JP2690243B2 - Blister packaging method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blister packaging method, and more particularly, to a blister packaging method for minimizing curling of a blister package by reducing a heating area of a resin film.

[0002]

2. Description of the Related Art A blister package (hereinafter referred to as a PTP sheet) produced by blister packaging is, as shown in FIG. 9, a resin film x in which a container, that is, a pocket y is formed, and a container formed by joining the resin film x. It is formed of an aluminum foil covering y and is formed of a cover film z. Therefore, when the PTP sheet is formed, there is a problem that it curls, that is, curls due to the difference in shrinkage amount of both materials.

Conventionally, rigid vinyl chloride (PVC) has been the main material for resin films used for blister packaging, but unstretched polypropylene (hereinafter referred to as CP ) is used because of environmental problems.
P) is being used. However, CP
When P film is used for blister packaging, it warps (curls) more than PVC film, and the amount of curl also changes with time, and it becomes 30 to 60 before it stabilizes.
It takes time. The unstretched polypropylene is a mixture of isotactic polypropylene whose molecular orientation is a crystalline structure and atactic polypropylene whose molecular orientation is disordered and amorphous. When a CPP film made of this mixture is heated to form a container, the crystals collapse, the crystallinity decreases, the specific volume increases, and the volume expands. When the CPP film is then cooled and its temperature drops to room temperature, it recrystallizes and shrinks. Moreover, it takes a certain time to recrystallize, and even if the CPP film is cooled to room temperature in a short time, the recrystallization is continuously performed (because the cooling rate of the CPP film and the recrystallization rate do not match. ). Therefore, the CPP film cooled to room temperature continues to shrink, the time being 30 to 60 hours.

On the other hand, in a blister packaging line for medicines and the like, it takes about 10 minutes from the start of packaging to the inner and outer packaging in order to improve production efficiency.
The CPP film will continue to shrink during the entire packaging process as well as after the packaging is completed, and the curling degree of the PTP sheet will continue to increase. Therefore, PTP
While the sheet is passing through a series of packaging lines (accumulation process, interior process, etc.), the curl state increases momentarily, which makes the transport of the PTP sheet unstable and the appearance of the PTP sheet deteriorates.

On the other hand, a conventional blister packaging machine for making a PTP sheet uses a heating device a to heat a resin film x at a position A and compressed air to a molding device b at a position B as shown in FIG. molding a plurality of pockets y to warm softened film x by heating Te, cover film z heat pressure bonding consisting of aluminum foil on a resin film x tablet is filled in a container y by a seal device d in position D Then, at position E, cooling is performed by the cooling roller e, at position F, perforations are formed by the perforation forming device f, and at position G, the PTP sheet is punched out by the punching device g.

In the blister packaging machine as described above, C
The positions where the heating / cooling process (crystal collapse → recrystallization process) that causes curling of the PP film are performed are positions A and B, and positions D and E. At the position A, in the resin film x, as shown in FIG. 10, the resin film x has a flat area S ′ considerably larger than the flat area S of the container y formed by the heating device a, as shown in FIG. It is heated during the intermittent stop, and at position B, only the region S of the heated portion is molded into a container, and the other portion is cooled after molding. Further, at the positions C and D, heating and cooling of the film similar to the above are performed. Moreover, since the part of the region S ′ of the resin film x excluding the region S is joined to the cover film in the sealing step, the resin film is not aged with time even after the aluminum film z is joined to the resin film x. Shrinks,
A curl as shown in FIG. 11 is generated on the PTP sheet, and the curl increases with time (H increases for the same width L).

Various methods for preventing the occurrence of such curl in a PTP sheet have been conventionally proposed. Such a conventional method is such that a perforation which is arranged at a position corresponding to the longitudinal centerline of the packaging sheet, for example, at the same time as or after the formation of the pocket in the packaging film or after that, as shown in FIG. A notch n is formed, and before punching out as a packaging sheet, the position of the perforation n is pushed by a pressing tool o as shown in FIG. 13 to reversely fold it into a dogleg shape, or as shown in FIG. The film after the sealing is completed is squeezed between the squeezing rollers q and r, which have different large and small diameters and are elastically pressed in the direction in which they are pressed against each other, thereby preventing the curling of the packaging sheet.

However, the former method has a problem that when the film is reversely folded and tension is applied to the film, the film returns to its original state. In the latter case, the film returns to the original state after a lapse of time after punching into the packaging sheet. In addition to the above , the problem of scratches on the surface of the packaging sheet due to ironing,
There is a problem that only the X-shaped curl can be prevented because the packaging sheet is punched out from a continuous strip-shaped film in a horizontally long state. Furthermore, neither of the above methods can be a fundamental solution when the curl increases over time.

[0009]

The problem to be solved by the present invention is to determine the area of the heating region of the film before molding the pocket in the resin film as the area of the plane region of the pocket formed in the resin film. By making them almost the same, the total area where the resin film shrinks over time is reduced, and thereby the curl of the PTP sheet is minimized.

[0010]

The present invention provides a blister packaging method in which a resin film is heated and then a container is formed in the resin film, and the container is filled with an article and sealed with a cover film. Heating 2 to n
The heating area for one container is sequentially increased from the first stage to the n-th stage, and the heating area of the final stage is made substantially equal to the area of the plane area of the container. .

[0011]

In the above construction, the area of the portion where the resin film is heated before molding the container is substantially equal to the area of the flat area where the container is formed, so that the portion where the resin film is joined to the cover film is It is hardly heated before molding the container, and the cause of shrinkage of the resin film with time after the cover film is pressure-bonded and sealed is reduced. Therefore, there is no increase in curl over time due to shrinkage of the resin film over time.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. It is to be noted that those having the same configuration as the conventional blister packaging machine shown in FIG. 8 will be described using the conventional device. FIG.
And in FIG. 2, a part of the heating device 2 used for carrying out the invention is shown. This heating device is provided with upper and lower heating blocks 21 and 22 which are heated by an electric heater or the like embedded therein, like the conventional heating device a. A plurality of heating projections 23 and 24 are formed on the lower surface of the upper heating block 21 and the upper surface of the lower heating block at predetermined intervals in the width direction and the longitudinal direction of the film x to be heated. In this embodiment, the number of heating convex portions in the width direction of the film is 10, but only 5 are shown to simplify the drawing. Further, the heating device 2 is divided into a plurality of zones (first to third zones in this embodiment) A ₁ , A ₂ and A ₃ in the longitudinal direction of the film, that is, in the traveling direction (the horizontal direction in FIG. 2). , Heating projections 23a, 24 for each area as seen in the direction of travel of the film
The number of a, 23b, 24b, 23c, 24c is four.

In this embodiment, since the container y formed on the resin film x has a circular planar shape, the heating projections 23a, 24a, 23b and 24 formed on the upper and lower heating blocks are formed.
The planar shapes of b, 23c, and 24c are also circular. Heating protrusions 23a, 23b and 23c and heating protrusions 24a, 2
Since the shapes and sizes of 4b and 24c are the same, the latter heating convex portion will be described. The diameters of the circular heating projections 24a, 24b, and 24c are respectively D ₁ ,
The dimensions are determined so that D ₁ <D ₂ <D _{3 where} D ₂ and D ₃ . The third direction at the end of the direction of travel of the resin film x
The diameter D of the diameter D ₃ of the heating convex portion 24c of the area A ₃ of the container y
_The dimensions are determined so that they are almost equal to ₀ (D ₃ = D ₀ ).

In the heating device having the above construction, the resin film x is intermittently sent between the upper heating block 21 and the lower heating block 22 at the pitch P shown in FIG. Then, while the resin film x is intermittently stopped, the lower heating block 22 approaches the upper heating block 21 and first presses the resin film with the heating convex portions 23a and 24a of the _first area to form the area S ₁ having the diameter D _1. Heat to a predetermined temperature (Fig. 1
A). Next, the lower heating block is moved downward to separate the heating convex portion from the resin film, and then the resin film x is moved by one pitch P.
Only the resin film heated by the heating projection of the first area A ₁ by intermittently moving in the direction of the arrow is moved to the second area A ₂ . Then, the lower heating block is again brought close to the upper heating block 21, and the area S ₂ having the diameter D ₂ is heated to a predetermined temperature by the heating projections 23b and 24b in the _second area. At this time, the pitch between the heating convex portions and the feed pitch of the film are determined so that the center of the area S _{1 and} the center of the area S ₂ coincide with each other. Furthermore, the lower heating block 2
2 is moved downward to separate the heating convex portion from the resin film, and then the resin film x is intermittently moved by one pitch P in the direction of the arrow to move the resin film heated by the heating convex portion of the second area A ₂ to the first position. Move to area A ₃ of ₃ . Then, the lower heating block is again brought close to the upper heating block, and the region S ₃ having the diameter D ₃ is heated to a predetermined temperature by the heating projections 23c and 24c in the third area A ₃ . At this time, the pitch between the heating convex portions and the feed pitch of the film are determined so that the center of the area S _{2 and the} center of the area S ₃ coincide with each other.

In FIGS. 4 and 5, the sealing device 3 is shown. This sealing device 3 is a replacement for the conventional sealing device c shown in FIG. 8, and has a seal roll 31 having a structure and function similar to that of the seal roll.
It has a heat seal roll 33 that cooperates with the seal roll 31 to press-bond the cover film z to the resin film x. A plurality of recesses 32 for receiving the container y formed of a resin film are formed on the outer periphery of the seal roll 31 while being separated in the axial direction and the circumferential direction. This seal roll 31 is designed to be cooled by passing cooling water through it like the conventional one. The heat seal roll 33 is also heated to about 200 ° C. by an electric heater as in the conventional one. In this embodiment, the sealing device 3 is a cooling block 3 arranged close to the outer circumference of the sealing roll.
5 is provided. This cooling block is a seal roll 31
The surface 36 facing toward is arc-shaped, and a large number of nozzle holes 37 are formed in the surface. The nozzle hole 37 communicates with a passage 38 formed in the cooling block, and the cooling air sent from the cooling air source (not shown) into the passage 38 is directed toward the resin film x and the cover film z wound around the seal roll 31. It is designed to be blown to cool those films. This is done by heating only the surface layer of the resin film, which is a CPP film, for thermocompression bonding of the cover film to the resin film, and after pressure-bonding and sealing with a heat-sealing roll, cooling air is blown to generate heat. By preventing the resin film from penetrating into the inside, the amount of the crystal collapse layer due to heating is reduced, and the amount of curl generated over time can be reduced accordingly.

Next, the overall operation of the blister wrapping by the blister wrapping machine having the above structure will be described with reference to FIG.
First, the resin film x is intermittently fed in every 1 pitch P,
As described in the above-mentioned heating device 2, the heating projections 23a, 24a, 23b, 24 of the heating device 2 while the three areas A ₁ , A ₂ and A ₃ of the heating device 2 are sequentially and intermittently fed.
b, 23c, and 24c are sequentially heated, and finally only a portion having an area equal to the area of the region S ₀ in which the container is molded, that is, the region S ₃ is heated. Then, it is sent to a molding device b (FIG. 8) and the container y is molded by the molding device. In this case, since the area of the finally heated region S ₃ is the same as the area of the flat region S ₀ of the container y,
As in the conventional blister packaging, the portion of the container that is bonded to the aluminum foil cover film is not heated at the peripheral portion of the container.

The resin film x in which the container y is formed is sent to a position C, and at the position C, an item such as a tablet is filled in the container y by the filling device c. The resin film x in which the product is filled in the container is sent to the sealing device D, and the sealing film 31 is heat-pressed by the sealing roll 31 and the heat sealing roll 33 of the sealing device d to seal the container. After the cover film is crimped,
While the resin film is wound around the seal roll 31, cooling air is blown toward the resin film and the cover film from the nozzle holes 37 formed in the cooling block 35. Therefore, the resin film x comes into contact with the seal roll 31 and is cooled by the seal roll 31 and at the same time is rapidly cooled by the cooling air.

6 and 7, the temperature change of each part of the resin film when the resin film x and the cover film z are cooled by using the sealing device 3 of the above embodiment and the conventional device shown in FIG. The change in temperature of each part of the resin film when used is shown over time (horizontal axis). In the above figure, time 0 is when the resin film x and the cover film y are just pressure-bonded by the seal roll 31 and the heat seal roll 33, and the position at that time is Da.
Expressed by The resin film of Db is a seal roll 31.
Indicates a position where the resin film starts to contact the cooling roll e, and Eb indicates a position where the resin film separates from the cooling roll. Also, in the above figure, the solid line (a) is the temperature of the surface of the resin film x to which the cover film y is pressure bonded, the broken line (b) is the temperature at the position of 1/2 of the resin film thickness, and the chain line (c) is the thickness from the cover film side of the resin film 1/4 of the thickness
And the solid line D indicates the temperature of the surface of the resin film in contact with the seal roll 31. As is clear from the comparison of this figure, when the sealing device of the present example is used, the degree of crystal collapse can be reduced by rapidly cooling the film, and the curl over time can be reduced accordingly. You can reduce the increase.

After leaving the sealing device 1, it is cooled by the cooling roll e in the same manner as the conventional device shown in FIG. 8 , and then at the position F, a perforation forming device f forms a resin film and a cover film between the containers. A container is formed and punched into a PTP sheet at a position G by a punching device g.

According to the present invention, the width L of the PTP sheet is 4
When it is 9 mm, the curl height H of the PTP sheet formed by the conventional blister packaging method is about 8 mm.
On the other hand, the curl height of the PTP sheet formed by the method of the present invention was about 4.5 mm, which could be reduced by about 44%. It should be noted that, in the above example, since the case where the planar shape of the container formed on the resin film is circular is dealt with, the planar shape of the heating convex portion formed on the heating block of the heating device is shown. It goes without saying that the shape is adjusted to the planar shape of the container. That is, if the planar shape of the container is rectangular, elliptical or oval, the planar shape of the heating convex portion is also rectangular,
Make it oval or elliptical.

[0021]

(1) According to the present invention, the heating of the resin film before molding the container is limited to only the molding region of the container. Therefore, the increase in curl of the PTP sheet with time can be reduced. (2) According to the method of the embodiment, cooling air is blown toward the cover film and the resin film immediately after heat sealing to rapidly lower the temperature of those films. The degree of contraction is reduced, and the increase in curl over time can be reduced accordingly.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heating device used to carry out the blister packaging method of the present invention.

FIG. 2 is a plan view of a part of the heating device of FIG. 1, showing the arrangement and shape of heating projections.

FIG. 3 is a plan view showing a heated state of a resin film.

FIG. 4 is a side view of the sealing device according to the present embodiment.

FIG. 5 is a perspective view of a cooling block of the sealing device.

FIG. 6 is a diagram showing a temperature change of a film when the sealing device shown in FIG. 5 is used.

FIG. 7 is a diagram showing a temperature change of a film when a conventional sealing device is used.

FIG. 8A is a schematic side view of a conventional blister packaging process, and B.
FIG. 6 is a perspective view showing the flow of a film in the blister packaging process.

FIG. 9 is a side view of a PTP sheet.

FIG. 10 is a perspective view showing a conventional heating method for a resin film.

FIG. 11 is a side view showing a curled state of the PTP sheet.

FIG. 12 is a plan view of a PTP sheet showing a conventional curl prevention method.

FIG. 13 is a side view of a PTP sheet showing a conventional curl prevention method.

FIG. 14 is a side view of a PTP sheet showing another conventional curl preventing method.

[Explanation of symbols]

2 heating device 21, 22 heating block 23a, 23b, 23c heating convex part 24a, 24b, 24c heating convex part 3 sealing device 31 seal roll 33 heat seal roll b molding device c filling device x resin film y container z cover film

Claims (2)

(57) [Claims] 1. A blister packaging method in which a resin film is heated and then a container is formed in the resin film, and an article is filled in the container and sealed with a cover film. A blister packaging method characterized in that the heating area for one container is sequentially increased from the 1st stage to the nth stage, and the heating area of the final stage is made substantially equal to the area of the plane region of the container. . 2. A heating device for heating the resin film in a blister package in which a resin film is heated and then a container is formed in the resin film, and an article is filled in the container and sealed with a cover film. The heating surface of the resin film is divided into a plurality of areas along the moving direction of the resin film, and a plurality of heating convex portions having a planar shape similar to the planar shape of the container are formed on the heating surface. The heating device is characterized in that the surface areas of the heating convex portions are the same and the surface areas of the individual heating convex portions in different areas are increased toward the downstream side in the moving direction of the resin film.