CN1065342A - Contact lens cast moulding and packing - Google Patents

Abstract

A kind of mould of molded production contact lenses comprises have male mold surfaces first cup shell (11) of (14) and second cup shell (16) with female mold surfaces (19).Two cup shells (11,16) have constituted a piston and cylinder and have been used in the pressure vessel (26), so that apply load pressure, with mold surface (14,19) deflection deformation, keep this surface to contact with lens surface.When mould was opened, surface (14) up.Aqua liquid (35) is added in first cup shell (11), and a closure (34) is sealed to the top of first cup shell (11).

Description

Contact lens cast moulding and packing

The present invention relates to the molding contact lenses, particularly relate to equipment and the method making and pack this eyeglass.

Mould-forming is a kind of known method of producing contact lenses.With additive method, compare it with centrifugal casting as turning processing and have very high crudy and with low cost.Mould-forming still be a kind of can repeated job operation.

In mould-forming processing, it is extremely important to keep a good sealing between mold members, and it can prevent to be used for to make volatilization composition in the monomer of eyeglass and leak and the edge contour of a cleaning is provided for the eyeglass of molding.Use existing method, mold members normally is clamped together by mechanical hook-up.But in solidification process, mold members may be loose, causes seal load heterogeneous to produce.In addition, it is also very difficult to design such mould, that is, it can be applied to enough pressure on the seal between the mold members, so that be in unnecessary monomer in the material overflow cavity and the monomer in the lens cavities separately.The inspection process that bad sealing can cause damaging eyeglass and need the labor intensive material resources is to reject substandard products.

In mould-forming processing, the contraction of compensation monomer in the polymerizing curable process forms also very important with bubble or the hole that prevents to produce owing to cavitation.For lowering above-mentioned influence, known method is to provide a flexible edge to one of them mold members, and this edge shrinks in polymerization process.Other system allows to flow back to lens cavities from the monomer in the storage chamber in the mould under the swabbing effect of shrinking, and allows die surface move toward one another under swabbing effect.But, the method affect of flexible edge and storage chamber sealing, produced the eyeglass that need polish in substandard products eyeglass and edge.The job operation of this die surface motion is that than the advantage of additive method it can make seal remain intact, but carefully design of formwork, so that under suction force, shrink evenly.The variation of mold thickness, material or solidification temperature will influence the rigidity of mould, and then changes shrinkage degree.Shrink the rigidity that the suction that produces must overcome mould structure itself by monomer, can not for example aspirate into the monomer in material overflow cavity around the mould again.In molding processing, in die device, one or several cavity must be set, be used for holding when mold members is closed the excessive monomer of extruding.In solidification process, these excessive monomers have constituted flash, and before packing, these flashes must be separated with eyeglass.In some cases, by a gripping ring is set, flash is easily attached on the mould, but in general detachment process is to carry out and expend cost by hand.

In molding processing, after curing, eyeglass trends towards adhering on one of them mould randomly, unless mould is designed to eyeglass is remained on that selected mould.When mould separated behind curing process, it was favourable can controlling or be limited to eyeglass in the selected mould.Rely on the flexible edge to compensate the mould that monomer shrinks, tend to eyeglass is remained in that mould with flexible edge.This is because common this flexible edge bend into lens cavities, and the cause of the sclerosis of the monomer around the lens cavities.Although to a certain extent, can utilize this method that eyeglass is fixed on the mould, but the net effect at this edge will make the lens edge distortion, cause the lens edge profile inconsistent, produce substandard products and those unspoiled eyeglasses that take out by mechanical means from mould are still needed with the edge polishing evenly.The other method that eyeglass is remained on a selected mould is to produce the shape of turning back at the lens cavities edge with the hard lens of wedging.For example: the lens cavities in the die can have the edge contour of the shape of turning back, and it can maintain hard lens.Yet this has limited the design of rims of the lens profile greatly, and rims of the lens thickness is increased greatly.

In mould-forming processing, some batch product needed is painted.Many coloring systems are arranged, but all need carefully to locate and supports lens, so that ink or dyestuff can accurately be applied to lens surface, convex front face normally, and can not damage eyeglass.If desire reduces to minimum with substandard products, the location of this eyeglass just need be expended very big work and need the operator to have certain technology.

In mould-forming processing, may require eyeglass is carried out some processing, as surface treatment.It is low-cost and high-quality carrying out this operation when eyeglass still remains in the mould, but must be able to guarantee that eyeglass is maintained in this mould.

In mould-forming processing, when the check of eyeglass experience, multiplying power are measured, selected, hydration, arrive finished product packing then, normally during a vial, these operations are to finish in different containers.If these operations can be carried out in a mould, this mould still is a chief component of finished product packing, then can realize low cost and high-quality.If the mould of component part packing is designed to eyeglass and appropriately is orientated, the user can easily be taken out, then have bigger ground superiority.This can obtain topmost by the convex surface that makes eyeglass.In addition, one " basket " is provided or carries device holding eyeglass and the user can easily be taken out in the packing of eyeglass, may some superiority.

In mould-forming, the optical surface of protection mould is very important, causes substandard products because the slightest scar also can be transferred on the eyeglass.When mould when the molding machine is upspring, will produce damage.Similarly, for healthy reason, with optical surface with both made that to be that the possibility that contacts of soft object drops to minimum also very important.

An object of the present invention is to the mould-forming contact lenses provide a kind of improved equipment and method, and then improved contact lenses are provided and improve the contact lenses of packing.

Another object of the present invention provides a kind of improved method and apparatus, and wherein, when die sinking, the eyeglass of molding is to be bearing in male mold surfaces and to form a kind of packing effectively in the container that is made of a part of mould by eyeglass is sealed in.

The method that mould-forming provided by the present invention is produced contact lenses comprises:

Polymerization single polymerization monomer in the die cavity that the female mold surfaces of the male mold surfaces of first mold members and second mold members constitutes;

Open mould, the eyeglass that exposes molding makes it be bearing in male mold surfaces simultaneously;

By a closure being sealed on first mold members and eyeglass is sealed and packed.

Be easy to act as most female mold surfaces and feed monomer in the die cavity up the time, then mould is turned around, make that when die sinking, male mold surfaces up.

The present invention also comprises a mould that is used for said method, wherein, this mould comprises that one has first mold members and second mold members with female mold surfaces of male mold surfaces, each mold members has a pedestal, the mould-forming surface is respectively formed on separately the pedestal, and a circular wall extends upward from this pedestal, and the circular wall setting of first and second mold members becomes to resemble the juncture being slidingly matched, thereby two mold members can resemble moves with open-close module piston and the cylinder.

Best, the male mold surfaces in the first mold members pedestal and the circular wall of first mold members separate, and make to form an annular groove around this male mold surfaces in this circular wall.

The other method that mould-forming provided by the present invention is produced contact lenses comprises:

But polymerization single polymerization monomer in mould with a die cavity that forms between by the formpiston of relative motion and female mold surfaces;

One rigidity shoulder is used for forming the edge sealing with the sealing die cavity between two die surfaces;

At least one mold surface is flexible under load pressure;

This method is characterised in that injects die cavity with monomer, then with its sealing, applying a super-atmospheric pressure in a pressure vessel makes load pressure affact mold surface and forms a pressurization around the rigidity shoulder, follow curing monomer, in polymerization process, along with monomer shrinks, load pressure makes a mold surface shrink, and keeps this surface to contact with eyeglass.

Preferably the surface of formpiston and former is formed on separately the mold members, and this mold members is arranged to engage with the piston that slides and the form of air cylinder device, and the super-atmospheric pressure that applies acts on two mold members, forces formpiston and female mold surfaces move toward one another.

The present invention also comprises a kind of method of mould-forming production contact lenses, and it comprises:

Polymerization single polymerization monomer in the die cavity that between the surface of formpiston and former, forms;

Open mould, expose the intact eyeglass of molding and make it be bearing in a mold surface simultaneously;

Be used to punch to eyeglass, so that the eyeglass of a required hole count to be provided from the laser beam of excimer laser instrument;

Medicine is put on the eyeglass, makes the drug dose that carries on the eyeglass by the quantity of hole and the concentration decision of medicine;

And by above the mold members that a closure is sealed to supports lens that eyeglass is sealed and packed.

The present invention also provides a device that is used for the mould-forming contact lenses of said method.This device preferably includes a dimeric mould.Wherein, a male mold surfaces is arranged in the cup shell, and female member is arranged on the piston piece that slides in cup shell.One outwardly bead preferably is set on the cup shell so that the upper surface of male member be positioned at bead below, thereby after eyeglass was shaped, a closure was salable on this bead, and the eyeglass that is bearing on the male mold surfaces is positioned under this closure.

Some embodiment of the present invention will by way of example and be described below with reference to the drawings.

Fig. 1 is the used cross-sectional view of die device before placing a pressure vessel among the present invention;

The enlarged drawing of Fig. 2 for sealing between two mold members in the device shown in Fig. 1;

Fig. 3 is the diagrammatic sketch after device shown in Figure 1 is put into a pressure vessel;

Fig. 4 is the eyeglass that first mold members of die device among Fig. 1 has molding, the diagrammatic sketch after opening at die flip and with mould;

Fig. 5 is the seal-packed diagrammatic sketch that has hydration molding eyeglass of the present invention;

Fig. 6,7 and 8 is a multi-form perforation eyeglass of the present invention.

Present embodiment relates to the manufacturing of molding contact lenses, it be by one in first mold members male mold surfaces and the die cavity between the female mold surfaces in second mold members in polymerization single polymerization monomer finish.In the accompanying drawings, first mold members 11 comprises that one has the cup shell of pedestal 12, is circular wall 13 around the pedestal.Male mold surfaces 14 is formed on pedestal 12 central authorities and separates with circular wall 13, makes a ring band 15 form between circular wall 13 and male mold surfaces 14.Second mold members 16 also is cup-shaped, and it has a pedestal 17, and circular wall 18 is around pedestal 17.Female mold surfaces 19 is formed in the basal seat area 17, separates with circular wall 18 by flat annulus 20.The circular wall 13 interior formation that the circular wall 18 of second mold members 16 is arranged in first mold members 11 tightly are slidingly matched.Like this, two mold members can be combined together and form a piston cylinder device as shown in Figure 1, and wherein, two mold members can be slided relatively, with open-close module.Male mold surfaces 14 is arranged in the cup of first mold members, and female mold surfaces 19 makes when two mold members are combined together as shown in Figure 1 outside the cup of second mold members, and a die cavity 21 is formed between the matched molds surface.The circular wall 13 of first mold members 11 has a collar flange 22 in its end away from pedestal 12.

The wall portion that constitutes male mold surfaces 14 and female mold surfaces 19 has enough rigidity, they can not shunk the big deflection deformation of generation under the suction that produces by the monomer in the die cavity 21, but can apply under the selected load pressure, deflection deformation is to keeping in touch with the monomer that shrinks.This load pressure can obtain by in pressure stove or other pressure vessels super-atmospheric pressure being applied on two mold members.Around the female mold surfaces 19 rigidity shoulder 25 is arranged, as shown in Figure 2.Rigidity shoulder 25 so that between yin, yang mould surface, forms a sealing reliably in abutting connection with male mold surfaces 14, is applied in the converging operation that produces on two mold members at pressure, and sealing can not distort or deflection deformation.

Mould shown in Figure 1 is an injection mould, for the plastic material that is suitable for as the polypropylene injection molded.

In use, when female mold surfaces 19 up the time, liquid monomer is injected the concave surface of former.Then, as shown in Figure 1, patrix moves downward seals counterdie, touches rigidity shoulder 25 until male mold surfaces 14.At this moment, formpiston 11 is in topmost.Any unnecessary liquid monomer all is extruded between the optical surface of matched molds, enters ring groove 23, so that 24 discharges from the hole.

Then, as shown in Figure 3, this device is put into a pressure vessel 26.Pressure in the container makes two mold members 11 and 16 be forced to move toward one another by increasing from compressed gas source 27 applied pressures.Pressure in the container cans be compared to high 0.2 to 1 crust of atmospheric pressure most.Particularly, matched molds surface 14 and 19 is forced to move toward one another by applied pressure, shown in arrow 30 and 31.Engaging force between two mold members concentrates near the shoulder 25, because bonding area is quite little, therefore, has constituted effective seal.This sealing makes eyeglass have the edge of a cleaning and has constituted an isolation layer, to prevent that the volatile composition from lens monomer spills in the mould cavity.In container 26, apply super-atmospheric pressure and guaranteed that a gratifying load pressure is applied to matched molds surface 14 and 19, makes that they can produce deflection deformation with the volumetric contraction of lens monomer in polymerization process.Like this, the optical surface of matched molds becomes by colloidal state the solid-state whole process from liquid state at monomer, remains to be in contact with it.The super-atmospheric pressure that applies has produced a more effective sealing and has made the mold surface deflection deformation and then contact with monomer all the time, and this is to only depend on monomer to shrink the suction that produces can not reach.Thickness that the matched molds wall thickness of manufacturing present embodiment is required and process control do not need very strict, because wall thickness is complementary to the swabbing effect that the resistance that moves need not to shrink with monomer.The resistance of motion of mold members overcomes by applying superatmospheric pressure, and this air pressure is easy to control, from obtaining required deflection deformation.

The optical surface 14 of formpiston in this example, is to process through flame, and this is a kind of method that improves surface smoothness and increase surface energy.It has guaranteed the eyeglass of polymerization and protruding male member keeps in touch so that following process.As shown in Figure 3, after handling in pressure stove 26, die flip also is separated into two halves.Mould 16 is taken away, and as shown in Figure 4, the eyeglass 32 of molding remains on the male mold surfaces 14 in the cup shell 13, is lower than the surface of bead 22.Like this, the eyeglass of molding is maintained easily, and its outer optical surface exposes, so that further processing.In the example of Fig. 4, a selectable print head 33 is positioned at the top of molding eyeglass, makes any printing treatment can be applied on the outside surface of eyeglass.When eyeglass was maintained at position shown in Figure 4, following process can further comprise and adds color on lens front surface.In this sense, the front surface of eyeglass 32 is a nonreentrant surface.As seen from Figure 4, the circular wall 13 of mold members 11 extends upward, and is higher than male mold surfaces 14, makes that the bead 22 of circular wall 13 upper ends is higher than the eyeglass 32 on the male mold surfaces when mould is opened.In the time of in eyeglass remains on cup-shaped spare 13, mould and eyeglass can accurately be located, and can not produce to resemble issuable damage when placed apart of eyeglass and mould.Cup-shaped spare 13 for rectifying and/or aqua liquid receiving space is provided, these liquid are used for taking off eyeglass and making it injury-free from the mould optical surface.Mould and eyeglass can be controlled effectively by automatic processing device, those danger that do not have frangible eyeglass to have.And eyeglass is suitable for being positioned at position shown in Figure 4, so that laser boring or other processing.

After the process surface treatment, eyeglass 32 still remains in the cup shell 13 through hydration-treated simultaneously.This comprises the flute profile district 15 injection salt solusions in cup shell, but need not to take away eyeglass.Because the problem that air gap during monomer shrinks and flash are detained lens edge has been avoided in the present invention, can produce high quality mirror, make and to adopt the pick test technology and need not to adopt 100% method of inspection that adopts in the present eyeglass commercial production.Like this, will have equal in quality and need the mode of production of a large amount of works for inspection to spend lower cost than those.

At last, a mobilizable lid 34 is sealed on the bead 22 of mold members 11, makes eyeglass 32 and salt solusion 35 be sealed in the packing.The material of lid and sealing all have goodish isolated characteristic, to guarantee that sealed solution is not through degenerating for a long time yet.As shown in Figure 5, the wrappage of selection can bear sterile environment such as high-pressure steam sterilization.

In use, lid 34 can be torn from the cup-shaped spare that holds eyeglass 32.After lid was taken away, salt solusion can be poured out from packing, and eyeglass 32 is remained on wrapping position on the male mold surfaces 14.Its special usefulness is, eyeglass towards reserving in advance with respect to the position of packing, this make by a known direction take out eyeglass become be easy to many.This has just been avoided eyeglass to be poured out from container picking up before eyeglass puts into eyes, be in a unknown towards.And the outside surface of eyeglass is up in packing, then, can catch and touch and can be before eyeglass is not put into eyes, with its pollution.

In male mold surfaces 14 ring groove 15 being set on every side helps the eyeglass of molding is taken out from packing.Because annular groove provides enough spaces around eyeglass, the help user holds eyeglass and it is taken out from packing.

As mentioned above, eyeglass can further be stamped many micropores, and this is to utilize laser beam, finishes as the shortwave excimer laser beam.These laser beam can be broken chemical bond and run through eyeglass and can not dissolve eyeglass or its material is flowed or produce fragment and other thermal effect.This method is called as light and cleans decomposition method.This can apply laser beam and realize by with the short pulse duration.Jagged and the worn-out outside of pore area has been avoided in the hole of getting like this.These defectives make the user of eyeglass feel to feel bad very much.Fig. 6,7 and 8 has represented the different hole patterns that forms by excimer excimer device.These holes help improving the perviousness of gas penetration potential or eyeglass.The quantity of hole and position can change the air flux of finished product eyeglass.Tear stream, permanance and wettable.Therefore, lens designers can be optimized the performance of eyeglass by suitable punching.In this example, the hole 36 that is formed by laser beam is about 150 microns rectangular opening.Can allow the hole be covered with whole eyeglass, only stay at the edge very little one to keep the complete of lens edge, as shown in Figure 6.Can also only form hole as shown in Figure 7 at central optical zone 37.Can also be as shown in Figure 8 in non-optical zones, promptly the ring-shaped area 38 in the central optical zone outside forms hole, but reserves a fritter at lens edge.Hole can be formed on the dried eyeglass before the hydration or be formed on hydration after wet eyeglass on.

As shown in Figure 5, the treatment step before the package encapsulation comprises when eyeglass is maintained at exposure position shown in Figure 4, puts medicine to eyeglass.

As mentioned above, the eyeglass by excimer laser punching can be used as a kind of medicinal sponge, and wherein, the quantity of the medicine that is absorbed depends on the degree of eyeglass punching and sends into the intensity of the medicine in the cup-shaped spare at eyeglass place.Eyeglass can be processed into to have required hole degree and absorbs required medication amount, makes that this packing comprises that one contains the eyeglass of required dosage medicine when being sealed to as shown in Figure 5 structure.Like this, the medicine of required dosage can be packaged in the disposable eyeglass specification in advance.

Punching shown in Fig. 6,7 and 8 with excimer laser.Can be used for by differing from the molding contact lenses that the method and apparatus shown in Fig. 1 to 5 is made.

Superiority of the present invention is that also it can use the monomer that needs ultraviolet curing or other non-heat curings and heat treatment for solidification.Should be understood that when utilizing heat treatment for solidification the deflection that mold surface produces during monomer is shunk has less resistance.But when using non-thermoset monomer, mold surface will have big resistance to deflection, and the power that is only produced by the monomer contraction is not enough to guarantee that when monomer shrank, mold surface kept being in contact with it.Yet the use of super-atmospheric pressure can be controlled in degree required on the atmospheric pressure, even make it be enough to allow mold surface deflection and also can keep contacting with monomer when the non-thermal treatment as ultraviolet curing.

The present invention is not limited to the content of above-mentioned example.

For example, former and male mold surfaces can be passed through flame polish, to improve the surface smoothness on eyeglass two sides.After relieving, control in addition by that surface bearing eyeglass in order to decontrol eyeglass from mould, mould can partially open, inject salt solusion and discharge this solution, mould upset simultaneously with the cavity between the increase matched molds surface and by one side of opening 24 by the another side of opening 24.Flowing of salt solusion will be decontroled eyeglass, and before salt solusion is discharged, by mould being turned to vertically or overturned position, the eyeglass of relieving will be fallen and be bearing on the required formpiston or female mold surfaces.

Claims (21)

1, a kind of method of mould-forming production contact lenses is included in a kind of monomer of polymerization in the die cavity, this die cavity is between the female mold surfaces of the male mold surfaces of first mold members and second mold members, opening the mould eyeglass that molding is intact exposes, be bearing in male mold surfaces simultaneously, eyeglass be sealed in the packing by a closure being sealed on first mold members.

2, according to the method for claim 1, be characterised in that when female mold surfaces up the time monomer is injected this die cavity, and the mould that reverses then makes when opening mould, male mold surfaces is up.

3, according to the method for claim 1 or 2, be characterised in that first and second mold members are relative sliding joint, resemble piston and air cylinder device with open-close module, first mold members formation one has the cup shell of base part, pedestal is cooperated the upright circular wall of second mold members to center on by one, and male mold surfaces is formed on the pedestal and in circular wall and be spaced from forming a groove district, so that mould is when opening, aqua liquid is sent into this groove, this eyeglass of hydration.

4,, be characterised in that closure is sealed to the upper limb of this circular wall according to the method for claim 2.

5,, be characterised in that male mold surfaces through flame polish, helps when mould is opened eyeglass to be remained on male mold surfaces according to the method for claim 1.

6,, be characterised in that male mold surfaces through flame polish, helps when mould is opened eyeglass to be remained on female mold surfaces according to the method for claim 1.

According to the method for claim 5 or 6, be characterised in that 7, after mould was opened, eyeglass was held in and is exposed to die surface and on the eyeglass outside surface that exposes, accepts further processing.

8,, be characterised in that further processing comprises color or printing according to the method for claim 7.

9,, be characterised in that further processing comprises one or more hole of running through lens thickness by the formation of application laser beam according to the method for claim 7.

10,, be characterised in that this laser beam is an excimer laser beam according to the method for claim 9.

11,, be characterised in that on eyeglass, can form many holes to form an eyeglass with required hole count according to the method for claim 9.

12,, be characterised in that on eyeglass to form many holes, so that an eyeglass with required permanance to be provided according to the method for claim 9.

13,, be characterised in that the medicine of required dosage is put into the porous structure that is formed by hole according to the method for claim 11.

14, according to the method for claim 1, be characterised in that a kind of monomer of polymerization in the die cavity between a formpiston and female mold surfaces, open mould, expose the intact eyeglass of molding, it is bearing on one of them mold surface.Utilize a laser beam to punch to eyeglass, so that the eyeglass with required hole count to be provided, on eyeglass, apply medicine, make of what and the drug concentrations decision of the dosage of the entrained medicine of eyeglass, by above the part mould that a closure is sealed to supports lens eyeglass being sealed in the packing by hole.

15,, be characterised in that after the medicine of above-mentioned dosage applied, this eyeglass stood hydration-treated according to the method for claim 14.

16, a kind of method according to claim 14, be characterised in that when opening mould, the eyeglass that molding is good is bearing in male mold surfaces, this surface has by one and is projected into the cup-shaped of circular wall that is higher than eyeglass and centers on, when eyeglass is bearing on the male mold surfaces, aqua liquid is sent into cup shell with this eyeglass of hydration, a covering is sealed on the cup shell, be higher than eyeglass, so that in cup shell, form packaged eyeglass.

17, a kind of method according to one of claim 14 to 16 is characterised in that laser instrument is an excimer laser.

18, a kind of mould that is used for according to the method for aforementioned any top claim, this mould comprises that one has first mold members and second mold members with female mold surfaces of male mold surfaces, each mold members has a pedestal, mold surface separately just is formed on this pedestal, one circular wall becomes cooperatively interacting resemble the sliding fit from the circular wall setting that this pedestal protrudes upward first and second mold members, thereby two mold members can resemble moves with open-close module piston and the air cylinder device.

19, according to the mould of claim 18, be characterised in that male mold surfaces is formed on the base part of first mold members, this surface is in first mold members; In the circular wall and be spaced from, so that in the circular wall of male mold surfaces, forming a groove district.

20, according to the mould of claim 18 or 19, be characterised in that there is a bead circular wall upper end of first mold members, the closure that is used to seal is salable in this protruding end.

21, according to the mould of claim 20, the circular wall that is characterised in that first mold members extends to and is higher than male mold surfaces.

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