APPARATUSES AND METHODS FOR MULTISTAGE MOLDING OF LENSES
20220332067 · 2022-10-20
Assignee
Inventors
Cpc classification
B29D11/00038
PERFORMING OPERATIONS; TRANSPORTING
B29D11/00807
PERFORMING OPERATIONS; TRANSPORTING
G02C7/049
PHYSICS
B29D11/00048
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
Apparatuses and methods for multistage molding of contact lenses containing low oxygen permeable components or oxygen impermeable components. Components may be embedded within a contact lens by forming a device on a polymer substrate, molding a spacer onto a male mold, bonding the device to the spacer, removing the polymer substrate, and molding the remainder of the contact lens.
Claims
1. A method of forming a contact lens, the method comprising: providing a component; providing a soft female mold insert; disposing the component in the soft female mold insert; providing a pre-polymerized lens material; disposing the pre-polymerized lens material upon the component; providing a male mold; and applying the male mold to the pre-polymerized lens material.
2. The method of claim 1, further comprising: allowing the pre-polymerized lens material to cure; and removing the soft female mold insert.
3. The method of claim 2, further comprising: deforming the soft female mold insert prior to removing the soft female mold insert.
4. The method of claim 3, wherein deforming the soft female mold comprises: rotating an edge of the soft female mold insert away from the male mold.
5. The method of claim 1, further comprising: providing a rigid housing; and disposing the soft female mold insert within the rigid housing before applying the male mold to the pre-polymerized lens material.
6. The method of claim 5, further comprising: allowing the pre-polymerized lens material to cure; and removing the rigid housing from the soft female mold insert after allowing the pre-polymerized lens material to cure.
7. The method of claim 6, further comprising: removing the soft female mold insert after removing the rigid housing.
8. The method of claim 7, further comprising: deforming the soft female mold insert prior to removing the soft female mold insert.
9. The method of claim 8, wherein deforming the soft female mold insert comprises: rotating an edge of the soft female mold insert away from the male mold.
10. The method of claim 9, further comprising: applying a female mold containing pre-polymerized lens material to the male mold having the attached component and the cured polymerized spacer; and curing the pre-polymerized material to produce a full lens body having a posterior surface, a lens body containing a spacer and component, and an anterior surface.
11. A method of forming a contact lens, the method comprising: providing a component; providing a soft female mold insert; disposing the component in the soft female mold insert; providing a male mold; providing a pre-polymerized lens material; disposing the pre-polymerized lens material upon the male mold; and bringing the soft female mold insert and the male mold together such that the pre-polymerized lens material contacts the component.
12. The method of claim 11, further comprising: allowing the pre-polymerized lens material to cure; removing the soft female mold insert
13. The method of claim 12, further comprising: deforming the soft female mold insert prior to removing the soft female mold insert.
14. The method of claim 13, wherein deforming the soft female mold comprises: rotating an edge of the soft female mold insert away from the male mold.
15. The method of claim 11, further comprising: providing a rigid housing; and disposing the soft female mold insert within the rigid housing before bringing the soft female mold insert and the male mold together.
16. The method of claim 15, further comprising: allowing the pre-polymerized lens material to cure; and removing the rigid housing from the soft female mold insert after allowing the pre-polymerized lens material to cure.
17. The method of claim 16, further comprising: removing the soft female mold insert after removing the rigid housing.
18. The method of claim 17, further comprising: deforming the soft female mold insert prior to removing the soft female mold insert.
19. The method of claim 18, wherein deforming the soft female mold insert comprises: rotating an edge of the soft female mold insert away from the male mold.
20. The method of claim 19, further comprising: applying a female mold containing pre-polymerized lens material to the male mold having the attached component and the cured polymerized spacer; and curing the pre-polymerized material to produce a full lens body having a posterior surface, a lens body containing a spacer and component, and an anterior surface.
21. An apparatus for molding a contact lens, the apparatus comprising: a female mold insert, wherein the female mold insert is soft; and a male mold, wherein the male mold mates with the soft female mold insert.
22. The apparatus of claim 21, further comprising: a rigid housing, wherein the male mold mates with the soft female mold insert while the soft female mold insert resides within the rigid housing.
23. The apparatus of claim 22, further comprising: a wave washer, wherein the wave washer resides between the female mold insert and the rigid housing.
24. The apparatus of claim 21, wherein the female mold insert is a first female mold insert, the apparatus further comprising: a second female mold insert, wherein the second female mold insert is soft, wherein the male mold mates with the second female mold insert.
25. The apparatus of claim 24, further comprising: a rigid housing; wherein the male mold mates with the first female mold insert while the first female mold insert resides within a rigid housing; and wherein the male mold mates with the second female mold insert while the second female mold insert resides within a rigid housing.
26. The apparatus of claim 24, further comprising: a first rigid housing, wherein the male mold mates with the first female mold insert while the first female mold insert resides within a rigid housing; and a second rigid housing, wherein the male mold mates with the second female mold insert while the second female mold insert resides within a second rigid housing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of this invention.
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DETAILED DESCRIPTION OF THE DRAWINGS
[0038] Many aspects of the invention can be better understood with the references made to the drawings below. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts through the several views in the drawings.
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[0046] Furthermore, while it may be possible to use the first female mold insert and second female mold insert with the same housing, it is nonetheless possible and in certain embodiments may be preferable to have two same or similar housings, one to house the first female mold insert and one to house the second female mold insert.
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[0048] According to certain embodiments disclosed herein, the female inserts are rigid, relatively inflexible molds. However, alternative embodiments of the current disclosure include soft, flexible female inserts. The use of soft, relatively flexible female inserts may be used to adapt to non-spherical male molds, such as those used to create lenses with cylinder power, as well as to potentially allow for a more effective de-molding operation.
[0049] For example, two methods are possible when removing the female inserts: direct axial separation and edge lifted separation. Direct axial methods are harder to execute because they require the entire female insert to open simultaneously, which often results in a suction effect. The suction effect may be detrimental to allowing the cast material to remain on the base mold surface. Edge lifting methods are similar, but are gentler as they allow for one side to open and relieve suction while the balance of the female insert remains attached. Additional rotation of the insert results in more detachment from the cast material in a progressive peel separation. However, an edge lifting method still imparts a fairly high suction lifting force until the inception of the seal break to relieve the suction, and continues to add high risk during mold opening.
[0050] With a soft female mold insert, the suction zone can be reduced or nearly eliminated by local deformation of the insert right at the edge of the cast material to force the seal of the soft female mold insert and male mold to break and initiate the peel process for mold opening. Subsequent peeling of the soft insert continues to advance the peel zone as it progresses across the cast material without imparting a suction force on the balance of the cast material that is not yet exposed.
[0051] Now a process for forming a lens using a soft female mold insert is described according to some embodiments of the disclosed technologies. The process may begin with a component. The component may be as described elsewhere herein, and may be provided in a flat or curved state.
[0052] A soft female mold insert may be provided. The soft female mold insert may be as described elsewhere herein. The component may be applied to the inner concave surface of the soft female mold insert.
[0053] In some embodiments, a cap may be applied to the soft female mold insert to keep the component applied to the soft female mold insert. The resulting article of manufacture may be inventoried and distributed for further processing after. For example, the cap may be removed and the soft female mold insert with the component applied may be processed as described below.
[0054] A male mold may be provided.
[0055] In an alternate embodiment the spacer 94 may be formed when the soft female mold insert 92, containing the applied component 91, is filled with pre-polymerized lens material, applied to the convex surface of a male mold 93, and subsequently cured.
[0056] A rigid housing may be provided. The rigid housing may be as described elsewhere herein. The rigid housing may be supported by a compression spring or a closing force may be otherwise created. The soft female mold insert may rest within the rigid housing. The male mold bearing or not bearing the spacer may be applied to the soft female mold insert bearing the component while the soft female mold insert rests within the rigid housing.
[0057] After the spacer has cured, the rigid housing may be removed.
[0058] One significant advantage of the use of a soft female insert is that removal of the male mold bearing the spacer and component may be facilitated by deforming the soft female mold insert, for example by rotating an edge of the soft female mold insert away from the male mold. The spacer and component remain together, and attached to the male mold.
[0059] In some embodiments, a cap may be applied to the male mold 93 to keep the spacer 94 and component 91 applied to the male mold intact and ready for subsequent processing. The resulting article of manufacture may be inventoried and distributed for further processing after. For example, the cap may be removed and a female mold filled with pre-polymerized lens material may be applied and processed as described elsewhere herein.
[0060]
[0061] Referring to
[0062] The process 1800 may include providing a rigid housing, at 1804. The rigid housing may be as described above.
[0063] Referring again to
[0064] Referring again to
[0065] The process 1800 may include disposing the component in the soft female mold insert, at 1810. For example, referring to
[0066] Referring again to
[0067] The process 1800 may include disposing the pre-polymerized lens material upon the component, at 1814.
[0068] The process 1800 may include providing a male mold, at 1816. For example, referring to
[0069] Referring again to
[0070] Referring again to
[0071] The process 1800 may include removing the rigid housing, at 1822.
[0072] The process 1800 may include removing the soft female mold insert, at 1824. For example, referring to
[0073] Referring again to
[0074]
[0075] Referring again to
[0076] Referring again to
[0077] The process 1900 may include disposing the soft female mold insert within the rigid housing, at 1906. For example, referring to
[0078] Referring again to
[0079] The process 1900 may include disposing the component in the soft female mold insert, at 1910. For example, referring to
[0080] Referring again to
[0081] Referring again to
[0082] The process 1900 may include disposing the pre-polymerized lens material upon the male mold, at 1916. For example, referring to
[0083] Referring again to
[0084] Referring again to
[0085] The process 1900 may include removing the rigid housing, at 1922.
[0086] The process 1900 may include removing the soft female mold insert, at 1924. For example, referring to
[0087] Referring again to
[0088] Certain methods of the current disclosure promote adhesion to specific mold surfaces to gain advantages during de-molding. One such method intentionally interferes with polymerization on one surface, while not interfering or even enhancing the polymerization on alternate mold surface(s).
[0089] The most common methods of manipulating preferential adhesion include methods of surface modification to increase or decrease bond surface adhesion. In some cases, the surface modification is a plasma energy activation mechanism, and in other cases it involves the pre-application of primers (promotion) or release agents (interference) to a mold surface to alter the strength of the bond between the mold surface and fully polymerized material being cured.
[0090] Another possible method may be implemented where a specific alteration mechanism on the surface of the mold is applied to interfere with polymerization at the surface to a controlled depth into the cast material. The results of this cure inhibition could be to either increase adhesion or decrease adhesion at that boundary such that cast material would remain connected to a desired mold surface. A further benefit of this method would be enhanced adhesion of the subsequent layer at this inhibited boundary. As a result of not fully polymerizing, there are partially completed polymer chains that are at the surface waiting for more monomer and activator to complete the polymerization. When a subsequent layer is applied and cured, the inhibited zone is properly finalized (polymerized) by exposure to newly delivered activator to overcome the deactivated activator from the prior round of cure.
[0091] Certain embodiments of the current disclosure describe the lens to be built from back to front, as shown in
[0092] The apparatuses and methods disclosed herein include embedding components that are to be placed at a desired distance form a finished lens surface, for example, the anterior or posterior surface of a finished lens. Moreover, the instant disclosure should not be limited to uses of components having a polymer layer that is removed after being cast or adhered to a lens material. Certain components that are to be embedded within a contact lens may not have any layers that are to be removed during the fabrication process. For example, the step(s) described in
[0093] Components are shown placed in the geometric center of the male or female mold. However, displacement of the components from the geometric center is possible, and may in some instances be desirable. Certain embodiments displace the insert from the center of the mold to which it is applied. In other embodiments, the component may be displaced in a second stage on an otherwise geometric centered first stage cured material. For example, methods according to selected embodiments of the current disclosure either displace the insert of the first stage and second stage to achieve a displaced component; or, center the first stage and displace the component when it is placed on the cured first stage. Such methods may be used to achieve a displaced or de-centered component relative to the geometric center of the molds and/or resulting finished lens. Additionally, the wave washer may be rotationally asymmetric to allow for the decentration of the insert and resultant spacer.
[0094] Certain embodiments of the current disclosure include polydimethylsiloxane, however, other materials may be implemented for other embodiments, such as low expansion silicone hydrogels or low expansion hydrogels.
[0095] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. Likewise, the various diagrams may depict an example architectural or other configuration for the invention, which is provided to aid in understanding the features and functionality that can be included in the invention. The invention is not restricted to the illustrated example architectures or configurations, but the desired features can be implemented using a variety of alternative architectures and configurations.
[0096] Indeed, it will be apparent to one of skill in the art how alternative functional configurations can be implemented to implement the desired features of the present invention. Additionally, with regard to flow diagrams, operational descriptions and method claims, the order in which the steps are presented herein shall not mandate that various embodiments be implemented to perform the recited functionality in the same order unless the context dictates otherwise.
[0097] Although the invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in various combinations, to one or more of the other embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.