An applicator for use with a hot melt adhesive dispensing system

Abstract

An applicator for use with a hot melt adhesive dispensing system is provided. The applicator includes an applicator body configured to receive a collapsible tube of adhesive. The applicator body includes a housing wall defining a receiving cavity capable of housing the collapsible tube, a dispensing port defined within a distal portion of the housing wall, a cooling air inlet formed w ithin a first side portion of the housing wall, and a cooling air outlet formed through a second side portion of the housing wall. In one embodiment, the cooling air outlet is disposed at a location within the housing wall that is substantially opposite from the portion of the housing wall through which the cooling air inlet is formed. The applicator may also include an end cap comprising a collapsing air inlet; a piston configured to be disposed within the receiving cavity; an angled heat conductor disposed within the dispensing port of the applicator body; and athermal isolator disposed about the angled heat conductor.

Description

Attorney Docket No. 006641-01197WOeAN APPLICATOR FOR USE WITH A HOT MELT ADHESIVE DISPENSING SYSTEMRELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application, No. 63 / 691,000, filed September 5, 2024, and incorporated herein in its entirety.RELATED TECHNOLOGY

[0002] The disclosure relates to an applicator for use with a hot melt adhesive dispensing system. Specifically, this disclosure relates to an applicator that is configured to receive a collapsible tube of PUR adhesive.BACKGROUND

[0003] Certain high speed dispensing systems include the use of heated PUR (polyurethane reactive) adhesives and other heated materials housed in applicators that include 30 ml plastic syringes. Because the entire mass of adhesive within the syringe remains heated throughout the production day, the PUR ingests moisture from the air. The length of time the PUR remains heated and the prolonged exposure to the air may cause degradation of the adhesive material over time and cause inconsistency in the dispense mass and bond strength, requiring unused adhesive to be prematurely discarded. In addition, the disposable plastic syringe is also discarded after the adhesive is used. This wasted material is costly, inefficient, and detrimental to the environment.SUMMARY

[0004] An applicator for use with a hot melt adhesive dispensing system is provided. The applicator includes an applicator body configured to receive a collapsible tube of adhesive. The applicator body includes a housing wall defining a receiving cavity' capable of housing the collapsible tube, a dispensing port defined within a distal portion of theAttorney Docket No. 006641-01197WOe housing wall, a cooling air inlet formed within a first side portion of the housing wall, and a cooling air outlet formed through a second side portion of the housing wall. In one embodiment, the cooling air outlet is disposed at a location within the housing wall that is substantially opposite from the portion of the housing wall through which the cooling air inlet is formed. The applicator may also include an end cap comprising a collapsing air inlet; a piston configured to be disposed within the receiving cavity; an angled heat conductor disposed within the dispensing port of the applicator body; and athermal isolator disposed about the angled heat conductor.BRIEF DESCRIPTION OF THE DRAWINGS

[0001] Figure 1 is a front perspective view of one embodiment of an example PUR adhesive dispensing system.

[0002] Figure 2 is a side perspective view of the PUR adhesive dispensing system of Figure 1.

[0003] Figure 3 is a front perspective view of one embodiment of an applicator for use with a hot melt dispensing system.

[0004] Figure 4 is a front perspective view of another embodiment of an applicator for use with a hot melt dispensing system.

[0005] Figure 5 is an exploded view of the applicator shown in Figure 3.

[0006] Figure 6 is a front cross-sectional view of the applicator shown in Figure 3.

[0007] Figure 7 is a front cross-sectional view of the applicator shown in Figure 4.

[0008] Figure 8 is a front view of an example of an uncollapsed tube of PUR adhesive that may be used with an applicator of Figures 3-7.

[0009] Figure 9 is a front view of an example of a collapsed tube of PUR adhesive that may be used with an applicator of Figures 3-7.Attorney Docket No. 006641-01197WOeDETAILED DESCRIPTION

[0010] As shown in Figures 1 and 2, by way of illustration, existing PUR adhesive dispensing systems 10 may generally include an applicator 12 configured to store a supply of adhesive material. The dispensing system 10 may also include a pump 14 fluidly connected to the applicator 12. The pump 14 may include a stem (not shown) that is configured to move from a retracted and an extended position using pressurized air supplied to the pump via a valve 16, such as a solenoid, or other suitable valve. The valve 16 may be connected to the pump 14 via a connector 18. The valve can be a pneumatic valve, an electronic valve, or any other suitable type of valve. The pump 14 may be fluidly connected to a nozzle assembly 20 and configured to guide an amount of adhesive material from a pump outlet (not shown) to the nozzle assembly 20 for application on to a substrate. It should be appreciated that any suitable valve, pump, connector, and nozzle assembly may be used in this dispensing system 10. In some embodiments, the dispensing system 10 may be removably attached to a robotic arm (not shown) with a mounting plate 22. The robotic arm may be configured to control the pattern of adhesive dispensed from the dispensing system 10.

[0011] Referring now to Figures 3 and 4, in one embodiment, an applicator 200 (shown attached to a pump, removable mounting plate, and nozzle assembly) may be configured to receive an amount of solid PUR adhesive material disposed in a collapsible metal tube or casing (Figures 8 and 9) that, when inserted into the applicator 200, is melted only at its distal end. By melting the adhesive only at the distal end of the applicator 200 (Figure 6). the adhesive is melted on demand, rather than all at once, reducing degradation of the adhesive and waste of unused premelted material. It should be appreciated that this applicator 200 may replace known applicator 12 and be combined with dispensing components with suitable modifications to existing pumps, valves, and nozzle components (shown in Figures 1 and 2).Attorney Docket No. 006641-01197WOe

[0012] Referring now to Figures 3-7, the applicator 200 may generally include an applicator body 202 having a housing wall 204 defining a receiving cavity7206 configured to receive the collapsible tube 208 (Figures 8 and 9) and a dispensing port 210 defined w ithin a distal portion 212 of the housing wall 204. As shown in Figures 3 and 4, the applicator body 202 may be generally rectangular in shape (Figures 3, 5, and 6), or it may be modified to mirror the shape of the tube 208, as shown in Figures 4 and 7. The applicator body 202 may be made of aluminum or other suitable materials.

[0013] The applicator 200 may also include a cooling air inlet 214 and a cooling air outlet 216. The inlet 214 and outlet 216 may be disposed through the distal portion 212 of the housing wall 204 and may include protrusions therefrom that enable the inlet 214 to be fluidly attached to a supply of pressurized cooling air that may7be turned on an off electrically or manually, depending on the choice of the user. The protrusion associated with the cooling air outlet 216 may be used to direct the exhaust (A) from the cooling air inlet 214 away7from the applicator body 202, as shown in Figure 6. Also as shown in Figures and 6 and 7, the cooling air inlet 214 and cooling air outlet 216 may be positioned directly across from one another (Figure 6) or slightly above or below the other (Figure 7) along the housing wall 204.

[0014] Referring again to Figures 3, 4, and 5, the applicator 200 may also include a removable end cap 218 having a collapsing air inlet 220. The end cap 218 may be configured to connect the applicator 200 to a supply of pressurized air capable of exerting a downw ard force on to the contents of the applicator 200 through the collapsing air inlet 220. In one embodiment, as shown in Figure 4. the end cap may be rotatably attached to the applicator body 202 using mating threads on the proximal end of the applicator body 202 and internal surface of the end cap 218. In another embodiment, as shown in Figures 2 and 5, the end cap 218 may include threads on an exterior surface and may be rotatably inserted into an opening 222 in the top of the applicator body 202 that includes mating threads. However, itAttorney Docket No. 006641-01197WOe should be understood that any suitable attachment methods may be used to connect the end cap 218 to the applicator body 202.

[0015] Referring now to Figures 5-7, the applicator 200 may also include a piston 224 that is configured to fit within the interior cavity 206 of the applicator body 202. In one embodiment, the piston 224 is disc shaped and configured to exert pressure on the top of the tube 208 as collapsing air is forced in a downward direction toward the distal end 212 of the applicator 200. The piston may be made of aluminum or any other suitable material. It may also be any shape that is capable of exerting the pressure required to evenly collapse the tube 208 wi thin the cavity 206.

[0016] Other internal components of the applicator include a thermal isolator 226 and an angled heat conductor 228. As can be seen in Figures 6 and 7, the thermal isolator 226 is configured to sit on top of and around at least a portion of the angled heater 228. The thermal isolator 226 may be made of any suitable insulative material, such as PTFE, and is configured to isolate and transfer heat produced by a cartridge heater housed in the nozzle assembly 20 to the threaded portion of the adhesive tube 208, while limiting the amount of heat transferred to the housing wall 204. The angled heat conductor 228 may be disposed between the base of the applicator body 202 and an upper surface of a nozzle assembly 20 attached to the applicator 200. The nozzle body 20 may then be easily attached to the applicator body 202 using two attachment screws 230a and 230b, as shown in Figure 5. In use, the angled heat conductor 228 conducts heat from a cartridge heater disposed in the nozzle body 20 to the threaded portion of the tube 208, causing at least the portion of the adhesive within the threaded portion of the tube 208 to melt.

[0017] Referring now to Figures 8 and 9, the applicator 200 shown in Figures 3-7 is configured to receive a collapsible tube 208 of PUR adhesive material. The tube 208 may be made of any suitable material, such as aluminum. In one embodiment, the tube is sizedAttorney Docket No. 006641-01197WOe to be filled with about 30 ml to about 300 ml of solid adhesive material. As shown in Figure 8, the tube 208 may have an elongated circular outer shape with a threaded tip 232. The tube may be a smooth metal material, or it may be corrugated, i.e. have stress risers, (Figure 7) to aid in the collapse of the tube.

[0018] In one embodiment, the tube 208 may be filled with solid PUR adhesive and be open at the upper end, with the threaded end 232 closed with a breakable seal made of foil or other suitable membrane material. In one embodiment, the open end of the tube 208 is circular in shape, mirroring the shape of the tube. In one embodiment, it may be topped with a removable tube plug 234 that is configured to evenly distribute the weight of the piston 222 across the circumference of the tube. In one embodiment, as the tube of adhesive 208 is melted at its threaded end 232, and the adhesive is expelled through the dispensing port 210 of the applicator body 202, the outer wall of the tube 208 is configured to collapse upon itself from the bottom up, as shown in Figure 9. In other embodiments (not shown), the upper end of the tube 208 may be closed by pressing the opposing sides of the tube together to make a seal. In one embodiment, the pressed edges may then be folded upon itself to reinforce the end seal. In this embodiment, it is contemplated that the pressed edges would then fit into a groove formed in a bottom surface of the piston 222, thus alleviating the need for the tube plug 234, while still evenly distributing the pressure applied by the piston 222 to the top of the tube 208.

[0019] Referring again to Figure 6, in use the collapsible tube 208 of PUR adhesive material may be inserted into the applicator 200 by either removing the nozzle assembly 20 and angled heat conductor 228 at the bottom of the applicator body 202 and screwing the threaded end 232 of the tube into the mating threads on the angled heat conductor 228. This may be achieved by removing the replacement screws 230a,b. Alternatively, the end capAttorney Docket No. 006641-01197WOe218 may be unscrewed from the top of the applicator body and the tube 208 inserted along with the piston 218.

[0020] It should be appreciated that the PUR adhesive in the tube 208 will be solid, semisolid or a very viscous fluid at room temperature and must be heated by the dispensing system before it can be used. In one embodiment, the inserted tube 208 of adhesive is heated as the collapsing air through the collapsing air inlet 220 exerts downw ard force on the tube 208 and the cooling air supply from the cooling air inlet 214 provides a cooling across a portion of the tube above the melted portion. The cooling air inlet 214 is disposed along the length of the applicator body 202 in a position that will direct the cooling air across the width of the tube 208, maintaining the adhesive within the tube located at a position adjacent the inlet and above in a solid, semi solid, or highly viscous fluid state.

[0021] As the angled heat conductor 228 conducts heat around the threaded end 232 of the tube, the PUR adhesive at the bottom of the tube 208 is melted so that it may be dispensed. And, as the collapsing air supply continues to exert pressure in a downward manner, tow ard the dispensing port 210, the tube 208 is collapsed from the bottom up, placing additional solid (i.e. cooled) adhesive within the heating zone 236 of the applicator. Using this method, only the adhesive within the heating zone 236 of the applicator is melted, preventing unwanted degradation of the adhesive that may have occurred if it were all melted within the applicator throughout the workday. Moreover, this method also limits the amount of unused adhesive and plastic packaging material to be discarded.

[0022] In one embodiment, the collapsing air exerted in a downward direction against the piston is about 50 psi. while the pressure of the cooling air across the distal end of the tube 208 is about 10 psi. However, it should be understood that any suitable pressure settings may be used, depending on the application and intended use of the applicator.Attorney Docket No. 006641-01197WOe

[0023] This written description sets forth the best mode of carrying out the invention and describes the invention so as to enable a person of ordinary skill in the art to make and use the invention, by presenting examples of the elements recited in the claims. The detailed descriptions of those elements do not impose limitations that are not recited in the claims, either literally or under the doctrine of equivalents.

Claims

Attorney Docket No. 006641-01197WOeWhat is claimed is:

1. An applicator for use with a hot melt adhesive dispensing system, the applicator comprising: an applicator body configured to receive a collapsible tube of adhesive, w herein the applicator body comprises a housing wall defining a receiving cavity capable of housing the collapsible tube, a dispensing port defined within a distal portion of the housing wall, a cooling air inlet formed within a first side portion of the housing wall, and a cooling air outlet formed through a second side portion of the housing wall; wherein the cooling air outlet is disposed at a location within the housing wall that is substantially opposite from the portion of the housing w all through w hich the cooling air inlet is formed; an end cap comprising a collapsing air inlet; a piston configured to be disposed within the receiving cavity7; an angled heat conductor disposed within the dispensing port of the applicator body; and athermal isolator disposed about the angled heat conductor.

2. The applicator of claim 1 , wherein the applicator further comprises a tube plug disposed within the receiving cavity between the piston and the dispensing port.

3. The applicator of claim 1, wherein the applicator further comprises a mounting bracket removably attached to at least a portion of the applicator body.

4. An applicator for use with a hot melt adhesive dispensing system, the applicator comprising: an applicator body configured to receive a collapsible tube of adhesive, wherein the applicator body comprises a housing wall defining a receiving cavity capable of housing the collapsible tube, a dispensing port defined within a distal portion of the housing wall; an end cap comprising a collapsing air inlet;Attorney Docket No. 006641-01197WOe a piston configured to be disposed within the receiving cavity; an angled heat conductor disposed within the dispensing port of the applicator body; and a thermal isolator disposed about the angled heat conductor.

5. The applicator of claim 4, further comprising a cooling air inlet formed within a first side portion of the housing wall, and a cooling air outlet formed through a second side portion of the housing wall; wherein the cooling air outlet is disposed at a location within the housing wall that is substantially opposite from the portion of the housing wall through which the cooling air inlet is formed.

6. The applicator of claim 4, wherein the applicator further comprises a tube plug disposed within the receiving cavity7between the piston and the dispensing port.

7. The applicator of claim 4, wherein the applicator further comprises a mounting bracket removably attached to at least a portion of the applicator body.

8. An applicator for use with a hot melt adhesive dispensing system, the applicator comprising: an applicator body configured to receive a collapsible tube of adhesive, wherein the applicator body comprises a housing wall defining a receiving cavity capable of housing the collapsible tube, a dispensing port defined within a distal portion of the housing wall, a cooling air inlet formed within a first side portion of the housing wall, and a cooling air outlet formed through a second side portion of the housing wall; wherein the cooling air outlet is disposed at a location within the housing wall that is substantially opposite from the portion of the housing wall through which the cooling air inlet is formed; an angled heat conductor disposed within the dispensing port of the applicator body; and a thermal isolator disposed about the angled heat conductor.Attorney Docket No. 006641-01197WOe9. The applicator of claim 8, wherein the applicator further comprises an end cap comprising a collapsing air inlet and a piston configured to be disposed within the receiving cavity.

10. The applicator of claim 8, wherein the applicator further comprises a tube plug disposed within the receiving cavity between the piston and the dispensing port.

11. The applicator of claim 8, wherein the applicator further comprises a mounting bracket removably attached to at least a portion of the applicator body.

12. A method of dispensing hot melt adhesive material, the method comprising: providing an applicator comprising: an applicator body configured to receive a collapsible tube of solid adhesive, wherein the applicator body comprises a housing wall defining a receiving cavity capable of housing the collapsible tube, a dispensing port defined within a distal portion of the housing wall; an end cap comprising a collapsing air inlet; a piston configured to be disposed within the receiving cavity; and an angled heat conductor disposed within the dispensing port of the applicator body; inserting the collapsible tube containing an amount of adhesive into the receiving cavity of the applicator body; melting at least a portion of the solid adhesive within the collapsible tube; and exerting an amount of collapsing air through the collapsing air inlet.

13. The method of claim 12. wherein the applicator further comprises: a cooling air inlet formed within a first side portion of the housing wall, and a cooling air outlet formed through a second side portion of the housing wall; wherein the cooling air outlet is disposed at a location within the housing wall that is substantiallyAttorney Docket No. 006641-01197WOe opposite from the portion of the housing wall through which the cooling air inlet is formed; and a thermal isolator disposed about the angled heat conductor.

14. The method of claim 13, wherein the method further comprises providing a flow of cooling air through the cooling air inlet.

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