US 5,207,352 A · Method and apparatus for dispensing high viscosity fluid materials

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.

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Drawings

Claims26

Dependent claims

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.

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.

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.

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.

5 more elements

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.

7 more elements

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.

10 more elements

Dependencies are inferred from the claim text.

Description9,932 words

Summary2,812 words

#This invention relates to dispensing apparatus, and, more particularly, to an apparatus for dispensing a mixture of highly viscous polymeric material and a gas, such as air, to form a polymer foam on a substrate while avoiding the production of pressure surges and pressure drops when the apparatus is operated intermittently.

#The assignee of this invention has pioneered the development and application of methods and apparatus for foaming polymeric materials such as hot melt thermoplastic adhesives, polymeric coatings, paints and other thermoplastic and/or thermosetting materials. In the case of hot melt adhesives, for example, it has been discovered that the strength of an adhesive bond achieved with a given volume of selected hot melt adhesive can be appreciably improved if the adhesive is applied as a foam rather than as a conventional non-foamed adhesive.

#As disclosed, for example, in U.S. Pat. Nos. 4,059,466 and 4,059,714 to Scholl et al, initial attempts at "foaming" polymeric materials involved the mixture of hot melt thermoplastic adhesive and a blowing agent wherein a polymer/gas adhesive solution is formed and transmitted under pressure to and through a dispenser. Upon emerging from the nozzle of the dispenser into atmospheric pressure, the gas evolves from the solution in the form of small bubbles causing the adhesive to expand volumetrically. The resultant adhesive in an uncompressed state sets up as a homogeneous solid foam having gas cells substantially evenly distributed throughout the adhesive.

Brief description of the drawings5 figures

#The structure, operation and advantages of the presently preferred embodiment of this invention will become further apparent upon consideration of the following description, taken in conjunction with the accompanying drawings, wherein:

#FIG. 1 is a schematic view in partial cross section of the apparatus of this invention including a dispenser, pressure regulator and swivel mount, and a system for supplying a liquid/gas solution thereto;

#FIG. 2 is an enlarged cross sectional view taken on line 2--2 of FIG. 1 illustrating the needle valve guide of the dispenser;

Detailed description6,960 words

#Referring now to FIG. 1, the dispensing apparatus 10 of this invention includes a dispenser 12, a pressure regulator 14, and, in the presently preferred embodiment, a swivel mechanism 16 adapted to connect to a source of polymer/gas solution. A method and apparatus of producing a solution of polymeric material and gas in preparation for foaming by the dispensing apparatus 10 of this invention is disclosed in U.S. Pat. No. 4,778,631 to Cobbs, Jr. et al, owned by the assignee of this invention, the disclosure of which is incorporated by reference in its entirety herein.

#One preferred embodiment of the apparatus disclosed in U.S. Pat. No. 4,778,631 to Cobbs, Jr. et al is schematically illustrated in FIG. 1 and identified generally with the reference number 18. The identical apparatus is employed in other embodiments of this invention, but for ease of illustration the apparatus is shown schematically in a single block labeled "polymer/gas solution" 18 in FIGS. 3 and 4.

#As shown in FIG. 1, apparatus 18 employs a bulk source of polymeric material such as a bulk melter 300 containing heating means for liquifying a solid or semi-solid polymer material and pumping it from the tank. An example of a bulk melter is shown in U.S. Pat. No. 4,073,409, assigned to the assignee of this invention, the disclosure of which is incorporated by reference in its entirety herein. The pump associated with the bulk melter 300 is a cartridge-type gear pump, however, any pump capable of providing sufficient pressure to pump the material from the bulk melter 300 is suitable.

Facts

Application

07/688,905Filed 19 Apr 1991

Granted

4 May 1993

Term ended

19 Apr 2011

Estimated · how

Pre-1995 term; greater of 17 years from grant or 20 years from filing when eligible. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification9 codes

B05C 5/0225
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…:…
B05B 12/087
Responsive to flow or pressure of liquid or other fluent material to be discharged: flow or presssure regulators, i.e. non-electric unitary…
B05C 5/02
Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work: the liquid or other…
B29B 7/7409
Mixing devices specially adapted for foamable substances: with supply of gas

Method and apparatus for dispensing high viscosity fluid materials

Life of this patent

Method and apparatus for dispensing high viscosity fluid materials

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims26

Description9,932 words

Classification9 codes

Life of this patent

Drawings

Description9,932 words