Method and system for integrating additive to substrates

Abstract

A system and method for integrating an additive onto a substrate to alter characteristics of the substrate includes a roller for impregnating or integrating the additive into the substrate; and a heating element for applying heat and improving adhesion of the additive to the substrate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 328,481, filed on April 7, 2022, entitled “METHOD AND SYSTEM FOR INTEGRATING AN ADDITIVE TO A SUBSTRATE,” the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a method and system for integrating additives into a substrate that may be included in a bandage suitable for wound care. Background Art

[0004] Bandages comprising absorbent materials can be embedded in porous substrates and are generally used to cover wounds when wounds heal. In embodiments, bandages may include other materials that may not have holes, such as skin contact layers. Bandages may also be used as preventive measures for preventing the formation of ulcers or wounds. Bandages may be used in conjunction with drugs or other substances for adjuvant therapy, yet this substance is usually directly applied to the user's skin and covered by a bandage. This application may affect how the bandage adheres to the skin, and may provide uneven material application on the wound. In addition, the bandage may be or may become contaminated by microorganisms, thereby possibly increasing the risk of the wound covered by the bandage being contaminated. In addition, too much moisture in the wound can delay wound healing, thereby possibly causing excessive scarring, maceration and inflammation at the wound.

[0005] It would therefore be beneficial to provide a substrate for use in bandages that avoids these and other problems. Summary of the invention

[0006] It is an object of the present disclosure to provide a method and system for integrating an additive into a substrate, which may be part of a bandage or wound dressing used to treat a wound, wherein the additive may aid in wound healing or protection.

[0007] A system for integrating an additive into a substrate comprises: a dispensing element configured to hold a first amount of the additive; an applicator operably connected to the dispensing element to receive the additive and apply the additive to the substrate; and a conveyor operable to advance the substrate beneath the applicator, wherein the additive is applied to the substrate by the applicator so that the additive is integrated into the substrate.

[0008] In embodiments, the additive is a powder.

[0009] In an embodiment, the applicator is a roller, the roller being positioned in contact with the substrate such that the roller presses the additive into the substrate.

[0010] In embodiments, the additive includes a binder such that the additive remains integrated into the substrate.

[0011] In embodiments, the substrate includes a binder configured to retain the additive in the substrate.

[0012] In embodiments, the additive is electrostatically charged.

[0013] In an embodiment, the system includes: a first electrode positioned above the substrate; and a second electrode positioned below the substrate, wherein an AC electric field is established across the substrate between the first electrode and the second electrode to drive the additive through the substrate.

[0014] In an embodiment, the first electrode is disposed on a roller.

[0015] In an embodiment, the first electrode is the roller.

[0016] In embodiments, distribution of the additive across the substrate is dependent upon a voltage set across the AC electric field between the first electrode and the second electrode.

[0017] In an embodiment, the additive is one of a liquid and a semi-liquid.

[0018] In embodiments, the applicator is positioned above the substrate, wherein a gap is provided between the applicator and the substrate to allow a layer of the additive to be disposed on the substrate.

[0019] In embodiments, the heating element is configured to receive the substrate after the additive is integrated into the substrate to heat the substrate and the additive, wherein the additive at least partially melts to improve adhesion to the substrate.

[0020] In embodiments, the heating element heats the additive to activate one or more properties thereof.

[0021] A method of integrating an additive into a substrate includes providing the additive to a dispensing element; advancing the substrate under an applicator operably connected to the dispensing element; and applying the additive to the substrate as the substrate passes under the applicator such that the additive is integrated into the substrate.

[0022] In embodiments, the additive is a powder.

[0023] In embodiments, the method may include electrostatically charging the powder additive.

[0024] In embodiments, the step of applying the additive comprises applying an AC voltage across the depth of the substrate, wherein varying the AC voltage varies the distribution of the additive through the depth of the substrate.

[0025] In embodiments, the method includes, after the step of applying the additive, applying heat to the substrate and the additive to at least partially melt the additive and improve adhesion to the substrate.

[0026] In embodiments, the step of applying heat to the substrate and the additive activates a property of the additive.

[0027] In an embodiment, the additive is one of a liquid and a semi-liquid.

[0028] In embodiments, the step of applying the additive comprises applying a layer of the additive to the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and related objects, features and advantages of the present disclosure will be more fully understood by referring to the following detailed description of preferred but exemplary embodiments of the present invention when taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 illustrates a schematic representation of a system for integrating an additive into a substrate according to an exemplary embodiment of the present disclosure;

[0031] Figure 1A illustrates a more detailed view of the contact between a roller of a system and a substrate onto which an additive is to be integrated, according to an exemplary embodiment of the present disclosure;

[0032] Figure 1B The exemplary embodiment according to the present disclosure is illustrated Figure 1 A more detailed view of the heating portion of the system;

[0033] Figure 2 illustrates an exemplary flow chart illustrating exemplary steps for integrating an additive into a substrate according to an exemplary embodiment of the present disclosure; and

[0034] FIG. 3A to FIG. 3E Cross-sectional views of substrates illustrating various distributions of additives through the substrate are illustrated. DETAILED DESCRIPTION

[0035] Figure 1, a system 10 according to an embodiment of the present disclosure is illustrated. In an embodiment, the system 10 can be used to integrate the additive 2 into the substrate 1. In an embodiment, the system 10 may include a roller 4 or other applicator, which is positioned so that the substrate 1 passes underneath it. In an embodiment, the additive 2 is integrated into or impregnated into the substrate 1 via the system 10. In an embodiment, the substrate 1 can be a porous material, and can be a bandage or wound dressing suitable for wound care, or can be a part of the bandage or wound dressing. In an embodiment, the porous substrate 1 can be any material used for wound care. In an embodiment, the porous substrate 1 can be made of one or more absorbent materials, such as medical grade polyurethane foam, superabsorbent fibers, superabsorbent polymers, hydrocolloids, carboxymethyl cellulose, alginate, spunbond polypropylene or meltblown polypropylene, etc.

[0036] In an embodiment, the substrate 1 may be a non-porous material and may be part of a bandage or wound dressing suitable for wound care. In an embodiment, the non-porous substrate 1 may be any material used for wound care, including a skin contact layer of a bandage or dressing. In an embodiment, the non-porous substrate 1 may be made of one or more materials such as a pressure-sensitive adhesive, a polyurethane film, or a silicone.

[0037] In an embodiment, the additive 2 may be provided in powder form. In an embodiment, the additive 2 may be applied to the substrate via a roller 4 or other applicator. In an embodiment, the powder-based additive 2 modifies the substrate 1 to provide characteristics or properties that are beneficial to the manufacturing process of the medical dressing, and / or to provide properties that improve the overall performance and / or safety of the substrate 1 when used as a component in a medical dressing. In an embodiment, such characteristics or properties modified by the powder-based additive 2 may include surface tension, wettability, absorption capacity, adhesive properties, protein adsorption, antibacterial activity, antifungal activity, and antiviral activity, etc. In an embodiment, the powder-based additive 2 may include one or more additives, such as any of the additives discussed above, as well as any of antibacterial agents, emollients, wound cleansers, extracellular matrix (ECM) components (e.g., collagen), thermoplastic polymers, thermosetting polymers, and any other additives that may prove beneficial to wound healing therapy.

[0038] In an embodiment, the binder, adhesive or binder system may be added to the substrate 1 and / or the powder-based additive 2 before applying the additive to the substrate. In an embodiment, the binder, adhesive or binder system may be part of the additive 2, i.e. mixed with the additive.

[0039] In an embodiment, the substrate 1 may be pre-treated with an adhesive or binder. In an embodiment, adding an adhesive, binder or binder system to an additive 2 or substrate 1 after the additive or substrate has been integrated or impregnated into its material improves the attachment / anchoring of the additive to the substrate. In an embodiment, this prevents the additive from leaching or migrating out of the dressing and into the wound during use.

[0040] While system 10 is preferably used to provide additives 2 to a substrate 1 for use in a bandage or other wound dressing, system 10 may be used to integrate additives into substrates for other applications.

[0041] In embodiments, the additive 2 may be a liquid or semi-liquid (i.e., a viscous liquid / gel). In embodiments where the additive 2 is a liquid or semi-liquid, the electrostatic powder impregnation process discussed below for applying and dispensing the additive to the substrate is generally disadvantageous. In embodiments where a liquid or semi-liquid additive 2 is used, a stamping method may be used to apply the additive to the substrate. In embodiments where a liquid or semi-liquid additive is used, the additive may be applied as a thin film of liquid / gel that is absorbed into the bulk material of the substrate or onto the material surface of the substrate.

[0042] In an embodiment, the powder additive 2 can be provided to a dispensing element 3, such as a hopper or other suitable structure, so that the additive is substantially evenly applied over the length of a roller 4 or other applicator. In an embodiment, the powder additive 2 drips from the dispensing element 3 onto the roller 4 and, when the roller contacts the substrate 1, is pressed into the substrate 2 by the additive, as is typically done in a Figure 1A In embodiments where a liquid or semi-liquid additive 2 is used, a small gap may be provided between the roller 4 and the substrate 1 to allow the liquid / gel film to be stamped or applied to the substrate. In embodiments, no gap may be provided. In embodiments, the size of the gap may be adjustable.

[0043] In an embodiment, an AC electric field may be applied across either side of the porous substrate 1, perpendicular to the direction of travel of the substrate through the system 10. In an embodiment, the substrate 1 may travel on a conveyor system below the roller 4. In an embodiment, the conveyor system may include a first spindle S1 and a second spindle S2 positioned on opposite sides of the system 10. Spindle S1 pushes the substrate 1 into the system 10, and spindle S2 pulls the substrate with the additive 2 integrated or impregnated therein through the roller 4 and out of the system 100. In an embodiment, the AC electric field may also drive the powder-based additive 2 across the entire thickness of the porous substrate 1. In an embodiment, the AC electric field may be used to evenly distribute the powder-based additive 2 across the entire thickness of the porous substrate 1 and / or to create a controlled concentration gradient of the powder-based additive 2 across the thickness of the porous substrate 1. In an embodiment, the particles of the additive 2 may be charged. In an embodiment, the dry powder additive 2 may be provided in a high voltage alternating electric field to charge the additive particles. In embodiments, the charge may be formed on the powder additive 2 by friction (e.g., based on the triboelectric effect, tribocharging, or tribocharging). In embodiments, tribocharging of the particles may occur when the powder is transferred from a reservoir to a spray gun, coater, or other applicator (such as a roller 4).

[0044] In embodiments, the electrostatic charge on the powdered additive 2 can be used to: (1) attract the powdered additive 2 to the substrate 1 (as long as the substrate exhibits an opposite charge); (2) prevent the powdered additive from agglomerating in or on the substrate because the particles of the additive 2 have the same charge and therefore repel each other; and (3) allow the use of a controllable high voltage alternating electric field provided by electrodes placed on either side of the substrate 1 to drive the charged particles to different depths into the substrate material to achieve uniformity. In embodiments using a liquid or gel additive 2, the additive is typically uncharged.

[0045] In an embodiment, an AC electric field may be applied across the substrate 1 using two or more electrodes arranged on either side of the porous substrate. In an embodiment, the roller 4 may be used as an electrode, or may include an electrode, and another electrode 5 may be positioned on the other side of the substrate 1. In an embodiment, the strength of the AC electric field may be adjusted to control the distance over which the powder-based additive 2 is distributed across the thickness of the substrate 1. In addition, in an embodiment, the AC electric field may be adjusted to control the concentration gradient of the powder-based additive 2 across the thickness of the porous substrate 1. In an embodiment, the voltage of the AC electric field and the duration of applying the electric field to the substrate 1 will determine the distribution of the powder-based additive 2 across the substrate. In an embodiment, when the substrate 1 passes through the high voltage electric field, the electric field will cause the charged powder-based additive 2 to migrate downward from the top surface of the porous substrate to which it was initially applied toward the bottom surface of the substrate. In an embodiment, the stronger (higher) the voltage, the more powder-based additives are sucked into the porous substrate 1 and the farther they penetrate. In an embodiment, the longer the electric field is applied, the deeper the powder-based additives penetrate into the porous substrate. In an embodiment, the voltage of the AC electric field can be between 0.1 kV and 50 kV, however, other voltages can be used. In an embodiment, the voltage and time of exposure to the electric field can vary based on the following factors: (1) the porosity of the substrate material, (2) the grain size of the powder additive, (3) the electrostatic charge of the powder additive, and (4) the desired depth of penetration of the powder additive into the material. In an embodiment, substrate porosity, small powder additive grain size, high electrostatic charge retention on the powder additive, and shallow desired penetration depth are all properties that are conducive to lower AC electric field voltages and / or exposure times. In an embodiment where substrate 1 is a non-porous material, particles of additive 2 will typically remain on the surface of the substrate.

[0046] In an implementation scheme, FIG. 3A to FIG. 3E The particles of the additive 2 are shown to penetrate into the porous substrate 1. Figure 3A In the process, particles of additive 2 are applied to the surface of substrate 1. Figure 3B In the process, the particles begin to penetrate downward into the substrate 1 and FIG. 3C to FIG. 3D Continue to penetrate downward. Figure 3E In the embodiment of the present invention, the particles of the additive are completely integrated into the substrate 1 .

[0047] In an embodiment, some additives (e.g., fine metal powders such as silver / nanosilver) may not retain a charge because they are conductive, making it difficult or ineffective to integrate or impregnate electrostatic powders into a substrate. In an embodiment, an alternative approach is to compound such conductive additives into a polymer carrier and then granulate the polymer to apply to the substrate 1. In an embodiment, the pellets of the polymer may be ground into a fine powder, which may then be applied as a powder to the substrate 1 using electrostatic powder impregnation as discussed herein. In an embodiment, the polymer powder carrier may retain an electrostatic charge and be impregnated into / on a porous substrate using an AC electric field as may be discussed below. In an embodiment using a low melting point polymer such as PE, applying some heat may melt the polymer to the surface of the substrate, thereby improving the adhesion of the additive 2 to the substrate.

[0048] In an embodiment, the powder-based additive 2 adheres to the substrate 1 by electrostatic forces or with the aid of an adhesive or binder system added to the substrate 1 or the powder-based additive 2 before the additive is integrated into the substrate. In an embodiment, a tubular electrode arranged parallel to the substrate can be used to provide an electrostatic charge on the powder additive 2 as the substrate travels. In an embodiment, the roller 4 or other application can be made of a conductive material and deposit the additive on the substrate. In an embodiment, a monopolar output is used to connect the electrode to a high voltage electrostatic generator, and the roller or applicator is grounded to serve as a counter electrode.

[0049] In an embodiment, several electrodes arranged on both sides of the substrate material 1 may be used to provide the electrostatic charge. The additive 1 may be pre-dispensed on the substrate 1. The unipolar output is used to connect the bias electrode to a high voltage electrostatic generator, while the electrode on the opposite side of the substrate 1 is grounded and used as a counter electrode.

[0050] In embodiments, after the additive 2 is added to the substrate 1, a post-impregnation / coating process may improve the adhesion and / or distribution of the powder-based additive 2 to the substrate 1. In embodiments, as described above, an AC electric field may be applied to drive particles of the additive 2 into the substrate and / or provide a desired particle distribution throughout the thickness of the substrate. In embodiments, the substrate 1 may be heated to melt the powder-based additive 2 and / or an adhesive / binder system that is added to the substrate 1 or the powder-based additive 2 between coatings to improve the adhesion / bonding of the powder-based additive 2 to the substrate 1. Additionally, this annealing step may be used to produce a uniform layer of the additive 2 covering the exposed surface areas of the substrate 1, thereby producing a core-shell coating 2A that may be used to alter the characteristics or properties exhibited by the substrate 1 (e.g., see Figure 2 B), as discussed above. The heating process can be carried out, for example, in Figure 1B100, through which the substrate 1 passes after the additive has been added via the rollers 4. After heating, the impregnated substrate 7 including the new properties provided by the additive 2 can be removed from the system 100.

[0051] In embodiments, the temperature used in the heating process may depend on the purpose of the treatment and the materials involved. In embodiments, for treating a substrate 1 with a powder-based additive 2, the temperature used in the process may depend on the melting point or activation temperature of the materials used in the adhesive or binder system and the tolerances of the substrate materials of the additive 2 and the substrate 1. In embodiments, the heating process may use a temperature range of 50°C to 200°C. In embodiments, when applying a liquid / gel-based additive, the heating process may be used to drive off solvents. In embodiments, the temperature used for this process may depend on the solvent and may be below 120°C.

[0052] Figure 2 An exemplary flow chart is illustrated that illustrates steps that may be used to integrate an additive 2 into a substrate 1 using the system 10 discussed above. In an embodiment, in step S100, for example, a substrate 1 may be provided to the system 10. As described above, the substrate may be positioned on a conveyor system, such as including spindles S1 and S2, and passed through the system 10. At step S102, an additive may be provided to the system. As described above, in an embodiment, the additive 2 may be loaded into a dispenser element 3. In step S104, the additive is applied to the substrate. As described above, in an embodiment, the additive 2 may be dripped onto a roller 4, and as the substrate passes under the roller 4, the roller may contact the substrate 1 and integrate or impregnate the substrate, such as Figure 1A As shown. In an embodiment, in step S106, an AC electric field may be applied across the substrate 1 to distribute the additive 2 across the substrate and / or distribute the additive into the substrate. In an embodiment, two or more electrodes may be used to apply the AC electric field, and the roller 4 may be or may include an electrode. In an embodiment, step S106 is optional. In an embodiment, at step S108, the substrate 1 including the impregnated additive 2 may be heat treated, for example, via a heating element 6, to improve the adhesion of the additive 2 to the substrate 1, thereby activating one or more properties of the additive and / or driving the solvent out of the additive. In step S110, the impregnated and treated substrate 7 including the integrated additive may be removed from the system 10, for example, via the spindle S2.

[0053] The methods and systems of the present disclosure provide numerous advantages, including: (1) development of cost-effective materials that exhibit properties beneficial for effective wound treatment, and (2) modulation / modulation of material properties where it matters most: i.e., the wound contact surface.

[0054] Although the invention has been described with respect to specific embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is therefore preferred that the invention not be limited by the specific disclosure herein.

Claims

1. A system for integrating an additive into a substrate, the system comprising: a dispensing element configured to hold a first amount of the additive; an applicator operably connected to the dispensing element to receive the additive and apply the additive to the substrate; and a conveyor operable to advance the substrate beneath the applicator, The additive is applied to the substrate by the applicator so that the additive is integrated into the substrate.

2. The system of claim 1, wherein the additive is a powder.

3. The system of claim 2, wherein the applicator is a roller positioned to contact the substrate such that the roller presses the additive into the substrate.

4. The system of claim 3, wherein the additive comprises a binder such that the additive remains integrated into the substrate.

5. The system of claim 3, wherein the substrate comprises an adhesive, the binder being configured to retain the additive in the substrate.

6. The system of claim 2, wherein the additive is electrostatically charged.

7. The system according to claim 6, further comprising: a first electrode positioned above the substrate; and a second electrode positioned below the substrate; An AC electric field is established across the substrate between the first electrode and the second electrode to drive the additive through the substrate.

8. The system of claim 7, wherein the first electrode is disposed on the roller.

9. The system of claim 7, wherein the first electrode is the roller.

10. The system of claim 7, wherein distribution of the additive across the substrate is dependent upon the AC voltage field applied between the first electrode and the second electrode.

11. The system of claim 1, wherein the additive is one of a liquid and a semi-liquid.

12. The system of claim 11, wherein the applicator is positioned above the substrate, wherein a gap is provided between the applicator and the substrate to allow a layer of the additive to be disposed on the substrate.

13. The system of claim 1, further comprising a heating element configured to receive the substrate after integrating the additive into the substrate to heat the substrate and the additive, wherein the additive at least partially melts to improve adhesion to the substrate.

14. The system of claim 13, wherein the heating element heats the additive to activate one or more properties thereof.

15. A method of integrating an additive into a substrate, the method comprising: providing the additive to a dispensing element; advancing the substrate beneath an applicator, the applicator being operably connected to the dispensing member; as well as The additive is applied to the substrate as the substrate passes beneath the applicator, such that the additive is integrated into the substrate.

16. The method of claim 15, wherein the additive is a powder.

17. The method according to claim 16, further comprising: The powder additive is electrostatically charged.

18. The method of claim 17, wherein the step of applying the additive comprises applying an AC voltage across a depth of the substrate, wherein varying the AC voltage varies the distribution of the additive through the depth of the substrate.

19. The method of claim 18, further comprising, after the step of applying the additive, applying heat to the substrate and the additive to at least partially melt the additive and improve adhesion to the substrate.

20. The method of claim 19, wherein the step of applying heat to the substrate and the additive activates a property of the additive.

21. The method of claim 15, wherein the additive is one of a liquid and a semi-liquid.

22. The method of claim 21, wherein the step of applying the additive comprises applying a layer of the additive to the substrate.

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