This application claims the right of U.S. provisional application No. 11/201,410, filed on 9/8/2005, the contents of which are incorporated herein by reference in their entirety.
Detailed Description
The lenses described herein are preferably injection molded contact lenses that are molded between contact lens mold sections that are themselves molded articles.
In a broad aspect of the present invention, a method of manufacturing a silicone hydrogel contact lens is provided. The methods of the present invention include methods of demolding a lens mold and removing a lens (e.g., a silicone hydrogel lens). In a preferred embodiment of the present invention, the method generally includes providing a mold assembly 2, such as the mold assembly 2 shown in cross-section in FIG. 1. The mold assembly 2 generally comprises a first mold section 3 having a first lens defining surface 4, such as a generally concave lens shaped surface; and a second mold section 5 having a second lens defining surface 6, such as a generally convex lens shaped surface. The mold assembly 2 further includes a polymeric lens-shaped article 8 disposed between the first lens defining surface 4 and the second lens defining surface 6 that needs to be removed from the mold sections 3 and 5 for final processing steps and packaging.
For simplicity and clarity of illustration, the following detailed description will be directed primarily to demolding of lens molds and removal of molded silicon-containing hydrogel contact lenses, such as lenses formed from polymerizable compositions comprising formulations based on combinations of polysiloxanyldimethacrylate silicone monomers or polysiloxanyldimethacrylate silicone monomers and polydimethylsiloxane methacrylate derivatives. The particular features and demolding conditions described in specific detail below are not to be considered limiting to the scope of the invention, which has been found to be advantageous for the manufacture of silicone hydrogel lenses. The lens-shaped article in the mold assembly can be a silicon-containing hydrogel lens that has been manufactured using radiation-initiated polymerization of a monomer composition, such as in the form of ultraviolet light.
Preferred polymerizable compositions suitable for making silicone hydrogel lenses using the systems, apparatuses and methods of the various aspects of the present invention are described in PCT publication No. WO2006026474, which is incorporated herein by reference in its entirety. The polymerizable composition may include components such as a tinting component, an ultraviolet blocker component, and/or the like.
It will be appreciated by one of ordinary skill in the art that the methods and systems according to the present invention, which may additionally have suitable modifications, can be used to demold other types of molded lenses formed from other polymerizable composition formulations, and all such modified methods and systems are considered to be within the scope of the present invention.
In some embodiments of the present invention, the mold assembly 2 preferably comprises a molded plastic material that is at least partially transparent to ultraviolet light. For example, mold portions 3 and 5 according to the present invention may comprise ethylene vinyl alcohol resin (hereinafter, typically EVOH).
Turning now to fig. 2, a flow chart is provided to illustrate the demolding steps according to embodiments of the invention. The demolding method primarily involves the step of demolding the mold assembly to the extent that the lens-shaped article is exposed on a predetermined portion of the mold section for a post-processing step.
The demolding method may be performed in a demolding treatment station or demolding station of a contact lens manufacturing facility or contact lens manufacturing system. The method involves a stage in the manufacturing process, sometimes referred to as a release stage, that includes separating or prying apart the first and second mold sections to physically expose a polymerized contact lens shaped article in only one mold section. After the demolding stage, the exposed lens-shaped article remaining on one mold section is conveyed to a delensing station configured for removal of the lens-shaped article (delensing) from the mold section and an extraction/hydration station (not shown) located downstream of the delensing station.
As will be described in detail below, the demolding process preferably occurs under carefully controlled conditions so as to separate the first mold portion 3 from the second mold portion 5 without damaging the integrity of the lens-shaped article 8 formed in the mold assembly 2.
In one aspect of the invention, the method of the invention includes a step involving preparing a predetermined mold section (e.g., a first mold section) to assist in retaining the lens shaped article from the first mold section and to enable efficient removal of the second mold section therefrom. More specifically, to prepare the predetermined mold portion, the method includes cooling the predetermined mold portion, such as by applying a coolant to at least a portion of an outer surface thereof. It should be understood that the cooling step is often an optional step and may not be included in many embodiments of the invention.
After the optional cooling step, the demolding process includes placing the mold assembly in a fluid, such as a high temperature liquid, to help de-fuse the bonded regions between the mold sections. In some embodiments, the step of placing the mold assembly in a fluid comprises applying heat to the mold assembly, such as at least partially immersing the mold assembly in a bath of deionized water at a temperature not exceeding 100 ℃. It can be appreciated that placing the mold assembly in the fluid can be the first step of the demolding process when the cooling step is not included in the process.
The method further comprises a step involving physically separating (e.g., separating) the predetermined mold section from another mold section to expose the lens-shaped article or the polymerized silicone hydrogel contact lens product remaining on the lens-shaped surface of the predetermined mold section. The lens-shaped article can thereafter be removed from the predetermined mold portion using suitable techniques known in the art, and the lens-shaped article subjected to extraction and hydration steps as desired.
By "predetermined mold section" is meant one mold section selected from the first mold section and the second mold section that is to be the mold section that retains the contact lens shaped article after separation of the first mold section from the second mold section. In the illustrated embodiment, the predetermined mold part is a first mold part 3, which is often referred to hereinafter as a "mold cup" because the first mold part is a female mold part having a concave lens shaped surface 4.
In a high volume, highly automated contact lens manufacturing facility using the present methods, it is desirable that all contact lens mold assemblies be demolded in a manner that is highly likely that contact lens shaped articles will reliably adhere to or be retained by only one of the first mold section or the second mold section. For purposes of the present invention, although not to be considered as limiting the scope of the invention, the first mold section is typically a front mold section, sometimes referred to as a female mold section or mold cup, and the second mold section is typically a rear mold section, sometimes referred to as a male mold section.
In a more specific aspect of the invention, the cooling step includes cooling the predetermined mold sections such that the lens is retained by the cooled mold sections after separation of the mold sections. In the described embodiment, the cooling step includes applying an agent, such as a coolant, to at least a portion of the predetermined mold portion. The application of the coolant helps to extract heat from the predetermined mold portions. The coolant may comprise any suitable agent that can be readily applied to one mold portion to cool or freeze the mold portion without, in some cases, causing any significant cooling of the other mold portion. For example, the coolant may comprise liquid nitrogen applied to the outer surface of the predetermined mold portion by a suitable means such as, but not limited to, dipping or in the form of droplets (e.g., spraying).
Alternatively, the mold sections may be cooled by applying one or more of the following agents to the mold sections: carbon dioxide, difluoroethane or other cryogen, cold air or other gas, cooling liquid or solvent, which is applied as a spray, droplets, or other suitable means, including (but not limited to) dipping one or both of the mold sections into the reagent.
The cooling step preferably comprises cooling the predetermined mold portion such that the temperature of the mold portion is between about 0 ℃ and about-200 ℃.
In other embodiments of the invention, the predetermined mold portion is not cooled in the cooling step. For example, in other embodiments of the present invention, the cooling step comprises cooling the mold first mold portion, the second mold portion, or both mold portions, depending at least in part on the type of material from which the lens and/or mold portions are made.
For example, one of ordinary skill in the art can determine from the type of material from which the lens or mold sections are made whether one or both of the mold sections are to be cooled to obtain a desired result using routine experimentation. Knowledge of which mold sections most often or consistently retain the lens after cooling or freezing known mold sections can be used from the experiments to help automate the processing of the lens quickly after the decoupling process.
For example, in one aspect of the present invention, the method includes determining which of the mold sections will tend to reliably and most often retain the lens product when a particular one or both of the mold assemblies is cooled, e.g., to a desired temperature. The determining step can comprise providing a plurality of identical mold assemblies containing identical lens products and cooling a particular one of the first mold section and the second mold section of all of the mold assemblies, and thereafter separating the mold sections to determine which of the mold sections of the mold assemblies most commonly retains the lens after separation. Once this determination is made, the known predetermined mold portions are demolded, for example using a high speed and/or automatic demolding process and/or equipment, for the purpose of assisting in demolding a relatively large number of such particular types of mold assemblies.
For example, some embodiments of the present invention can include cooling the first mold section to retain the lens-shaped article by the second mold section. In yet another embodiment of the present invention, the method includes cooling both the first mold portion and the second mold portion such that a predetermined one of the first mold portion and the second mold portion retains the lens-shaped article when the first mold portion is separated from the second mold portion. All such variations of demolding techniques, including cooling or freezing one or both mold sections to aid or cause retention of the lens product on the intended one of the mold sections, are considered to be within the scope of the present invention.
The mold assembly used in the method of the present invention is contacted with a liquid to assist in separating the first mold portion from the second mold portion. Typically, the contacting step comprises placing the mold assembly in a fluid, such as an immersion mold assembly in a liquid, such as an aqueous liquid, such as deionized water. More specifically, the contacting step can include heating the mold assembly with a high temperature liquid to help decouple the first mold portion from the second mold portion.
In certain embodiments, the heating step comprises placing the cooled mold assembly in a relatively warm or hot fluid for a period of time effective to reduce adhesion between the lens-shaped article and the lens-shaped surface of another mold section (i.e., a mold section that is not the intended mold section). The mold assembly is left in the fluid for about 1 second to about 10 seconds, such as about 7 seconds.
The effectiveness of the heating step in separating the mold sections can be enhanced by immersing the mold assembly in a liquid, such as deionized water, while transmitting ultrasonic energy through the liquid. Thus, some embodiments of the present methods include transmitting ultrasonic energy through the liquid while immersing the mold assembly in the liquid to reduce the amount of time the mold assembly must remain in the liquid to effect the heating step. The ultrasonic energy cavitates the fluid, e.g., forming microbubbles, to aid in decoupling.
The ultrasonic energy is at a frequency effective to enhance separation of the first mold assembly from the second mold assembly, for example, the ultrasonic energy can be applied at about 38 KHz.
The liquid is preferably at a temperature of up to about 100 c but preferably no more than about 100 c. For example, the liquid may have a temperature between about 20 ℃ and about 95 ℃.
Alternatively, the step of heating the mold assembly may include the application of heat steam to the mold assembly or other means of heating the mold assembly to achieve the goal of assisting in decoupling the mold sections.
After the step of heating the mold assembly, the demolding method may further comprise a step involving separating or physically separating the first mold portion from the partial mold portion. Although the heating step facilitates decoupling of the first mold portion from the second mold portion, it is to be understood that in most cases, the mold portions must also be subjected to processes that involve physically separating (e.g., peeling) the mold portions from one another. According to the present invention, the physical separation step involves removing another mold section (e.g., a second mold section) from the lens-shaped article while the lens-shaped article remains retained by the predetermined mold section (e.g., the first mold section).
Referring now specifically to the step of physically separating the mold portions, after the mold portions have been optionally cooled and subsequently heated as described above, they are placed in a mold separation apparatus configured to mechanically pry up the mold portions without lens remaining. In this example, the second mold section is separated from the predetermined mold section to physically expose the lens shaped article retained by the predetermined mold section. The mold separation apparatus may include a device having a cutting element and/or a prying element.
The mold assembly may be disposed between two cutting/prying elements, such as two wedge-shaped elements having tapered edges. The tapered edges of the wedge members are wedged between the abutting peripheral portions of the first and second mold portions. The mold assemblies are separated by moving the mold assemblies along the wedge elements from the thin edge to the thick edge of the wedge elements so that the mold portions are pried apart and separated.
Other ways of decoupling the mold sections may alternatively or additionally be used in the steps. For example, rather than using linear wedge elements to pry apart the mold sections, it is contemplated that a rotating element (e.g., a helical element) can be used to engage the mold assembly edge and open the assembly as it engages and rotates about the mold assembly perimeter. Other alternatives for decoupling the mold sections include, but are not limited to, the use of lasers, infrared light, and soaking the mold assembly in acetic acid. In certain embodiments, the mold assembly and the wedge members are moved relative to each other without heating the mold assembly during the movement.
The lens shaped article is now physically exposed and left adhered to or on the lens shaped surface of the predetermined mold section until further processing steps can be performed thereon. The other mold portion is typically discarded.
In order to release or assist in the release of the now exposed lens shaped article from the predetermined mold section lens shaped surface, the method of the present invention may further comprise soaking the mold section and the exposed lens shaped article adhered thereto in a soaking liquid or contact lens product contacting liquid while continuously circulating and filtering the soaking liquid. The steps may also be performed in a manner that causes the lens-shaped article to undergo the desired hydration. The soaking solution is preferably deionized water at a temperature of no greater than about 100 deg.c. For example, the soak solution may include deionized water at a temperature of about 75 ℃. The method may also include transmitting ultrasonic energy through the soaking liquid during the soaking step. Some extraction and hydration of the lens-shaped article may occur in conjunction with the soaking step.
Turning now to fig. 3 and 4, an optional method and apparatus are provided to de-fuse the fused regions between the mold sections of the mold assembly, for example to aid in the decoupling and separation process described above.
For example, a defusing assembly 410 that can be used to defuse fused portions of assembled mold sections or cut them to aid in the decoupling process can be provided as a component of the present demolding station and demolding method. The defluxing process is preferably at least partially automated. The assembly 410 may include means to ensure that the fused molding assembly is in a fixed position, means to insert one or more blades into the fixed molding assembly, and means to rotate the molding assembly such that the one or more blades cut the weld area of the mold assembly and separate the mold portions. The defusing assembly 410 can effectively separate the fused portions of the contact lens mold assembly, but typically the defusing assembly does not demold the two mold portions.
For example, according to some embodiments of the present invention, the mold assembly 40 is placed in a holder or nest 414 of the decoupling assembly 410, the holder or nest 414 being configured to securely hold the mold assembly 40 in a laterally fixed position on a nest platform 418. The defusing assembly 410 may further include structure to secure the mold assembly 40 in a longitudinally fixed position. For example, the decoupling assembly 410 can include a downwardly extending arm 422 (fig. 4), which arm 422 can be automatically or manually moved toward the nest 414 and the mold assembly 40. The downwardly extending arm 422 can include a mechanism 423 that contacts the mold assembly 40 and secures the mold assembly 40 in a longitudinally fixed position between the nest platform 418 and the downwardly extending arm 422. Once the mold assembly 40 is properly secured, it is substantially fixed in position and cannot rotate relative to the nest 416 and the downwardly extending arms 422.
The defusing assembly 410 further includes one or more inwardly extending cutting assemblies 424 that can be automatically moved toward the nest 416 and the mold assembly 40 secured thereto. Each inwardly extending cutting assembly 424 includes a cutting element 426, such as a blade, e.g., a heated blade 426, on a distal end thereof. Upon inward movement, the inwardly extending cutting mechanism engages the stationary mold assembly 40 and is inserted between the flange regions of the mold sections. In the particular decoupling assembly 410 shown, 3 blades 426 are automatically inserted into the mold assembly 40, typically between the mold sections thereof.
The defusing assembly 410 further includes structure effective to rotate the nest 416 and mold assembly 40 therein, such as in the direction represented by arrow 430 in fig. 3. In this case, the assembly is rotated in a counter-clockwise direction towards the right bottom cutting element. It will be appreciated that the nest 416 may rotate in either a clockwise or counterclockwise direction depending on which direction the sharpened face of the blade is facing. The rotation causes the cutting element to be inserted therein to cut through the mold sections at the fused region. The rotating means may include an actuator adapted and configured to rotate the clamped mold assembly in an appropriate direction such that the rotational motion causes the hot blade 426 to sever the ultrasonic weld joint between the mold sections. The cutting element 426 may then be automatically withdrawn and the mold assembly removed from the nest 416.
Turning now to fig. 4A and 4B, after the lens precursor composition is polymerized and optionally a defluxing step is performed, the method includes the step of separating the second mold portion from the first mold portion. In certain embodiments, the separation comprises placing a wedge or other separation device 610 between the first mold portion and the second mold portion as shown in fig. 4A. This can be accomplished by moving the wedge relative to the stationary mold section, or by moving the mold assembly relative to the stationary wedge. In embodiments where the wedge is linear, the movement is typically a linear movement from a thin region of the wedge to a thick region of the wedge. In embodiments where the wedge is circular, such as a disk, the movement may be a circular movement such that the wedge or assembly rotates about the central axis and such that the first mold section is separated from the second mold section. In certain embodiments, the wedge is unheated. However, in other embodiments the wedge may be heated to assist in separating the mold sections. Alternatively, the wedge may be cooled. Other embodiments may use a laser cutting blade to separate the mold sections.
As shown in FIG. 4A, a mold assembly separation device according to an aspect of the present invention is illustrated at 610. The device 610 includes a first separator 612a and a second separator 612 b. The first separator 612a and the second separator 612b are spaced apart to form a mold assembly track 614 a. The mold assembly 710 can be moved along track 614a in the direction of the arrow to separate the two mold sections of the mold assembly. The first separator 612a includes a wedge 616 a. Similarly, the second separator 612b comprises a wedge 616 b. Additionally, the second separator 612b includes a second wedge 616c and may be used to form a side of a second track 614b formed with a third separator (not shown).
As shown in the side view of fig. 4B, the first wedge 616a tapers along the length of the separator 612 a. For example, the wedge 616a has a small thickness, such as a knife edge, at a first end 618 of the separator 612a and a relatively larger thickness at a second end 620 of the separator 612 a. The wedge thickness gradually increases along the length of the separator. In certain embodiments, the thickness may remain constant (i.e., not tapered) in a portion of the separator proximate the second end 1520. Wedges 616b and 616c are substantially identical in structure to wedge 616 a.
To separate the mold sections of the mold assembly 710, the mold assembly 710 contacts the wedges 616a and 616b between the two mold sections of the mold assembly. The mold assembly 710 moves relative to the wedges 616a and 616b until the second mold section separates from the first mold section due to the stress caused by the gradually increasing thickness of the wedges. Alternatively, the separator may be moved relative to the mold assembly, if desired.
According to another aspect of the invention, the invention further provides methods, systems, and components of the systems for removing or removing a contact lens from a mold and treating the contact lens (e.g., a newly formed contact lens). In the context of the present invention, the delensing process can be understood as an integral part of the silicone hydrogel contact lens manufacturing process, or the delensing process can be a separate process.
The present delensing methods, systems and apparatus can be used to remove a swellable polymeric contact lens (e.g., a contact lens comprising a hydrophilic polymeric material) from a mold section or mold cup and to hold the removed lens during other processing steps. The contact lenses are often described as swellable contact lenses because during use of the contact lenses, the lenses include sufficient water to swell with such water. For example, the contact lenses often comprise from about 10% or about 15% or about 20% to about 50% or about 60% or about 80% by weight water when in equilibrium (e.g., when worn on the eye). Such contact lenses are often referred to as soft hydrophilic contact lenses or hydrogel contact lenses. In one particularly useful embodiment, the contact lens comprises a hydrophilic silicon-containing polymeric material. Such contact lenses are often produced using a hydrophilic monomeric material (i.e., a hydrophilic monomer) together with one or more other monomers that are polymerized during the formation of the contact lens.
As discussed herein, the methods and systems of the present invention include removing elements of a contact lens (e.g., a newly formed contact lens or a polymeric silicone hydrogel contact lens product) from a mold cup, such as a demolded mold section. The removed lens can then be processed in any suitable manner, such as an extraction process to remove extractable material from the lens, a hydration process to hydrate the lens, and packaging to provide a final contact lens product suitable for safe and effective wear. The system of the present invention includes equipment (hereinafter, generally "removal equipment") for effectively removing or assisting in the removal of contact lenses from mold cups, for example, in an effective and efficient manner with a reduced risk of damaging or otherwise damaging the lenses.
In another aspect of the invention, apparatus is provided to process the newly formed lenses that have been removed from the mold cups. The present invention further provides apparatus that effectively holds a newly formed contact lens during processing steps such as extraction and hydration (e.g., during treatment with a fluid (e.g., liquid) to remove extractable material from the contact lens) and provides a contact lens for safe and effective use.
Referring to FIG. 5, a removal apparatus, shown generally at 810, includes a series of four (4) vacuum bodies 812, 814, 816, and 818 in accordance with an aspect of the present invention. These vacuum bodies 812, 814, 816 and 818 are each connected to a respective vacuum generator 822, 824, 826 and 828 via a vacuum manifold 820, respectively. Manifold 820 provides fluid communication between each vacuum 812, 814, 816, and 818 and each vacuum generator 822, 824, 826, and 828, respectively. In addition, the manifold 820 includes a laterally extending portion 830 that is operatively attached to a robot or other operating/control mechanism during use of the removal device 810.
Thus, in the illustrated embodiment, the removal device 810 may be used in conjunction with a robot (e.g., a conventionally designed robot). The robot may be adapted, for example, may be preprogrammed or configured to respond to commands from a human operator to move the removal apparatus 810 as described above to perform the functions of removing a contact lens from a mold cup and placing the contact lens in a lens processing tray. In one embodiment, the removal apparatus 810 may be adapted to be directly manually operable to perform the functions described above. However, because of the highly repetitive nature of running the removal apparatus 810 and the considerable number of contact lenses being produced and processed, at least some degree of automation in the operation of the removal apparatus 10 is advantageous.
Each of the vacuum generators 822, 824, 826, and 828 may be controlled manually or automatically, such as by a robot, to provide vacuum 812, 814, 816, and 818, respectively, or to withdraw vacuum from the vacuum 812, 814, 816, and 818, respectively, to cause the removal device 810 to perform its function.
Each vacuum generator 822, 824, 826 and 828 advantageously comprises a syringe-like assembly including, for example, a movable piston that is suitably movable relative to the vacuum bodies 812, 814, 816 and 818, respectively, to create or eliminate a void in the hollow spaces 832, 834, 836 and 838, respectively.
The vacuum generator 822 is schematically illustrated in fig. 5A. Each of the other vacuum generators 824, 826 and 828 are constructed identically to vacuum generator 822. As shown in fig. 5A, the vacuum generator 822 includes a housing 823 and a drive member or mechanism 825 and a syringe-like piston 827 in the housing 823. The drive member 825 operates to move the syringe-like piston 827 controllably up and down within a space 831 defined by an inner wall 833. A substantially pressure-tight seal is formed between piston 827 and wall 833.
If desired, a number of drive members 825 may be used to move the piston 827 to create or withdraw a vacuum in the hollow space 832 of the vacuum body 812. For example, the piston 827 may be pneumatically operated, i.e., the drive member 825 is powered by air or other gas pressure; may be mechanically and/or electronically operated, such as by using a drive member 25 comprising an electric drive motor (e.g., a servo motor, etc.); other conventional and well-known drive members 825, and the like. In view of the conventional nature of many useful drive members, the drive members are not described in detail herein. For simplicity, the figures do not show the lines, conduits, and/or other components used to power the individual vacuum generators 822, 824, 826, and 828. However, it should be understood that such components are necessary for the removal device 810 to function as described herein.
Referring again to fig. 5A, when it is desired to generate a vacuum in the hollow space 832 of the vacuum body 812, the drive member 825 is actuated to move the piston 827 upward in the space 831. When it is desired to withdraw the vacuum in the hollow space 832, the drive member 825 is actuated to move the piston 827 downwardly in the space 831. If it is desired to provide positive air pressure (i.e., air pressure greater than atmospheric pressure) in the hollow space 832 of the vacuum body 812, the drive member 825 is actuated to move the piston 827 further downward in the space 831.
Referring to fig. 6-10, the operation of the removal device 810 is described with particular reference to the vacuum body 812. However, it should be understood that the vacuum bodies 814, 816, and 818 may operate in the same manner. Additionally, each vacuum body 812, 814, 816, and 818 may operate together or may each operate independently within the scope of the present invention.
The vacuum bodies 812, 814, 816 and 818 are all identically constructed. Accordingly, all references to the structure of the vacuum body 812 apply equally to the structure of each of the lens bodies 814, 816, and 818. The vacuum bodies 812, 814, 816 and 818 are preferably made of polymeric components, such as one or more acetyl copolymers; other suitable polymers and/or copolymers, such as polyethylene, polypropylene, polytetrafluoroethylene, polyetheretherketone, and the like; and mixtures thereof. Alternatively, a metal construction may be used, such as stainless steel,And/or other corrosion resistant alloys.
The distal curved surface 842 of the vacuum body 812 is convex and is shown in plan in fig. 7. The through holes 844 provide fluid communication between the hollow space 832 and the curved surface 842. As shown in fig. 7, the vacuum body 812 includes nine (9) through holes 844 in a circular array having a central through hole 844. The through holes 844 extend radially outward from the center of the surface 842 to expose an effective portion (e.g., at least about 10%, at least about 25%, or at least about 50%, and in some embodiments, a majority) of the surface of the contact lens to be secured to the vacuum body to the vacuum. In the illustrated embodiment, each through-hole 844 is a discrete structure that, at least on the surface 842, does not contact another through-hole 844. This feature advantageously reduces the amount of stress on the hydrated lens, thus reducing the risk of damage or even loss of the lens when the lens is removed from the mold cup and placed in a tray for further processing using the removal device 810. In addition, the relatively discrete application of vacuum to the contact lens, for example via the plurality of spaced apart through holes 844, advantageously reduces the amount of water from partially hydrated or fully hydrated contact lenses that enters the hollow space 832 during operation of the removal apparatus 10. The water reduction is relative to the same constructed system that includes only a single through hole for applying vacuum to the contact lens surface. The reduced amount of water entering hollow space 832 reduces the load on vacuum generator 822 and allows system 810 to be operated with reduced maintenance and downtime, and ultimately at reduced cost.
As shown in fig. 6, a vacuum body 812 included in or coupled to the removal device 810 is disposed directly above a female mold cup 850 carrying a newly formed hydrated hydrophilic polymeric contact lens 852. The female mold part or cup 850 is part of a mold assembly in which the lens 852 is formed. Thus, there is some degree of adhesion between the mold cup 850 and the lens 852 that needs to be overcome if the lens is removed from the mold cup 850.
The vacuum body 812 is moved into close proximity to the mold cup 850 such that the convex distal surface 842 is proximate to or in contact with the outwardly facing concave surface 851 of the contact lens 852. The convex distal surface 842 of the vacuum body 812 substantially complements at least a majority of the concave surface 851 of the contact lens 852.
As discussed elsewhere herein, vacuum generator 822 creates a vacuum in hollow space 832 that extends through holes 844 toward surface 851 of lens 852. The vacuum is strong enough to overcome the adhesion of the contact lens 852 to the mold cup 850 such that the contact lens 852 adheres to the convex distal surface 842 of the vacuum body 812 as shown in fig. 8 due to the vacuum. As further shown in FIG. 8, the vacuum body 812 is withdrawn from the mold cup 850 and the contact lens 852 is adhered to the vacuum body 812.
Vacuum body 812 and attached contact lens 852 are then moved directly over lens processing tray 860, as shown in fig. 9. Preferred eyeglass handling trays are described in detail elsewhere herein with respect to another aspect of the invention. Generally, the lens processing tray 860 includes a concave surface 862 that at least partially defines a lens cup 864. The vacuum body 812 is then moved so that the contact lens 852 is in close proximity to the concave surface 862 or in contact with the concave surface 862. At this point, the vacuum generator 822 operates as described elsewhere herein to withdraw the vacuum in the hollow space 832. The lack of vacuum causes lens 852 to fall into lens cup 864.
Optionally, vacuum generator 822 operates as described elsewhere herein to apply positive pressure to hollow space 832 and to lens 852 via through holes 844. In effect, the positive pressure forces lens 852 away from vacuum body 812 and into lens cup 864. Once the lens 852 is in the lens cup 864, the vacuum body is withdrawn from the processing tray 860 as shown in fig. 10.
Turning now to FIG. 9, another advantageous feature of the present invention is shown to assist in releasing the lens from the vacuum body 812. Specifically, FIG. 9 shows a shroud element 866 disposed on the proximal portion of the vacuum body 812, the shroud element 866 being effective to produce a cylindrical flow of air in the direction of arrow 867. The cover element 866 may comprise, for example, a ring having a plurality of ports 868 disposed adjacent to an outer peripheral surface of the vacuum body. The cover element is configured to create a cylindrical flow of air substantially around the outer peripheral surface of the vacuum body 812. Advantageously, an "air shroud" or air column provides a barrier around the perimeter of the lens 852 as it is being released into tray 860. The air shroud 866 is effective to maintain the eyeglasses in a substantially flat position when the eyeglasses are dropped into the tray recess 862. Without the provision of the air cap component of the present invention, it is highly likely that the released lens will fold, twist or slide along the vacuum head, for example due to surface tension of water on the lens.
Turning again to fig. 10, once the lens 852 has been released into the tray 860, the vacuum body 812 can now be used to remove additional contact lenses from the mold cups. This operation can be repeated for different contact lenses, if necessary.
It should be noted that the distal surface of the vacuum body 812 has a generally convex configuration. Thus, the vacuum body 812 is well suited for removing a lens from a female mold section of a mold, such as female mold cup 850.
In the case of a contact lens on or adhered to a male mold cup, an alternative vacuum body 870, shown in fig. 11, may be used. The surrogate vacuum body 870 is constructed and operates in substantially the same manner as vacuum body 812, except as explicitly described herein. Also, it should be noted that alternate vacuum body 870 may be used in conjunction with a series of such vacuum bodies (e.g., in a substantially similar or analogous apparatus to removal apparatus 810).
Vacuum body 870 includes a generally concave distal surface 872. Through hole 874 extends from hollow space 876 to surface 872.
As shown in fig. 12, vacuum body 870 includes a series of nine (9) through holes 874 in an annular array with a single through hole 870 passing through the center of distal surface 872.
As shown in fig. 11 and 13, an alternative vacuum body 870 may be advantageously used to remove the partially hydrated hydrophilic polymeric contact lens 878 from the male mold cup or piece 880. The contact lens 878 includes a generally convex, outwardly facing surface 879. The concave surface 872 of the replacement vacuum body 870 generally complements the convex surface 879 of the contact lens 878.
As shown in fig. 11, the vacuum body 870 is placed directly above the male part 880 carrying the contact lens 878. The vacuum body 870 is then moved to bring the surface 872 into close proximity to the surface 879 of the lens 878 or into contact with the surface 879 of the lens 878. At this point, a vacuum generator (such as vacuum generator 822) coupled with alternate vacuum body 870 operates as described elsewhere herein to provide a vacuum in hollow space 876 and to surface 872 via through-holes 874. The vacuum is sufficient to overcome any adhesion and/or other fastening forces between the contact lens 878 and the male mold part 880. Contact lens 878 becomes adhered to vacuum body 870 and vacuum body 870 is withdrawn from mold part 880 with contact lens 878.
As particularly shown in fig. 13, vacuum body 870 and contact lens 878 adhered thereto are moved and disposed directly above contact lens processing tray 882 comprising convex surface 884. The vacuum body 870 is moved so that the contact lens 878 is in close proximity to the surface 884 or even in contact with the surface 884. At this point, a vacuum generator associated with vacuum body 870 is operated as described elsewhere herein to withdraw the vacuum in hollow space 876 and apply a positive pressure to hollow space 876 in order to overcome the adhesion between contact lens 878 and vacuum body 870 and drop lens 878 onto convex surface 884. The vacuum body 870 is then withdrawn from the tray 882 and may be further used to remove additional lenses from the other male mold parts as described above.
Another embodiment of the removal apparatus of the present invention is shown in fig. 14 and 15. It should be noted that another vacuum 890 may be used in place of vacuum 812, 814, 816, and 818 in removal apparatus 810 shown in fig. 5.
Another vacuum body 890 includes a distal surface 892 that is generally concave. A single through hole 894 provides fluid communication between hollow space 96 and distal surface 892.
The other vacuum body 890 includes a ridge 898 extending radially outward from the through opening 894 and partially surrounding the through opening 894. The central ridge 899 partially defines the through-hole 894 and partially surrounds the through-hole 894. Ridges 898 and 899 both extend toward distal surface 892 of another vacuum body 890. Surface 892 includes an inner edge 900. In another vacuum body 890, the combination of inner edge 900, ridges 898 and 899, and through hole 894 form two recessed channels 902 and 904. The channels 902 and 904, which are in fluid communication with each other, effectively provide or transmit or contain the vacuum created in the hollow space 896 via the through hole 894. In other words, the channels 902 and 904 effectively spread the vacuum from the through hole 894 over a substantial portion of the area bounded by the distal surface 892.
The other vacuum body 890 operates in a substantially similar manner as the alternative vacuum body 870 to remove the contact lens from the male mold part and place the contact lens in a processing tray as described herein. However, instead of using a series of through holes, such as replacing through hole 874 in vacuum body 870, another vacuum body 890 uses a single through hole 894 and channels 902 and 904 to spread the vacuum over a substantial portion of the contact lens removed from the male mold part.
Other configurations of the through-holes in the vacuum body (as described herein) are contemplated and considered to be within the scope of the present invention.
In another aspect of the invention, the newly formed swellable polymeric contact lenses (e.g., those containing hydrophilic silicon-containing polymeric materials) are now typically treated with one or more liquids to prepare the lenses for packaging and shipping. Such lenses newly removed from the mold cups, for example, using the removal apparatus 10 described and illustrated elsewhere herein, include unreacted monomer and possibly other extractable materials that will be removed from the lenses prior to packaging the lenses for shipment/sale.
Turning now to fig. 16, each newly removed lens is preferably placed in the holding apparatus 910 of the present invention and held therein during the liquid treatment steps (e.g., treatment steps involving extraction of unreacted monomer and hydration of the lens). Thus, the lens processing tray 860 shown in fig. 9 is preferably replaced with the holding apparatus 910 of the present invention.
Typically, a plurality of newly formed lenses are held within holding apparatus 910 while the lenses are contacted with one or more liquid compositions during several stages of processing. The holding apparatus 910 of the present invention is configured to effectively achieve significant mass transfer of liquid to the lens and advantageously provide cost effective and efficient lens treatment.
In the illustrated embodiment, the holding apparatus 910 comprises a tray set 912 comprising an array of cells 916, each cell 916 being configured to contain an individual contact lens.
The structure of the tray set 912 will be more clearly understood with reference to FIG. 17 and the cross-sectional view of the tray set 912 of FIG. 18. The tray set 912 includes a plurality of trays 914, 914', each tray 914, 914' being configured to be couplable with the other of the trays 914, 914 '. More specifically, each tray set 912 can include two (2) trays 914, 914', such as two (2) identical or substantially identical trays 914, 914' stacked on top of each other. For the purposes of the present description, trays 914 and 914 'are provided with different numerical designations in FIG. 17, although the structure of trays 914 and 914' is the same.
Each tray 914, 914' includes a plurality of spaced apart chamber walls 922 and a plurality of spaced apart lid walls 924. Each cell 916 can be a contact lens shaped space defined between an individual chamber wall 922 and a generally opposing individual lid wall 924.
Each chamber wall 922, e.g., chamber wall 922 of tray 914, is sized and adapted to at least partially define a space, e.g., chamber 916, that carries the contact lens to be treated. Each chamber wall 922 is configured to allow the treatment fluid to pass through the space or chamber 916 to contact the contact lens located therein.
Similarly, each lid wall 924 (e.g., lid wall 916 of tray 914 ') is sized and adapted to cover a wall 922 of tray 914 that is generally opposite the tray 914 to which the tray 914' is coupled and thus limit the contact lens carried in the space or chamber 916. Each cover wall 924 is configured to allow the processing fluid to pass through the chamber 916 when the tray 914 is coupled with the tray 914'.
For example, each chamber wall 922 and each cover wall 924 includes at least one through-hole 930. In the illustrated embodiment, each chamber wall 922 and each cover wall 924 includes a plurality of through-holes. As shown, when the tray 914 is coupled with the tray 914', the through-holes 930 of the chamber walls 922 are aligned or substantially aligned with the through-holes 930 of the cover walls 924. The through holes 930 are very effective in allowing treatment fluid to enter and flow through the space or chamber 916 to contact the lens therein. The entry is very advantageous with respect to mass transfer (e.g., extraction between the lens within the space or cell 916 and the fluid passing through the space or cell 916).
In the illustrated embodiment, each chamber wall 922 is generally concave and each cover wall 924 is generally convex. However, the opposite arrangement may also be used. That is, each chamber wall may be generally convex and each cap wall may be generally concave. When the tray 914 and the tray 914' are coupled together, the chamber walls 922 are located at generally opposite positions relative to different ones of the cover walls 924. Additionally, each tray 914 can include a series of spacers 934, each spacer 934 providing a means to couple and/or align the chamber wall 922 of one tray 914 with the cover wall 924 of another try 914'. The configuration of spacers 934 is also shown in detail in fig. 18.
The number of chamber walls 922 and lid walls 924 included in each tray 914 may vary widely. For example, the cells 916 at least partially defined by the chamber walls 922 and the lid walls 924 can be arranged in an array or other particular pattern, such as a rectangular array as shown in fig. 16. Alternative cell arrangements may include square arrays or any other suitable geometrically configured array. In one aspect of the invention, each tray 914 includes about 20 to about 100 chamber walls and about 20 to about 100 lid walls. Each tray 914 preferably includes about 25 to 65 chamber walls and about 25 to about 65 lid walls.
The compartments 916 of the trays 914 (i.e., the spaces defined between the individual chamber walls of one tray 914 and the individual cover walls of the other tray 914 'when the two trays 914, 914' are coupled together) are advantageously designed such that movement of the glasses within each compartment 916 is restricted during processing to prevent folding and/or damage to the glasses in the compartments 916. As shown, the chamber 916 is perforated to allow fluid to enter and exit around the lens located in the chamber 916.
The tray design may include features to minimize the transfer of process fluid from one process stage to another. For example, a plurality of small holes 918 may be provided between the lens-holding cells 916 to trap increased drainage of fluid from the tray. Apertures 919 are provided to aid in automating the handling of the tray 914.
The tray 914 is constructed the same as the tray 914'. Thus, each reference to the structure of the tray 914 applies equally to the tray 914'. In a preferred embodiment of the present invention, the tray 914 is manufactured so that it is substantially unaffected by the conditions and materials used to treat the contact lenses carried in the tray cells. For example, the tray 914 is made of a material such that the tray 914 is substantially resistant to degradation caused by frequent contact with alcohols (e.g., alcohols such as methanol, ethanol, and the like, and mixtures thereof). In one very useful embodiment, the tray 914 is substantially resistant to ethanol. For example, tray 914 can comprise a polymeric material (e.g., a polymeric material such as polypropylene homopolymer) or other material suitable for use in alcohols such as an ethanol-containing environment. Additionally, the tray 914 is preferably designed to have low attenuation of ultrasonic energy that may be used during fluid processing of the contact lens to help stir the fluid used in the processing. The agitation or movement of the fluid assists in the mass transfer between the lens and the treatment fluid. The tray 914 may be a unitary, one-piece polymeric material, such as molded plastic.
Turning now to fig. 19, a system 1010 according to an embodiment of the invention containing a number of newly formed eyeglasses during fluid processing is shown, wherein the system 1010 includes a tray set carrier 1012 configured to contain a plurality of tray sets 912 in a stacked configuration. A system 1010 according to the described embodiments may include a plurality of tray sets 912, a tray set carrier 1012, and a plurality of carried contact lenses. For example, referring briefly back to fig. 17, each carried contact lens is located in a chamber 916 between one chamber wall 922 of one tray 914 of tray set 912 and one cover wall 924 of another tray 914'. In one embodiment of the present invention, the system 1010 includes a plurality of distinguishable sets of trays (e.g., mechanically or visually distinguishable trays or sets of trays), a tray set carrier 1012, and various different batches of contact lenses, which batches are distinguishable by their position in the distinguishable sets of trays.
The tray set carrier 1012, preferably having the tray set 912 and contact lens, is constructed so that it is portable. For example, the tray set carrier 1012 is sized and adapted to be moved around (e.g., from one contact lens processing stage to another contact lens processing stage) manually, automatically, or with the assistance of a robot. Typically, the newly formed lens-laden tray set carrier 1012 is submerged in a container of one or more different treatment liquids for the desired time. Thus, it is advantageous that the system 1010 be designed to enable easy lifting and transport between different contact lens processing stages. In some embodiments of the invention, a feature may be provided that enables automated, machine-operated (e.g., robotic-operated) pallet set 1012. For example, in the embodiment shown, the system 1010 is designed to enable robotic lifting and transport between different processing stages. For example, the rods 1013 at the top of the carrier 1012 are configured to allow an arch-type robot to transport the carrier 1012 through an extraction and hydration process that typically includes a series of tanks containing solutions.
The tray set carrier 1012 is preferably configured to enhance brightness, strength, and stiffness. For example, the tray set carrier 1012 is made of a stainless steel construction. More specifically, the tray stack carrier 1012 may be made of about 316 grade electropolished stainless steel or equivalent. This material is not corroded in a solvent deionized water environment. Advantageously, the stainless steel construction of the tray set carrier 1012 provides a negative buoyancy to ensure that the trays held therein are completely submerged in the solution during the processing steps.
In the embodiment shown, the tray set carrier 1012 includes a series of compartments 1015, each configured to hold one tray set 912. In the embodiment shown, the carrier 1012 is configured to hold forty-eight (48) tray sets 912, with each tray set 912 holding thirty-two (32) contact lenses. The tray group carrier 1012 is configured to allow each tray group 912 to be slidably received within a compartment, for example, by means of a bracket 1014 engaging an edge of the tray group 912.
More specifically, the support 1014 includes a wheel 1016 for holding each tray set 912 in a suspended position in the tray set carrier 1012. For example, a pair of spaced apart brackets 1014 are provided within each compartment. The support 1014 is configured to engage the edge of the individual tray set 912 in a manner that leaves the cells of the tray set 912 open for exposure to the processing fluid within the tray set carrier 1012. The wheel 1016 of the support 1014 holds the tray stack 912, for example, with an allowance sufficient to minimize separation or openness of the tray stack 912 seated in the compartment 1015 while still allowing the tray stack 912 to easily slide into the compartment. Each compartment is separated from each adjacent compartment by a wheel 1016 so that the extraction and hydration fluid or other treatment fluid can reach the top and bottom surfaces of all trays and all glasses held therein, for example, when the filled tray set carrier 1012 is in the treatment fluid. The system 1010 is constructed and designed to allow for efficient transfer of fluid between the lenses. Typically, the gap between the compartments measures about 1.0mm to about 3.0 mm. The gap between the pair of trays is defined by the gauge (thickness) of stainless steel used for the runner 1016.
The tray stack carrier 1012 may include a suitable blocking device 230 for preventing the trays 914 or tray stacks 912 from sliding out of the compartments 1016 during movement and handling of the carrier 1012 (e.g., between processing stages). For example, the blocking device 1030 may include a strap, such as a hinge strap 1032, and a catch 1034 for coupling the strap 1032. The catch 1034 is preferably positioned near the top of the pallet group carrier 1012. The stop 1030 is configured so that the hinge strap 1032 folds flat and out of the way when the tray set carrier 1012 is being loaded or unloaded. In fig. 19, the strap 1032 is shown in elevation view in the center of the carrier 1012, with the strap 1032 in an engaged position securing the tray stack 912.
In another aspect of the invention, the plurality of trays 914 comprises a different series of trays, wherein each series of trays is distinguishable from another series of trays. The distinction may be used to help identify the different contact lenses carried in each series of trays 114.
For example, the differences between different series of trays 914 may be visually identified. For example, the plurality of trays may include different series of trays 914, with each series of trays having a different color. The difference between different series of trays 914 may be a mechanical difference or a structural difference.
For example, turning now to fig. 20, 21, and 22, each series of trays may have one or more differently shaped grooves (e.g., peripheral grooves), one or more additional (e.g., raised) portions, one or more additional holes or indentations, and the like mechanical/structural differences and combinations of the differences. More specifically, tray 914a in fig. 20 includes raised features 940 that provide a visually identifiable distinction of tray 914a when tray 914a is compared to another tray that does not include the visually identifiable distinction.
In fig. 21, a tray 914b is shown that includes visually identifiable holes or apertures 942 for facilitating visual distinction. In fig. 22, tray 914c includes a recessed feature 944, which is a visually distinctive feature of tray 914 c. Other visually and mechanically distinctive features of the tray 914 may be provided that are not listed herein and are considered to be within the scope of the present invention. In addition, a single tray or set of trays may have one or more visually identifiable distinctions and one or more mechanical/structural distinctions that are separate.
Advantageously, the distinction between different trays and tray groups may be automatically monitored to help identify any one tray or tray group from another different tray or tray group. Being able to identify or distinguish one tray or tray group from another tray or tray group reduces the risk that a contact lens carried by any tray or tray group will be incorrectly characterized or identified.
Examples of the invention
The trays of contact lens mold assemblies are housed in a loading station, each assembly containing a freshly cured silicone hydrogel contact lens product. From the tray, the pair of mold assemblies are removed and placed in nests on a rotating pan. Pairs of mold assemblies are moved between the various processing stations while they remain in the nest.
Each mold assembly was moved to an immersion station where the mold assembly was placed in a liquid bath containing deionized water at a temperature of 75 ℃. Ultrasonic radiation is passed through the liquid bath to help decouple the mold sections. The mold assembly is substantially completely immersed in the liquid bath. Alternatively, the mold assembly is immersed in a liquid bath such that at least the mold sections comprising the concave lens shaped surface (i.e., "lens cups") are in contact with the liquid. The mold assembly was left in the liquid for about 7 seconds. The liquid bath process operates to break or de-fuse the bonded region between the first mold portion and the second mold portion. In addition, the impregnated female mold section can help adhere the ophthalmic product to the eyewear cup rather than to the convex lens shaped surface of the male mold section. In addition, the heating of the water may help release extractables from the lens and/or improve the lubricity of the lens.
After 7 seconds of bath soak, the mold assembly was removed from the liquid and transferred into a cleavage assembly. The mold sections adhere to each other despite the weld between the mold sections having been substantially or completely broken by the liquid bath. Each pair of molds is placed on a carrier that holds the molds without clamping the molds. The splitting or separation of the mold sections occurs by the splitting assembly prying the mold sections apart from one another.
In detail, the carriers of the paired mold assemblies are located on rails. The splitting assembly includes a block containing three blade assemblies (left, middle, and right). The left and right blade assemblies each include a single wedge-shaped blade and the middle blade assembly includes two opposing wedge-shaped blades. Thus, the three blade assemblies define two channels, each channel configured to accommodate a single mold in one carrier. Each blade is wedge-shaped because the front end of the blade is very thin and the rear end is thicker. Which tapers from end to end. The blade pitch is from about 0.5mm to 3.5mm over a length of about 10 inches.
The carrier slides the mold along the blades. The blade front end contacts the mold assembly and passes between the mold sections. As the carrier and the mold assembly carried thereby advance toward the back of the blade assembly, the top mold section (male mold section) separates from the bottom mold section (female mold section). Any residual monomer mixture on the flange of the mold section (i.e., around the edge of the contact lens) remains adhered to the top mold section and is removed therefrom. After the splitting process, the top mold portion rests on the bottom mold portion with the eyewear disposed therebetween.
The robot arm grasps the top mold portion and discards it.
Each lens-containing lower mold section is then immersed in a fluid bath. The fluid bath was deionized water at 75 ℃, optionally with ultrasonic waves transmitted through the fluid. High temperatures help control bacterial development and lens contamination. The fluid portion releases or decouples the lens from the mold portion by causing the lens to swell. The swelling or expansion of the lens body substantially lifts the lens from the lens cup surface. Other fluids that may be used to swell the lens to release the lens from the molding surface include ethanol, acetic acid, 20% IMS/80% water (change in pH, change in salt concentration).
In the stage, the fluid may become contaminated with unpolymerized monomer over time, although this step is not a true extraction of all unpolymerized monomer. Thus, the fluid of the bath is filtered through carbon, particulate and chemical filters. The water also passes through UV lamps to reduce contaminants in the water.
Subsequently, the robot arm grips the mold section and the lens and tilts the mold section forward to drip water from the lens cup into the water bath. The glasses slide forward just off the center of the glasses cup.
When clamped, the mold may be passed through an optional reader to ensure that the lens is properly identified and will go to the correct location. Other readers, such as UPC symbols or other indicia, may be provided on the mold sections and used in order to ensure proper identification of the lens throughout the various stages of processing.
The vacuum head (such as according to certain aspects of the invention and described elsewhere herein) is lowered to contact the lens and the lens is drawn onto the vacuum head. The vacuum head has a plurality of vacuum ports. In this step, the four vacuum heads approach the four lens cups at an angle of about 10 degrees to about 15 degrees so that the vacuum heads are substantially perpendicular to the location of the concave surface of the lens due to the tilting of the lens during liquid dispensing. An air shroud is provided along the periphery of the vacuum head to help retain the lens in a desired position on the vacuum head during release. In a sense, the shroud is a cylindrical column of air that hangs down around the vacuum head. Without the cover, the lens may fold back or slide onto the vacuum head due to the high surface tension of the water as the lens is released from the vacuum head.
The lenses were removed from the vacuum head and placed in a tray. The tray is color coded to contrast with the glasses so that the glasses can be seen. The tray has walls with holes to assist in the downstream extraction process. Each tray containing the glasses is covered with a lid and moved to a downstream processing stage.
In view of the foregoing, it should be understood that the present invention relates to contact lenses, such as silicone hydrogel contact lenses; a manufacturing system and a manufacturing method; and system components for use in the systems and methods.
For example, a method of demolding a contact lens mold assembly includes placing a contact lens mold assembly comprising a polymerized silicone hydrogel contact lens product in a heated water bath, and separating a male mold section from a female mold section of the mold assembly by moving the mold assembly relative to a splitter comprising a wedge-shaped component. Various embodiments of the demolding method may include one or more steps as described herein.
A method of removing a silicone hydrogel contact lens product from a mold section of a mold assembly comprises placing the silicone hydrogel contact lens product located on a surface of the mold section in a heated bath, such as a hot water bath, and removing the hydrated silicone hydrogel contact lens product from the mold section using a vacuum device comprising a plurality of vacuum ports on a lens contacting surface of the device and a gas cap forming device. Various embodiments of the delensing method can include one or more steps as described herein.
Methods of manufacturing silicone hydrogel contact lenses can comprise the demolding methods of the invention and the delensing methods of the invention.
The invention also covers a system for carrying out the method of the invention.
In addition, the present invention encompasses components of the system. For example, embodiments of the present invention relate to a vacuum device for removing hydrated silicone hydrogel contact lenses from mold sections and placing the removed contact lenses in the cells of an extraction tray. Another embodiment of the invention relates to an extraction tray comprising a plurality of cells configured to hold hydrated silicone hydrogel contact lenses. Various embodiments of the system components may include one or more features or elements as described herein.
Certain aspects and advantages of the present invention may be more clearly understood and/or appreciated with reference to the following commonly owned U.S. patent applications, filed on even date herewith, the disclosure of each of which is hereby incorporated by reference in its entirety: U.S. patent application No. 11/200,848 entitled Contact lenses Molds and Systems and Methods for Producing Same and attorney docket No. D-4124; U.S. patent application No. 11/200,648 entitled "Contact lenses molds and Systems and Methods of Producing Same" and attorney docket No. D-4125; U.S. patent application No. 11/200,644 entitled "Systems and Methods for Producing contact lenses from a Polymerizable Composition" and attorney docket No. D-4126; U.S. patent application No. 11/200,863 entitled "Contact Lens Extraction/hydrogenation Systems and Methods of processing fluid Used Therein" and attorney docket No. D-4128; U.S. patent application No. 11/200,862 entitled Contact Lens Package and attorney docket No. D-4129; U.S. patent application No. 60/707,029 entitled Compositions and Methods for Producing Silicone hydrogel Contact Lenses and attorney docket No. D-4153P; and U.S. patent application No. 11/201,409 entitled "Systems and Methods for Producing silicon Hydrogel Contact Lenses" and attorney docket No. D-4154.
A number of publications and patents have been cited above. The disclosures and patents cited are each incorporated herein by reference in their entirety.
While the invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not so limited and that it can be practiced in various ways within the scope of the following claims.