JP3707189B2 - Plastic product manufacturing method and manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND 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 and a manufacturing apparatus suitable for a molding mold configured by assembling a plurality of molds with a tape or the like. .
[0002]
[Prior art]
As a plastic lens manufacturing method, 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. The molding mold 5 has two glass molds 1 and 2 having lens molding surfaces 1a and 2a on one surface, and the molding surfaces 1a and 2a facing each other at a predetermined interval. The two glass molds 1 and 2 are fixed by adhesively winding the adhesive tape 3 around the outer peripheral surfaces 1b and 2b of the glass molds 1 and 2 and around the outer peripheral surfaces 1b and 2b of both glass molds. It is formed by holding. Then, a plastic lens raw material liquid that is polymerized and cured is injected into a space (cavity) 4 formed between the two glass molds 1 and 2, and is subjected to a treatment such as heating to be polymerized and cured. Molded.
[0003]
As a method for injecting a plastic lens raw material liquid (stock solution) into such a lens mold 5, a method of making an opening by partially peeling the adhesive tape 3 wound around the peripheral surfaces of the two glass molds 1 and 2. There is. In this method, a plastic lens is manufactured by the following process.
[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 joining portion to form an opening.
[0005]
2. The tank filled with the plastic lens raw material solution and the injection pipe are connected via a filtration device or the like, and the tip of the injection pipe is put into the opening.
[0006]
3. The raw solution is injected into the cavity 4 using a device that injects the raw material solution into the lens mold 5 by means such as a pump or pumping.
[0007]
4). After the stock solution is filled in the cavity 4, the part from which the adhesive tape 3 has been peeled off is attached again to seal the cavity 4.
[0008]
5. Cure the stock solution.
[0009]
In addition, there is a method of injecting the stock solution by inserting the tip portion of the injection tube having a sharp tip through the adhesive tape 3 of the lens mold 5 and inserting it. Then, after filling the cavity 4 with the stock solution, the injection tube is pulled out, and the insertion port of the injected injection tube is attached with another adhesive tape or is closed by applying an adhesive.
[0010]
[Problems to be solved by the invention]
Conventionally, a series of operations for peeling off the adhesive tape 3 as described above, inserting an injection tube, and filling a resin is performed manually. If an operator touches this undiluted solution, the skin may be irritated, and if the stimulating odor of the undiluted solution is sniffed, it may make you feel unwell. For this reason, work is carried out using a drafter in a shut-off environment complete with facilities such as ventilation, or work is carried out with protective equipment such as glasses, a mask, and gloves. Therefore, the working efficiency is very poor, and this is one of the major factors that cannot reduce the manufacturing cost of plastic lenses. For this reason, it is an urgent task to automate the process of injecting the stock solution, and various automation methods and devices are being studied.
[0011]
Therefore, in the present invention, when automating the process of injecting the stock solution into the mold 5 in which the glass molds 1 and 2 are fixed with the thin film-like adhesive tape 3 to form the cavity 4, a product is manufactured at a predetermined stable speed. It is an object of the present invention to provide a manufacturing method and manufacturing apparatus for plastic products. For example, when injecting a stock solution into a molding mold in which a plurality of glass molds are fixed with an adhesive tape, if the injection speed is too fast, a large amount of the stock solution overflows from the molding mold with a slight shift in the timing of stopping the injection. It will catch on the chuck that holds the mold. When the stock solution is solidified, the function of the chuck is hindered, and stable operation cannot be performed. On the other hand, if the injection rate of the stock solution is made too slow, the amount of leakage can be reduced, but the injection time becomes very long, and the processing time with the previous and subsequent steps cannot be matched. Furthermore, even if an appropriate injection rate is selected, the mold capacity for the plastic lens changes the capacity of the cavity individually, so equipment for detecting the state of filling of the stock solution in the cavity is required, and the manufacturing apparatus is expensive. Become.
[0012]
Therefore, an object of the present invention is to provide a manufacturing method and a manufacturing apparatus that can prevent the leakage of the stock solution and reduce the injection time of the stock solution. Furthermore, it is possible to provide a manufacturing method and a manufacturing apparatus capable of preventing the leakage of a stock solution even for a molding mold for a plastic lens in which the capacity of the cavity fluctuates, and injecting the stock solution at a speed that can maintain consistency with the preceding and following processes. It is aimed.
[0013]
[Means for Solving the Problems]
For this reason, in the plastic product manufacturing method of the present invention, the stock solution injection process is first divided into at least two stages, the stock solution is injected at a large flow rate for a predetermined time, and then the flow rate is reduced toward the end of the injection. By injecting the stock solution, the injection time is shortened and the amount of leakage can be reduced. That is, in the method of manufacturing a plastic product according to the present invention, in which a mold for molding is formed by closing a cavity formed by a plurality of wall portions with a tape, and a plastic stock solution is injected into the cavity, the first is placed in the cavity. A first step of injecting the plastic stock solution at a flow rate for a first time; and a second step of injecting the plastic stock solution into the cavity at a second flow rate less than the first flow rate following the first step. It is characterized by having. Thus, the injection time can be shortened by switching the flow rate during the injection, and at the same time, the leakage amount can be greatly reduced by reducing the flow rate at the end. Such a manufacturing method includes an injection device capable of injecting a plastic stock solution at at least two different flow rates into a molding mold in which cavities formed by a plurality of walls are closed with tape, a first time, and a first flow rate. And a control device for injecting at a second flow rate less than the first flow rate after the injection at step 1.
[0014]
However, in the case where the molding mold is for a plastic lens having a first wall portion that defines the eyeball side surface of the plastic lens and a second wall portion that defines the object side surface, depending on the specifications of the lens Since the curvature and thickness are different, it is difficult to select the optimum flow rate. Therefore, in the present invention, the capacity of the cavity is estimated by measuring the end width between the first and second walls prior to the first step, and the first flow rate and the first time are calculated. I am trying to set it. Further, in the plastic lens for correcting astigmatism, since the inner surface of the cavity is a toric surface, the end width varies depending on the position to be measured. Therefore, by setting the first flow rate and the first time so as not to exceed the minimum cavity capacity assumed from the end width, the injection is always finished at a small flow rate. For this reason, it becomes possible to set the combination of flow rate and time suitable for each mold for molding plastic lenses having different specifications, and the injection time can be shortened and liquid leakage can be prevented.
[0015]
In the plastic product manufacturing method and manufacturing apparatus of the present invention, in the step of injecting the stock solution, the injection time can be shortened and the liquid leakage can be prevented by switching the injection amount during the injection process. For this reason, injection | pouring of stock solution can be automated and a stable operation | movement can be performed continuously. It is also possible to set the injection time according to the upstream and downstream processes. Accordingly, it is possible to automate the entire manufacturing process of the plastic product including the step of injecting the stock solution, thereby improving the working environment and reducing the manufacturing cost.
[0016]
Furthermore, in the manufacturing method and manufacturing apparatus of the present invention using a molding mold for plastic lenses, an injection pattern suitable for the molding mold can be set by measuring the end width. It is possible to provide a highly reliable manufacturing apparatus without error. In addition, since the injection pattern can be determined without introducing data of individual molding molds from the outside, the manufacturing cost of the plastic product manufacturing apparatus according to the present invention can be reduced.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 3 shows a planar arrangement of a plastic lens manufacturing apparatus 10 that automatically performs a process of injecting a plastic lens raw material liquid (raw solution) into a plastic lens molding mold. The manufacturing apparatus 10 of this example is an apparatus for injecting a stock solution into a molding mold 5 having a configuration as shown in FIGS. 1 and 2, and the molding mold 5 is provided so as to obtain a predetermined curvature and lens thickness. It is set downstream of the tape mold device (not shown) to be formed, and the operations from injecting the stock solution into the molding mold 5 to storing it in the thermal polymerization pallet are automatically performed. Therefore, in order to maintain the product time of the tape molding apparatus, it is important to finish the injection process at an appropriate processing time and carry it into the pallet.
[0018]
In the manufacturing apparatus 10 of this example, the molding mold 5 manufactured by the tape molding apparatus is sequentially sent by the transport belt 9 in a horizontal state with the convex surface up. The manufacturing apparatus 10 simultaneously grips (chucks) these molding molds 5 two at a time by the mold supply apparatus 11 and transfers them to the measuring station 20. As shown in FIG. 4, the measuring station 20 stands the molded mold 5 sent vertically by a chuck 29, and contacts the dial gauge 21 with the glass mold outer peripheral surfaces 1 b and 2 b at the apex position of the molding mold 5. In this state, the tape 3 moves so as to cross. Then, according to the position at which the tip 22 of the dial gauge changes up and down when moving, the end width of the cavity 4 (a dimension corresponding to the edge thickness of the lens) 8 is measured. In the manufacturing apparatus 10 of this example, the injection position of the stock solution is determined by the end width 8, and the injection pattern of the stock solution is further determined.
[0019]
Next, in the measuring station 20, as shown in FIG. 5, the molding mold 5 is turned 180 ° with the chuck 29 standing vertically, and the injection hole 7 is opened from below. The perforating unit 25 can move in the direction along the end width 8 and blows compressed air heated to about 200 ° C. by an air heater from a metal nozzle 26 to a predetermined position for about 0.1 to 1 second. Then, the injection hole 7 is processed. Thereafter, the molding mold 5 is set so as to turn 180 ° again so that the injection hole 7 faces upward.
[0020]
Returning to FIG. 3, the molding mold 5 in which the injection hole 7 is formed is transferred from the measuring station 20 to the transfer chuck 12a. The transfer chuck 12 a is reciprocated linearly by the transfer belt 12. The transfer chuck 12 a moves the molding mold 5 from the measurement station 20 toward the injection station 50. When the molding mold 5 reaches the injection station 50, the molding mold 5 is transferred from the transfer chuck 12a to the chuck 61 of the injection station 50.
[0021]
FIG. 6 shows an outline of an injection station 50 for injecting a plastic lens stock solution into the molding mold 5. In the injection station 50 of this example, the pressurized stock solution is supplied from the pressurized plastic lens raw material supply device stored in the lower part of the manufacturing apparatus 10 through the raw solution supply pipe 51, and the discharge amount of the raw material 59 is reduced. It is connected to a pin valve 52 to be controlled. A pulse motor 53 for changing the injection pattern is installed above the pin valve 52, and the flow rate and time of the stock solution 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. It is like that. The pulse motor 53 is connected to the control device 40. The control device 40 obtains the data of the end width 8 from the measurement station 20, and automatically selects an injection pattern suitable for the molding mold 5 being injected. The pulse motor 53 can be instructed. The excess stock solution overflowing from the molding mold at the moment when the stock mold 5 is filled with the stock solution is sucked by the suction nozzle 55 for vacuum suction and is stored in the pressure-resistant bottle 56 connected to the vacuum generator 57. A capacitance sensor 58 that senses the presence or absence of the stock solution is provided between the piping connecting the suction nozzle 55 and the pressure bottle 56, and when the stock solution overflowed by the suction nozzle 55 is sucked, the pin valve 52 is turned off. The injection of the stock solution can be stopped automatically.
[0022]
Returning to FIG. 3, the molding mold 5 into which the stock solution has been injected at the injection station 50 is rotated 180 ° horizontally by the rotary transfer means 60 while being held by the chuck 61 as it is, and the sealing station 70. Move to. In the sealing station 70, a UV curable resin is applied to the injection port formed in the molding mold 5, and the UV resin is further cured by irradiation with ultraviolet rays. The molding mold 5 in which the injection port is sealed in this way is removed from the rotary transfer means 60. Then, it is made horizontal by the reversing chuck 15 and placed on a transport device 90 for transporting to the pallet. The conveying device 90 is a robot for palletizing the molding mold 5 in which the stock solution is sealed onto a dedicated pallet 91 for thermal polymerization. Therefore, the manufacturing apparatus 10 of this example can completely perform the process of injecting the stock solution into the molding mold 5 supplied from the tape molding apparatus and storing it in the thermal polymerization dedicated pallet 91 by an unmanned operation.
[0023]
In the manufacturing apparatus 10 of this example, it is important to perform various operations as described above at a predetermined speed so that the product time of the tape molding apparatus can be maintained. In addition, since it is a manufacturing device that handles plastic stock solutions, leakage of the stock solution may hinder the operation of the chuck and the like, and preventing the stock solution from leaking is important for stable and reliable work. is there. For this reason, in the manufacturing apparatus 10 of this example, the injection pattern of the stock solution is set in the control device 40 that controls the injection station 50 as shown in FIG. Occurrence is prevented. First, in step 31, the end width 8 is measured using the dial gauge 21 at the measurement station 20. Since the molding mold 5 of this example is for molding a plastic lens, the capacity of the cavity 4 of the molding mold 5 can be assumed by measuring the end width 8 corresponding to the edge thickness of the lens. Therefore, the end width 8 is classified into 2 mm, 7 mm, and 10 mm in each stage of steps 32, 33, and 34. When the end width 8 is 2 mm or less, the capacity of the cavity 4 is as small as about 10 cc. Therefore, the injection pattern 1 for injecting the stock solution at a small flow rate of 1 cc / sec is selected in step 35, and the injection of the stock solution is completed in about 10 seconds. On the other hand, when the end width 8 which is the next class is 7 mm or less, the capacity of the cavity 4 becomes as large as about 10 to 20 cc. Therefore, in step 36, the second implantation pattern is selected. In the second injection pattern, 2 cc / sec is selected as the first flow rate. After the stock solution is injected at the first flow rate for 4.1 seconds, the flow rate is switched to a low flow rate of 1 cc / sec and injection is performed to the end. Accordingly, the stock solution can be injected into the cavity 4 whose capacity has increased to about 20 cc by selecting the second injection pattern in about 16 seconds.
[0024]
When the end width 8 is further increased to 10 mm or more, the capacity of the cavity 4 is increased to about 20 to 26 cc. Therefore, in step 37, the third implantation pattern is selected. In this third injection pattern, 3.3 cc / sec is selected as the first flow rate, and after the stock solution is injected at the first flow rate for 4.3 seconds, the flow rate is switched to a small flow rate of 1 cc / sec and injection is performed to the end. Do. Therefore, the stock solution can be injected into the cavity 4 whose capacity has increased to about 26 cc by selecting the third injection pattern in about 16 seconds.
[0025]
Further, when the end width 8 exceeds 10 mm, the capacity of the cavity 4 increases and reaches about 32 cc at the maximum. Therefore, in step 38, the fourth implantation pattern is selected. In this fourth injection pattern, 3.3 cc / sec is selected as the first flow rate, and after the stock solution is injected at the first flow rate for 5.6 seconds, the flow rate is switched to a small flow rate of 1 cc / sec and injection is performed to the end. Do. Therefore, the stock solution can be injected into the cavity 4 whose capacity has increased to about 32 cc by selecting the fourth injection pattern in about 19 seconds. Therefore, in the manufacturing apparatus 10 of this example, the stock solution can be injected in approximately 20 seconds or less from a mold for molding a thin plastic lens to a mold for molding a thick plastic lens. Further, at the end of the injection, the flow rate is very suppressed at 1 cc / sec. Accordingly, by stopping the injection as soon as the stock solution overflows from the injection hole 7, it is possible to stop the injection without overflowing the stock solution to the extent that it hangs down on the chuck, and it is possible to prevent liquid leakage almost completely. .
[0026]
In addition, since the plastic lens for correcting astigmatism adds C power to S power, the molding surface 1a of the glass mold 1 that defines the surface on the eyeball side becomes a toric surface. For this reason, the end width 8 differs depending on the position to be measured, and the measured value of the end width 8 changes as the C frequency increases or decreases. FIG. 8 to FIG. 10 show examples of implantation patterns selected for the combination of S frequency and C frequency by the above method when the end width 8 is measured. FIG. 8 shows the injection pattern selected for the power of the minus lens, FIG. 9 shows the injection pattern selected for the plus lens, and FIG. 10 shows the injection pattern selected for the mix lens. Since the capacity of the cavity 4 is substantially determined by the S frequency, there is a possibility that an implantation pattern having a short implantation time with respect to the capacity of the cavity 4 may be selected as the absolute value of the C power increases. If the injection time is too short, injection may be completed while the injection is performed at a large flow rate, and a large amount of the stock solution may overflow. Therefore, in the manufacturing apparatus 10 of this example, the first flow rate of each injection pattern and the amount of the stock solution to be injected at the injection time (first time) of the cavity 4 selected by the end width 8 are set. The setting is made so that the minimum volume is not reached, and the injection is not terminated while the stock solution is injected at a large flow rate. For example, the mold 5 for plastic lens with S power of −2.25 and C power of −2.00 has a cavity 4 capacity of about 18.6 cc, an end width 8 of 7.1 mm at the maximum, and a minimum of 8 mm. It becomes about 4.0 mm. Therefore, in many cases, the injection pattern 2 is selected, but when the maximum end width 8 is measured, the injection pattern 3 is selected. In this injection pattern 3, the amount of the stock solution injected at a large flow rate is 14.2 cc, which is smaller than the capacity of the cavity 4, and is injected when the large flow rate injection is completed and a small flow rate of 1 cc / sec is injected. Is supposed to end.
[0027]
Thus, in the manufacturing apparatus of this example, the end width (edge thickness) 8 is measured to determine the injection pattern of the stock solution, and the stock solution can be injected with an injection pattern suitable for each molding mold 5. . Therefore, the stock solution can be automatically injected into each molding mold 5 so that no liquid leakage occurs in a short time, and the step of injecting the stock solution can be completely automated. Furthermore, since the manufacturing apparatus of this example automatically measures the end width 8 at the measuring station 20, the subsequent processing can be automatically performed only by receiving the molding mold 5 from the tape molding apparatus. ing. For this reason, it is not necessary to acquire the design data etc. of the molding mold 5 from a tape mold apparatus. Similarly, it is not necessary to exchange design data and data forming the molding mold 5 with other apparatuses. Therefore, the control configuration can be simplified, and the manufacturing cost of the manufacturing apparatus can be reduced. Further, since the subsequent processing can be managed with only the end width 8 for each of the supplied molding molds 5, the control system of the manufacturing apparatus can be simplified, and malfunction can be prevented. Therefore, it is possible to maintain the product time of the manufacturing apparatus located upstream or downstream of the tape mold apparatus or the like, and further increase the productivity. Further, since liquid leakage can be prevented, stable processing can be continuously performed for a long time, and maintenance work can be reduced. As described above, according to the present invention, it is possible to provide a manufacturing apparatus capable of high-speed processing and having high reliability.
[0028]
In the present example, the present invention has been described in detail based on a plastic lens manufacturing apparatus. However, a tape molding method in which a mold space is formed by closing a wall portion of a mold with a thin film tape. The same applies to other products as well as plastic lenses. By providing multiple injection speeds as disclosed above, the stock solution can be injected at high speed without liquid leakage. Furthermore, in the present invention, focusing on the fact that the molding mold is for spectacle lenses, the injection pattern can be selected and optimized for each molding mold as described above by measuring the end width. Yes. Further, the injection amount and time of the injection pattern shown in this example, and the injection pattern selected for each lens type shown in FIGS. 8 to 10 are merely examples, and these values are the values of the molding mold. Of course, it is determined in each case depending on the size and the type of plastic lens.
[0029]
【The invention's effect】
As described above, by using the production method and production apparatus of the present invention, the injection can be completed in a short time by switching the injection amount of the stock solution from a large flow rate to a small flow rate during the injection. Furthermore, since the liquid is injected at a small flow rate when it is finished, the occurrence of liquid leakage can be prevented. Therefore, the operator does not have to monitor the injection level, and further, no malfunction due to liquid leakage occurs, so that the process of injecting the stock solution into the molding mold can be completely automated. Furthermore, since the cycle time of the injection process can be controlled within a predetermined time, consistency with the apparatus installed upstream or downstream is taken, and from the process of forming the molding mold, injection, and further thermal polymerization It becomes possible to automate a series of operations up to. Therefore, according to the present invention, the productivity of plastic manufacturing work using the molding mold can be increased, the manufacturing cost of the plastic product can be reduced, and the manufacturing time can be shortened. In addition, by completely automating the injection process, it is possible to avoid problems in the working environment such as odors and gases of the plastic raw material liquid, 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 an appearance of a plastic lens molding mold using a tape molding method.
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 schematically showing a state in which an end width of a cavity is measured at a measurement station of the manufacturing apparatus shown in FIG. 3. FIG.
FIG. 5 is a diagram schematically showing how an injection hole is opened at the measurement station of the manufacturing apparatus shown in FIG. 3;
6 is a diagram showing a schematic configuration of an injection station of the manufacturing apparatus shown in FIG. 3. FIG.
7 is a flowchart showing processing for selecting an implantation pattern in the manufacturing apparatus shown in FIG. 3;
FIG. 8 is a diagram showing an example in which an injection pattern is selected for S and C degrees of a negative plastic lens.
FIG. 9 is a diagram illustrating an example in which an injection pattern is selected with respect to S power and C power of a plus plastic lens.
FIG. 10 is a diagram showing an example in which an injection pattern is selected with respect to S power and C power of a plastic lens of a mix.
[Explanation of symbols]
1, 2 ·· Glass mold 1a, 2a ·· Molding surface 1b, 2b ·· Glass mold outer peripheral surface 4 ·· Cavity (space filled with stock solution)
5. Molding mold 7 Injection hole 8 End width (edge thickness)
10. Manufacturing apparatus 20 Measuring station 25 Drilling unit 29 Measuring station chuck 40 Injection station controller 50 Injection station 61 Rotary chuck 70 Sealing station

Claims (4)

A method for producing a plastic product, comprising: forming a molding mold by closing a cavity formed by a plurality of walls with a tape, and injecting a plastic stock solution into the cavity;
The plastic product is a plastic lens, and the molding mold includes a first wall portion that defines an eyeball side surface of the plastic lens, and a second wall portion that defines an object side surface;
The end width between the first and second walls is measured, a first flow rate and a first time are set, and the plastic stock solution is loaded into the cavity at the first flow rate for the first time. A first step of injecting;
And a second step of injecting the plastic stock solution into the cavity at a second flow rate less than the first flow rate following the first step.   2. The method of manufacturing a plastic product according to claim 1, wherein the first flow rate and the first time are set so as not to exceed a minimum cavity capacity assumed from the end width. At least two different plastic stock solutions are formed in a molding mold in which a cavity formed by a first wall portion defining the eyeball side surface of the plastic lens and a second wall portion defining the object side surface is closed with tape. An injection device capable of injection at a flow rate;
A measuring device for measuring an end width between the first and second walls;
The first flow rate and the first time are set according to the end width, and after the first flow rate is injected at the first flow rate, the second flow rate is lower than the first flow rate. And a control device for controlling the injection device.   5. The plastic product manufacturing apparatus according to claim 4, wherein the control device sets the first flow rate and the first time so as not to exceed a minimum cavity capacity assumed from the end width.

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