CN111483099B - Mold for demolding contact lenses and method thereof - Google Patents

Abstract

The invention provides a mold for demolding a contact lens, which comprises a first mold and a second mold, wherein the first mold comprises a mold cavity sunken towards a first direction, a bending section extending outwards from the periphery of the mold cavity, a first mounting part adjacent to the bending section and a sunken section formed between the first mounting part and the bending section, and the wall thickness of the bending section is thinner than that of the mold cavity so as to be matched with the sunken section to help the mold cavity to deform and fold backwards; the second mold comprises a round protrusion part protruding towards the mold cavity and a second mounting part adjacent to the round protrusion part, and an assembly structure is formed between the second mounting part and the first mounting part, so that when the contact lens is demolded by using the mold, the mold cavity can be easily deformed by turning over to complete the demolding.

Description

Mold for contact lens release and method therefor

technical field

The present invention relates to a mold, in particular to a mold for manufacturing contact lenses and a method for demoulding contact lenses by using the mold.

Background technique

The production method of modern contact lenses is mainly formed by polymerizing and solidifying the raw materials of liquid contact lenses by heating or irradiating light, and then pouring water to soften them.

According to the step process, it can be further subdivided into a turning method, a rotary casting method, and a casting method. Among them, the turning method is to pour the liquid contact lens raw material monomer into a tube, polymerize it into a long rod shape, and then cut it into a circular body. Because the lens can be processed according to different designs, it has the advantage of variability. , but because the process steps are complicated and errors are prone to occur, a satisfactory reproduction rate cannot be produced, and it is not suitable for the manufacture of contact lenses with a large demand. The rotary casting method is to inject the liquid contact lens raw material monomer into the rotating mold and make the mold rotate. Through the action of centrifugal force, gravity and surface tension, the liquid contact lens raw material monomer is distributed on the mold, and the raw material monomer The injection volume and the rotational speed of the mold determine the variation of the lens. Although the rotational molding method is economical, it is difficult to produce lenses with high complexity. The casting method is to place the liquid contact lens raw material monomer between two molds to polymerize and solidify into a suitable shape. After the mold is taken off, the contact lens can be manufactured by edging, polishing, and then soaking the lens in warm water to soften it. The casting method has high reproducibility and can obtain thin lenses, but has the disadvantage of high equipment cost.

Among the above methods, the casting method is the most commonly used in recent years. Many manufacturers make improvements based on the casting method to solve the problems of residual material and demoulding in the production process. For example, Chinese Patent Publication No. CN103465410B proposes an ultrasonic mold release device and a method for its application in contact lens manufacturing. The mold has the advantages of extremely short demolding time, increased production speed, and improved accuracy of subsequent testing procedures due to the dry contact lens after demolding.

However, there is still room for further improvement in the demolding efficiency in practical use, and it is still necessary for those in the art to continuously conduct research and development improvements to improve the manufacturing efficiency of contact lenses.

SUMMARY OF THE INVENTION

One of the objectives of the present invention is to provide a mold for manufacturing a contact lens, which can improve the problem that the conventional casting method is used to manufacture contact lenses with unsatisfactory mold release efficiency.

Another object of the present invention is to provide a method for releasing a contact lens from the mold, so as to quickly release the contact lens from the mold during the manufacturing process of the contact lens.

In order to achieve the above-mentioned purpose, the present invention provides a mold for contact lens demoulding, comprising a first mold and a second mold cooperating with the first mold, the first mold including a concave in a first direction. a mold cavity, a bent section extending outwardly from a peripheral edge of the mold cavity, a first mounting portion adjacent to the bent section, and a recessed section formed between the first mounting portion and the bent section , the wall thickness of the bending section is thinner than the wall thickness of the mold cavity to match the concave section and help the mold cavity to deform and fold in a second direction opposite to the first direction; the second mold includes a direction A round protrusion protruding from the mold cavity, a second mounting portion adjacent to the round protrusion, and an assembly structure is formed between the second mounting portion and the first mounting portion.

The present invention also provides a method for demoulding contact lenses using the mould, comprising:

(S1) Provide a mold, the mold includes a first mold and a second mold cooperating with the first mold, the first mold includes a cavity recessed in a first direction, a circumference from the cavity A bent section with an edge extending outward, a first mounting portion adjacent to the bent section, and a concave section formed between the first mounting portion and the bent section, and the bent section has a thicker wall than the bent section. The wall thickness of the mold cavity is thin to match the concave section and help the mold cavity to be deformed and folded in a second direction opposite to the first direction; the second mold includes a circular protrusion protruding toward the mold cavity, a and A second mounting portion adjacent to the round protrusion, an assembly structure is formed between the second mounting portion and the first mounting portion;

(S2) placing a liquid contact lens raw material in the mold cavity, and pressing the round protrusion of the second mold against the mold cavity;

(S3) separating the first mold and the second mold, so that the liquid contact lens material adheres to the first mold and presents an arc-shaped film; and

(S4) Folding to make the cavity deformed and folded to complete demoulding.

Accordingly, through the feature that the wall thickness D1 of the bending section in the first mold is thinner than the wall thickness D2 of the mold cavity, the mold cavity can be easily deformed by folding during the process of demolding the contact lens by using the mold. The demoulding is completed, so the manufacturing efficiency of the contact lens can be effectively improved.

Description of drawings

FIG. 1 is a schematic diagram of a mold for releasing a contact lens according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a first mold in the mold of FIG. 1 .

FIG. 3 is a schematic diagram of a second mold in the mold of FIG. 1 .

FIG. 4 is a schematic cross-sectional view of the first mold and the second mold when they cooperate with each other according to an embodiment of the present invention.

Detailed ways

The detailed description and technical content of the present invention are described as follows in conjunction with the drawings:

1 is a schematic diagram of a mold for contact lens demolding according to an embodiment of the present invention, which mainly includes a first mold 10 and a second mold 20 that can cooperate with each other. Generally speaking, in the process of manufacturing contact lenses, the The liquid contact lens raw material monomer is placed between the first mold 10 and the second mold 20, pressed against each other and illuminated or heated to polymerize and solidify the liquid contact lens raw material monomer. Then demoulding is carried out, followed by edging, polishing, and then soaking the lenses in warm water to soften and so on to complete the manufacture of contact lenses. In this embodiment, the material of the first mold 10 and the second mold 20 can be transparent or opaque, with some allowable flexibility, such as plastic, for example, but the present invention is not limited to this, other suitable materials Materials can also be used.

Please continue to refer to Figure 1, Figure 2 and Figure 4. The first mold 10 includes a cavity 11 recessed in a first direction, a bending section 12 is formed extending outward from a peripheral edge of the cavity 11 , and an inclined surface is formed between the cavity 11 and the bending section 12 15. The bending section 12 adjoins and extends outward to form a first mounting portion 13 . At this time, an angle between the bending section 12 and the first mounting portion 13 is between 10 and 80 degrees.

In this embodiment, the wall thickness D1 of the bending section 12 is thinner than the wall thickness D2 of the mold cavity 11 so as to fit a concave section 14 formed between the first mounting portion 13 and the bending section 12 . The structure helps the cavity 11 to be deformed and folded in a second direction opposite to the first direction.

The cavity 11 can be subjected to hydrophilic treatment such as plasma, flame treatment, or short-wave ultraviolet irradiation, so that when the first mold 10 is separated from the second mold 20 in a subsequent step, the contact lens can adhere to the on the cavity 11.

Regarding the second mold 20 , please refer to FIGS. 1 , 3 and 4 , it mainly includes a round protrusion 21 and a second mounting portion 22 . The round protrusion 21 protrudes toward the cavity 11 of the first mold 10 , and includes a neck and a curved surface. The neck is surrounded by a plurality of bumps 24 , and each bump 24 is formed with a score The groove 25 divides the bump 24 into upper and lower parts. The notching groove 25 can be formed by, for example, a disc-shaped tool rotating the bumps 24 to produce the notching groove 25. In this embodiment, the notching groove 25 is formed. , each of the notch grooves 25 is formed as a V-shaped notch groove. This design is helpful for the excess liquid contact lens raw material monomer to overflow between the notch grooves 25 and the bumps 24 during the manufacturing process of the contact lens, and after the polymerization and curing, the excess material can be Tightly glued between grooves and bumps.

The second mounting portion 22 is formed to extend adjacent to the outer edge of the circular protrusion 21 . When the first mold 10 is matched with the second mold 20 , the second mounting portion 22 and the first mounting portion 13 can form a Assemble the structure. In this embodiment, an angle between 85° and 95° is sandwiched between the second mounting portion 22 and the round protrusion 21 , for example, 90° in a specific embodiment.

The second mounting portion 22 extends in a direction opposite to the circular protrusion 21 to form a ring wall 27 . A plurality of positioning members 28 can be arranged around the ring wall 27 , and a fixed space can be spaced between two adjacent positioning members 28 . the distance. In this way, when the first mold 10 and the second mold 20 cooperate with each other, a stronger engagement effect can be provided through the ring wall 27 .

In this embodiment, when the first mold 10 and the second mold 20 are overlapped and pressed against each other, in order to prevent the contact lenses disposed therein from being damaged due to excessive extrusion, the first mounting portion 13 is provided with multiple A plurality of second blocking protrusions 26 are correspondingly disposed on the second mounting portion 22 , so that a partial area of each second blocking protrusion 26 can be connected with the first blocking protrusion 26 . The stop bump 16 is in contact; alternatively, the size and position of the second stop bump 26 can also be completely corresponding to the first stop bump 16 so that the second stop bump 26 and the first stop bump The blocks 16 can be completely overlapped and contacted, effectively avoiding the problem of contact lens damage during the manufacturing process. The first blocking protrusions 16 and the second blocking protrusions 26 are respectively disposed on the first mounting portion 13 and the second mounting portion 22 at a fixed interval. In this embodiment, it is also possible to design The second blocking protrusions 26 are arranged corresponding to the positioning members 28 surrounding the ring wall 27 , but the invention is not limited thereto.

In addition, even if the first mold 10 and the second mold 20 include a design of many parts, during implementation, the first mold 10 and the second mold 20 can be separately formed through methods such as injection molding. The first mold 10 and the second mold 20 which are integrally formed are obtained.

In this way, when using the mold to demold the contact lens, the demolding can be easily accomplished by folding the mold cavity to deform the mold cavity through the following steps S1 to S4:

In step S1, firstly, a mold having the structure as described above is provided for releasing the contact lens.

In step S2, a liquid contact lens raw material is placed in the mold cavity 11 of the first mold 10, and the round protrusion 21 of the second mold 20 is aligned with the mold cavity 11 and pressed down until it is set in the mold cavity 11. Part or all of the area of the second blocking protrusions 26 of the second mounting portion 22 is in contact with the first blocking protrusions 16 provided on the first mounting portion 13 . At this time, the excess raw material monomer of the liquid contact lens can overflow between the notch grooves 25 and the bumps 24, so as to avoid the interference of the residual material in the subsequent process.

In step S3, the first mold 10 and the second mold 20 are separated, and the liquid contact lens raw material will be adhered to the cavity 11 of the first mold 10 after the hydrophilic surface treatment after extrusion. And showing an arc-shaped film.

Finally, in step S4, the mold cavity 11 is folded over so that the mold cavity 11 is deformed and folded in the opposite direction, so that the contact lens can be simply released from the mold cavity 11 to complete demolding. The specific folding method in this step, for example, because of the mold used in this embodiment, the wall thickness D1 of the bending section 12 is thinner than the wall thickness D2 of the mold cavity 11, and the operation can be easily performed by The protruding end of the back side of the mold cavity 11 exerts force to cause the mold cavity 11 to be folded and deformed.

Further, a curing step may be performed after step S2 or step S3, so that the liquid contact lens raw material is cured into a contact lens. The above-mentioned curing step can be a curing process by light, such as irradiating the liquid contact lens raw material with light; or a curing process by heating, such as drying and blowing hot air on the liquid contact lens raw material.

Therefore, under the premise of not affecting the yield rate of contact lens production, the present invention can easily deform the cavity through folding by means of the design that the wall thickness of the bending section in the mold is smaller than the wall thickness of the cavity. The demoulding step achieves the purpose of improving the manufacturing efficiency of the contact lens.

The present invention has been described in detail above, but the above is only a preferred embodiment of the present invention, and should not limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made according to the scope of the application of the present invention should still fall within the scope of the patent of the present invention.

Claims (8)

1. a mold for contact lens demoulding, wherein the mold comprises: a first mold, the first mold includes a cavity recessed in a first direction, a bending section extending outward from a peripheral edge of the cavity, and a first cavity adjacent to the bending section The installation part, an inclined plane is formed between the mold cavity and the bending section, and an angle between 10° and 80° is sandwiched between the bending section and the first installation part, so A concave section is formed between the first installation part and the bending section, and the wall thickness of the bending section is thinner than the wall thickness of the mold cavity, so as to cooperate with the concave section and help the mold cavity to move toward one side. Deformation and reflex in a second direction opposite to the first direction; and A second mold that cooperates with the first mold, the second mold includes a round protrusion protruding toward the mold cavity, a second mounting portion adjacent to the round protrusion, and the second mold An assembly structure is formed between the mounting portion and the first mounting portion. 2 . The mold according to claim 1 , wherein the second mold further comprises a stopper disposed between the circular protrusion and the second mounting portion and pressed against the bending section. 3 . top section. 3 . The mold according to claim 1 , wherein an angle between 85° and 95° is sandwiched between the circular protrusion and the second mounting portion. 4 . 4 . The mold according to claim 1 , wherein a plurality of bumps are provided on the circular protrusion, and each bump is formed with a notch groove to divide the bump into an upper and a lower part. 5 . . 5 . The mold according to claim 1 , wherein a plurality of first blocking protrusions are provided on the first mounting portion. 6 . 6 . The mold according to claim 5 , wherein a plurality of second blocking protrusions are provided on the second mounting portion, so that when the first mold is matched with the second mold, each A partial area of the second blocking protrusion contacts the first blocking protrusion. 7 . The mold according to claim 1 , wherein the second mounting portion extends in a direction opposite to the circular protrusion to form a ring wall, and a plurality of positioning members are arranged on the ring wall. 8 . . 8. a method utilizing mould to demould contact lens is characterized in that, described method comprises: A mold is provided, the mold includes a first mold and a second mold that cooperates with the first mold, the first mold includes a cavity recessed in a first direction, a cavity from the cavity A bending section with a peripheral edge extending outward, and a first mounting portion adjacent to the bending section, an inclined plane is formed between the mold cavity and the bending section, and the bending section is connected to the bending section. An angle between 10° and 80° is sandwiched between the first installation parts, a concave section is formed between the first installation part and the bending section, and the wall thickness of the bending section is higher than that of the bending section. The wall thickness of the mold cavity is thin, so as to cooperate with the concave section and help the mold cavity to be deformed and folded in a second direction opposite to the first direction; the second mold includes a protrusion protruding toward the mold cavity. and a second mounting portion adjacent to the circular protrusion, an assembly structure is formed between the second mounting portion and the first mounting portion; A liquid contact lens raw material is placed in the mold cavity, and the round protrusion of the second mold is aligned with the mold cavity and pressed down; Separating the first mold and the second mold, so that the liquid contact lens raw material adheres to the first mold and presents an arc-shaped film; and Folding makes the mold cavity deform and fold back to complete demoulding.

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