JP4618625B2 - Heat seal device for lens package - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for forming a sealed package by heat-sealing a case containing a contact lens. In particular, the present invention relates to an apparatus for adjusting the adhesion between a sheet and a case and achieving a flat and uniform sealing of a heat seal surface.
[0002]
[Prior art]
Generally, soft contact lenses are stored by immersing them in a predetermined aqueous solution in order to maintain a water-containing state in the distribution process. Conventionally, a lens and an aqueous solution are sealed in a resin lid after being placed in a small glass or plastic container. In recent years, soft contact lenses are becoming the mainstream type that is disposable every day or for a short period of one to two weeks. These distribution cases form a dent for placing the lens on a plastic flat plate called a blister case. After the lens and the aqueous solution are put into the case having the simple structure, the indentation opening is sealed by heat sealing, and the case itself is also disposable. This plastic flat plate is generally made of a thermoplastic resin (for example, polystyrene, polypropylene, etc.) that can be molded by injection molding, and the seal covering the recess is a composite film with an aluminum foil whose heat seal surface is made of polyethylene, polypropylene, polystyrene, etc. The After the lens or the like is heat-sealed and sealed, the package is subjected to autoclave sterilization or the like to maintain the aseptic hydration state until it is passed to the consumer.
[0003]
Conventionally, this type of contact lens packaging device seals a plurality of contact lens cases side by side and separates them into individual packages after sealing, or puts a broken line that can be separated into a single product and collects them. It was distributed in units. As these prior arts, there are JP-A-8-47989, JP-A-8-54824, and JP-A-9-169357. The purpose of these technologies is to let the user recognize that the blister case is heat-sealed in a single unit and that it is different from the original shipment base if it is a single item separated from the unit. In consideration of the efficiency of performing a so-called unauthorized opening prevention function and sealing together. The invention disclosed there is approximately as follows. Multiple cases are mounted in a fixed carrier rack with holes for receiving each case, and after contact lenses and liquids are placed in each case, check the lenses for defects at the inspection station To do. Thereafter, the carrier rack is moved onto the platen in the heat sealing station, the sheet is placed on the case, and predetermined heat and pressure are applied by a heated mandrel to heat seal the case to form a sealed package. As a result, each case shares a sheet to form a package in which a large number of cases are joined together.
[0004]
However, the packaging method has the following disadvantages as described in Japanese Patent Laid-Open No. 2000-203505 by the applicant. For example, mounting multiple lens cases on each carrier rack complicates the detection and recognition of lens defects and their absence at the inspection station, ie which lenses on the carrier rack are inspected. It is necessary to use a complex matrix tracking system to determine if they have failed and track them through the above process until they are removed. Another disadvantage is that each lens case on the carrier rack is subjected to the same heat sealing conditions. Each lens case has different molding height due to changes in molding conditions, or when the lens case is placed slightly inclined when placed on the carrier rack. Case height may be uneven. In such a case, the case higher than the standard height receives strong pressure from the mandrel, and conversely the low case is less likely to receive pressure, so a very strong force is required to peel the sheet from the lens case. The quality of the product can also be caused by the fact that a good lens can be discarded due to a poor seal, such as the possibility that the sealing force is too weak and liquid leakage or rupture of the seal part may occur during the sterilization process. In some cases, it is not acceptable. In addition, when heat sealing is performed using a sheet in which a break line is provided between sheets in order to make a single product for each case, if the adhesive part between the sheet and the case is misaligned, all cases in the group on the carrier rack are inferior. Matching occurs and a defective package is formed.
[0005]
In order to solve the above problems, Japanese Patent Application Laid-Open No. 2000-203505 proposes a heat seal device that can apply a predetermined amount of heat and pressure to each case. If this apparatus is used, a uniform pressure can be applied for each case, so that a sheet having a uniform degree of adhesion can be obtained in any case. Although the above-mentioned problems in quality can be cleared by such an apparatus, it is also important to improve the appearance as a so-called product as another important problem in heat sealing. When heat-sealing to the lens case, wrinkles on the sheet surface become a problem because the heater is pressed against the sheet surface. The heat seal must be bonded with a certain level of strength to prevent rupture in the sterilization process with auto steel after sealing. On the other hand, if the adhesive strength is too strong, there is a problem that it becomes difficult to peel off or the sheet is wavy and wrinkled, resulting in poor appearance.
[0006]
[Problems to be solved by the invention]
The present invention has been made in the background as described above, and provides a heat sealing device for a lens case, which can suppress the generation of wrinkles in the sheet as much as possible and can perform heat sealing with sufficient sealing force. The purpose is to do.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises the following constitution. That is, a device for packaging contact lenses, a lens case carrier for mounting a plurality of contact lens cases, a sheet feeding roller for supplying a sheet for heat sealing to the lens cases, and a heated mandrel A heat seal device having a cylinder that presses under a certain pressure, and presses a mandrel twice or more after placing a sheet in a recessed opening of a case.
[0008]
The apparatus of the present invention further includes a cutter for cutting the belt-like sheet, and punches the sheet supplied from the roll into a necessary area or divides the sheet into appropriate groups, and the lens case alone or several pieces Separated for packaging. In addition, when it divides | segments by a suitable group, a broken line is given between cases so that it can isolate | separate into each lens case unit.
[0009]
The apparatus of the present invention has a lens case carrier for mounting a plurality of contact lens cases. The lens case has a flat sealing area and a recess for receiving the lens inside. The flat sealing region may further have a flange extending outwardly and a leg portion depending from the flange. This leg portion is intended to prevent the case from being rested stably when the case is placed only by the indentation of the case, and does not necessarily hang down from the entire circumference of the flange. The lens case carrier of the device of the present invention has a concave portion for accommodating the case recess and an annular mounting portion for supporting the flat sealing region of the case from below. This mounting part is designed to support the flat part with a predetermined pressure when the heating mandrel is pressed against the flat part of the case across the sheet. From the back side of the case to ensure the sealing of the case Support important positions. The lens case carrier is further provided with a conveyor for transporting them, and the lens case on the carrier is transferred to a position below the heated mandrel, and after two or more press heating welding processes by the mandrel, the cutter And is conveyed to a position where the lens case is detached from the carrier.
[0010]
If the belt-like sheet is not welded in a state where the lens case opening is pulled under a constant tension, the surface of the sheet after sealing will be wrinkled, or a part of the sheet will be incompletely welded by undulation during sealing. Therefore, when placing the cloth so as to cover the case opening, the case is placed in parallel with the flat part of the case and in direct contact with the flat part in a state where tension is applied by pulling the belt-like sheet from the roll. Placed on top. The first heat welding by the mandrel is performed with a light pressing force and a low temperature so that the sheet is uniformly adhered to the flat part around the recess, with the main purpose of positioning the sheet on the flat part on the case. (So-called temporary bonding). Next, it is moved from the welding position to a position directly below the second mandrel by the conveyor (in this case, the shape and pressing force of the mandrel may be changed at the same position). The sheet on the flat part of the case is pressed and pressed firmly with the pressing force. In this way, the heat-welding in two steps enables a strong adhesion that can withstand autoclave sterilization and uniform sealing without wrinkles on the sheet surface.
[0011]
In another preferred embodiment of the present invention, a pressure transducer is attached to the cylinder supporting the mandrel so that the pressure when the lens case is pressed through the seat can be adjusted. May be adjusted for each case to implement the best sealing. When the lens case is placed on the carrier, the way the case and carrier overlap is not always a constant relationship, and it is difficult to guarantee that the carrier on the conveyor is always at the same height. It is. For this reason, even when the heating mandrel is lowered by the cylinder, even if it is always lowered to the same position, the pressing force at this time is not always constant, so the pressure transducer detects the flat surface according to the position of each case. It is desirable to seal while adjusting the pressing force of the heating mandrel.
[0012]
When the lens case recess is directly covered with a sheet, the mandrel to be pressed has an annular pressure-bonding surface that is larger than the diameter of the recess opening and has a width of 2 mm or more. If it is a normal blister case, the first mandrel and the second mandrel may have the same shape, but the lens case is particularly effective when the mandrel is pressed twice or more, which is a feature of the present invention. Is a case where the surface is heat-sealed with the inner lid kept on the indentation opening as described in Japanese Patent Application No. 2000-68154. In such a case, when removing the sheet, if the inner lid cannot be removed at the same time, it takes time to take out the lens. Therefore, the sheet needs to be adhered to the inner lid when heat sealing. In this lens case, the outer diameter of the inner lid with respect to the indentation opening diameter is made small so that unevenness due to the protrusion of the inner lid on the sheet surface cannot be made. However, the outer diameter of the inner lid and the opening diameter of the indentation are almost equal, and the case of the heat-sealing is due to the pressing force of the heating mandrel when heat-sealing and the melting of the indentation opening resin and inner lid outer periphery resin by heat. In some cases, the inner lid is welded, and not only when the sheet is peeled off, but also when the inner lid is directly removed. The present invention is also a heat-sealable device that can remove the inner lid at the same time by a simple operation of peeling off the sheet without causing the above-described welding even in such a lens case. Unlike the above, the shape of the pressing portion of the mandrel for such a case has the following characteristics. The first stage pressing does not contact the upper surface of the inner lid of the dent, and has an annular heating portion with a diameter of about 2 to 5 mm that can melt the sheet around the dent. In the second stage, the same as described above. A double annular pressing surface is provided around the recess and around the inner lid so that the sheet adheres in an annular shape. For both pressings, it is necessary to make the shape so that the heating surface of the mandrel does not come into contact with the adjacent area between the indentation opening and the outer periphery of the inner lid. In the present invention, through the above two-step pressing process, the sealing of the mandrel is divided into twice by sealing the depression and the inner lid by one pressing, and the sealing is completely performed. This is an apparatus capable of adhering the inner lid to the sheet while avoiding fusion between the case and the inner lid. Sealing with adhesive force is possible with a single press, but if you try to increase the adhesive force, you have to press the mandrel for a long time or at high temperature and pressure, and if you do so, there will be It tends to weld easily. Such a seal also causes the sheet surface to appear wrinkled or wavy and unsightly. Therefore, as a heat sealing device that satisfies the improvement of the adhesive force related to sealing around the recess and the removal of the inner lid together with the sheet, or the appearance of the sheet surface is improved, the press of the present invention is performed twice or more. A device for applying was proposed.
[0013]
【Example】
A preferred embodiment of the present invention will be specifically described below with reference to the accompanying drawings.
[0014]
FIG. 1 is a schematic view of an example of the heat sealing apparatus 1 of the present invention as viewed from the side. This apparatus includes a conveyor 3 for advancing a plurality of contact lens cases 2 in a direction indicated by an arrow A, and a lens case carrier 4 is attached to the conveyor to fix the position of each lens case and heat seal. Sometimes the lower part of the case is supported from below. When the lens case is placed on the carrier attached to the conveyor, the lens case is transported from the lens case molding device by the arm 5 on the left side of the drawing with the recess open. In this example, the case and the preservative solution are already filled in the case, but other than that, the case may be filled with the lens or preservative solution before sealing after placing only the case on the conveyor. Alternatively, either one may be placed in the case and the other remaining on the conveyor may be stored.
[0015]
The lens case placed on the lens case carrier 4 is transported toward the heat seal device 1 by the conveyor 3, and the sheet 18 supplied from the roll 10 is first placed so as to cover the recess of the case. At this time, the sheet pressing rollers 11 and 12 are merely placed on the flat surface of the case and there is no adhesion to the case. When transported to the next position, a cylinder 8 having a heating mandrel 6 positioned above the case at its tip is lowered downward by, for example, a hydraulic method or a pneumatic method. Since the sheet is thermally welded to the case after the heating mandrel 6 is pressed across the sheet on the upper surface of the case, the sheet is continuously flat under a constant tension as the case is moved by conveying the conveyor. It will be placed on the surface. In the example of the present apparatus, since the sheet heat-sealed on the case is cut with an appropriate length by the cutter 9 as will be described later, only on the start of the apparatus until it is first bonded to the case, An operation to place is required. The operation is, for example, until the tip of the roll-shaped sheet 10 is grabbed and pulled to the position of the sheet pressing roller 13, and the heating mandrel 6 bonds the sheet and the case flat surface, and once the case and the sheet are bonded. Thereafter, since the sheet is fed from the roll by the movement of the case, continuous processing is easy. On the other hand, when the cutting by the cutter 9 is a use that cuts out the sheet in the area required for the case cover, the sheet pressing roller 15 is used as the sheet take-up roller so that the roll 10 to the take-up roller 15 can be removed. Can be pulled under a certain tension. Since the sheet pressing rollers 11 to 15 are intended to place the sheet on the upper surface of the lens case under a uniform tension, the number and position thereof are adjusted as appropriate.
[0016]
The sheet placed on the case is thermally welded to the flat part of the case in two steps by the downward pressing of the heating mandrels 6 and 7, and then can be used as an appropriate length (for example, as a gripping part when the sheet is opened) by the subsequent cutter 9. Is cut to such a length). Furthermore, the case conveyed by the conveyor is carried out from the heat seal apparatus 1 and is advanced to the next process by a gripping means such as an arm 16.
[0017]
FIG. 2 is a perspective view showing an example of a contact lens case 2 preferably used in the device of the present invention. In the figure, in the center of the case 2 is shown a recess 20 for storing a lens and a storage solution and a lid 21 for covering the recess. The lid 21 may or may not be in the lens case, and in the case of being attached, the reinforcing effect of the sheet covering the recessed opening of the case can be expected as compared with the cover only of the sheet. A flat region is secured on the upper surface 22 of the case 2 in order to weld the sheet, and leg portions 23 hang down around the upper surface 22. This leg portion is stable and difficult to stand with only the convex surface 24 of the recess 20 when the case is placed. In order to pull the leg portion from the roll 10 with a constant tension while the sheet surface is adhered to the flat portion as described above. There are effects such as more reliable placement on the lens case carrier 4. A stepped portion, an annular groove, etc. may be formed so that the surface of the lid and the upper surface 22 are on the same plane when the lid 21 is placed around the opening 25 around the opening 20. By this, the sheet can be adhered more smoothly. Further, a stepped portion, an annular ridge portion, or the like may be formed in the peripheral portion 26 of the lid 21 so as to correspond to the recessed opening. The case and the inner lid are usually formed by injection molding or heat compression molding, and the resin used is appropriately selected from polyethylene, polypropylene, ethylene vinyl acetate, propylene copolymer, polystyrene, nylon, etc. so as to be inexpensive and easy to handle. Made of thermoplastic material. Also, the sheet is generally oxidized to form a barrier material having an aluminum foil laminate or plastic layer with a material similar to that of the case material such as polyethylene or polypropylene on the surface so as to give good adhesion to these plastic materials. Other materials composed of silicon can be used.
[0018]
At the time of heat sealing, a heating mandrel is pressed around the recess, and heat and pressure are applied to a predetermined position for a predetermined time. Therefore, the shape of the pressing portion is a ring shape as shown in FIG. The ring inner circle 33 is not in contact with the sheet, and only the ring portion 31 is in contact with the sheet and pressurizes. FIG. 3 is a view of the mandrel 6 as viewed from below. The inner diameter 30 is naturally larger than the opening diameter of the recess 20, and the outer diameter 32 must be inside the outer periphery of the case upper surface 22. The width of the ring 31 is preferably about 2 to 5 mm. The first-stage pressing is for the purpose of bonding and fixing the sheet and the upper surface of the lens case, and it is preferable to bond the sheet between the case and the mandrel in the most tensioned state. When the inner lid 21 is used, the mandrel 7 used for the second-stage pressing has an outer diameter 34 of the inner ring-shaped adhesive portion so that the sheet adheres to the periphery of the inner lid 21 as shown in the lower diagram of FIG. Is set slightly smaller than the diameter of the inner lid 21. Between the inner ring portion 35 and the outer ring portion 31, there is an annular gap 36 having a width of 0.2 to 2.0 mm, so that the inner lid and the case body are not melted and bonded to each other. It has a structure. The inner diameter 37 of the inner ring 35 is not in contact with the sheet as described above, and does not bond the entire surface of the inner lid to the sheet. When the inner lid 21 is not used, the inner ring portion 35 is not necessary, and a contact surface equivalent to the mandrel 6 may be used. The pressure at the time of heat sealing is detected by a pressure transducer attached to the cylinder 8, and the cylinder is lifted or processed through an electrically connected controller 19, so that the pressing force by the heating mandrel becomes uniform for each case. Adjusted to
[0019]
The carrier 4 on which the lens case is placed has a structure shown in FIG. 4, for example. The carrier is housed inside the lens case 2 and has a recess 40 that houses a convex portion 24 corresponding to the recess on the back side of the case 2. When the lens case 2 is placed on the carrier 4, the leg portion 23 is supported so as to surround the peripheral wall portions 43 to 46 of the carrier and the flat portion 22 of the case is brought into contact with the upper surface 42 of the carrier from the back surface. In particular, the recess 40 has a depth that does not contact the case protrusion 24 and a diameter of its inner diameter 47 so that the protrusion 24 is completely accommodated so that it does not contact the opening of the recess 40 in the middle of the protrusion. It is desirable that the upper surface 42 of the carrier 4 is in contact with the rear surface of the case and supports the entire case so as to lift the entire case. This is because it is necessary to hold the case firmly in accordance with the location where the mandrel is pressed. Also, since the carrier is fixed on the conveyor, the position of the lens case is accurately specified, and the cylinder that supports one mandrel is also installed at a certain position, so if the conveyor is stopped just below its lowered position, Compared to the heat seal device, the positional relationship between the heating mandrel and the case flat portion can be kept constant within an appropriate range.
[0020]
By performing pressure bonding with a heating mandrel in two stages, not only the pressure can be adjusted, but also the adhesion by the sheet can be effectively strengthened, and the sheet surface is not wrinkled or wavy due to thermal welding, and has a good appearance. Is possible. In addition, since the pressure is applied in two stages, even if the seal surfaces are slightly shifted from each other or there is a place where there is an airtight defect such as a wave in part of the annular seal, the place is pressurized again with another heating mandrel. Therefore, it is possible to seal completely without missing any fine defects. Furthermore, even if the upper surface 22 of the case is wet with a storage solution or the like and a seal failure occurs in a wide range, the occurrence of such a defective product can be prevented by two-stage heating.
[0021]
After the two-stage pressure bonding with the heating mandrel, the sheet is cut to an appropriate length by the cutter 9 shown in FIG. The cutter 9 of this example is supported by the support 17 so as to be movable up and down, and is a structure for cutting the sheet. It may be one that can be accommodated. Further, for physical cutting by a cutter, cutting or breaking lines may be formed by a laser. As shown in FIG. 1, the cases after seal sealing are divided into single items, and then the case conveyed from the heat seal device is transferred to the next process by the arm 16.
[0022]
Using the heat sealing device shown above, after sealing the contact lens in the case, when sealing with the preservation solution, there is no liquid leakage and the sheet surface can be welded in a good-looking manner, for example, in the indentation of the lens case. Even if an inner lid is used, welding is possible so that the inner lid can be removed at the same time as the sheet is peeled off. In addition, a uniform seal can be obtained for each lens case, producing the entire contact lens product. Efficiency and yield rate are improved.
[0023]
The heat sealing apparatus according to the present invention has been described in detail above. However, this is merely an example, and it should be understood that various modifications and improvements can be made without departing from the spirit of the present invention. It is. For example, it is easy to separate the case by printing the product name / standard of the lens in advance on the surface of the sheet to clearly indicate what the lens is in the case, or by giving a break line to the roll sheet in advance. The number of times of pressing is two in the above example, but it does not depart from the gist of the present invention, such as taking three or more pressing steps, or adhering a sheet to the inner lid even in the first stage pressing. However, it should be understood that various changes, modifications, improvements, and the like can be made based on the knowledge of those skilled in the art.
[0024]
【The invention's effect】
As described above, according to the device of the present invention, when a blister case is adopted as a contact lens distribution case, a sheet and a storage solution are stored in the case, and then the case surface is sealed with a cover sheet. Adhesive strength between the case and the case is appropriate, and a good-looking seal without wrinkling or undulating the sheet surface is possible. Also, for example, even when a resin inner lid is used for the lens case recess, it is possible to bond the inner lid so that the inner lid can be removed at the same time as the sheet is peeled off. As a result, the overall production efficiency of contact lens products and the yield rate are improved.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing a heat sealing apparatus as one embodiment of the present invention.
FIG. 2 is a perspective view showing a lens case as an embodiment of the present invention.
FIG. 3 is a view of a mandrel as a heating unit according to the present invention as viewed from below.
FIG. 4 is a perspective view showing an example of a carrier on which a lens case used in the present invention is placed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat seal apparatus 2 Lens case 3 Conveyor 4 Lens case carrier 5 Case gripping arm 6 First mandrel 7 Second mandrel 8 Cylinder 9 Cutter 10 Sheet supply rolls 11-15 Sheet pressing roller 16 Case gripping arm 18 Sheet 19 Controller 20 Recess 21 inner lid

Claims (1)

A lens case carrier for mounting a plurality of contact lens cases, and a lens case for packaging a contact lens by heat-sealing the surface with the inner lid at the recessed opening of the contact lens case A sheet feeding roller that supplies a sheet for heat sealing under a constant tension, a sheet cutting cutter that cuts a sheet into a predetermined position of the fed sheet, and a cylinder that presses the heated mandrel under a certain pressure. And having the sheet placed in the case opening and operating the mandrel twice or more , forming the pressing parts of the first and second mandrels in different shapes, at least once with a part of the inner lid and the periphery of the depression Autoclave sterilization by heating and welding at least once around the cavity Heat-sealing device also has the adhesion withstand strength, to avoid fusion of the case and the inner cover, characterized in that it allows to remove the inner lid with the seat.

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