JPH10264178A - Method and device for manufacturing plastic product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automate a step in which a plastic raw liquid is injected into a mold for molding in a manufacturing process for plastic lens. SOLUTION: When an injection hole 7 is formed in a mold 5 for molding in which a glass mold 1 on the side of an eyeball is connected to a glass mold 2 on the side of an object through an adhesive tape 3, the hole 7 is formed at a location spaced apart from the mold 1 by a minimum distance L. Thus, even if the tape 3 is curved toward a cavity 4 to form a recess in the mold 5, bubbles are prevented from being generated, and hence a plastic product free from defective shapes can be manufactured so that plastic lenses of good quality can be provided even if they are manufactured in an automated process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method and a manufacturing apparatus for molding a plastic product such as a plastic lens, and more particularly to a manufacturing method suitable for a molding mold formed by assembling a plurality of molds with tapes or the like. And a manufacturing apparatus.

[0002]

2. Description of the Related Art As a method for producing a plastic lens, a so-called tape molding method using an adhesive tape is known. In this method, a molding mold 5 as shown in FIGS. 1 and 2 is used. This molding mold 5
Is a method in which two glass molds 1 and 2 having one surface as lens molding surfaces 1a and 2a are opposed to each other with a predetermined spacing between molding surfaces 1a and 2a. An adhesive tape 3 is adhesively wound around the outer peripheral surfaces 1b and 2b of both glass molds so as to straddle the outer peripheral surfaces 1b and 2b, and the two glass molds 1 and 2 are fixed and held. . Then, a raw material liquid for a plastic lens that is polymerized and hardened is injected into a space (cavity) 4 formed between the two glass molds 1 and 2, and is subjected to a process such as heating to be polymerized and hardened. It is molded.

[0003] As a method of injecting a plastic lens material solution (stock solution) into such a lens mold 5, an adhesive tape 3 wound around the peripheral surfaces of two glass molds 1 and 2 is partially peeled to open the lens mold 5. There is a way to make In this method, a plastic lens is manufactured in the following steps.

[0004] 1. The lens mold 5 formed by adhesively winding the adhesive tape 3 prepared in advance is manually peeled off a part of the adhesive tape 3 from the joint portion to form an opening.

[0005] 2. The tank filled with the plastic lens raw material liquid and the injection pipe are connected by piping through a filtration device or the like, and the tip of the injection pipe is inserted into the opening.

[0006] 3. An undiluted solution is injected into the cavity 4 using a device that injects the raw material liquid into the lens mold 5 by means such as a pump or a pump.

[0007] 4. After filling the cavity 4 with the undiluted solution, the portion where the adhesive tape 3 has been peeled off is adhered again to seal the cavity 4.

[0008] 5. The stock solution is cured.

[0009] In addition, there is a method of injecting the undiluted solution by inserting a tip portion of an injection pipe having a sharp tip by breaking through the adhesive tape 3 of the lens mold 5 and inserting the same. And cavity 4
After filling with the undiluted solution, pull out the injection tube and glue the insertion hole of the pierced injection tube with another adhesive tape,
A method of applying an adhesive and closing it is used.

[0010]

Conventionally, a series of operations for peeling off the adhesive tape 3 as described above, inserting an injection tube, and filling the resin have been performed manually. If workers touch this undiluted solution, skin may be irritated,
Sniffing the irritating odor of the stock solution may make you feel sick. For this reason, in a closed environment with facilities such as ventilation,
Work with a drafter, or use glasses,
Work is being done with protective equipment such as masks and gloves. Therefore, it is one of the major factors in which the working efficiency is extremely low and the manufacturing cost of the plastic lens cannot be reduced. Therefore, there is an urgent need to automate the step of injecting the undiluted solution, and various automation methods and devices are being studied.

Therefore, in the present invention, when the process of injecting the undiluted solution into the mold 5 in which the cavities 4 are formed by fixing the glass molds 1 and 2 with the adhesive tape 3, a high-quality product having a stable shape is manufactured. It is an object of the present invention to provide a method and an apparatus for manufacturing a plastic product that can be used. In a molding mold in which multiple glass molds are fixed with adhesive tape, the adhesive tape often curves inward between the glass molds. The process of injecting undiluted solution to make up for the shape of the tape cannot be taken. Therefore, the mold solution cannot be completely filled with the undiluted solution, causing bubbles to occur, or a failure in a subsequent manufacturing process due to a failure to obtain a product having the same shape as the mold. Is concerned. For this reason, in the present invention, in particular, when using a molding mold such as a plastic lens mold forming a cavity for injecting the undiluted solution by connecting the molds with a tape, the undiluted solution due to the distortion of the tape. It is an object of the present invention to provide a manufacturing method and a manufacturing apparatus capable of preventing defective filling.

[0012]

For this reason, in the method for producing a plastic product of the present invention, an injection hole is provided not in the center of the tape but in the vicinity of a wall-shaped mold where poor filling of the stock solution is likely to occur. This allows the stock solution to be filled in the cavity without gaps. That is, in the method of manufacturing a plastic product of the present invention, in which a cavity formed by a plurality of walls is closed with a tape to form a molding mold, an injection hole is formed in the tape, and a plastic undiluted solution is injected and molded. A first step of providing an injection hole at a position near at least one of the wall portions. In this way, by injecting the undiluted solution from the wall, the undiluted solution can be injected into the cavity without any gap even if the tape is distorted or bent, so that the process of injecting the undiluted solution can be automated, The working environment can be improved, and the manufacturing cost can be reduced.

Further, when the width of the cavity changes as in a molding mold for a plastic lens, it is desirable to automatically cope with the fluctuation of the width of the cavity. For this purpose, the minimum distance between the inner surface of the wall and the injection hole is set in advance, and the position of the injection hole is automatically adjusted in the first step so that the injection pipe and the wall do not interfere even if the width of the cavity changes. It is desirable to be able to make a decision. In addition, when the width of the cavity cannot secure the minimum distance from any of the walls, a second step of providing an injection hole near the center of the tape is provided, so that the width of the cavity can be reduced with respect to the mold for molding. Even automatic injection holes can be made.

In particular, the plastic product is a plastic lens, and has a first wall defining a surface on the eyeball side of the plastic lens and a second wall defining a surface on the object side. In the first step, it is desirable to provide an injection hole near the first wall in the first step. Since the first wall portion has a convex surface protruding into the cavity, a stock solution is injected into the cavity while flowing along the convex surface by forming an injection hole near the first wall portion. Therefore, a high-quality plastic lens can be manufactured without generating bubbles in the cavity.

[0015] Further, the first and second tapes are closed by a tape.
By providing a process to measure the distance between the walls of
Since the width of the cavity is automatically measured, the position where the injection hole is opened is not mistaken. In addition, since there is no need to externally introduce molding mold data, the manufacturing cost of the plastic product manufacturing apparatus can be reduced.

Such a manufacturing method includes a mold holding device for supporting a molding mold in which a cavity formed by a plurality of walls is closed with a tape, and a plastic undiluted solution at a position near at least one of the tape walls. The present invention can be employed in a plastic product manufacturing apparatus having a punching device capable of forming an injection hole for injection. Also, the drilling device,
When a predetermined distance between the inner surface of the wall portion and the injection hole cannot be ensured with respect to any of the wall portions, the injection hole can be formed near the center of the tape so that the cavity of any width can be formed. It is possible to provide a manufacturing apparatus capable of automatically forming an injection hole even in a molding mold of (1). Further, in the manufacturing apparatus for a plastic lens molding mold, as described above, it is desirable to form the injection hole at a position close to the first wall, and measure the interval between the first and second walls. By further providing a measuring device, malfunction can be prevented and the manufacturing cost of the manufacturing device can be reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings. FIG. 3 shows a planar arrangement of a plastic lens manufacturing apparatus 10 for automatically performing a process of injecting a plastic lens raw material liquid (stock solution) into a plastic lens molding mold. A molding mold 5 formed in advance so as to obtain a predetermined curvature, a lens thickness, and the like with the configuration shown in FIGS. 1 and 2 is sequentially fed by a conveyor belt 9 in a horizontal state with a convex surface facing upward. Come. These molding molds 5 are simultaneously gripped (chucking) two by two by the mold supply device 11.
Then, it is transferred to the measuring station 20. As will be described in detail later, in the measuring station 20, the molding mold 5 is set upright, and the dial gauge is brought into contact with the outer peripheral surfaces 1b and 2b of the glass mold at the positions of the vertices of the molding mold 5, and in this state, the tape 3 is placed. Move to cross. And
The distance between the glass molds 1 and 2, that is, the end width (dimension corresponding to the edge thickness of the lens) 8 between the glass molds 1 and 2 is calculated based on the position where the tip of the dial gauge changes up and down when moving. In the manufacturing apparatus 10 of the present example, the injection position of the stock solution is determined by the end width 8, and further, the injection pattern of the stock solution is determined. Next, at the measuring station 20, the molding mold 5 is
Turn 0 ° to make an injection hole from below. After that, once again
The molding mold 5 is set with the injection hole turned upward by 80 °.

The molding mold 5 in which the injection hole is formed,
It is transferred from the measuring station 20 to the transfer chuck 12a. The transfer chuck 20 is connected to the transfer belt 1.
2 reciprocates linearly. Transfer chuck 12
In a, the molding mold 5 is moved from the measuring station 20 to the injection station 50, and the molding mold 5 is held by the chuck 61 of the injection station 50. FIG. 4 shows an outline of an injection station 50 for injecting a stock solution of a plastic lens into the molding mold 5. In the injection station 50 of the present example, a stock solution pressurized from a pressurized plastic lens material solution supply device housed in the lower part of the manufacturing apparatus 10 is supplied via a stock solution supply pipe 51, and the discharge amount of the material 59 is controlled. It is connected to a pin valve 52 to be controlled. A pulse motor 53 for changing the injection pattern is provided above the pin valve 52.
The flow rate and time of the stock solution to be injected into the cavity 4 of the molding mold 5 from the injection needle 54 provided at the tip of the pin valve 52 can be controlled. The surplus undiluted solution that overflowed from the molding mold at the end of filling the undiluted solution into the molding mold 5 is sucked by a suction nozzle 55 for vacuum suction, and is stored in a pressure-resistant bottle 56 connected to a vacuum generator 57. A capacitance sensor 58 for detecting the presence or absence of a stock solution is provided between a pipe connecting the suction nozzle 55 and the pressure-resistant bottle 56. When the stock solution overflowing by the suction nozzle 55 is sucked, the pin valve 52 is turned off. The injection of undiluted solution can be stopped automatically.

The casting mold 5 into which the undiluted solution has been injected at the injection station 50 is held 180 ° by the rotary transfer means 60 while being held by the chuck 61 as it is.
Swivels horizontally and moves to sealing station 70.
In the sealing station 70, a UV curable resin is applied to an injection port formed in the molding mold 5, and is further irradiated with ultraviolet rays to cure the UV resin. The molding mold 5 whose injection port is sealed in this way is removed from the rotary transfer means 60. Then, the reversing chuck 15
, And is placed on a transport device 90 for transferring to a pallet. The transfer device 90 is provided with a molding pallet 91 for thermal polymerization, which is used for molding the mold 5 in which the stock solution is sealed.
Robot for palletizing. Accordingly, the process of injecting the undiluted solution into the supplied molding mold 5 and storing it in the dedicated pallet 91 can be performed completely unattended by the manufacturing apparatus 10 of this example.

Hereinafter, the configuration and processing of the measuring station 20 of the manufacturing apparatus 10 of this embodiment will be described in more detail. As shown in FIG. 5, in the measuring station 20, the end width 8 of the molding mold 5 held vertically by the chuck 29 is measured by the dial gauge 21. For this purpose, first, the tip 22 of the dial gauge 21 is set in contact with the outer peripheral surface 1b of the glass mold 1 defining the surface on the eyeball side, and the height is stored as an original position. Next, the dial gauge 21 is moved toward the outer peripheral surface 2b of the glass mold 2 that defines the surface on the object side so as to cross the adhesive tape 3. In this process, first,
The location where the tip 22 of the dial gauge falls by about 0.1 mm is detected and stored as the boundary with the glass mold 1, that is, the starting point of the cavity 4. Further, the dial gauge 21 is moved in the direction of the glass mold 2 to detect and store the position where the tip 22 of the dial gauge has returned to the original position as the boundary with the glass mold 2, that is, the end point of the cavity 5. If you know the coordinates of the start point and the end point, you can also know the distance between them,
This means that the end width 8 of the cavity has been measured.

In the manufacturing apparatus of this embodiment, the injection pattern of the undiluted solution is determined based on the edge width (edge thickness) 8 thus measured, and the position of the injection hole is also determined. Therefore, the manufacturing apparatus of this example can automatically perform the subsequent processing only by receiving the molding mold 5, and can perform the operation without acquiring the design data of the molding mold 5 and the like. it can. Therefore, it is not necessary to exchange design data and data on forming the molding mold 5, so that the configuration can be simplified and the manufacturing cost of the manufacturing apparatus can be reduced. In addition, since the subsequent processing can be managed only by the end width 8 for each of the supplied molding molds 5, the control system of the manufacturing apparatus can be simplified and malfunctions can be prevented. Therefore, it is possible to provide a manufacturing apparatus that can perform processing at high speed and has high reliability.

The molding mold 5 whose end width 8 is measured is
While being held by the chuck 29, as shown in FIG. 6, the measured portion is turned in the vertical direction so as to face 180 ° downward, and the injection hole 7 is formed. Drilling unit 25
Can be moved in a direction along the end width 8, and the compressed air heated to about 200 ° C. by an air heater is blown to a predetermined position for about 0.1 to 1 second to inject the injection hole 7.
Can be processed. The pressure of the compressed air and the time for blowing the air can be changed depending on the type of the adhesive tape and the processing area of the injection port. For example, a metal nozzle 26 having an inner diameter of 3 mm is attached
Compressed air of ~ 4 kgf / is used, and the blowing time is 0.1 kg.
It can be set to about 2 seconds.

FIG. 7 is a flow chart showing a process for processing the injection hole 7 in the tape 3. First, in step 31, the end width 8 is measured using the dial gauge 21. Next, the end width 8 measured in step 32 is determined,
If the end width 8 exceeds 7 mm, the injection hole 7 is provided in a step 33 at a position 3 mm, which is the minimum distance L from the inside of the glass mold 1 on the eyeball side. On the other hand, when the end width is 7 mm or less, the injection hole 7 is provided at the center of the end width 8 in step 34. In the manufacturing apparatus 10 of this example, the end width 8 is
When measurement is performed, data of a reference point (measurement start point) inside the glass mold 1 is obtained, and the molding mold 5 is rotated by 180 ° and the position measured by the dial gauge 21 from below is measured. Make holes available. Therefore, the drilling unit 25 is provided with the dial gauge 2
Based on the reference point measured in step 1, the injection hole 7 can be accurately moved to a position separated by a minimum distance L from the inside of the glass mold 1 or to a predetermined punching position in the center of the tape 3.

FIG. 8 shows how the stock solution 59 is injected into the cavity 4 from the injection hole 7 provided in the molding mold 5. Through the steps described above, the injection hole 7 is formed at a position close to the glass mold 1, that is, the glass mold that defines the surface on the eyeball side when the end width 8 has a certain degree. Since the inner surface 1a of the glass mold 1 defines the surface on the eyeball side, the inner surface 1a often has a convex shape protruding toward the inside of the cavity 4. Therefore, the injected undiluted solution 59 flows quietly along the inner surface 1a of the glass mold 1. Therefore, the undiluted solution becomes turbulent during the injection and bubbles are generated in the undiluted solution 5, and the undiluted solution 5 is directly discharged to the tape 3 on the opposite side of the injection hole 7 and the tape 3 and the glass mold are discharged. It is possible to prevent troubles such as the occurrence of a gap between the first and second liquids and the leakage of the stock solution 5.

FIG. 9 shows a state when the filling of the stock solution 59 into the cavity 4 is completed. As shown in FIG. 9A, the adhesive tape 3 wound on the outer peripheral surfaces 1b and 2b of the glass molds 1 and 2 is thin and hardly rigid. For this reason, the shape near the outer peripheral surfaces 1b and 2b of the glass mold is almost the same as that of the glass mold. However, in the middle portion between the glass molds 1 and 2, that is, near the center of the end width 8, the tape 3 is distorted or bent. Easy to occur. In most cases, as shown in FIG. 9, the tape 3 is curved so as to protrude toward the cavity 4, and has a shape in which the center of the end width 8 is concave. Therefore, when the injection hole 7 is provided at the center of the end width 8 as shown in FIG. 9B, when the stock solution 59 overflows from the injection hole 7 and the injection is stopped, the portions near the glass molds 1 and 2 are stopped. 39 is not filled with the stock solution 59, and large bubbles are generated. If the production of the lens is continued by sealing with the UV curing resin in this state, when the molding mold 5 is replaced from the vertical state to the horizontal state, bubbles are generated in the cavity 4.
And the spherical surface as designed cannot be obtained. The resin may be polymerized in the vertical state, but in this case, the lens does not become circular because there are large bubbles at the edge (edge) of the lens. Therefore, the operation of chucking the lens or exposing the center of the lens becomes a serious obstacle, and it becomes impossible to manufacture a high-precision, high-quality spectacle lens.

On the other hand, as shown in FIG.
When the injection hole 7 is set in the vicinity of the first glass mold 1, the undiluted solution can be filled into an acute space above the cavity 4 formed by the glass molds 1 and 2 and the tape 3. Therefore, defects that directly affect the performance of the lens, such as air bubbles, can be prevented, and the subsequent processing such that the edge of the lens is missing and the center of the lens cannot be recognized by a machine is obstructed. Defects can be prevented beforehand.

As described above, the position of the injection hole is desirably close to the glass mold, and further, it is desirable to provide the injection hole 7 near the glass mold 1 forming the surface on the eyeball side.
However, if the injection hole 7 is too close to the glass mold 1 or 2, the injection needle 54 inserted from the injection hole 7 at the injection station 50 may collide with the inner surface 1a of the glass mold 1, and the molding surface of the glass mold 1 1a may be damaged. Therefore, in this example, the glass mold 1 and the injection hole 7 are used.
Is set to 3 mm so that the position of the injection hole 7 can be determined regardless of the value of the end width 8 when the end width 8 is sufficient. If the end width 8 of the mold 5 is short, the minimum distance L from the glass mold 1 or the glass mold 2 may not be secured. In this example, step 32 in FIG.
As shown in the figure, a case in which the end width 8 has a margin of about 1 mm or less with respect to twice the minimum distance L and is 7 mm or less corresponds to this case. The injection hole 7 is provided at the farthest distance from 1 and 2, that is, at the center of the end width 8. Of course, these minimum distances of 3 mm and 7
The distance of mm is merely an example, and can be determined in consideration of the thickness of the injection needle, the shape of the glass mold, the penetration depth of the injection needle, and the like.

As described above, when the injection hole 7 for the undiluted solution is opened in the molding mold 5 in which the glass walls 1 and 2 are connected by the tape 3, the air bubbles are opened as close as possible to the glass wall 1 as described above. It is possible to reliably mold an excellent plastic lens which is free from the occurrence and the shape of the lens. Therefore, it is possible to mass-produce plastic lenses having sufficient performance without automating the process of injecting the undiluted solution and checking the state of bubbles one by one by an operator. Furthermore, by setting the minimum distance between the glass wall and the injection hole, the possibility of damaging the glass mold can be eliminated even if the injection process is automated. In addition, when the minimum distance cannot be secured, by providing a process of providing an injection hole in the center of the tape 3, the position of the injection hole is automatically set for the molding mold 5 having any end width. It is possible to do.

In the present embodiment, the present invention has been described in detail based on a plastic lens manufacturing apparatus. However, a mold space (cavity) is formed by closing a wall of a mold frame with a tape.
In the tape molding method for forming the same, not only for plastic lenses, but also for other products,
By using the manufacturing method and the manufacturing apparatus provided with the injection holes as disclosed above, it is possible to prevent troubles such as generation of bubbles and chipping of edges, and to manufacture a high-quality product.

[0030]

As described above, by using the manufacturing method and the manufacturing apparatus of the present invention, the tape is bent inward like a plastic lens molding mold in which the space between the glass molds is closed with an adhesive tape. It is possible to automate the step of injecting the plastic undiluted solution even into a molding mold that may be inadvertent. For example, by forming an injection hole at a position separated by a minimum distance from the glass mold on the eyeball side, it is possible to prevent the production of plastic products having bubbles or lacking in shape. Therefore, according to the present invention, it becomes possible to completely automate the step of injecting the undiluted solution into the mold, and it is possible to automatically produce high-quality plastic products without bubbles and shapes. Therefore, according to the present invention, productivity can be increased, manufacturing costs of plastic products can be reduced, and manufacturing time can be shortened. Furthermore, by fully automating the injection process, it is possible to avoid problems in the working environment such as odor and gas contained in the plastic raw material liquid, thereby reducing the cost of environmental measures and reducing the labor of workers. can do.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a plastic lens molding mold using a tape molding method.

FIG. 2 is a cross-sectional view showing a configuration of a molding mold shown in FIG.

FIG. 3 is a plan view showing an outline of a plastic lens manufacturing apparatus according to the present invention.

4 is a diagram showing a schematic configuration of an injection station of the manufacturing apparatus shown in FIG.

FIG. 5 is a diagram schematically showing a state where an end width of a cavity is measured by a measuring station of the manufacturing apparatus shown in FIG. 3;

FIG. 6 is a view schematically showing a state in which an injection hole is formed at a measurement station of the manufacturing apparatus shown in FIG. 3;

FIG. 7 is a flowchart showing a process of forming an injection hole of the manufacturing apparatus shown in FIG.

FIG. 8 is a view showing a state when the injection of the stock solution is started from the injection hole in the manufacturing apparatus shown in FIG. 3;

FIG. 9 is a view showing a state when filling of the stock solution is completed in the manufacturing apparatus shown in FIG. 3; FIG. 9A shows a case where an injection hole is provided near a glass mold; ) Indicates a case provided at the center of the tape.

[Explanation of symbols]

 1, 2 ··· glass mold 1a, 2a ··· molding surface 1b, 2b ··· outer peripheral surface of glass mold 4 ·· cavity (space for filling undiluted solution) 5 ··· molding mold 7 ··· injection hole 8 ·· end Width (edge thickness) 10. Manufacturing equipment 20. Measuring station 25. Drilling unit 29. Chuck of measuring station 50. Injecting station 61. Chuck of rotary 70. Sealing station

Claims (8)

[Claims] 1. A method of manufacturing a plastic product, comprising: forming a molding mold by closing a cavity formed by a plurality of walls with a tape, forming an injection hole in the tape, and injecting a plastic undiluted solution. A first step of providing the injection hole at a position near at least one of the wall portions of the tape; 2. The tape according to claim 1, wherein a minimum distance between the inner surface of the wall and the injection hole is set, and the width of the cavity cannot secure the minimum distance with any of the walls. A second step of providing the injection hole near the center of the plastic product. 3. The plastic product according to claim 1, wherein the plastic product is a plastic lens, and the molding mold defines a first wall defining an eyeball-side surface of the plastic lens and an object-side surface. And a second wall portion, wherein the pouring hole is provided at a position near the first wall portion in the first step. 4. The plastic product according to claim 3, further comprising a step of measuring a distance between the first and second walls closed with the tape prior to the first step. Production method. 5. A mold holding device for supporting a molding mold in which a cavity formed by a plurality of walls is closed with a tape, and an injection for injecting a stock solution of plastic into a position near at least one of the walls of the tape. An apparatus for manufacturing a plastic product, comprising: a punching device capable of forming a hole. 6. The punching device according to claim 5, wherein:
When a predetermined minimum distance between the inner surface of the wall portion and the injection hole cannot be ensured for any of the wall portions, the injection hole is formed near the center of the tape. Manufacturing equipment. 7. The molding mold according to claim 5, wherein the molding mold includes a first wall defining a surface of the plastic lens on the eyeball side and a second wall defining a surface of the plastic lens on the object side. An apparatus for manufacturing a plastic product, comprising: a mold for molding a plastic lens, wherein the hole forming device can form the injection hole at a position near the first wall. 8. The method according to claim 7, wherein
An apparatus for manufacturing a plastic product, comprising: a measuring device for measuring an interval between wall portions of a plastic product.