WO2021178470A1 - Conception compacte et procédé pour distribuer uniformément, égaliser et atomiser efficacement un fluide - Google Patents

Conception compacte et procédé pour distribuer uniformément, égaliser et atomiser efficacement un fluide Download PDF

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Publication number
WO2021178470A1
WO2021178470A1 PCT/US2021/020572 US2021020572W WO2021178470A1 WO 2021178470 A1 WO2021178470 A1 WO 2021178470A1 US 2021020572 W US2021020572 W US 2021020572W WO 2021178470 A1 WO2021178470 A1 WO 2021178470A1
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WO
WIPO (PCT)
Prior art keywords
dispensing
coating material
gas
nozzle
passage
Prior art date
Application number
PCT/US2021/020572
Other languages
English (en)
Inventor
Timothy GIRVIN
Alan Lewis
Original Assignee
Nordson Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nordson Corporation filed Critical Nordson Corporation
Publication of WO2021178470A1 publication Critical patent/WO2021178470A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/02—Spray pistols; Apparatus for discharge
    • B05B7/06—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane
    • B05B7/062—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet
    • B05B7/066—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet with an inner liquid outlet surrounded by at least one annular gas outlet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/02—Spray pistols; Apparatus for discharge
    • B05B7/04—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge
    • B05B7/0416—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid
    • B05B7/0441—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid with one inner conduit of liquid surrounded by an external conduit of gas upstream the mixing chamber
    • B05B7/045—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge with arrangements for mixing one gas and one liquid with one inner conduit of liquid surrounded by an external conduit of gas upstream the mixing chamber the gas and liquid flows being parallel just upstream the mixing chamber
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
    • B05C5/02—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 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
    • B05C5/0225—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 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 characterised by flow controlling means, e.g. valves, located proximate the outlet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
    • B05B1/30—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages
    • B05B1/3033—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the control being effected by relative coaxial longitudinal movement of the controlling element and the spray head
    • B05B1/304—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the control being effected by relative coaxial longitudinal movement of the controlling element and the spray head the controlling element being a lift valve
    • B05B1/3046—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the control being effected by relative coaxial longitudinal movement of the controlling element and the spray head the controlling element being a lift valve the valve element, e.g. a needle, co-operating with a valve seat located downstream of the valve element and its actuating means, generally in the proximity of the outlet orifice
    • B05B1/306—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the control being effected by relative coaxial longitudinal movement of the controlling element and the spray head the controlling element being a lift valve the valve element, e.g. a needle, co-operating with a valve seat located downstream of the valve element and its actuating means, generally in the proximity of the outlet orifice the actuating means being a fluid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B15/00—Details of spraying plant or spraying apparatus not otherwise provided for; Accessories
    • B05B15/50—Arrangements for cleaning; Arrangements for preventing deposits, drying-out or blockage; Arrangements for detecting improper discharge caused by the presence of foreign matter
    • B05B15/58—Arrangements for cleaning; Arrangements for preventing deposits, drying-out or blockage; Arrangements for detecting improper discharge caused by the presence of foreign matter preventing deposits, drying-out or blockage by recirculating the fluid to be sprayed from upstream of the discharge opening back to the supplying means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B15/00—Details of spraying plant or spraying apparatus not otherwise provided for; Accessories
    • B05B15/60—Arrangements for mounting, supporting or holding spraying apparatus
    • B05B15/65—Mounting arrangements for fluid connection of the spraying apparatus or its outlets to flow conduits

Definitions

  • This disclosure generally relates to devices and methods of atomizing a fluid for dispensing from fluid dispensers.
  • Fluid dispensing devices are used in various industries, such as electronic and packaging assemblies. Portions of the fluid can be dispensed, jetted, or otherwise applied to a substrate in the form of minute dots or droplets, streams, and/or non-contiguous volumes of material. Numerous applications exist for dispensers, such as those concerning underfill materials, encapsulation materials, surface mount adhesives, solder pastes, conductive adhesives, solder mask materials, fluxes, thermal compounds, and/or the like.
  • some or all of the material being dispensed can be atomized by mixing the dispensing material with another material that causes the atomization, such as air.
  • another material that causes the atomization such as air.
  • operation of dispensing devices with atomizing capabilities may present various challenges.
  • air-assisted atomization may require specific distributions of airflow to achieve the desired atomization, which, in turn, may require larger or specifically-dimensioned pathways for the air to flow through.
  • Such arrangements can lead to undesired results, such as undesired accumulation of dispensing material, imprecise patterns of airflow, and/or the like.
  • a dispensing assembly for dispensing a coating material may include a dispensing head configured to receive a coating material and to move the coating material therethrough and a nozzle configured to receive the coating material from the dispensing head.
  • the nozzle may include a body defining a proximal end and a distal end spaced along a dispensing direction opposite the proximal end; a coating material conduit in the body and configured to receive the coating material into the nozzle from the dispensing head, at least one portion of the coating material conduit extending along the dispensing direction and defining a dispensing axis extending through the coating material conduit along the dispensing direction; a coating material outlet defined on the coating material conduit and configured to discharge the coating material therethrough out of the coating material conduit; and a gas passage in the body and configured to receive a gas into the nozzle at a gas inlet at a first end of the gas passage and to discharge the gas from the nozzle through a gas outlet at a second end of the gas passage, wherein the gas passage is defined between the first and second ends of the gas passage.
  • At least one portion of the gas passage may be configured to receive the gas in a direction angularly offset from the dispensing axis to impart rotation to the gas in the gas passage, and at least another portion of the gas passage may be configured to receive the gas in a direction parallel to the dispensing axis.
  • the body may include an inner body and an outer body, with the gas passage being defined between the inner body and the outer body.
  • the gas passage may include a first portion that extends around the dispensing axis, a second portion that extends radially inward from the first portion toward the dispensing axis, and a third portion that extends from the second portion toward the gas outlet along the dispensing direction.
  • the nozzle may be configured to receive the gas at the gas inlet and guide the gas along a path that extends from the gas inlet to the first portion so as to impart a rotational component to the gas, and from the first portion, radially inward through the second portion to the third portion, and out of the gas outlet so as to reduce the rotational component of the gas.
  • the third portion of the gas passage may be tapered toward the dispensing axis between the second portion of the gas passage and the gas outlet.
  • the second portion may include a plurality of radial channels disposed between the first portion and the third portion, each of the plurality of radial channels being in fluid communication with the first portion and the third portion.
  • At least one portion of the coating material conduit may extend from the inner body within the outer body along the dispensing axis.
  • the at least one portion of the coating material conduit may have a proximal end adjacent the inner body and a distal end spaced along the dispensing direction from the proximal end.
  • the coating material outlet may be defined at the distal end of the portion of the coating material conduit.
  • the gas outlet may be disposed at a first distance along the dispensing direction from the proximal end of the body.
  • the coating material outlet may be disposed at a second distance along the dispensing direction from the proximal end of the body.
  • the first distance may be greater than the second distance.
  • the first distance may be less than the second distance.
  • the first distance may be the same as the second distance.
  • the gas may include pressurized air.
  • the dispensing assembly may further include a fourth portion of the gas passage between the third portion and the gas outlet.
  • the fourth portion may be cylindrical.
  • the gas passage may define a first cross-sectional dimension at the gas outlet that is greater than a second cross-sectional dimension defined at the coating material outlet of the coating material conduit.
  • the first portion of the gas passage may define a cross- sectional dimension that is greater than the first cross-sectional dimension at the gas outlet.
  • the first portion of the air passage may be greater than the third passage.
  • a combination of the first portion of the air passage and the second portion of the air passage may be greater than the combination of the third portion of the air passage and the fourth portion of the air passage.
  • the dispensing assembly may include a recirculation pathway that includes a recirculation conduit fluidly connected to the dispensing head and configured to receive a portion of the coating material from the dispensing head.
  • the air passage may be disposed between the coating material outlet and the connection of the recirculation conduit of the dispensing head.
  • the dispensing assembly may include a fluid chamber and a valve seat in the dispensing head.
  • the coating material may flow in a fluid pathway through the dispensing head and the nozzle, with the fluid pathway flowing through the valve seat, the valve seat being opened and closed for fluid flow by movement of a valve needle between a first position in contact with the valve seat and a second position spaced from the valve seat, with the portion of the fluid pathway between the valve seat and the coating material outlet comprising a downstream portion of the fluid pathway.
  • the gas in the gas passage and the coating material flowing through the fluid pathway may come into contact with each other in the downstream portion of the fluid pathway.
  • the dispensing assembly may include a recirculation conduit connected to the fluid chamber to remove coating material from the dispensing head before the coating material enters the downstream portion of the fluid pathway.
  • the dispensing assembly may include a pump that pumps coating material through the recirculation conduit back to the fluid supply.
  • the dispensing assembly may include a controller that is operably connected to, and is configured to control the flow of gas into the gas passage of the body.
  • the controller may control the pump that pumps coating material through the recirculation conduit back to the fluid supply.
  • the controller may control an actuator that controls the movement of the valve needle between the first position and second position.
  • the coating material may be dispensed from the coating material outlet onto a substrate having electronic components located on the substrate.
  • the coating material may be applied in a gap defined between adjacent electronic components.
  • a nozzle for use with a dispensing assembly and being configured to receive a coating material therein may include a body defining a proximal end and a distal end spaced along a dispensing direction opposite the proximal end; a coating material conduit in the body and configured to receive the coating material into the nozzle from the dispensing head, at least one portion of the coating material conduit extending along the dispensing direction and defining a dispensing axis extending through the coating material conduit along the dispensing direction; a coating material outlet defined on the coating material conduit and configured to discharge the coating material therethrough out of the coating material conduit; and a gas passage in the body and configured to receive a gas into the nozzle at a gas inlet at a first end of the gas passage and to discharge the gas from the nozzle through a gas outlet at a second end of the gas passage, wherein the gas passage is defined between the first and second ends of the gas passage.
  • At least one portion of the gas passage may be configured to receive the gas in direction angularly offset from the dispensing axis to impart rotation to the gas in the gas passage, and at least another portion of the gas passage may be configured to receive the gas in a direction parallel to the dispensing axis.
  • the body may include an inner body and an outer body, with the gas passage being defined between the inner body and the outer body.
  • the gas passage may include a first portion that extends around the dispensing axis, a second portion that extends radially inward from the first portion toward the dispensing axis, and a third portion that extends from the second portion toward the gas outlet along the dispensing direction.
  • the nozzle may be configured to receive the gas at the gas inlet and guide the gas along a path that extends from the gas inlet to the first portion so as to impart a rotational component to the gas, and from the first portion, radially inward through the second portion to the third portion, and out of the gas outlet so as to reduce the rotational component of the gas.
  • the third portion of the gas passage may be tapered toward the dispensing axis between the second portion of the gas passage and the gas outlet.
  • the second portion may include a plurality of radial channels disposed between the first portion and the third portion, each of the plurality of radial channels being in fluid communication with the first portion and the third portion.
  • At least one portion of the coating material conduit may extend from the inner body within the outer body along the dispensing axis.
  • the at least one portion of the coating material conduit may have a proximal end adjacent the inner body and a distal end spaced along the dispensing direction from the proximal end.
  • the coating material outlet may be defined at the distal end of the portion of the coating material conduit.
  • the gas outlet may be disposed at a first distance along the dispensing direction from the proximal end of the body.
  • the coating material outlet may be disposed at a second distance along the dispensing direction from the proximal end of the body.
  • the first distance may be greater than the second distance.
  • the first distance may be less than the second distance.
  • the first distance may be the same as the second distance.
  • the gas may include pressurized air.
  • the nozzle may further include a fourth portion of the gas passage between the third portion and the gas outlet.
  • the fourth portion may be cylindrical.
  • the gas passage may define a first cross-sectional dimension at the gas outlet that is greater than a second cross-sectional dimension defined at the coating material outlet of the coating material conduit.
  • the first portion of the gas passage may define a cross- sectional dimension that is greater than the first cross-sectional dimension at the gas outlet.
  • the first portion of the air passage may be greater than the third passage.
  • a combination of the first portion of the air passage and the second portion of the air passage may be greater than the combination of the third portion of the air passage and the fourth portion of the air passage.
  • the nozzle may be used with a dispensing assembly that may include a recirculation pathway that includes a recirculation conduit fluidly connected to the dispensing head and configured to receive a portion of the coating material from the dispensing head.
  • the air passage may be disposed between the coating material outlet and the connection of the recirculation conduit of the dispensing head.
  • the nozzle may be operably connected with a dispensing assembly that includes a controller that is operably connected to, and is configured to control: the flow of gas into the gas passage of the body.
  • the controller may be configured to control a recirculation pump that pumps coating material through a recirculation conduit back to the fluid supply.
  • the controller may control operation of an actuator that controls the movement of a valve needle within the dispensing assembly between a first position and a second position.
  • the coating material may be dispensed from the coating material outlet onto a substrate having electronic components located on the substrate.
  • the coating material may be applied in a gap defined between adjacent electronic components.
  • a method of dispensing a coating material from a nozzle may include the steps of receiving a coating material into a coating material conduit in the nozzle and defining a dispensing axis extending therethrough; moving the coating material through the coating material conduit towards a coating material outlet along a dispensing direction and out of the nozzle through the coating material outlet; receiving pressurized air into an air inlet of an air passage in the nozzle, such that the pressurized air is guided from the air inlet into a first portion of the air passage that extends around the dispensing axis, such that a rotational component is imparted onto the pressurized air; receiving the pressurized air into a second portion of the air passage in a radial direction toward the dispensing axis from the first portion of the air passage; and receiving the pressurized air into a third portion of the air passage from the second portion of the air passage and guiding the pressurized air through the third portion toward an air outlet defined on the nozzle.
  • the second portion of the air passage may include a plurality of channels disposed circumferentially around the dispensing axis, each of the plurality of channels extending in the radial direction from the first portion of the air passage toward the dispensing axis.
  • Receiving the pressurized air into the second portion of the air passage may include receiving the pressurized air from the first portion of the air passage into each of the plurality of channels of the second portion of the air passage.
  • the third portion of the air passage may be tapered inward toward the dispensing axis in a direction from the second portion towards the air outlet.
  • the method may further include the step of receiving the pressurized air into a fourth portion of the air passage from the third portion of the air passage and moving the pressurized air through the fourth portion toward and out through the air outlet.
  • the fourth portion of the air passage may be cylindrical.
  • the method may include dispensing the coating material from the coating material outlet onto a substrate having electronic components located on the substrate.
  • the method may include applying the coating material in a gap defined between adjacent electronic components on the substrate.
  • FIG. 1 shows a front elevation view of a dispensing assembly for liquid or viscous material according to an aspect of this disclosure
  • Fig. 2 shows a front cross-sectional view of the dispensing assembly shown in Fig. 1 ;
  • FIG. 3A shows a perspective view of a nozzle attached to a dispensing head of a dispensing assembly for liquid or viscous material according to an aspect of this disclosure
  • Fig. 3B shows a perspective view of a portion of the dispensing head and nozzle of Fig. 3A with portions of the nozzle being shown as transparent according to an aspect of this disclosure;
  • Fig. 4A illustrates a cross-sectional view of a portion of a dispensing assembly with a nozzle assembly attached thereto and depicts a dispensing material therein according to an aspect of this disclosure;
  • FIG. 4B illustrates a cross-sectional view of a nozzle assembly according to an aspect of this disclosure
  • FIG. 4C illustrates a closer view of a portion of the nozzle assembly shown in Fig. 4B;
  • FIG. 5 shows an enlarged perspective of the nozzle of Fig. 3B according to an aspect of this disclosure, with a portion of the nozzle being shown as transparent;
  • FIG. 6A shows a perspective view of a nozzle with an air conduit connected thereto according to an aspect of this disclosure
  • Fig. 6B shows a side elevation view of the nozzle of Fig. 6A;
  • Fig. 6C shows a bottom plan view of the dispensing end of the nozzle of Fig. 6A;
  • Fig. 6D shows another side elevation view of the nozzle of Fig. 6A;
  • FIG. 7 shows an exploded perspective view of a nozzle with an outer body portion and an inner body portion according to an aspect of this disclosure
  • Fig. 8 shows an exploded cross-sectional perspective view of the nozzle shown in Fig. 7;
  • FIG. 9 shows a perspective view of the inner body portion of the nozzle shown in Fig. 7 according to an aspect of this disclosure
  • Fig. 10 shows a perspective view of a nozzle according to an aspect of this disclosure with a portion of the nozzle being shown as transparent and illustrating a flow of pressurized air and therethrough;
  • Fig. 11 shows a side cross-sectional view of a portion of a nozzle showing a dispensing material and an atomizing material forming an atomized material on a substrate according to another aspect of the disclosure;
  • Fig. 12A shows an exemplary dispensing assembly comprising a dispenser for liquid or viscous materials having a nozzle assembly with a dispensing head and a nozzle, a syringe for the liquid or viscous materials, a recirculation conduit, and a recirculation pump according to an aspect of this disclosure, with an electronic substrate below the dispenser;
  • Fig. 12B shows a front cross-sectional view of a portion of the dispensing assembly shown in Fig. 12A according to an aspect of the disclosure, showing a recirculation conduit connected to the dispensing head;
  • Fig. 13 shows a schematic depicting components of an exemplary dispensing system.
  • This disclosure relates to the atomization of coating material, such as conformal coating material, sprayed from a dispenser.
  • the disclosed systems can be utilized in various applications that involve atomizing a liquid, viscous, or semi- viscous material.
  • the disclosed atomizing systems may require much smaller footprints than existing atomizers or atomizing components, and so can be used in environments where larger components cannot fit or cannot properly operate with other components of the dispensing system.
  • Existing atomizing arrangements may typically have a long flow path that carries the atomizing fluid (e.g. pressurized gas, such as air) in a straight or nearly-straight flow path that follows the direction of dispensing of the material.
  • the atomizing fluid e.g. pressurized gas, such as air
  • the straight flow path allows for the atomizing fluid to be discharged substantially along the same direction as the discharge of the dispensed material.
  • the contact of the atomizing fluid with the dispensed material can cause atomization of the dispensed material, and the flow of the dispensed material and the atomizing fluid helps direct the atomized material along a desired direction towards the target substrate or surface.
  • the atomizing fluid flow path is not entirely straight adjacent an atomizing fluid source, the long flow path that can be utilized in some existing systems allows the flow path to be straightened out gradually so that the atomizing fluid can flow in a linear direction that is substantially parallel to the direction of dispensing of the material when the atomizing fluid exits the atomizing fluid flow path and contacts the dispensed material.
  • some systems may utilize a rotational flow path that may include a helical or spiral fluid flow path for the atomizing fluid.
  • the helical or spiral flow path may be more compact and require less space than a straight flow path described above.
  • the rotational component of the atomizing fluid may cause a uniform distribution around the nozzle 14. However, if the atomizing fluid has such a rotational component and exits the helical or spiral flow path, the atomizing fluid continues to follow the angled trajectory to which it was subjected while in the helical or spiral flow path.
  • a rotational component of the atomizing fluid flow may be beneficial to achieving a concentric airflow pattern through a portion of the dispenser, the rotational component can also result in undesired directions and application patterns of the atomizing fluid as the atomizing fluid contacts the dispensed material.
  • an air-assisted atomization is performed with an evenly distributed airflow to achieve a symmetrical, concentric, and efficient process.
  • Systems and methods described herein relate to dispensing assemblies that can be used in small areas while also providing the desired orientation of atomizing fluid to cause even atomization of dispensed material and generate an accurate stream of atomized material (see, e.g., atomized material 19 in Fig. 12A) that can be applied to a substrate (see, e.g., substrate 11 in Fig. 12A).
  • the stream of atomized material may be formed having a cross-sectional dimension of up to 10 mm, up to 5 mm, up to 3 mm, or another suitable size.
  • the stream of the atomized material may be between about 0.5 mm and about 5 mm, between about 1 mm and about 3 mm, between about 2 mm and about 3 mm, or another suitable range. In some applications, the stream of the atomized material may be significantly smaller, such as between about 1 pm and about 500 pm, between about 50 pm and about 300 pm, between about 75 pm and about 200 pm, or another suitable range.
  • the specific size of the atomized material stream can depend on the desired applications, the dispensing material being utilized, physical and/or chemical parameters of the dispensing material (such as pressure, temperature, and/or the like), the substrate being dispensed onto, the atomizing material being used, and/or the parameters of the atomizing material (such as temperature, pressure, and/or the like).
  • This disclosure is not limited to a particular size or dimension of the atomized material stream.
  • a dispensing assembly 40 can include a nozzle assembly 10 configured to receive dispensing material 16 (labeled in Fig. 4A) and atomizing fluid (e.g. pressurized air) therein to dispense and atomize the dispensing material as desired.
  • the dispensing material 16 is introduced into the dispensing assembly 40 from a material source 18 via known methods.
  • the material source 18 may be a syringe, a hopper, a holding tank, or the like.
  • the dispensing material 16 may include coating material that is applied to a substrate, to a component on a substrate, or adjacent a component on a substrate.
  • dispensing material 16 and coating material 16 can be used interchangeably, but, although reference is made throughout this application to coating material 16, it will be appreciated that a different dispensing material may be utilized, and that this disclosure is not limited to a particular type of dispensing or coating material.
  • the dispensing assembly 40 may include one or more mechanisms to cause the coating material 16 to be discharged. As shown in Figs. 1 , 2, and 4A, coating material 16 may be introduced into a material chamber 41.
  • a movable needle valve 43 may be disposed in, and reciprocated within, the chamber 41 to cause discharging of the coating material 16 from the chamber 41.
  • the chamber 41 may be defined, in part, or may include therein, a valve seat 44.
  • the valve seat 44 may define a chamber outlet 45 therethrough, through which the coating material 16 may be discharged out of the chamber 41.
  • the needle valve 43 is configured to be selectively moved between a first position within the chamber 41 relative to the valve seat 44 and a second position different from the first position. When the needle valve 43 is in the first position, the needle valve 43 may contact the valve seat 44, such that the chamber outlet 45 is not in fluid communication with the chamber 41. When the needle valve 44 is in the first position, the coating material 16 is precluded from being discharged out of the chamber 41. When the needle valve 43 is in the second position, the needle valve 43 is spaced away from the valve seat 44, and the chamber outlet 45 is in fluid communication with the chamber 41.
  • the coating material 16 can be discharged out of the chamber 41 through the chamber outlet 45.
  • the coating material 16 may be discharged out of the chamber 41 via one or more known mechanisms for doing so, such as due to pressure within the chamber 41 , and/or forceful jetting or pushing of the coating material 16 towards and through the chamber outlet 45 by the needle valve 43 as the needle valve 43 is moved from the second position towards the first position towards the valve seat 44.
  • the material that is discharged from the chamber 41 can be moved towards the nozzle 14.
  • the needle valve 43 may be operably connected to a piston 39 that can be moved by an actuator 42. Movement of the piston 39 can cause movement of the needle valve 43 into the first position or into the second position.
  • the actuator 42 may include a solenoid configured to direct pressurized air toward the piston 39 to cause the piston 39 to move in a first direction.
  • the needle valve 43 is retracted away from the valve seat 44 to allow viscous or liquid materials to flow through a chamber outlet 45 defined through the valve seat.
  • the piston 39 may be moved in a second direction opposite the first direction by a biasing element 38.
  • the biasing element 38 may be a spring.
  • Components of the dispensing assembly 40 may be operated by a controller 47 (see Fig. 13) operably connected to the dispensing assembly 40.
  • the controller 47 may be configured to operate the actuator 42 to cause movement of the piston 39.
  • the controller 47 may also control the flow of the atomizing fluid (e.g. pressurized air 15) into the nozzle 14 from the air source 13.
  • the controller 47 may control additional components of the dispensing assembly 40 or alternate dispensing assemblies 40. This disclosure is not limited to the exemplary dispensing assemblies that are depicted herein. Other suitable dispensing assemblies and their respective internal components and mechanisms of operation are described in greater detail in U.S. Patent No. 6,270,019 and U.S. Patent No. 5,747,102, both of which are incorporated herein by reference for purposes of describing the dispensing assembly and its components.
  • a dispensing assembly 40 can include a nozzle assembly 10 configured to receive the coating material 16 and the atomizing fluid therein to dispense and atomize the coating material 16 as desired.
  • the nozzle assembly 10 may be removable from the dispensing assembly 40 and may be replaceable with another nozzle assembly having the same or different structural features.
  • a nozzle assembly 10 may include a dispensing head 12 and a nozzle 14 attached thereto.
  • the dispensing head 12 may be releasably attached to one or more additional components of a dispensing assembly that are configured to introduce the dispensing material into the dispenser head 12 and into the nozzle 14 (such as those components described above).
  • the nozzle 14 may be removably attached to the dispensing head 12 via a known attachment mechanism, such as threading, snap fit, friction fit, clamping, welding, adhesive, and/or the like.
  • the nozzle 14 may define an attachment interface 14c configured to releasably engage with a complementary attachment interface 14d on the dispensing head 12 or on a connected component (see, e.g., Fig. 4A).
  • the attachment interface 14c may include a thread thereon configured to releasably engage with a complementary thread on the attachment interface 14 of the dispensing head 12. It should be appreciated that the attachment interfaces 14c and 14d may be disposed elsewhere on the nozzle 14 and the dispensing head 12, respectively, and that other or additional connection mechanisms may be utilized.
  • the dispensing head 12 is configured to move the coating material 16 to the nozzle 14 and to cause dispensing of the coating material 16 from the nozzle 14 onto a substrate 11 (labeled in Figs. 11 and 12).
  • the coating material 16 may be dispensed along a dispensing axis A that extends along a dispensing direction D.
  • the nozzle 14 may have a proximal end 14a and a distal end 14b that is offset from the proximal end 14a along the dispensing direction D.
  • the nozzle 14 has a body that may include an outer body portion 20 that extends between the proximal end 14a and the distal end 14b along the dispensing direction D.
  • the body of the nozzle 14 may include an inner body portion 22 disposed within the outer body portion 20.
  • the outer body portion 20 and the inner body portion 22 can be monolithic with one another so as to form a unitary body, can be separate portions that are coupled to one another, and/or the like.
  • the inner body portion 22 may be nested within the outer body portion 20 and may be separable from the outer body portion 20, for example along the dispensing axis A.
  • the nozzle 14 may define an air passage 30 (or an atomizing material passage 30 or a gas passage 30) and a material passage 50 (or material conduit) (see, e.g., Figs. 4A-4C).
  • the material passage 50 may be configured to receive the coating material 16 from the dispensing head 12 and to pass the coating material 16 therethrough towards, and out through, a material outlet 54 of the material passage 50 along the dispensing direction D.
  • the dispensing direction D may be the general direction of flow of the coating material 16 through the material passage 50.
  • the air passage 30 may surround the material passage 50, such that air 15 (or another atomizing material) and coating material 16 may be moved in the same direction through at least a portion of the nozzle 14.
  • passage 30 is referred to as an “air passage,” it will be understood that the air passage 30 can be a gas passage 30 that is configured to receive suitable gasses other than air.
  • the inner body portion 22 may have a proximal end 22a and a distal end 22b that may be offset from the proximal end 22a along the dispensing direction D.
  • the inner body portion 22 may extend between the proximal end 22a and the distal end 22b along the dispensing direction D.
  • the inner body portion 22 may include an outer surface 22c that extends between the proximal end 22a and the distal end 22b, such as along the dispensing direction D.
  • the outer surface 22c can extend around the dispensing axis A and face outwardly.
  • the outer surface 22c can define at least a portion of the air passage 30.
  • the inner body portion 22 may include an end surface 22d.
  • the end surface 22d can be disposed at the distal end 22b.
  • the end surface 22d can have an annular shape or any other suitable shape.
  • the nozzle 14 can comprise a tubular wall 52 that extends at least from the end surface 22d in the dispensing direction D.
  • the tubular wall 52 may have a cylindrical shape that extends circumferentially around the material passage 50 so as to define the material passage 50 therethrough. In other embodiments, the tubular wall 52 can have another suitable shape. At least a portion of the tubular wall 52 may be within the air passage 30.
  • the tubular wall 52 has a length L measured from the end surface 22d to the material outlet 54, the length L being measured along the dispensing direction D.
  • tubular wall 52 may extend into the inner body portion 22 along a direction opposite the dispensing direction D.
  • the tubular wall 52 can have an overall length that is greater than the length L.
  • the tubular wall 52 may define a part of, or the entirety of, the material passage 50 (or conduit).
  • the tubular wall 52 may be part of a dispensing needle 51 configured to be received into the dispensing head 12 and into the nozzle 14. The dispensing material 16 may be moved into and through the dispensing needle 51 out of the dispensing head 12 and into the nozzle 14.
  • the dispensing needle 51 may include any suitable shape or dimension, and that the nozzle 14 may be dimensioned in a complementary manner so as to receive at least a portion of the dispensing needle 51 (e.g. the tubular wall 52 of the dispensing needle 51) therein.
  • the tubular wall 52 may be a separate component from the nozzle 14 and may be slidably receivable therein.
  • the outer body portion 20 may have a proximal end 20a, and a distal end 20b that is offset from the proximal end 20a along the dispensing direction D.
  • the outer body portion 20 may define an outer surface 20c that extends between the proximal and distal ends 20a, 20b and faces outwardly.
  • the outer body portion 20 may have an inner surface 20d that is opposite the outer surface 20c along an inward direction.
  • the inner surface 20d can define at least a first portion 32 of the air passage 30 (labeled in Figs. 4B and 10, for example).
  • the first portion of the air passage 30 can be defined between the inner surface 20d of the outer body portion 20 and the outer surface 22c of the inner body portion 22.
  • the outer body portion 20 can define an air inlet 24, through which pressurized air 15 from the pressurized air source 13 is received into the air passage 30.
  • the air inlet 24 can extend through the outer surface 20c and the inner surface 20d such that the air inlet 24 is in fluid communication with the air passage 30.
  • the air inlet 24 can extend through the outer surface 20c and the inner surface 20d at a position that is between the proximal end 20a and the distal end 20b.
  • the air inlet 24 extends along an inlet axis A2 that extends into the air passage 30 without intersecting the dispensing axis A.
  • the inlet axis A2 is offset from, such as outwardly spaced from, the dispensing axis A.
  • the outer body portion 20 can define an air outlet 26 that is configured to expel the air 15 out of the nozzle 14.
  • the air outlet 26 can be disposed at the distal end 20b of the outer body portion 20.
  • the air passage 30 is configured to receive pressurized air 15 from a pressurized air source 13 and to pass the pressurized air 15 towards, and out through, the air outlet 26.
  • the air inlet 24 may be configured to connect to an air conduit 17 that is connected to the air source 13.
  • the air conduit 17 can extend from the air inlet 24 and away from the outer body portion 20 along the inlet axis A2. At least a portion of the air conduit 17 can extend along the inlet axis A2.
  • the air outlet 26 may be adjacent to the material outlet 54.
  • the material outlet 54 may be disposed within the air passage 30, such that when the coating material 16 exits the material passage 50 through the material outlet 54, the coating material 16 is within the air passage 30. In other examples, part of the material passage 50 may be disposed within the air passage 30, while the material outlet 54 may be disposed outside of the air passage 30. As noted above, a gas other than air, or in combination with air, may be utilized, and references throughout this application to air inlet 24, pressurized air source 13, etc. should not be construed as being limited only to implementations utilizing air.
  • the air passage 30 may include a first portion 32 that extends circumferentially around the material passage 50.
  • the first portion 32 may have an annular shape in a plane that is orthogonal to the dispensing axis A and to the dispensing direction D. When viewed in this plane, the first portion 32 may define a circular path for the air flow.
  • the first portion 32 may have a circular cross-section therethrough.
  • the first portion 32 may have an annular shape.
  • the first portion 32 may have an oval cross-section, a rectangular cross-section, and/or that of another suitable cross-section shape.
  • the first portion 32 may have a constant cross-section therethrough or, alternatively, a variable cross-sectional shape or dimension.
  • a rotational component is imparted to the flowing pressurized air 15 as the pressurized air 15 is moved through the first portion 32.
  • the first portion 32 of the air passage 30 fluidly communicates with the air inlet 24 and is configured to receive the pressurized air 15 therein through the air inlet 24.
  • the first portion 32 may be disposed such that it surrounds, but does not intersect, the dispensing axis A.
  • the first portion 32 may extend circumferentially around the dispensing axis A. In some aspects, the first portion 32 may extend around the entire circumference of the dispensing axis A for at least one revolution (i.e. 360 degrees). Alternatively, the first portion 32 may extend circumferentially around the dispensing axis A for less than 360 degrees.
  • the first portion 32 may be angularly offset from the dispensing axis A and the dispensing direction D.
  • the pressurized air 15 (or another atomizing fluid) that is moving through the first portion 32 moves along a direction that is substantially not parallel to the dispensing axis A and the dispensing direction D (for example, along a direction that is parallel to the axis A2).
  • the first portion 32 may be arranged such that the pressurized air 15 may be moved through the first portion 32 along a direction that is substantially perpendicular to the dispensing direction D (i.e. at a direction approximately 90 degrees offset from the dispensing axis A).
  • the first portion 32 may be arranged such that the pressurized air 15 may be moved through the first portion 32 along a direction that is offset by another angle between 0 and 180 degrees relative to the dispensing axis A.
  • the nozzle 14 defines a radial channel 34 extending radially away from the material passage 50 and towards the first portion 32 of the air passage 30 along a radial axis.
  • the radial channel 34 may be disposed adjacent the end surface 22d.
  • the end surface 22d may define a recess therein that at least partially defines the radial channel 34.
  • the recess can extend into the end surface 22d towards the proximal end 22a of the inner body portion 22.
  • the radial channel 34 may have an at least partially circular cross-section therethrough along a plane that is perpendicular to the radial axis.
  • the radial channel 34 may have an oval or rectangular cross-section, or that of another suitable shape.
  • the radial channel 34 may have a constant cross-section therethrough or, alternatively, a variable cross-sectional shape or dimension.
  • the radial channel 34 is in fluid communication with the first portion 32 of the air passage 30 and is configured to receive pressurized air 15 from the first portion 32.
  • the cross-sectional area of the radial channel 34 may be smaller than the cross-sectional area of the first portion 32.
  • the pressurized air 15 may be straightened as it moves through the radial channel 34 to reduce or remove the rotational component of the flow that the pressurized air 15 exhibits when in the first portion 32.
  • the outer body portion 20 and the inner body portion 22 may define a plurality of radial channels 34, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, or another suitable number of radial channels 34.
  • the plurality of radial channels 34 may be disposed in a wheel-and-spoke pattern, such that all of the radial channels 34 are spaced circumferentially around the material passage 50 with substantially equal distances between adjacent radial channels 34.
  • the nozzle 14 may include 6 radial channels 34 arranged circumferentially on the end surface 22d of the inner body portion 22, but it will be appreciated that other arrangements can be utilized.
  • the radial channel 34 defines a second portion of the air passage 30.
  • Each of the plurality of radial channels 34 may be in fluid communication with the first portion 32 and be configured to receive the pressurized air 15 therein from the first portion 32.
  • the nozzle 14 may further define a third portion 36 of the air passage 30.
  • the third portion 36 may extend from the end surface 22d towards the air outlet 26 along the dispensing axis A along the dispensing direction D.
  • the third portion 36 may have a proximal end 36a (labeled in Figs. 4C and 5) defined by the end surface 22d, and a distal end 36b opposite the proximal end 36a along the dispensing direction D.
  • the third portion 36 can have a tapered shape that tapers inwardly as the third portion 36 extends along the dispensing direction D.
  • the third portion 36 can have a cone shape or truncated cone shape.
  • the third portion 36 is open at the proximal end 36a and at the distal end 36b, and thus the proximal end 36a and the distal end 36b are both intangible planes rather than physical barriers.
  • the third portion 36 may have a height H1 from the proximal end 36a to the distal end 36b, the height H1 being measured along the dispensing direction D.
  • the height H1 of the third portion 36 may be greater than the length L of the tubular wall 52 as measured from the end surface 22d. In other words, the third portion 36 may extend past the tubular wall 52 along the dispensing direction D.
  • the height H1 of the third portion 36 may be less than the length L of the tubular wall 52 as measured from the end surface 22d. In other words, the tubular wall 52 can extend past the third portion 36 along the dispensing direction D. In yet other examples, the height H1 of the third portion 36 may be substantially equal to the length L of the tubular wall 52 as measured from the end surface 22d.
  • the third portion 36 may be tapered, such that a diameter D1 of the proximal end 36a of the third portion 36 is greater than a diameter D2 of the distal end 36b. In some exemplary aspects, the taper is linear, but it will be appreciated that the taper may be non-linear.
  • the material passage 50 may be disposed, at least partly, within the third portion 36.
  • the third portion 36 may be in fluid communication with the radial channel 34, or with the plurality of radial channels 34, and may be configured to receive pressurized air 15 from the one or more radial channels 34.
  • the third portion 36 may extend from the end surface 22d along the dispensing direction D.
  • the nozzle 14 can define a cylindrical channel 38 adjacent the third portion 36 and extending between the third portion 36 and the air outlet 26.
  • the cylindrical channel 38 can extend from the third portion 36 along the dispensing direction D.
  • the cylindrical channel 38 has a height H2, measured between the third portion 36 and the air outlet 26, and a diameter D3.
  • the diameter D3 of the cylindrical channel 38 may be the same as the diameter D2 of the distal end 36b of the third portion 36 (see, e.g., non-limiting aspect shown in Fig. 4C). In other aspects, the diameter D3 may be smaller than the diameter D2 (see, e.g., non-limiting aspect shown in Fig. 5).
  • the cylindrical channel 38 may be in fluid communication with both the third portion 36 and the air outlet 26, and may be configured to receive pressurized air 15 from the third portion 36 and to discharge the pressurized air 15 from the air outlet 26.
  • the cylindrical channel 38 may define a fourth portion of the air passage 30.
  • the cylindrical channel 38 may comprise the entirety of the fourth portion of the air passage 30, such that the cylindrical channel 38 can also be referenced in the figures as the fourth portion 38.
  • the air passage 30 may define a total length or distance measured between the air inlet 24 and the air outlet 26.
  • the first portion 32, second portion 34, third portion 36, and fourth portion 38 may each have a length measured between adjacent components and may comprise segments of the total length of the air passage 30.
  • the first portion 32 may be measured between the air inlet 24 and the second portion 34; the second portion 34 may be measured between the first portion 32 and the third portion 36; the third portion 36 may be measured between the second portion 34 and the fourth portion 38; and the fourth portion 38 may be measured between the third portion 36 and the air outlet 26.
  • one or more of the portions that comprise the air passage 30 may have different lengths relative to one or more of the other portions, or, alternatively, some or all of the portions of the air passage 30 may have substantially the same length.
  • the first portion 32 may be longer than the second portion 34, the third portion 36, and/or the fourth portion 38.
  • the combination of the first portion 32 and the second portion 34 may be longer than the combination of the third portion 36 and the fourth portion 38.
  • the first portion 32 may account for up to 20 percent, up to 30 percent, up to 40 percent, up to 50 percent, up to 60 percent, up to 70 percent, up to 80 percent, up to 90 percent, or up to 95 percent of the entire length of the air passage 30.
  • the combination of the first portion 32 and the second portion 34 may account for up to 20 percent, up to 30 percent, up to 40 percent, up to 50 percent, up to 60 percent, up to 70 percent, up to 80 percent, up to 90 percent, or up to 95 percent of the entire length of the air passage 30.
  • the first portion 32 of the air passage 30 may have a substantially circular cross-section when viewed orthogonally to the direction of the flow of the pressurized air 15.
  • the first portion 32 may define a diameter D4 therethrough (labeled in Fig. 5).
  • the diameter D4 may be greater than the diameter D1 , diameter D2, and/or diameter D3.
  • the tubular wall 52 that defines the material passage 50 may extend into the cylindrical channel 38.
  • the length L of the tubular wall 52 from the end surface 22d is greater than the height H1 of the third portion 36.
  • the tubular wall 52 may extend through the entirety of the cylindrical channel 38 and out of the air outlet 26.
  • the offset between the axis A2 of the first portion 32 of the air passage 30 and the dispensing axis A allows for the pressurized air 15 to be introduced into the first portion 32 of the air passage 30 with a rotational component, and then to be equally distributed to the one or more radial channels 34 in the second portion of the air passage 30.
  • Having a rotational component to the air flow allows for more even distribution of the air through the air passage 30 to more evenly atomize the material.
  • the air flow is straightened to create a tight pattern that is desirable for atomization of the material. This reduces or removes the rotational component from the pressurized air.
  • the outer body portion 20 and the tubular wall 52 defining the material passage 50 may define an air choke location P1 , where the air passage 30 (for example, in the third portion 36 or fourth portion 38) has the smallest cross sectional area therethrough (also referred to as a choke point).
  • the choke location P1 may be determined by the length L of the tubular wall 52 (or the length of the portion of the tubular wall 52 extending between the end surface 22d of the inner body portion 22 and the material outlet 54), a thickness of the tubular wall 52, the diameter D2 of the distal end 36b of the third portion 36, the diameter D3 of the cylindrical channel 38, and/or the like.
  • the position and dimensions of the tubular wall 52 may also define a mixing location P2, where the coating material 16 and the pressurized air 15 first mix to form an atomized fluid 19 (labeled in Figs. 11 and 12A), which includes the atomizing pressurized air 15 (or another suitable atomizing fluid) and the coating material 16 (or another material being dispensed). Since the material passage 50 is, at least partly, within the air passage 30, the mixing location P2 is adjacent to the material outlet 54 of the material passage 50.
  • the airflow may be straightened out before it reaches the choke location P1 and the mixing location P2.
  • the choke and mixing locations P1 , P2 may be arranged relative to one another to achieve a desired air flow and a desired velocity of the coating material 16.
  • the choke and mixing locations P1 , P2 may be aligned relative to one another with respect to the dispensing direction D.
  • the mixing location P2 may be disposed upstream of the choke location P1 , such that the coating material 16 and the pressurized air 15 mix before the pressurized air 15 reaches the choke location P1 , or the mixing location P2 may be disposed downstream of the choke location P1 , such that the coating material 16 and the pressurized air 15 mix after the pressurized air 15 has already reached the choke location P1.
  • aligning the mixing location P2 and the choke location P1 with respect to the dispensing direction D based on predetermined calculations and relative positioning may result in a maximum transfer of energy from the pressurized air 15 and cause preferred levels of atomization.
  • a preferred choke location P1 may be determined to cause the airflow to have a high shear and low flow rate (relative to shear and flow rate of different choke locations) that results in desirable atomization characteristics and efficiency. It will be appreciated that the arrangement of components to result in the desired relative positioning of the choke location P1 and the mixing location P2 may be optimized, and the particular dimensions, relative distances, and/or the like can be determined based on additional algorithms, properties of the components and the materials being dispensed, and/or other operating parameters. The particular arrangements or dimensions can vary, and the exemplary depictions and descriptions throughout this application are not limiting.
  • the disclosed embodiments address the aforementioned problems of existing technology.
  • the offset air inlet introduces air flow that equally distributes the supply air to a further portion of the air passage, which reduces or removes the previously introduced rotational component. With the atomizing airflow straightened out, the airflow then moves towards the choke and mixing locations, which may be arranged or aligned according to aspects described above to minimize the required airflow and maximize the relative velocity for optimum atomization.
  • the disclosed aspects allow for various advantages over existing technologies, such as resulting in narrow and selective atomization patterns and processes, allowing for minimum over spray, allowing for a thickness of between about 3p-8pm, allowing for a reduction of scrapped product to save on material costs, and/or the like.
  • the disclosed embodiments may be utilized in a dispensing system in which the atomized fluid may need to be introduced in a relatively small volume compared to existing systems.
  • the dispensing system may include a recirculation pathway, through which a portion of the dispensing material is moved from the nozzle (or adjacent the nozzle) back to the material source. This may be beneficial in applications related to dispensing material that includes one or more particles suspended therein. To maintain the desired suspension and distribution of particles within the dispensing material, it may be preferred to refrain from keeping the dispensing material immobile for long durations. This can be avoided by continuously or periodically causing the dispensing material to move.
  • any dispensing material that is not dispensed from the dispenser towards the substrate may thus be moved back to the material supply, so as to impart motion on the material to reduce stagnation.
  • the atomizing fluid may need to be introduced downstream of the recirculation pathway so that only the dispensing material that is being dispensed (not recirculated) can come in contact with the atomizing fluid.
  • the space between the recirculation pathway and the outlet of the nozzle may be too small to allow for a long, straight atomizing fluid pathway.
  • a smaller, more compact pathway such as those described herein, may be preferred.
  • an exemplary dispensing assembly 40A is depicted according to an aspect of this disclosure. Components of the dispensing assembly 40A are substantially the same as those described throughout this application with respect to other disclosed dispensing assemblies, such as dispensing assembly 40, unless indicated otherwise.
  • the dispensing assembly 40A shows a dispensing head 12 of a dispenser for liquid or viscous materials with a nozzle 14 attached thereto.
  • Dispensing assembly 40A may similarly be a needle valve type dispenser having a needle valve 43 selectively movable toward and away from a valve seat 44 (e.g. valve seat 44 similar to the dispensing assembly 40 (see, e.g. Fig. 2).
  • a recirculation conduit 48 may be fluidly affixed to the dispensing head 12. A portion of the coating material 16 that is present in the dispensing head 12 may be moved into the recirculation conduit 48. At its other end, the recirculation conduit 48 is in fluid communication with the coating material source 18.
  • the coating material source 18 may include a syringe affixed to, and fluidly connected with, the dispensing assembly 40A. The coating material 16 that is moved into the recirculation conduit 48 from the dispensing head 12 may be moved to the material source 18. The movement may be facilitated by a recirculation pump 46, for example, a peristaltic pump.
  • the controller 47 may be configured to control operation of the recirculation pump 46. It will be appreciated that the dispensing assembly 40 may include a plurality of controllers 47, and the components described above can be operated by one or more of the controllers 47.
  • the coating material 16 is typically recirculated such as described above when the valve is closed (i.e. when the needle valve 43 is in contact with the valve seat 44 to preclude the coating material 16 from being moved out of the dispensing head 12 towards the nozzle 14). Recirculation is performed so that the coating material 16 can be kept moving and recirculated back to the coating material source 18. This prevents stagnation of the coating material 16 and prevents the coating material 16 from being “dead ended,” which can allow solids (e.g. solid particles) suspended in the coating material 16 to settle out of the fluid stream, thus changing the desired characteristics of the coating material 16. For this reason, the coating material 16 can be removed from the chamber 41 above the valve seat 44 when the dispensing assembly 40A is in the vertical orientation shown in Fig. 12A.
  • the atomizing fluid in this case, the pressurized air 15
  • the fluid pathway below the valve seat 44 when the dispensing assembly 40 is in the vertical orientation shown in Fig. 12A.
  • This part of the fluid pathway can also be referred to as the “downstream” portion of the fluid pathway, which is between the valve seat in the fluid chamber and the distal end 14b of the nozzle 14 (where the coating material outlet 54 is located).
  • the described nozzle 14 can be used to retrofit existing dispensing systems to introduce an atomizing capability and/or to replace an existing atomizing arrangement with a smaller, more efficient embodiment such as described here.
  • a substrate 11 is shown receiving the atomized material 19 thereon.
  • the atomized material 19 comprises the coating material 16 (or other dispensing material) that has been atomized by the pressurized air 15 (or other atomizing fluid).
  • the atomized material 19 may be applied as a thin stream. As described above, the stream of the atomized material 19 may have various cross-sectional dimensions based on the desired application and on the dispensing material.
  • the atomized material 19 can be applied directly to the substrate 11 , or, alternatively, the atomized material 19 can be applied to one or more workpieces 9 on the substrate 11. In some aspects, the atomized material 19 may be applied adjacent to one or more workpieces 9.
  • the atomized material 19 may be applied in a gap defined between adjacent workpieces 9 so as to fill the gap. It will be appreciated that the stream of atomized material 19 can be applied at any desired angle relative to the substrate 11 and/or the workpiece 9.
  • the substrate 11 may be an electronic component, such as a printed circuit board, and the workpieces may be electronic components or the like.
  • a schematic is shown depicting possible arrangements and control scenarios of a dispensing assembly 40, 40A, or another suitable dispensing assembly.
  • the controller 47 is operably connected to, and is configured to control operation of, the air source 13, the actuator 42, and the recirculation pump 46.
  • the dispensing assembly may be devoid of a recirculation conduit 48 and recirculation pump 46, or be disconnected from such recirculation components.
  • a method of dispensing a coating material from a nozzle comprises a step of receiving pressurized air in an air inlet of a body of the nozzle such that the pressurized air is guided from the air inlet to a first portion of an air passage that is defined by the body and extends around a dispensing axis that extends along a dispensing direction so as to impart a rotational component to the pressurized air, and from the first portion, radially inward through a second portion of the air passage to a third portion of the air passage that is tapered along the dispensing direction, and out of the air outlet so as to reduce the rotational component.
  • Dispensing a coating material from a nozzle can include receiving a coating material into a coating material conduit and receiving pressurized gas (e.g. air) into an air passage disposed with respect to the material conduit.
  • the conduit may be positioned in or defined in the nozzle along the dispensing axis. The coating material can be moved through the conduit towards a material outlet and out of the nozzle.
  • the pressurized air can be guided from the air inlet into a first portion of the air passage that extends around the dispensing axis to impart a rotational component to the flow of the pressurized air. From the first portion of the air passage, the pressurized air can be moved into a second portion of the air passage in a radial direction toward the dispensing axis. This contributes to reduce or remove the rotational component that was previously imparted onto the flow of the pressurized air when the pressurized air was introduced into and moved through the first portion of the air passage. The pressurized air can then be moved into the third portion of the air passage from the second portion.
  • the pressurized air can then be guided to a fourth portion of the air passage and then out of the nozzle through the air outlet. Movement through the third portion and/or the fourth portion may reduce or remove the rotational component imparted on the pressurized air previously.
  • the disclosed dispensing assemblies may be used with an existing dispensing system.
  • parts of the disclosed dispensing assemblies, such as the nozzle may be implemented into existing dispensing assemblies or dispensing systems.

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Abstract

L'invention concerne des dispositifs et des procédés destinés à distribuer un matériau de revêtement. Un ensemble de distribution (40) comprend une tête de distribution destinée à recevoir un matériau et une buse (14) destinée à recevoir le matériau en provenance de la tête de distribution (12). La buse comprend un corps (20, 22) comportant une extrémité distale espacée d'une extrémité proximale le long d'une direction de distribution ; un conduit de matériau (50) destiné à recevoir le matériau dans la buse et à travers lequel est défini un axe de distribution ; un orifice de sortie de matériau destiné à évacuer le matériau hors du conduit de matériau ; et un passage de gaz (30) destiné à recevoir un gaz dans la buse au niveau d'un orifice d'entrée de gaz et à évacuer le gaz à travers un orifice de sortie de gaz. De plus, au moins une partie du passage de gaz est destinée à recevoir le gaz dans une direction décalée angulairement par rapport à la direction de distribution, et au moins une autre partie est destinée à recevoir le gaz le long de la direction de distribution.
PCT/US2021/020572 2020-03-03 2021-03-03 Conception compacte et procédé pour distribuer uniformément, égaliser et atomiser efficacement un fluide WO2021178470A1 (fr)

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US62/984,340 2020-03-03

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US20010042506A1 (en) * 1996-07-19 2001-11-22 Patrick Thomas Hogan Method and apparatus for applying a liquid coating with an improved spray nozzle
US20030094254A1 (en) * 2001-10-22 2003-05-22 Abb Inc. Spraying nozzle for rewet showers
WO2004020111A1 (fr) * 2002-08-30 2004-03-11 Nordson Corporation Procede de puverisation de liquide
US20050095365A1 (en) * 2003-10-30 2005-05-05 Howard Acum Conformal coating applicator and method
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EP0225624A2 (fr) * 1985-12-09 1987-06-16 Nordson Corporation Tête de pulvérisation pour matière thermoplastique, en particulier pour un adhésif fusible
WO1996021518A1 (fr) * 1995-01-09 1996-07-18 Bete Fog Nozzle, Inc. Ajutage ameliore pulverisant un jet de liquide sous forme d'eventail aplati
US5747102A (en) 1995-11-16 1998-05-05 Nordson Corporation Method and apparatus for dispensing small amounts of liquid material
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