JP2005518959A - Hearing aid shell manufacturing method using photocuring device and curable resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: The apparatus of the inventive subject matter is particularly advantageous in the process of manufacturing a hearing aid shell, but can also be used in other light curing applications.
An apparatus is provided having a radiation curing chamber and at least one tubular gas diffuser for introducing an inert gas (eg, argon) into the curing chamber at multiple locations. The introduction of inert gas limits the contact of any resin that is cured in the chamber with oxygen by radiation curing such as UV curing. The introduction at multiple locations has the advantage of enabling a more complete inert gas coating within the curing chamber and thus reducing oxygen inhibition than provided in the prior art.

Description

  This invention relates to an apparatus and method for curing a photocurable resin, and more particularly to curing a photocurable resin in the formation of a hearing aid shell.

  Custom hearing aids have been developed by shaping the shell to match the human ear canal. In the prior art, a method for producing an investment mold (mold mold) for determining a hole that matches the shape of a human ear canal is known. In order to mold the corresponding hearing aid shell, one method in the prior art requires synthesizing a two-part mixture and then pouring the mixture into an investment mold. The filled mold is placed in a warm water bath, and the heat from the warm water cures the mixture to a limited depth and forms a shell. After a predetermined period, a shell of the desired thickness is formed. Also, the uncured mixture is poured from the shell. However, this scheme is time consuming.

  In addition, it is known to use radiation such as ultraviolet (UV) light to cure certain resins. Therefore, a mold in which a mold filled with resin is placed in a closed room, exposed to ultraviolet rays for a limited time, and the resin is cured to a limited depth to form a shell has been developed. When pouring uncured resin from the shell, a solution such as a water / glycol solution is poured into the emptied shell and the shell is re-entered into the UV device and further irradiated with UV light to completely cure. Certain photocuring compounds (eg, photocuring acrylic molding materials) are susceptible to “oxygen inhibition” when cured while exposed to oxygen—showing poor and / or incomplete curing. The solution in the shell limits the exposure of the inside of the shell to oxygen, resulting in a more complete cure.

  In an alternative approach to avoid oxygen inhibition, the chamber of the photocuring apparatus is equipped with a limited supply of inert gas. By introducing an inert gas, the amount of oxygen in the curing chamber can be reduced. After the shell is formed and the uncured resin is removed from the shell, the empty shell is placed in a curing chamber and an inert gas is introduced and allowed to fully cure. This scheme eliminates the need to introduce a solution into the opening before the shell is fully cured.

  Since the inert gas is introduced into the chamber from a limited point, known photocuring devices have limited dispersion of the inert gas. For example, a curing device sold under the trademark “POLYLUX-2000” by Dreve-Otopplastic GmbH of Unna (Germany) is a hose connected to a nozzle that is distributed and connected in parallel from one wall of the curing chamber. And carbon dioxide is spouted into the chamber in the same direction. Therefore, the detrimental effect of oxygen inhibition is somewhat resolved but not removed.

  In one aspect of the inventive subject matter, the apparatus includes a radiation curing chamber, the curing chamber, and at least one tubular gas for introducing an inert gas (eg, argon) from a plurality of locations into the curing chamber. An apparatus having a diffuser is provided. The introduction of an inert gas limits any resin that cures in the chamber by radiation curing, such as ultraviolet curing, from contacting oxygen. Advantageously, introduction from multiple locations allows more complete entrapment of the inert gas within the curing chamber and thus results in less oxygen inhibition than conventional prior art. Furthermore, less inert gas supplied with known devices is required to avoid oxygen inhibition. The device of the inventive subject matter is particularly suitable for the method of forming a hearing aid shell, but can also be used in other photocuring applications.

  In a second aspect of the subject invention, the inert gas is introduced at locations located along at least two sides of the curing chamber. Therefore, since the gas is introduced from different directions in the chamber, a complete introduction of the inert gas is possible compared to known devices.

  These and other features of the inventive subject matter will be better understood through the following detailed description and review of the accompanying drawings.

  FIG. 1 shows an apparatus 10 for curing a photocurable resin. The device 10 is particularly adapted for curing a photocurable resin in the manufacture of a hearing aid shell.

  The apparatus 10 includes a cabinet housing 12, a control panel 14, and a light curing chamber 16 that is selectively isolated by a movable cover 18. Light curing devices are known and the structure and operation of the cabinet housing 12, control panel 14, curing chamber 16 and cover 18 may be any structure known to those skilled in the art.

  The cabinet housing 12 includes an inert gas (for example, argon) supply port therein, or has a jig (not shown) for connecting the inert gas supply port. The inert gas may be of any type that is stable and does not adversely react with the resin cured in the curing chamber 16. It is desirable that the inert gas be selected to minimize the oxygen inhibition effect during curing, so the inert gas should not contain excessive amounts of oxygen, ideally no oxygen at all. Absent. In order to control the flow of inert gas, conventional valves (not shown) may be used with the control panel 14 and / or external equipment of the cabinet 12 with known controls and equipment.

  As shown particularly in FIGS. 2-5, in the first aspect of the subject invention, a tubular gas diffuser 20 is disposed within the curing chamber 16 for introducing an inert gas into the curing chamber 16. Preferably, the tubular diffuser 20 can coexist on the side wall 22 of the chamber 16 to be cured.

  Tubular diffuser 20 has a tubular body 24 that defines a lumen 26 that extends longitudinally of tubular diffuser 20 (FIG. 5). Tubular diffuser 20 may be connected to an inert gas supply at one or more midpoints and / or at one or both ends via connections in cabinet housing 12. Alternatively, the inert gas may be supplied at one or more midpoints or at one end of the tubular diffuser 20 with the open end plugged or opened and connected to the return system or exhaust. A plurality of ports 28 are formed along the length of the tubular diffuser 20 at intervals to communicate through the curing chamber 16 and the lumen 26. Port 28 may be an orifice (shown in FIG. 5), a nozzle, a diffuser, or a combination thereof. The tubular diffuser 20 may be configured in any way as long as an inert gas can flow to the port 28. In certain preferred arrangements, the ports 28 are spaced (preferably equally spaced) and are formed along the length of the tubular diffuser 20 so that they are generally coextensive with the side wall 22 of the curing chamber 16. An inert gas covering can be formed. The inert gas should be fully pressure controlled when supplied to the tubular diffuser 20 so that a relatively equal amount of inert gas is passed through each of the ports 28.

  The body 24 of the tubular diffuser 20 is shown in a cylindrical shape in FIG. 5, but may be in the form of other cross sections such as an ellipse or an irregular polygon.

  In a second aspect of the inventive subject matter, the plurality of tubular diffusers 20 are at least partially constrained to the curing chamber 16, most preferably entirely constrained to the curing chamber. With this arrangement, the port 28 is located along at least two of the side walls 22 and 30 of the curing chamber 16 so that the inert gas is from at least two different directions via the port 28 located along the side walls 22, 30. It may be introduced into the chamber 16 to be cured. For example, in FIG. 6, the inert gas is introduced in a direction perpendicular to the sidewall 22, and the inert gas is introduced in a direction perpendicular to the sidewall 30. Most desirably, the tubular diffuser 20 is disposed along each side wall of the curing chamber 16. When the inert gas is introduced into the side walls 22 and 30 from positions along a plurality of locations, a plurality of inert gas coatings can be simultaneously introduced into the curing chamber 16. Although turbulence effects may exist, the inert gas is more completely spread throughout all points of the curing chamber as compared to the prior art.

  As an additional variation, one or more tubular diffusers 20 may be in fluid communication, so that inert gas gases are passed directly from one tubular diffuser to the next. As indicated above, sufficient pressure should be provided to exit the inert gas 26 from all ports 28 connected to the tubular diffuser in equal amounts. In this second aspect of the invention, the port 28 may be mounted to the curing chamber 16 in any manner known to those skilled in the art and need not be supported by the tubular diffuser 20. For example, as shown in FIG. 7, the port 28 may be a nozzle or orifice disposed directly on the side walls 22, 30 of the curing chamber in communication with an inert gas supply port. The port 28 may be mounted in any manner that allows inert gas to be introduced into the curing chamber 16 in at least two different directions. For example, the ports 28 are oriented along different directions even though they are arranged along a single wall.

  As shown in FIG. 8, the curing chamber 16 includes a base 32 through which radiation can pass and a radiation source 34 disposed below the base 32 for radiating radiation through the base 32 to the curing chamber 16. Have. In a non-limiting example, the base 32 is glass and the irradiation source 34 is a UV lamp that emits UV energy through the base 32 and into the curing chamber 16. The structure of the base 32 and the irradiation source 34 may be any type known to those skilled in the art. As is readily apparent, the volume of the curing chamber 16 is a direct function of the size of the base 32. It has been found that the base 32 should not be excessively large in order to maximize the effect of the inert gas. In a non-limiting example, the base 32 may be 8 inches x 8 inches.

  Device 10 is used to cure various photocurable resins, but is particularly suitable for the formation of hearing aid shells. FIGS. 9A-9F depict an exemplary method of utilizing the apparatus 10.

  As shown in FIG. 9A, a photocurable resin 100 is synthesized and poured into a mold 102 formed by a known technique. The photocurable resin 100 may be any suitable type known to those skilled in the art, but is preferably an acrylic molding material. Resin 100 can be selected from a variety of materials, such as silicone, polyvinyl, polyurethane, polyester, polyether, acrylic- and methacrylic-type polymers, or combinations thereof. These compositions are typically combined with various colorants, photoinitiators and reactive diluents to adjust the viscosity of the composition. According to conventional methods in the art, the curable composition is a curable prepolymer or oligomer having at least one unsaturated site, which is a derivative of acrylic or alkylacrylic acid, and optionally acrylic or methacrylic acid. Monofunctional or polyfunctional monomers derived from can be included.

Once filled, the mold 102 is placed in the curing chamber 16 and isolated by the cover 18, as shown in FIG. 9B. Radiation, such as ultraviolet light, is emitted into the curing chamber 16 for a limited period of time so that the shell 104 has a limited depth (thickness) that is at least partially cured. As shown in FIG. 9C, the shell 104 conforms to the cavity 106 of the mold 102 and typically has a thickness T of about 0.030 inches. Since the uncured resin shields the shell 104 from the ambient atmosphere, oxygen inhibition is not a significant problem with the first dose of irradiation and there is no need to introduce an inert gas. To mold the shell 104, with a 400 watt metal halide ultraviolet lamp (50 mW / cm ² @ 365 nm), the ultraviolet energy is emitted for approximately 5-20 seconds (depending on the color of the resin 100). After this first dose, the mold 102 is removed from the curing chamber 16 and uncured resin is poured therefrom. As a result, the interior 108 of the shell 104 is open and exposed in the mold 102.

  Thereafter, the mold 102 is returned to the curing chamber 16 as shown in FIG. 9E. In order to fully cure the shell 104, ultraviolet energy is once again applied. Furthermore, with this second irradiation exposure, an inert gas is introduced into the curing chamber 16 in any manner as described above, preferably at least partially simultaneously during the second irradiation administration. The inert gas can be introduced for a period shorter than the period during which the radiation is emitted to the curing chamber 16. Typically, the 400 watt metal halide UV lamp described above emits UV light for a period of 60 seconds to cure the shell 104 completely or substantially completely. The inert gas can be introduced for a period of 25 seconds or more during the second irradiation period of ultraviolet rays. Alternatively, the introduction of inert gas into the curing chamber 16 can begin prior to the second irradiation. As mentioned above, sufficient pressure should be applied to ensure that a proper supply of inert gas is provided. In the case of argon, it is operated at a pressure in the range of 50-100 psi @ 150 SCFH, more preferably 60-100 psi @ 150 SCFH. Once the second radiation exposure step is over, the shell 104 is cured or substantially cured without the detrimental effects of oxygen inhibition. As shown in FIG. 9F, the shell 104 is used in the process of forming a complete hearing aid assembly 110 as is known in the prior art.

  Obviously, many modifications and variations will be apparent to practitioners skilled in this art and, therefore, it is not desired that the present invention be limited to the exact construction and operation shown and described herein. Accordingly, appropriately modified equivalents are within the scope of the claimed invention.

1 is a perspective view of an apparatus for curing a resin utilizing the principles of the inventive subject matter. FIG. It is a perspective view of the upper part of the apparatus of the state which exposed the hardening chamber. FIG. 2 shows the tubular diffuser of the subject invention located along the walls of the curing chamber. FIG. 2 shows the tubular diffuser of the subject invention located along the walls of the curing chamber. It is a cross-sectional view of a tubular diffuser. Figure 3 shows a plurality of tubular diffusers disposed within a curing chamber. The port placed directly on the wall of the curing chamber is shown. It is a figure which shows typically the base of an irradiation source and a curing chamber. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention. FIG. 6 illustrates a process for molding a hearing aid shell using a device molded in accordance with the subject invention.

Claims (21)

A resin curing device,
Curing chamber;
A radiation source arranged to emit radiation to the curing chamber; and at least one tubular diffuser having a plurality of ports, the port communicating with the curing chamber, the tubular diffuser being a port The resin curing device is configured to pass an inert gas through the port, and the port introduces the inert gas into the curing chamber.   The apparatus of claim 1, wherein the plurality of tubular diffusers are in communication with the curing chamber, and the tubular diffuser is disposed at least partially constrained to the chamber.   The apparatus of claim 2, wherein the diffuser is constrained to the curing chamber.   The apparatus of claim 1, wherein the irradiation source is an ultraviolet lamp.   The apparatus of claim 1, wherein the curing chamber is separable by a movable cover.   The apparatus of claim 1, wherein the diffuser includes a tubular body defining a cavity, and the port communicates with the cavity through the cylindrical body.   The apparatus of claim 1, wherein at least one port is a nozzle.   The apparatus of claim 1 wherein at least one port is an orifice.   The apparatus of claim 1, wherein the port is disposed at a plurality of locations on the tubular diffuser. A resin curing device,
Curing chamber;
An irradiation source arranged to emit radiation to the curing chamber; and at least a first port and a second port in communication with the curing chamber for introducing an inert gas into the curing chamber The first and second ports are resin curing devices that introduce an inert gas in different directions within the curing chamber.   The apparatus of claim 10, wherein the curing chamber is defined by a plurality of walls, the port is disposed along a first wall, and the second port is disposed along a second wall.   The apparatus of claim 10, wherein at least one port is disposed on a respective wall of the curing chamber.   The curing chamber is defined by a plurality of walls, the first and second ports are disposed on the same wall, and the first and second ports introduce an inert gas in different directions within the curing chamber. The apparatus of claim 10, wherein the apparatus is oriented to A method of curing a resin,
The process of pouring the resin into the mold,
Partially curing the resin inside the mold and extinguishing the shell having a limited thickness;
Removing uncured resin from the shell;
Placing the shell in a curing chamber;
A resin curing method comprising: curing the shell in the curing chamber; and introducing an inert gas into the curing chamber from a plurality of locations.   The method of claim 14, wherein the introduction of the inert gas occurs at least in part during the curing of the shell.   The method of claim 15, wherein the introduction of the inert gas is performed either during the curing of the shell or in a shorter time during the curing of the shell.   The method according to claim 14, wherein the resin is an acrylic molding material.   The method of claim 14, wherein the curing comprises exposing to radiation.   A hearing aid shell made by the method of claim 14.   15. The method of claim 14, wherein the plurality of locations for introducing inert gas are ports disposed along at least one tubular diffuser.   The method of claim 14, wherein the plurality of locations for introducing inert gas are arranged to introduce inert gas in different directions into the curing chamber.

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