THERMOFORMING MACHINE AND METHOD

Abstract

THERMOFORMING MACHINE AND METHOD. The present invention relates to a thermoforming machine (30) comprising a thermoforming chamber (32) having at least one heated air inlet (34) through which heated air flows into the thermoforming chamber (32) at a controlled pressure. The air inlet (34) cooperates with a heated air flow distribution regulator (40) located in the thermoforming chamber (32) and through which heated air flows out of the thermoforming chamber (32) at a predetermined temperature. The regulator (40) comprises a heated air flow regulating mask (42) that receives heated air flow, which has a plurality of flow restriction elements that provide different air flow restrictions.

Description

1 / 14 “THERMOFORMING MACHINE AND METHOD” FIELD OF DISSEMINATION

[0001] This disclosure relates to a thermoforming machine and method. Such thermoforming can, for example, be used in the process of laminating a functional multilayer film onto an optical article, such as an ophthalmic lens, through the use of increased pressure and temperature. BACKGROUND OF THE DISCLOSURE

[0002] By “functional film” it is understood that it is a film which provides the optical article with at least one characteristic among a rigid coating, anti-scratch properties, an anti-reflective coating, a polarizing film, a tint, a mirror or a filter for specific wavelengths, anti-shock, anti-smudge, anti-fog, self-healing, self-cleaning or anti-static properties, etc.

[0003] By “lamination” of a film onto an optical article, it is understood that this is the operation involving the deposition of a film onto a surface of the optical article to be laminated. The lamination operation is normally performed by first providing the film disposed on a carrier. The film and carrier are then compressed onto the surface to be laminated, applying a pressure difference between one side of the carrier that has both the film and the optical article and the other side, or by applying a force from the side of the optical article.

[0004] An adhesive, for example, a pressure-sensitive adhesive, is generally pre-applied to the face of the film that is intended to be pressed against the said surface in order to hold the film in place on the said surface.

[0005] In alternative processes, the adhesive is positioned on the optical article before pressing the film against the optical article and / or the Petition 870260036050, dated 04 / 17 / 2026, p. 6 / 50 2 / 14 film is pressed against the optical article without being fixed to a carrier, but, for example, by applying pressure directly to the film or by using a seal or a membrane or balloon for blowing.

[0006] In the field of optical goods manufacturing, the film lamination process generally requires pre-processing or “shaping” of the consumable or laminate complex, so as to give the film a given curvature, so that it conforms to, and matches, the curvature of the prescribed ophthalmic lens surfaced to laminate better than a flat film, whether the convex or concave side of the lens.

[0007] To laminate a lens, so as to induce a desired curvature with a customized radius in a film or consumable complex 10, as shown in Figure 1, the consumable 10 comprises a carrier 12 and a film patch 14 bonded to the carrier 12, the consumable 10 is normally fixed and inflated by thermoforming. Figure 2 shows from top to bottom three successive stages of the thermoforming of the consumable 10 of Figure 1.

[0008] During thermoforming, a uniform heat distribution within the member to be thermoformed is desirable, i.e., within patch 14 in Figure 2.

[0009] Additionally, it is desirable to maintain controlled pressure inside the thermoforming chamber.

[0010] When heated air is introduced into the thermoforming chamber, the flow of heated air is directional and is directed towards the patch in order to heat it by convection. The air temperature must be maintained within a predetermined range, e.g., between 100 and 115 degrees Celsius, depending on the desired arch or curvature of the film to be laminated.

[0011] If the air flows simply towards the center of the patch and heats it from the center outwards, this will result in a Petition 870260036050, dated 04 / 17 / 2026, page 7 / 50 3 / 14 large temperature gradient within the film, the area of ​​the film below the airflow being hotter than the other areas. This is unsuitable for thermoforming. SUMMARY OF THE DISCLOSURE

[0012] One objective of disclosure is to overcome the aforementioned disadvantages of the state of the art.

[0013] To this end, the disclosure provides a thermoforming machine comprising a thermoforming chamber having at least one heated air inlet through which heated air flows into the thermoforming chamber at a controlled pressure, wherein the air inlet cooperates with a heated air flow distribution regulator located in the thermoforming chamber and through which heated air flows out of the thermoforming chamber at a predetermined temperature, wherein the regulator comprises a heated air flow regulating mask that receives heated air flow, having a plurality of flow restriction elements that provide different air flow restrictions.

[0014] This makes it possible to reduce temperature gradients in the member to be thermoformed during thermoforming, resulting in significantly improved accuracy in the curvature of that member.

[0015] The disclosure also provides a thermoforming method that uses a thermoforming machine, as briefly described above, to give a predetermined curvature to a film to be applied to an optical article, the film being placed under the mask so as to be centered with respect to the mask, wherein heated air flows from the heated air inlet to the thermoforming chamber at a controlled pressure and flows out of the thermoforming chamber at a predetermined temperature. Petition 870260036050, dated 04 / 17 / 2026, p. 8 / 50 4 / 14 passes through the heated airflow regulating mask, thus generating uniform heat distribution within the film, until the predetermined target curvature is achieved.

[0016] The disclosure further provides an optical article comprising a front face and a back face, wherein at least one of the front and back faces is coated with a thermoformed film through implementation of a thermoforming method, as briefly described above.

[0017] The disclosure further provides an assembly comprising a thermoforming machine and a film and / or film patch and / or active film and / or adhesive to be thermoformed by the thermoforming machine, wherein the thermoforming machine comprises a thermoforming chamber having at least one heated air inlet through which heated air flows into the thermoforming chamber at a controlled pressure, wherein the air inlet cooperates with a heated air flow distribution regulator located in the thermoforming chamber and through which heated air flows out of the thermoforming chamber at a predetermined temperature, wherein the regulator comprises a heated air flow regulating mask that receives heated air flow, having a plurality of flow restriction elements that provide different air flow restrictions, in an embodiment for the assembly,The film and / or film patch and / or active film and / or adhesive have a predetermined non-circular shape, and the plurality of flow restriction elements have the same geometry as, or geometry similar to, the predetermined shape of the film and / or film patch and / or active film and / or adhesive; alternatively, the film and / or film patch and / or active film and / or adhesive have a predetermined shape, and the plurality of, Petition 870260036050, dated 04 / 17 / 2026, p. 9 / 50 5 / 14 flow restriction elements are distributed both in the center of the heated airflow regulating mask and in a predetermined number of concentric shapes, where the concentric shapes have the same geometry as the predetermined shape of the film and / or film patch and / or active film and / or adhesive.

[0018] In the context above, the predetermined non-circular shape of the film and / or film patch and / or active film and / or adhesive corresponds to the smallest feature between the film, a thermoforming chamber contour that imposes the thermoforming shape, and a possible patch present within the film; said patch being intended to be subsequently transferred to an ophthalmic lens.

[0019] In the context above, a non-circular shape means that more than 3% or preferably more than 5% of the effective surface of the film and / or film patch and / or active film and / or adhesive is present outside the largest inscribed circle that could be inscribed within the shape of the patch. The effective surface of the film patch in this context corresponds to the surface of the film patch, excluding one or more possible tabs or handling strips.

[0020] As with the method, the optical article and the assembly according to the disclosure have the same advantages as the thermoforming machine, and are not repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a fuller understanding of the description given herein and its advantages, reference is made to the brief descriptions below, considered in connection with the attached drawings and the detailed description, where equal reference numbers represent equal parts.

[0022] Figure 1 is a schematic view of a prior art consumable to be thermoformed. Petition 870260036050, dated 04 / 17 / 2026, p. 10 / 50 6 / 14

[0023] Figure 2 is a set of three schematic views showing successive stages of the thermoforming of the state-of-the-art consumable of Figure 1.

[0024] Figure 3 is a schematic view of a thermoforming machine according to the disclosure, in a particular embodiment.

[0025] Figure 4 is a schematic view of an airflow regulating mask comprised in a thermoforming machine according to the disclosure in a particular embodiment.

[0026] Figure 5 is a set of two schematic cross-sectional views of an airflow regulating mask comprised in a thermoforming machine according to the disclosure in a particular embodiment.

[0027] Figure 6 is a schematic view of an airflow regulating mask comprised in a thermoforming machine according to the disclosure in a particular embodiment and of a corresponding film patch comprised in an assembly according to the disclosure in a particular embodiment. DETAILED DESCRIPTION OF THE DISCLOSURE

[0028] In the description that follows, although the creation and use of various embodiments are discussed below in detail, it should be recognized that, as described herein, many inventive concepts are provided that can be incorporated into a wide variety of contexts. The embodiments discussed herein are merely representative and do not limit the scope of the disclosure. It will be equally obvious to a person skilled in the art that all the technical features that are defined in relation to a process can be transposed, individually or in combination, to a device and, by another Petition 870260036050, dated 04 / 17 / 2026, page 11 / 50 7 / 14 side, all technical characteristics relating to a device can be transposed, individually or in combination, to a process and the technical characteristics of different embodiments can be exchanged or combined with the characteristics of other embodiments.

[0029] The terms “comprise” (and any grammatical variation thereof, such as “comprise” and “comprising”), “have” (and any grammatical variation thereof, such as “has” and “having”), “contain” (and any grammatical variation thereof, such as “contains” and “containing”) and “include” (and any grammatical variation thereof, such as “includes” and “including”) are indefinite linking verbs. They are used to specify the presence of announced characteristics, integers, steps or components or groups thereof, but do not exclude the presence or addition of one or more other characteristics, integers, steps or components or groups thereof.As a result, a method, or a step in a method, that “comprises”, “has”, “contains”, or “includes” one or more steps or elements, possesses those one or more steps or elements, but is not limited to possessing only those one or more steps or elements.

[0030] As shown in Figure 3, a thermoforming machine 30 according to the disclosure comprises a thermoforming chamber 32.

[0031] The thermoforming chamber 32 has at least one heated air inlet 34 through which heated air flows, from an air inlet 31 at ambient temperature through an in-line heating tube 33, to the thermoforming chamber 32 at a controlled pressure. For this purpose, the thermoforming chamber 32 may comprise a backpressure regulating the diaphragm 36 and a pressurized air inlet 38 for backpressure regulation. The thermoforming chamber 32 may further comprise a Petition 870260036050, dated 04 / 17 / 2026, page 12 / 50 8 / 14 thermocouple 35 for temperature control. This additionally allows for process control to achieve or maintain a predetermined temperature.

[0032] The heated air inlet 34 cooperates with the heated air flow distribution regulator 40 located in the thermoforming chamber 32. The heated air flows through the air flow distribution regulator 40 out of the thermoforming chamber 32 at a predetermined temperature. The heated air flow distribution regulator 40 allows control of the airflow distribution within the thermoforming chamber 32. Since the airflow is heated air, this allows control of the temperature distribution within the chamber. In fact, with the airflow being heated before entering the thermoforming chamber 32, the airflow temperature is easily predetermined and controlled. Furthermore, controlling the temperature within the thermoforming chamber 32 is linked to controlling the rate of heated airflow within the thermoforming chamber 32.

[0033] According to one embodiment of the disclosure, the heated air flow distribution regulator 40 is oriented towards an opening in the thermoforming chamber 32 which is intended to be closed by the film to be thermoformed.

[0034] In a further embodiment, the heated air flow distribution regulator 40 is positioned relatively parallel to the aforementioned opening, or so that the film before thermoforming is essentially parallel to the heated air flow distribution regulator 40, if the film to be thermoformed is essentially flat before thermoforming.

[0035] According to the disclosure, the regulator 40 comprises a heated airflow regulating mask 42 that receives heated airflow and has a plurality of flow restriction elements 44 shown in Figure 4, which provides different restrictions of Petition 870260036050, dated 04 / 17 / 2026, page 13 / 50 9 / 14 airflow.

[0036] In one embodiment, the plurality of flow restriction elements 44 is distributed in such a manner from the periphery to the center of the mask 42 that a first of the flow restriction elements 44 restricts the airflow less than a second of the flow restriction elements 44.

[0037] This results in reduced direct airflow at the periphery of the patch, which balances the effect of indirect airflow heating, caused by heated air flowing from the center of the patch to its periphery. Uneven heating is thus avoided.

[0038] For example, the size of the first, above-mentioned, flow restriction element 44 may be larger than the size of the second, above-mentioned, flow restriction element 44.

[0039] In one embodiment, the first flow restriction element 44 is closer to the center of the mask than the second flow restriction element 44.

[0040] In another embodiment, conversely, the second flow restriction element 44 is closer to the center of the mask than the first flow restriction element 44.

[0041] In the specific embodiment shown in Figure 4, the plurality of flow restriction elements 44 is distributed in a predetermined number of concentric circles 46, the center of which is the center of the mask 42. Furthermore, at least one flow restriction element 44 may be provided at the center of the mask 42.

[0042] The circle is a non-limiting example of geometry that may be replaced by another shape. In another embodiment, the plurality of flow restriction elements 44 is distributed in a predetermined number of concentric contours, which may be related to the shape of the patch 14, such as an ellipse-like shape, as illustrated in Figure 6. Petition 870260036050, dated 04 / 17 / 2026, page 14 / 50 10 / 14

[0043] In the specific embodiment shown in Figure 4, the flow restriction elements 44 located in the same shape as the concentric shapes, that is, in a specific and the same circle as the concentric circles 46 in this non-limiting example, have the same size. Additionally, the flow restriction elements 44 located in the same shape as the concentric shapes, that is, in a specific and the same circle as the concentric circles 46 in this non-limiting example, may be equidistant from each other.

[0044] By way of non-limiting example, the number of concentric shapes may be 5 and the value of the angular sector between two adjacent flow restriction elements 44 in the same shape may be between 9° and 60°, in particular about 9° for the outermost concentric shape and about 60° for the more central concentric shape.

[0045] In one embodiment, at least two concentric forms are such that the aforementioned angular sector is larger for the concentric form closest to the center of mask 42.

[0046] In the specific embodiment shown in Figure 4, the flow restriction elements 44 are circular openings. By way of non-limiting example, the diameters of the openings can be between 1 mm and 10 mm, in particular about 1 mm for the openings of the outermost concentric shapes and about 10 mm for an opening in the center of the concentric shapes.

[0047] However, flow restriction elements 44 may have any other geometry such as square, rectangle, triangle, ellipse, a patch-like outline etc., and may have any suitable dimensions.

[0048] In one embodiment, the heated air flow distribution regulator 40 may have a flat surface.

[0049] In one embodiment, the heated air flow distribution regulator 40 may have a curved surface. Petition 870260036050, dated 04 / 17 / 2026, p. 15 / 50 11 / 14

[0050] Furthermore, the flow restriction element 44 may have a variable volume. In other words, the volume of a given element 44, e.g., the volume of the opening in a given element 44, may be different from the volume of the opening in another element 44 of the same regulator 40. Additionally, the airflow can be controlled by the size of the cross-sectional area of ​​the flow restriction elements 44, since a small cross-sectional area can cause significant friction, but the airflow can also be controlled by the depth or height of the flow restriction elements 44 and / or by the shape of the air path through the flow restriction elements 44. Figure 5 shows two non-limiting examples of the mask 42 in cross-section. In the example on the right of Figure 5, one of the elements 44 has a path with airflow changing directions and the flow restriction elements 44 have a variable volume.

[0051] A thermoforming method using a thermoforming machine as described above makes it possible to provide a predetermined curvature to a film to be applied to an optical article.

[0052] The film is placed under the mask 42 so that it is centered in relation to the mask 42. Fixing the film under the mask 42 allows the thermoforming chamber 32 to be sealed.

[0053] Then heated air flows from the heated air inlet 34 to the thermoforming chamber 32 at a controlled pressure up to an initial pressure zone 50 of the thermoforming chamber 32 (see zone 50 in Figure 3) and, at a predetermined low pressure limit, begins to flow out of the thermoforming chamber 32 through the heated air flow distribution regulator 40, at a predetermined temperature, passing through the mask 42, thus generating a uniform heat distribution within the film, until the predetermined target temperature is reached, and the target temperature Petition 870260036050, dated 04 / 17 / 2026, p. 16 / 50 12 / 14 depends on the desired material and / or the curvature or arch of the final film.

[0054] Once the target temperature is reached, the backpressure regulating diaphragm 36 used to control the pressure increases the pressure, for example by 0.003 MPa / s (0.03 bar / s), up to for example 0.5 MPa (5 bar), either in the upper heating chamber, or in a lower chamber, if one exists.

[0055] The pressure increases until the target thermoforming curvature is achieved or until the maximum allowable pressure (predetermined upper pressure limit) is reached.

[0056] The backpressure mechanism maintains the pressure inside the thermoforming chamber 32 by introducing pressurized air above the backpressure regulating diaphragm 36, through the pressurized air inlet 38. If the pressure inside the thermoforming chamber 32 exceeds the backpressure on the diaphragm 36, the diaphragm 36 opens and releases air from inside the thermoforming chamber 32, thus reducing the pressure. This allows control of the pressure inside the thermoforming chamber 32 throughout the process, while maintaining a constant flow of heated air from the heated air inlet 34, at a controlled temperature.

[0057] By way of non-limiting example, the temperature may be between 100 °C and 140 °C and is preferably 120 °C.

[0058] By way of non-limiting example, the pressure may be between 0.02 MPa (0.2 bar) and 0.8 MPa (8 bar), preferably between 0.05 MPa (0.5 bar) and 0.6 MPa (6 bar).

[0059] Depending on the dimensions of the thermoforming chamber 32, the heated air can have a flow rate between 20 l / min and 160 l / min and is preferably 60 l / min.

[0060] Alternatively, the pressure in the thermoforming chamber can be maintained at atmospheric pressure. In such a case, pressure Petition 870260036050, dated 04 / 17 / 2026, p. 17 / 50 13 / 14 increased for shaping can be applied to the film from the opposite side, where the film patch is facing down, in which pressure from below introduces a convex shape suitable for front-side lamination.

[0061] At least one of the front and back faces of an optical article, such as an ophthalmic lens, may be coated with a thermoformed film in the various ways described above.

[0062] In one embodiment of an assembly according to the present disclosure, comprising a thermoforming machine as described above and a film and / or film patch and / or an active (functional) film and / or an adhesive to be thermoformed by the thermoforming machine, wherein the film and / or film patch and / or the active film and / or the adhesive have a predetermined shape, in which the flow restriction elements 44 comprised in the heated air flow regulating mask 42 may have a geometry identical to, or similar to, or at least evocative of, the shape geometry of the film and / or film patch and / or the active film and / or the adhesive.

[0063] Figure 6 illustrates a non-limiting example of such flow restriction elements 44 (shown on the right in the drawing).

[0064] As shown in Figure 6, the outline of the flow restriction element assembly 44 has a geometry that approximately corresponds to the geometry of the film patch shape 14.

[0065] In this specific example, the concentric shapes are not circular, but rather elliptical, as shown by the 46' concentric ellipses. Two of the 46' concentric ellipses are shown in dashed lines, where the dashed lines were added to the drawing to better show the 46' concentric ellipses.

[0066] In this specific modality, the concentric shapes are the 46' concentric ellipses and correspond approximately to Petition 870260036050, dated 04 / 17 / 2026, page 18 / 50 14 / 14 film patch 14 (shown on the left in the drawing).

[0067] Furthermore, as also shown in the non-limiting example in Figure 6, each of the flow restriction elements 44 is itself an ellipse.

[0068] However, features relating to the elliptical or circular or other geometry of the flow restriction elements 44 themselves and / or the respective ellipses 46' of the concentric circles 46 and / or the similarities between the shape of the film patch 14 and the outline of the set of flow restriction elements 44 may be present, either in different embodiments, or in combination with each other in one or more embodiments.

[0069] In one embodiment, the thermoforming method described above may use an assembly as described above, to provide a predetermined curvature to a film to be applied to an optical article, wherein the film is applied from under the mask so as to be centered with respect to the mask. Heated air may flow from the heated air inlet to the thermoforming chamber at a controlled pressure and flow out of the thermoforming chamber at a predetermined temperature, passing through the heated air flow regulating mask, thus generating a uniform heat distribution within the film, until the predetermined target curvature is obtained.

[0070] Although representative systems and methods have been described here in detail, those skilled in the art will recognize that various substitutions and modifications can be made without departing from the scope of what is described and defined by the appended claims. Petition 870260036050, dated 04 / 17 / 2026, p. 19 / 50

Claims

1 / 4 CLAIMS 1. Thermoforming machine (30) used in the process of laminating a functional multilayer film onto an optical article, such as an ophthalmic lens, through the use of increased pressure and temperature, characterized in that it comprises a thermoforming chamber (32) having at least one heated air inlet (34) through which heated air flows into said thermoforming chamber (32) at a controlled pressure, wherein said air inlet (34) cooperates with a heated air flow distribution regulator (40) located in said thermoforming chamber (32) and through which said heated air flows out of said thermoforming chamber (32) at a predetermined temperature, said regulator (40) comprising a heated air flow regulating mask (42) that receives heated air flow, having a plurality of flow restriction elements (44) that provide different air flow restrictions.

2. Thermoforming machine (30), according to claim 1, characterized in that said plurality of flow restriction elements (44) are distributed in a predetermined manner from the periphery to the center of said mask (42), wherein a first of said flow restriction elements (44) restricts the airflow less than a second of said flow restriction elements (44).

3. Thermoforming machine (30), according to claim 2, characterized in that the first of said flow restriction elements (44) is closer to the center of said mask (42) than the second of said flow restriction elements (44).

4. Thermoforming machine (30), according to claim 2, characterized in that the said second of said flow restriction elements (44) is closer to the center of said mask (42) than the said first of said flow restriction elements (44).

5. Thermoforming machine (30), according to any one of claims 2, 3 or 4, characterized in that said plurality of flow restriction elements (44) is distributed both in the center of said mask (42) and in a predetermined number of concentric shapes, preferably circles (46), wherein the center of said concentric shapes is the center of said mask (42).

6. Thermoforming machine (30), according to claim 5, characterized in that the flow restriction elements (44) located in a specific of said concentric forms have the same size.

7. Thermoforming machine (30), according to any one of claims 5 and 6, characterized in that the flow restriction elements (44) located in a specific of said concentric forms are equidistant from each other.

8. Thermoforming machine (30), according to claim 7, characterized in that the said number of concentric forms is 5 and the value of the angular sector between two adjacent flow restriction elements (44) in the same form is between 9° and 60°.

9. Thermoforming machine (30), according to any of the preceding claims, characterized in that said flow restriction elements (44) are circular openings.

10. Thermoforming machine (30), according to claim 9, characterized in that the diameter of said openings is between 1 mm and 10 mm.

11. Thermoforming machine (30), as per Petition 870260036050, dated 04 / 17 / 2026, page 21 / 50 3 / 4 any of the previous claims, characterized by the fact that said regulator has a curved surface.

12. Thermoforming method characterized in that it uses a thermoforming machine (30), as defined in any of the preceding claims, to give a predetermined curvature to a film to be applied to an optical article, the film being placed under said mask (42) so as to be centered with respect to said mask (42), wherein heated air flows from said heated air inlet (34) to said thermoforming chamber (32) at a controlled pressure and flows out of said thermoforming chamber (32) at a predetermined temperature as it passes through said heated air flow regulating mask (42), thus generating uniform heat distribution within said film, until said predetermined target curvature is obtained.

13. Thermoforming method according to claim 12, characterized in that said temperature is between 100°C and 140°C, preferably 120°C.

14. Thermoforming method, according to any one of claims 12 and 13, characterized in that said pressure is between 0.02 MPa (0.2 bar) and 0.8 MPa (8 bar).

15. Assembly characterized in that it comprises a thermoforming machine (30) and a film and / or film patch (14) and / or active film and / or adhesive to be thermoformed by said thermoforming machine (30), wherein said thermoforming machine (30) comprises a thermoforming chamber (32) having at least one heated air inlet (34) through which heated air flows into said thermoforming chamber (32) at a controlled pressure, wherein said air inlet (34) cooperates with a regulator (40) Petition 870260036050, dated 17 / 04 / 2026, p.22 / 50 4 / 4 of heated air flow distribution located in said thermoforming chamber (32) and through which said heated air flows out of said thermoforming chamber (32) at a predetermined temperature, wherein said regulator (40) comprises a heated air flow regulating mask (42) that receives heated air flow, having a plurality of flow restriction elements (44) that provide different air flow restrictions, preferably said film and / or said film patch (14) and / or said active film and / or said adhesive have a predetermined non-circular shape and said plurality of flow restriction elements (44) have the same geometry as said predetermined shape of said film and / or said film patch (14) and / or said active film and / or said adhesive. Petition 870260036050, dated 17 / 04 / 2026, p. 23 / 50.

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