt adhesive dispensing unit of claim 2 , further comprising a sump pump connected between said adhesive supply and said pump.

6. The hot melt adhesive dispensing unit of claim 3 , wherein:
said manifold includes a rotatable shaft,
said flow rate sensor is coupled to said manifold, and
said encoder is configured to measure rotation of said rotatable shaft.

7. The hot melt adhesive dispensing unit of claim 1 , wherein said variable frequency drive compares the flow rate information with the control information and controls the speed of said pump motor in response to the comparison.

8. A metering system for a hot melt adhesive dispensing unit, comprising:
a manifold for splitting liquid hot melt adhesive material into flow streams,
a pump for pumping the liquid hot melt adhesive material from an adhesive supply of the hot melt adhesive dispensing unit to said manifold,
a pump motor associated with said pump,
a flow rate sensor for measuring the flow rate of the liquid hot melt adhesive material in the metering system, said flow rate sensor generating flow rate information,
a controller configured to provide control information to a variable frequency drive, and
said variable frequency drive in direct communication with said flow rate sensor and said controller, said variable frequency drive configured to receive said flow rate information,
wherein said variable frequency drive is further configured to control a speed of said pump motor using said control information and said flow rate information.

9. The metering system of claim 8 , wherein the control information includes a target flow rate, and
wherein said variable frequency drive is configured to control said pump motor in order to adjust the flow rate of the liquid hot melt adhesive to approximate the target flow rate.

10. The metering system of claim 8 , wherein said variable frequency drive compares the flow rate information with the control information and controls the speed of said pump motor in response to the comparison.

11. The metering system of claim 8 , wherein:
said manifold includes a rotatable shaft,
said flow rate sensor is coupled to said manifold, and
said flow rate sensor includes an encoder configured to measure the rotation of said rotatable shaft.

Assignees

• Bacco David Robert
• Pendley David Mark
• Nordson Corp

Inventors

• Bacco David Robert
• Pendley David Mark

Classifications

• Y02P70/38

  Cross-Sectional Technologies · mapped topic

• B05C11/1042

  provided with means for heating or cooling the liquid or other fluent material in the supplying means upstream of the applying apparatus · CPC title

• B05C5/001

  incorporating means for heating or cooling the liquid or other fluent material (B05C11/1042 takes precedence) · CPC title

• B05C11/1013 Primary

  responsive to flow or pressure of liquid or other fluent material (B05C11/101 takes precedence; control of flow in general G05D7/00; control of fluid pressure in general G05D16/00) · CPC title

• B05C11/1044

  Apparatus or installations for supplying liquid or other fluent material to several applying apparatus or several dispensing outlets, e.g. to several extrusion nozzles · CPC title