Method and apparatus for dispensing high viscosity fluid materials

• US 5,207,352 A
• Filed: 04/19/1991
• Issued: 05/04/1993
• Est. Priority Date: 04/19/1991
• Status: Expired due to Term

• Current Assignee: Nordson Corporation
• Original Assignee: Nordson Corporation
• Inventors: Hoover, Scott, Popesco, Mihail, Porter, George O.
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): Bomberg, Kenneth
• Application Number:
  US07/688,905
• Time in Patent Office: 746 Days
• Field of Search: 137/505.14, 137/505.39, 137/505.41, 137/613, 251/60, 251/63.5, 222/1, 222/56, 222/61, 222/190, 222/504, 222/510, 222/518, 222/396
• US Class Current: 222/1
• CPC Class Codes: B05B 12/087 Flow or presssure regulators, i.e. non-electric unitary devices comprising a sensing element, e.g. a piston or a membrane, and a controlling element, e.g. a valve
• CPC Class Codes: B05C 5/02 the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work
• CPC Class Codes: B05C 5/0225 characterised by flow controlling means, e.g. valves, located proximate the outlet B05C5/0258, B05C5/0275 take precedence; supply valves upstream the coating head B05C11/1036
• CPC Class Codes: B29B 7/7409 with supply of gas
• CPC Class Codes: B29C 44/60 Measuring, controlling or regulating

Abstract

A method and apparatus for dispensing a solution of highly viscous polymeric material and gas includes a dispenser connected to a pressure regulator which is adapted to connect to a source of a pressurized polymer/gas solution. Minimal pressure drop due to line losses occurs in the course of transmitting the solution from the pressure regulator into the dispenser because of their close proximity, and the solution is maintained under controlled pressure throughout passage to the discharge outlet of a nozzle carried by the dispenser so that the gas is maintained in solution in the polymeric material until it is discharged from the nozzle to atmosphere. The flow rate of solution through the dispenser is variable by operation of adjustable valve structure associated with the dispenser and/or by operation of the pressure regulator.

Claims

1. Apparatus for dispensing a polymer foam, comprising:

dispenser means for discharging a polymer foam;

regulator means, connected to said dispenser means, for introducing a pressurized solution of intermixed, highly viscous polymeric material and gas into said dispenser means and for maintaining the pressurized solution introduced into said dispenser means at a pressure which is slightly above the pressure at which the gas comes out of solution so that upon discharge of the pressurized solution from the dispenser means a substantially homogeneous polymer foam is formed.

2. Apparatus for forming and dispensing a polymer foam, comprising:

forming means for forming a pressurized solution of intermixed, highly viscous polymeric material and gas;

dispenser means for receiving the pressurized solution;

regulator means interposed between said forming means and said dispenser means for maintaining the pressurized solution introduced into said dispenser means at a pressure which is slightly above the pressure at which the gas comes out of solution so that upon discharge of the pressurized solution from the dispenser means a polymer foam is formed homogeneous.

3. The apparatus of claim 2 in which said dispenser means is a dispenser formed with a fluid passageway having a first inlet and a discharge outlet, and said regulator means is a pressure regulator having a second inlet connected to said forming means and a second outlet, said second outlet of said pressure regulator being located proximate to said dispenser and being connected to said first inlet thereof.

4. Apparatus for forming and dispensing a polymer foam, comprising:

forming means for forming a pressurized solution of intermixed, highly viscous polymeric material and gas;

dispenser means for receiving the pressurized solution;

regulator means interposed between said forming means and said dispenser means for reducing the pressure of the pressurized solution from a first, higher pressure upstream from said regulator means to a second, lower pressure within said dispenser means, said second, lower pressure being maintained at a level by said regulator means which is slightly above the pressure at which the gas comes out of solution so that upon discharge of the pressurized solution from the dispenser means a homogeneous polymer foam is formed.

5. Apparatus for dispensing a pressurized solution of intermixed highly viscous polymeric material and gas to form a polymer foam, comprising:

a pressure regulator formed with an internal cavity having a first inlet adapted to connect to a source of the solution and a first outlet, said pressure regulator including regulator means for controlling the pressure at which the solution is discharged through said first outlet of said internal cavity;

a dispenser formed with a fluid passageway having a second inlet and a second discharge outlet, said fluid passageway carrying a valve having a valve tip movable between an open position and a closed position relative to said second discharge outlet, said second inlet of said fluid passageway in said dispenser being connected to said first outlet of said internal cavity of said pressure regulator so that a flow path for the solution is formed between said internal cavity and said second discharge outlet of said fluid passageway within which sufficient pressure is maintained to substantially prevent the gas from leaving solution to form a polymer foam prior to discharge from said dispenser.

6. The apparatus of claim 5 in which said dispenser is formed with a first passageway connected to said first outlet of said pressure regulator, a nozzle having a bore terminating in a discharge outlet, and a fluid cavity connected between said first passageway and said nozzle, said first passageway, fluid cavity and nozzle bore collectively defining said fluid passageway of said dispenser, said valve being carried within said bore of said nozzle so that said valve tip seats against said discharge outlet of said nozzle in said closed position.

7. The apparatus of claim 5 in which said dispenser includes sensor means communicating with said fluid passageway for sensing the pressure of the solution passing through said fluid passageway, said sensor means sending signals correlated to the pressure of the solution in said fluid passageway to a controller which is effective to control the operation of said regulator means of said pressure regulator and thus control the pressure at which the solution is discharged into said fluid passageway of said dispenser.

8. Apparatus for dispensing high viscosity fluid material, comprising:

a pressure regulator formed with an internal cavity having an inlet adapted to communicate with a source of high viscosity fluid material, and an outlet;

a dispenser formed with a fluid passageway having an inlet connected to said outlet of said pressure regulator and a discharge outlet for dispensing fluid material, said dispenser having a valve which is movable between an open position and a closed position with respect to said discharge outlet of said fluid passageway;

regulator means carried within said internal cavity of said pressure regulator for maintaining the solution at a first pressure within said fluid passageway in said dispenser, and for maintaining the solution at a higher, second pressure upstream from said pressure regulator, with said valve in said closed position, said regulator means being effective upon movement of said valve to said open position to reduce the pressure of the fluid material as it passes through said pressure regulator and to transmit said fluid material into said fluid passageway of said dispenser without producing a pressure surge or a pressure drop in the fluid material before it is emitted from said dispenser.

9. The apparatus of claim 8 in which said pressure regulator and said dispenser are directly mounted to one another so that said outlet of said pressure regulator directly connects to said inlet of said fluid passageway in said dispenser, whereby a flow path is formed between said pressure regulator and said discharge outlet of said fluid passageway within which a pressure drop of the solution due to line losses is substantially eliminated.

10. The apparatus of claim 8 in which said dispenser includes sensor means communicating with said fluid passageway for sensing the pressure of the solution passing through said fluid passageway, said sensor means sending signals correlated to the pressure of the solution to a controller which is effective to control the operation of said regulator means of said pressure regulator and thus control the pressure at which the solution is discharged into said fluid passageway of said dispenser.

11. Apparatus for dispensing high viscosity fluid material, comprising:

a dispenser, including;

(i) a dispenser body formed with a fluid passageway having an inlet, and a discharge outlet for emitting fluid material;

(ii) a valve carried by said dispenser body having a valve tip axially movable with respect to said discharge outlet;

(iii) valve closure means for moving said valve to a closed position relative to said discharge outlet;

(iv) activating means for axially moving said valve in a first direction away from said discharge outlet;

(v) stop means for limiting the extent of axial movement of said valve relative to said discharge outlet to control the flow of fluid material therethrough;

(vi) adjustment means for adjusting the position of said stop means relative to said valve to vary the extent of axial movement of said valve which is permitted by said stop means;

a pressure regulator formed with an internal cavity having an inlet adapted to communicate with a source of fluid material, and an outlet connected to said inlet of said fluid passageway in said dispenser body, said pressure regulator including regulator means which is effective upon operation of said valve closure means of said dispenser to maintain the fluid material within said fluid passageway in said dispenser at a first pressure and to maintain the fluid material upstream from said pressure regulator at a second, higher pressure, said regulator means being effective upon operation of said activating means of said dispenser to reduce the pressure of the fluid material upstream from said pressure regulator as it passes therethrough and to transmit the fluid material into said fluid passageway of said dispenser without producing a pressure surge or a pressure drop in the fluid material before it is emitted from the dispenser.

12. The apparatus of claim 11 in which said adjustment means comprises:

a first member formed with means for retaining said stop means in a rotatably fixed position;

a second member carried by said dispenser body having a bore for receiving said stop means, said first and second members having means for releasably mounting said first member onto said second member in a rotatably fixed position;

retainer means extending between said stop means and said first member for urging said first member into engagement with said second member.

13. The apparatus of claim 11 in which said dispenser includes sensor means communicating with said fluid passageway of said dispenser for sensing the pressure of the solution passing through said fluid passageway, said sensor means sending signals correlated to the pressure of the solution to a controller which is effective to control the operation of said regulator means of said pressure regulator and thus control the pressure at which the solution is discharged into said fluid passageway of said dispenser.

14. Apparatus for dispensing high viscosity fluid material comprising:

a dispenser including;

(i) a dispenser body formed with a fluid passageway having an inlet, and a discharge outlet for emitting fluid material;

(ii) a valve carried by said dispenser body which is movable with respect to said discharge outlet of said fluid passageway;

(iii) valve closure means for moving said valve to a closed position relative to said discharge outlet;

(iv) first actuating means for moving said valve in a direction away from said discharge outlet;

a flow control module connected to said dispenser, said flow control module including;

(i) stop means for limiting the extent of axial movement of said valve relative to said discharge outlet;

(ii) means for positioning said stop means in a first position relative to said valve such that said valve is permitted to move to a first, open position with respect to said discharge outlet in response to operation of said first actuating means;

(iii) second actuating means for moving said stop means to a second position relative to said valve such that said valve is permitted to move to a second, open position with respect to said discharge outlet in response to operation of said first actuating means;

a pressure regulator formed with an internal cavity having an inlet adapted to communicate with a source of fluid material, and an outlet connected to said inlet of said fluid passageway in said dispenser, said pressure regulator including regulator means which is effective upon operation of said valve closure means of said dispenser to maintain the fluid material within said fluid passageway in said dispenser at a first pressure and to maintain the fluid material upstream from said pressure regulator at a second, higher pressure, said regulator means being effective upon operation of said first actuating means of said dispenser to reduce the pressure of the fluid material upstream from said pressure regulator as it passes therethrough and to transmit the fluid material into said fluid passageway of said dispenser without producing a pressure surge or a pressure drop in the fluid material before it is emitted from said dispenser.

15. The apparatus of claim 14 in which said dispenser carries a nozzle including an elongated throughbore having a first diameter forming a portion of said fluid passageway of said dispenser which terminates with said discharge outlet, said valve being formed with an elongated valve tip having a second diameter which is sized relative to said first diameter of said elongated throughbore of said nozzle so that said elongated valve tip forms a flow restriction within said elongated throughbore, said valve tip being movable to a first position within said nozzle throughbore relative to said discharge outlet thereof upon movement of said valve to said first, open position to provide a flow restriction which produces a first flow rate of the fluid material, and said valve tip being movable to a second position further from said discharge outlet upon movement of said valve to said second, open position to provide a flow restriction which produces a second, higher flow rate of the fluid material.

16. The apparatus of claim 14 in which said dispenser includes sensor means communicating with said fluid passageway for sensing the pressure of the fluid material passing through said fluid passageway, said sensor means sending signals correlated to the pressure of the fluid material to a controller which is effective to control the operation of said regulator means of said pressure regulator and thus control the pressure at which the fluid material is discharged into said fluid passageway of said dispenser.

17. Apparatus for dispensing fluid material, comprising:

a dispenser formed with a fluid passageway having an inlet adapted to connected to a source of fluid material, and a discharge outlet for emitting the fluid material;

a valve carried by said dispenser which is movable with respect to said discharge outlet of said fluid passageway;

first biasing means for applying a continuous force to said valve which urges said valve toward a closed position relative to said discharge outlet of said fluid passageway;

first actuating means for counteracting the force of said first biasing means so that said valve moves in a direction away from said discharge outlet;

a flow control module connected to said dispenser, said flow control module including;

(i) stop means for limiting the extent of axial movement of said valve relative to said discharge outlet;

(ii) second biasing means for applying a continuous force to said stop means which urges said stop means to a first position relative to said valve, said valve being permitted to move to a first, open position with respect to said discharge outlet with said stop means in said first position in response to operation of said first actuating means;

(iii) second actuating means for counteracting the force of said second biasing means which urges said stop means to a second position relative to said valve, said valve being permitted to move to a second, open position with respect to said discharge outlet with said stop means in said second position in response to operation of said first actuating means;

first adjustment means associated with said dispenser and said flow control module for varying the location of said first position of said stop means of said flow control module relative to said valve of said dispenser, said first adjustment means comprising;

(i) a shaft connected to said flow control module, said shaft being formed with a threaded portion which is received within a threaded bore formed in said dispenser body, said shaft being formed with a throughbore which receives said stop means;

(ii) a first member formed with means for retaining said stop means in a rotatably fixed position;

(iii) a second member carried by said dispenser body having a bore for receiving said stop means, said first and second members having means for releasably mounting said first member onto said second member in a rotatably fixed position;

(iv) retainer means extending between said stop means and said first member for urging said first member into engagement with said second member.

18. The apparatus of claim 17 in which said stop means is a plunger having a first end positioned to make contact with said valve of said dispenser, and a second end which mounts a piston within an air cavity formed in said flow control module.

19. The apparatus of claim 17 further including a second adjustment means associated with said flow control module for varying the location of said second position of said stop means of said flow control module relative to said valve of said dispenser, said second adjustment means comprising:

a shaft formed with a threaded portion which is rotatably received within a threaded bore formed in said flow control module and axially adjustable therealong, said shaft having an end engageable with said stop means of said control module;

a first member formed with means for retaining said shaft in a rotatably fixed position;

a second member carried by said flow control module having a bore for receiving said shaft, said first and second members having means for releasably mounting said first member onto said second member in a rotatably fixed position;

retainer means extending between said stop means and said first member for urging said first member into engagement with said second member so that said first member and said shaft are retained in a rotatably fixed position on said flow control module.

20. Apparatus for dispensing a polymer foam, comprising:

means for forming a pressurized solution of intermixed, highly viscous polymeric material and gas;

means for transmitting the pressurized solution at a first pressure to a pressure regulator;

means associated with said pressure regulator for reducing the pressure of the pressurized solution from said first pressure to a second, lower pressure in the course of passage of the pressurized solution through said pressure regulator and into a dispenser located downstream from said pressure regulator, said second, lower pressure being maintained at a level within said dispenser which is slightly above the pressure at which the gas comes out of solution so that upon discharge of the pressurized solution from said dispenser a homogeneous polymer foam is formed.

21. The method of dispensing a polymer foam, comprising:

transmitting a pressurized solution of intermixed, highly viscous polymeric material and gas into a dispenser means;

maintaining the pressurized solution introduced into said dispenser means at a pressure which is slightly above the pressure at which the gas comes out of solution so that upon discharge of the pressurized solution from the dispenser means a homogeneous polymer foam is formed.

22. The method of dispensing a polymer foam, comprising:

forming a pressurized solution of intermixed, highly viscous polymeric material and gas;

transmitting the pressurized solution to a dispenser means;

maintaining the pressurized solution introduced into said dispenser means at a pressure which is slightly above the pressure at which the gas comes out of solution so that upon discharge of the pressurized solution from the dispenser means a homogeneous polymer foam is formed.

23. The method of dispensing a polymer foam, comprising:

forming a pressurized solution of intermixed, highly viscous polymeric material and gas;

transmitting the pressurized solution to a dispenser means;

reducing the pressure of the pressurized solution from a first, higher pressure upstream from said dispenser means to a second, lower pressure within said dispenser means by operation of a regulator means located immediately upstream from said dispenser means, said second, lower pressure being maintained at a level by said regulator means which is slightly above the pressure at which the gas comes out of solution so that upon discharge of the pressurized solution from the dispenser means a homogeneous polymer foam is formed.

24. The method of dispensing a polymer foam, comprising:

forming a pressurized solution of intermixed, highly viscous polymeric material and gas;

transmitting the pressurized solution to a pressure regulator means at a first pressure;

reducing the pressure of the pressurized solution from the first pressure to a second, lower pressure in the course of passage of the pressurized solution through the pressure regulator means to a dispenser means located downstream from the pressure regulator means, the second, lower pressure being maintained at a level within the dispenser means which is slightly above the pressure at which the gas comes out of solution so that upon discharge of the pressurized solution from the dispenser means a homogeneous polymer foam is formed.

25. The method of dispensing a highly viscous fluid material, comprising:

maintaining the fluid material located in a flow passageway between a pressure regulator and the discharge outlet of a dispenser at a predetermined application pressure, and maintaining the fluid material between the pressure regulator and a source of fluid material at a pressure in excess of the application pressure, with the valve means of the dispenser in a closed position relative to the discharge outlet thereof;

providing a flow path between the pressure regulator and discharge outlet of the dispenser such that upon movement of the valve means to an open position the fluid material located downstream from the pressure regulator is emitted from the discharge outlet at substantially the predetermined application pressure, and such that the fluid material located upstream from the pressure regulator is emitted from the discharge outlet of the dispenser at substantially the predetermined application pressure.

26. The method of intermittently dispensing a highly viscous fluid material, comprising:

closing the discharge outlet of a flow passageway formed between a dispenser and a pressure regulator;

maintaining fluid material located within said flow passageway at a predetermined application pressure, and maintaining fluid material located upstream from the pressure regulator at a pressure in excess of said predetermined application pressure, with the discharge outlet closed;

opening said discharge outlet of said flow passageway to emit fluid material located therein from said discharge outlet at substantially the predetermined application pressure;

transmitting the fluid material located upstream from the pressure regulator into said flow passageway so that said fluid material is emitted from said discharge outlet at substantially the predetermined application pressure.