Patent Application
20230081069
The subject matter disclosed herein relates to systems and methods for high throughput printing of pressure sensitive adhesive.
Pressure sensitive adhesives (PSA) are adhesives that can be adhered to a surface and yet can be removed from the surface without transferring more than trace quantities of adhesive to the surface, and can be readhered to the same or another surface because the adhesive retains some or all of its tack and adhesive strength. PSA has a variety of uses. For example, various articles in the medical industry may utilize PSA (e.g., medical sensors, printed circuits, etc.).
PSA may be produced (e.g., printed) on substrates via screen printing techniques. However, current screen printing techniques for PSA are difficult to implement and present a number of challenges. For example, the solvent utilized in the PSA presents environmental health and safety (EHS) concerns. The solvent has extremely strong odors that may cause operators nausea and headaches. In addition, the solvent changes its behavior (e.g., becomes thicker) during the printing process due to solvent evaporation affecting the printing quality. Solvent evaporation also causes PSA to build up on the screen which leads to scrapping of material and having to clean the screen often. Further, the cleaning of the stencil utilized in printing requires the same solvents, thus, raising the same EHS concerns. Even further, after screen printing, air bubbles may form due to these materials which may require letting the printing parts sit to reduce air bubbles. Therefore, there is a need for an alternative method to apply this material that reduces EHS concerns and scrapping of material while improving production continuity.
Certain embodiments commensurate in scope with the originally claimed subject matter are summarized below. These embodiments are not intended to limit the scope of the claimed subject matter, but rather these embodiments are intended only to provide a brief summary of possible embodiments. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below.
In one embodiment, a system for printing PSA on a substrate is provided. The system includes a rigid support structure. The system also includes a plurality of dispensing heads disposed within the rigid support structure and configured to deposit PSA solution on the substrate in response to applied pressure. Each dispensing head of the plurality of dispensing heads includes a support structure and a wicking structure disposed within the support structure and configured to hold the PSA solution in place, wherein the wicking structure is configured to deposit the PSA solution in a desired shape on the substrate upon contact with the substrate.
In another embodiment, a method for printing PSA on a substrate is provided. The method includes flowing a PSA solution into a plurality of dispensing heads disposed within a rigid support structure, wherein each dispensing head of the plurality of dispensing heads is configured to deposit the PSA solution on the substrate in response to applied pressure and each dispensing head includes a support structure and a wicking structure disposed within the support structure to hold the PSA solution. The method also includes positioning the rigid support structure on the substrate with sufficient pressure to cause the PSA solution to be deposited in a desired shape on the substrate from each dispensing head upon contact with the substrate.
In a further embodiment, a system for printing PSA on a substrate is provided. The system includes a rigid support structure having a handle. The system also includes a robotic system coupled to the rigid support structure via the handle, wherein the robotic system is configured to move the rigid support structure to a desired position for depositing PSA solution on the substrate and to apply pressure to the rigid support structure for depositing the PSA solution. The system further includes a plurality of dispensing heads disposed within the rigid support structure and configured to deposit the PSA solution on the substrate in response to applied pressure, wherein each dispensing head of the plurality of dispensing heads includes a feed conduit. The system even further includes a programmed feeding system coupled to a respective feed conduit of each dispensing head, wherein the programmed feeding system is configured to provide the PSA solution to each respective feed conduit for deposition of the PSA solution.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present subject matter, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Furthermore, any numerical examples in the following discussion are intended to be non-limiting, and thus additional numerical values, ranges, and percentages are within the scope of the disclosed embodiments.
The present disclosure provides systems and methods for dispensing PSA (e.g., liquid PSA) onto a flat substrate. In particular, a dispensing system includes a dispensing tool including a rigid support structure having a plurality of dispensing heads that will dispense or deposit PSA solution onto to flat substrate when pressure is applied. A programmable closed feeding system is coupled to the dispensing heads. In addition, a robotic handling/positioning system is coupled to the rigid support structure that controls movement/positioning of the rigid support structure and associated dispensing heads during the printing of the PSA onto the substrate. The dispensing system is easily automated via the programmable closed feeding system and the robotic handling/positioning system to enable large scale or high throughput production. Each dispensing head includes a support structure and a wicking structure (e.g., porous membrane or sponge) disposed within the support structure. The wicking structure enables the holding of the PSA solution in place without dripping when uncapped. When not being utilized, the dispensing heads may be capped to keep solvent from evaporating. The wicking structure enables the PSA to be deposited in desired shape upon instantaneous contact with the substrate (e.g., via a stamping action) without the need of PSA solution being continuously provided to the wicking structure for dispensing the PSA. The dispensing system functions similar to a screen printing system and a needle dispensing system without their associated drawbacks (e.g., cost, maintenance, throughput level, etc.). The dispensing system as configured minimizes solvent evaporation (as well as EHS concerns) and material consumption or scrapping. In addition, the dispensing system reduces production cycle time.
The dispensing system 10 includes a dispensing tool 11 that includes a rigid support structure 12 (defined with one or more walls). The rigid support structure 12 includes a plurality of dispensing heads 14 disposed within the rigid support structure 12 for dispensing or depositing PSA solution onto the substrate in response to applied pressure. The number of dispensing heads 14 within the rigid support structure 12 could range from 2 to 100 or more dispensing heads 14. In certain embodiments, the dispensing system 10 may include more than one rigid support structure 12 with respective dispensing heads 14.
As described in greater detail below, each dispensing head 14 includes a support structure (e.g., defined by walls of the rigid support structure and/or other walls) and a wicking structure disposed within the support structure. The wicking structure may be a porous membrane or sponge. The wicking structure holds the PSA solution in place without dripping when the dispensing head 14 is uncapped. In particular, the wicking structure holds the PSA solution in place (e.g., due to the viscosity of the PSA solution) unless pressure is applied. The wicking structure may include controlled pore sizes to control liquid flow. In certain embodiments, an end of the dispensing head 14 adjacent the wicking structure may be open to enable direct contact between the wicking structure and substrate for dispensing the PSA solution onto the substrate. The wicking structure enables the PSA to be deposited in desired shape upon instantaneous contact with the substrate (e.g., via a stamping action) without the need of PSA solution being continuously provided to the wicking structure for dispensing the PSA. In certain embodiments, the end of the dispensing head 14 adjacent the wicking layer may be covered with a porous layer including pores or holes for dispensing the PSA solution onto the substrate in a controlled manner with a controlled volume (e.g., similar to needle dispensing) in a desired pattern. In certain embodiments, the end of the dispensing head 14 adjacent the wicking structure, a portion of a porous layer adjacent the wicking layer, and/or the wicking structure is similar in shape to the shape of the printed PSA.
In certain embodiments, when the dispensing heads 14 are not being utilized to print PSA, each end of the dispensing head 14 adjacent the wicking structure is capped with a cap or cover to keep the PSA solution from drying up. The capping of the dispensing heads reduces solvent loss to due solvent evaporation and, thus, also reduces EHS concerns.
In certain embodiments, each dispensing head 14 includes a feed conduit for receiving PSA solution within the dispensing head 14 (which then flows to the wicking structure). The dispensing system 10 includes a feeding system 16 (e.g., closed feeding system) coupled to each respective feed conduit of the dispensing heads 14. The feeding system 16 is programmable. Indeed, the feeding system 16 is coupled to a controller 18 that controls the operation of the feeding system 16 and the flow of the PSA solution to the dispensing heads 14. In certain embodiments, the feeding system 16 may provide PSA solution to the dispensing heads 14 during operation. The feeding system 16 includes one or more cartridges 20 that are coupled to respective feed conduits of the dispensing heads 14. The feeding system 16 also includes a pump 22 (e.g., motor driven pump) that facilitates the flow of PSA solution from a PSA supply or reservoir 24 to the cartridges 20 and then to the dispensing heads 14 (via the feed conduits). The closed feeding system 16 reduces solvent loss (e.g., due to solvent evaporation) compared to an open system utilized in screen printing (which increases a viscosity of the PSA solution leading to production consistency issues) and, thus, also reduces EHS concerns. The closed feeding system 16 also reduces material consumption (as well as the material lost due to scrapping) compared to screen printing. The configuration of the dispensing system 10 (including the closed feeding system 16) minimizes air bubbles (e.g., compared to screen printing) and, thus, avoids having to let the dispensing sit resulting in a reduced production cycle time (e.g., compared to screen printing).
In certain embodiments, the rigid support structure 12 includes a handle enabling the movement or positioning (e.g., via manual or robotic handling) of the rigid support structure 12 for printing PSA on the substrate. As depicted in
In certain embodiments, the rigid support structure 14 includes one or more pressure sensors 28 (e.g., strain gauges, MEMS based sensors, variable capacitance pressure sensors, etc.) disposed within. The number of pressure sensors 28 may be 1, 2, 3, 4, or more. The one or more sensors 28 are coupled to the controller 18. The sensors 28 provide feedback to the controller 18 regarding the pressure applied between the rigid support structure 14 and the substrate. Based on the feedback from the sensors 28, the controller 18 monitors and controls the pressure applied between the rigid support structure 14 and the substrate.
The controller 18 includes a processor 30 and a memory 32 (e.g., a non-transitory computer-readable medium/memory circuitry) communicatively coupled to the processor 30, storing one or more sets of instructions (e.g., processor-executable instructions) implemented to perform operations related to the dispensing system 10 (e.g., operations of the feeding system 16, the robotic handling/positioning system 26, etc.). More specifically, the memory 32 may include volatile memory, such as random-access memory (RAM), and/or non-volatile memory, such as read-only memory (ROM), optical drives, hard disc drives, or solid-state drives. Additionally, the processor 30 may include one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more general purpose processors, or any combination thereof. Furthermore, the term “processor” is not limited to just those integrated circuits referred to in the art as processors, but broadly refers to computers, processors, microcontrollers, microcomputers, programmable logic controllers, application specific integrated circuits, and other programmable circuits. The dispensing system 10 may include a single controller to control the various systems of the dispensing system 10. In certain embodiments, each system (e.g., the feeding system 16, the robotic handling/positioning system 26, etc.) of the dispensing system 10 may include a separate controller. The dispensing system 10 is easily automated through the programmable feeding system 16 and the robotic handling/positioning system 26 to enable the large scale production/printing of the PSA on the substrate.
As depicted, the dispensing tool 11 includes a handle 40 coupled to the top surface 36 of the rigid support structure 12. The handle 40 enables the movement or positioning (e.g., via manual or robotic handling) of the dispensing tool 11 (and, thus, the rigid support structure 12) for printing PSA on the substrate. A robotic handling/positioning system (e.g., robotic handling/positioning system 26 in
When the dispensing head 14 is not being utilized to print PSA, the second end 50 of the dispensing head 14 adjacent the wicking structure 54 is capped with a cap or cover 56 to keep the PSA solution from drying up as indicated by arrow 58. The capping of the dispensing head 14 reduces solvent loss to due solvent evaporation and, thus, also reduces EHS concerns.
The dispensing head 14 also includes a feed conduit 59 for receiving PSA solution within the dispensing head 14 (which then flows to the wicking structure 54). A feeding system (e.g., closed feeding system 16 in
Dispensing head 88 in
The method 106 also includes flowing a PSA solution into the dispensing heads (block 110). For example, PSA solution may be provided via a programmable closed feeding system (as described above in
The method 106 further includes positioning the dispensing tool (e.g., the rigid support structure) relative to the substrate for printing PSA (block 112). The method 106 even further includes, once the dispensing tool is properly positioned, applying pressure on the rigid support structure to dispense or dispose (e.g., via stamping) the PSA solution onto the substrate upon instantaneous contact with the substrate (block 114). The handling/positioning and application of pressure on the dispensing tool may be handled by a robotic handling/positioning system (e.g., robotic handling/positioning system 26 in
In certain embodiments, the method 106 includes monitoring the applied pressure on the dispensing tool (block 116). The dispensing tool may include one or more pressure sensors disposed within the rigid support structure that provide feedback to a controller as to an amount of pressure applied on the dispensing tool during the stamping operation. The method 106 may also include, when needed, altering the applied pressure on the dispensing tool based on the feedback received from the pressure sensors (block 118). Thus, the monitoring of the applied pressure enables the regulation of the applied pressure.
Upon completing the stamping operation, the method 106 includes stopping the flow of PSA solution to the dispensing heads (block 120). In certain embodiments, when the dispensing heads may not be utilized within a given time, the method 106 includes capping or recapping the dispensing heads with their respective or covers to avoid solvent evaporation (block 122).
Technical effects of the disclosed embodiments include providing a dispensing system that is easily automated via a programmable closed feeding system and a robotic handling/positioning system to enable large scale or high throughput production. In addition, the disclosed dispensing system enables easier cleaning compared to other PSA production techniques. Further, the disclosed dispensing system minimizes solvent evaporation and its associated EHS concerns. The disclosed dispensing system also minimizes material consumption or scrapping. In addition, the disclosed dispensing system reduces production cycle time (e.g., by minimizing introduction of air bubbles into the system. The disclosed dispensing system functions similar to a screen printing system and a needle dispensing system without their associated drawbacks (e.g., cost, maintenance, throughput level, etc.).
The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function]...” or “step for [perform]ing [a function]...”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).
This written description uses examples to disclose the present subject matter, including the best mode, and also to enable any person skilled in the art to practice the subject matter, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
