JPH0528653B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for forming a pocket in a PTP (Press Through Packaging) device and an apparatus therefor.

When PTP was first popularized, polyvinyl chloride (PVC) was used as the sheet material, and it still occupies the mainstream today. This is because the temperature range at which PVC can be molded into pockets is extremely wide, from 82 to 212 degrees Celsius, in the commonly used pressure forming method, and the temperature control width of the heating means can be as rough as ±10 degrees Celsius. This is because it is easy.

However, if the packaged item is a pharmaceutical or other product that requires moisture resistance, that is, moisture permeation resistance,
PVC's moisture resistance is insufficient and double packaging is required, but this cannot be guaranteed after unpacking.
For this reason, polyethylene (PE), polypropylene (PP), and various types of laminate sheets have been adopted one after another, but the temperature range at which they can be molded is extremely limited, ranging from a fraction of that to one-tenth of that of PVC. It is not easy as it is narrow.

The present invention provides a multi-layer laminate sheet comprising at least one high-density PE intermediate layer,
In particular, it relates to the formation of multi-laminate sheets with PP surface layers on both sides of a high-density PE interlayer.

[Conventional technology] To form a PVC single-layer sheet using the widely used pressure forming method, the heated sheet material is supported by a metal female die and pressurized air is supplied to the pocket forming part. Then, it may be expanded until its outer surface lines up with the inner surface of the female recess. PVC can be easily molded in this way due to its wide moldable temperature range and excellent molding methods due to its amorphous nature.

When the object is PP, which is a crystalline polymer, the moldable temperature range is narrow and the moldability is poor, making it difficult to apply these methods. In other words, if the entire sheet material is heated, it will become too soft and cause transport problems due to drawdown.
On the contrary, heating to a level that does not cause conveyance problems does not sufficiently soften the pocket molded portion, and the thickness of the deep-drawn pocket tends to be uneven.

Therefore, it becomes necessary to locally and selectively heat the pocket forming portion and to perform auxiliary forming using a plug heated to near the softening point of the original sheet.

Specifically, the sheet material that has been locally and selectively heated in the pocket forming area is sandwiched between a metal female mold and the top plate of the corresponding plug guide, and the sheet material is softened in a cooling state. A plug heated to nearly a point is pressed against the pocket forming part of the original sheet to preliminarily expand the specified part of the sheet to about 70% of the volume of the female mold recess, and then the plug is pressed against the expanded part. A method is adopted in which pressurized air is supplied through the gap between the plug and the guide.

[Problems to be Solved by the Invention] The sheet material to which the present invention is directed is a multilayer laminate sheet containing at least one high-density PE intermediate layer. (Composite plastic sheet described in Patent Application No. 101165 of 1985, ``Package and method for manufacturing the same''). The basic structure described above for PP is also used to form this multilayer laminate sheet.
Although it can be adopted as the basic idea, the temperature and required time of each part must be changed to new ones that are adapted to this new object, and of course, extremely precise control is required.

[Means for Solving the Problems] According to the present invention, there is provided a method for forming a PTP pocket on a multi-layer laminate sheet including at least one intermediate high-density polyethylene layer, which is characterized by comprising the following sequential steps. A molding method is provided. Here, each process is: (a) a process of locally and selectively heating the pocket forming part of the original sheet until its core temperature reaches 124°C to 132°C; (b) locally and selectively heating The heated original sheet is sandwiched between the metal female die and the corresponding plug guide plate, and the non-pocketed part is heated for 30 minutes.
(c) Under the cooling state, a plug heated to 100 to 120°C is pressed against the pocket-forming portion of the original sheet so that the specific part of the sheet has a volume of the female recess. 70
(d) A step of preliminarily inflating the expanded portion to approximately
Supplying pressurized air through the gap with the plate,
(e) removing the metal female mold, plug and plug guide plate; and (e) removing the metal female mold, plug and plug guide plate.

If the localized/selective heating described above does not reach 124°C, the molded pocket will become unbalanced in wall thickness or lose its shape, and if it exceeds 132°C, the sheet will sag in the conveyance path, making it impossible to convey it. invite
In the case of the present invention, it has been found that it is most preferable to control the temperature to about 127°C. In contrast, in the case of PP, this temperature range is 135°C to 155°C, which is wide and easy to control.

The top plate of the plug guide corresponding to the metal female die is preferably capable of cooling the non-pocket portion of the seat to 24° C. or lower and maintaining this temperature. This is important in order to minimize heat shrinkage of the non-formed portion of the pocket and to increase the dimensional stability of the sheet package required for subsequent transportation, filling, and the like. For this reason, particularly efficient cooling methods are employed.

In addition, if the temperature of the above-mentioned plug is less than 100℃, it will cause an excessive temperature drop in the pocket forming part.
The thickness of the molded pocket may become unbalanced or lose its shape, and the top of the pocket may become white (devitrification).
℃ leads to partial outflow of the intermediate PE layer. A plug temperature of about 110°C has been found to be most preferred. In addition, with PP, there is no problem of partial leakage of the intermediate PE layer, so this temperature range is
It is easy to control over a wide range up to nearly 150℃.

The local and selective heating of the pocket-forming part is achieved by sandwiching the original sheet between a pair of hot plates with convex surfaces corresponding to the pocket-forming parts facing each other, and heating the original sheet by heat conduction. It is preferable to increase the meat core temperature to the saturation temperature.

Specifically, the core temperature of the sheet material is quickly raised to the same temperature as the temperature of the pair of hot plates (saturation temperature), preferably to about 127°C.
It is necessary to take time to sufficiently increase the molding speed. For example, if the average sheet conveyance speed is 2.9
m/min (standard pocket 100 rows/min),
When the molding operation is one takt of intermittent conveyance, it is necessary to apply this selective heating for three takts or more. In contrast, in the case of PP,
Since the control temperature range is wide, two tacts are sufficient.

According to another aspect of the present invention, the PTP pocket forming method is arranged at two adjacent stations among the plurality of stations on the intermittent conveyance path of the PTP sheet material and is characterized by a correlated combination of the following means. Apparatus is also provided.

Each of these means: (a) is placed in a first station and is to be shaped;
The convex surfaces corresponding to the PTP pockets are provided to face each other, and the sheet material is sandwiched between them, and the core temperature of the sheet material can be raised to the saturation temperature by heat conduction, and at least one of the (b) a pair of hot plates that can be moved back and forth in a direction perpendicular to the conveyance path in synchronization with the intermittent conveyance of the original sheet;
(c) A solid female mold made of metal, which is provided with a recess that corresponds to the PTP pocket, has a cooling medium passage adjacent to the recess, and is capable of reciprocating motion in a direction orthogonal to the conveyance path; (c) corresponds to the recess; A plug is provided with a number of plug receiving/through passages, a cooling medium passage adjacent to the through passages, and a top plate capable of sandwiching an original sheet between the solid female mold and the plug.
(d) a guide, in which a number of plugs corresponding to the through passages of the top plate of the plug guide are installed, and is equipped with heating and temperature maintaining means, and the conveying passage is synchronized with the operation of the metal solid female mold; a plug base capable of reciprocating in a direction orthogonal to the plug base, each of the plugs acting on a pocket forming portion of the PTP sheet material sandwiched between the female die and the top plate of the plug guide; (e) the pre-expanded PTP through the gap between the plug and the plug guide; A means for supplying pressurized air to the pocket forming portion of the original sheet.

It is a means to do so.

As already mentioned regarding the method, the hot plate in (a) is
It is possible to quickly raise the core temperature of the sheet material to the same temperature as the temperature of the hot plate (saturation temperature), preferably about 127°C, and in order to sufficiently increase the forming speed, intermittent conveyance is required. The length of the conveyance path is required to be longer than 3 tacts (when the molding operation is 1 takt). It differs from the case of PP in that the control temperature range is wide, it does not necessarily have to be saturated, and two tacts are sufficient.

In addition, (b) metal solid female mold and (c) plug
The (top plates) of the guides are combined to form a pair, and in order to effectively cool the non-pocketed part of the PTP sheet material, in the case of a female type, the recess,
The top plate of the plug guide is characterized in that a cooling medium passage is provided adjacent to the plug passage. In the case of PP, this is not required, and the cooling medium passages were usually provided separately for ease of construction.

Proximity devices for cooling medium passages are essential.
This was discovered for the first time after handling the new multi-layer laminate sheet.

The plug (d) is equipped with heating and temperature maintaining means, and is designed to prevent the heated sheet from cooling down through contact. By the pressure of this plug, the pocket of the original sheet is preliminarily formed to about 70% of the recess volume of the female mold, and the outer surface of the sheet is shaped into the female mold by the pressurized air supplied in (e). Finish molding is performed until it conforms to the inner surface of the recess.

[Function] By means of the present invention configured as described above, a multi-layer laminate sheet including at least one high-density polyethylene intermediate layer is used.
PTP pockets can be efficiently molded.

[Example] FIG. 1 in the drawings is a partially cutaway side view for comprehensively showing the main parts of an apparatus for carrying out the method of the present invention, and shows an intermittent conveyance path 1 of a sheet 10.
The second preliminary station 20 is provided with a hot plate 22 that can reciprocate in a direction perpendicular to the conveyance path 12 and a hot plate 24 paired therewith. In the Tsuzuku forming station 30, the solid female mold 32, the corresponding plug guide 42, and the plug base 52 housed within the guide 42 operate sequentially in synchrony with each other to form the sheet 10. It is something.

The sheet 10 with the pockets 14 formed therein at the forming station 30 is conveyed to the next process by being sandwiched between a feed roller 60 provided with a recess 62 that engages with the pocket 14 and an idler 64.

A pair of hot plates 2 in the spare station 20
2 and 24 have built-in heating heaters (not shown), and as shown in detail in FIG. A large number of heating convex surfaces 23, 25 are provided corresponding to the pocket 14 forming portions. Note that 21 is a temperature sensor for generating a control signal. These heating convex surfaces 2
3 and 25 contact the pocket 14 forming portion of the sheet 10 that is intermittently conveyed and repeatedly inserted, and locally and selectively heats this by heat conduction.

These pair of heat plates 22, 24 are directly or indirectly supported by brackets 26, 28 on the vertical main frame of the overall apparatus (the plane corresponding to the plane of the paper in FIG. 1), for example, in a cantilevered manner as shown. ing. The upper hot plate 22 repeatedly moves back and forth in synchronization with the intermittent conveyance of the sheet 10 by an arbitrary drive device 27 placed on the bracket 26 and a buffer spring 29 to apply pressure to the pocket 14 forming portion of the sheet 10. It has become something that requires a lot of effort. Lower heat plate 2
4 is fixedly supported by the main frame. In the figure, 70 indicates a forced air cooling plate that can be attached as required, and 72 indicates a pressurized air supply pipe therefor.

The solid female die 32 of the metal in the molding station 30 has recesses 31 and recesses of the same number as the number of pockets 14 to be molded in one tact, the outer shape of the pocket 14 to be molded and the inner shape thereof matching. A cooling medium passageway 33 located adjacent to the sheet 10 is provided which also provides intermittent transport of the sheet 10 by means of drives such as cams 36, cam followers 38, etc. mounted on the vertical main frame. The reciprocating operation is repeated in synchronization as shown by the arrows. In its upper part, an auxiliary coolant passage 34 is also provided.

The plug guide 42 paired with the solid metal female mold 32 has an overall hollow box-like shape in order to accommodate the plug base 52 and serve as a distribution path for pressurized air. is fixedly supported on the vertical main frame, for example by brackets 46.

As shown in the schematic longitudinal section of the forming station in FIG. 3, the top plate of the plug guide 42 is capable of contacting the solid metallic female mold 32 and corresponds to the planar shape of the same number of pockets 14 to be formed. A plug receiving/through hole 41 is provided.

Further, a cooling medium passage 43 is arranged adjacent to the plug receiving/through hole 41. Auxiliary coolant passages 44 are also provided in the side wall 45 . Further, a cylinder 54 for operating the plug base 52 and a pressurized air supply pipe 48 are attached to the bottom plate 49.

A heater 56 is embedded in the plug base 52, and the same number of plugs 50 as the number of pockets 14 to be molded in one takt are implanted. A temperature sensor 58 is embedded in at least one of these plugs 50.

As shown in FIG. 4 in an enlarged manner, the sheet 10 is moved between the solid female mold 32 and the top plate of the corresponding plug guide 42 in synchronization with the intermittent conveyance of the sheet 10. After being inserted a, the plug base 52 is directed upward by the actuating cylinder 54, and the plug 50 is guided into the through hole 41 and the sheet 10 is directed toward the recess 31 of the metal middle female die 32. Press. This pressing operation increases the volume of the recess 31.
After about 70% preforming b, plug 50
Pressurized air is supplied through the gap between the through hole 41 and the through hole 41 as shown by the arrow, thereby completing the molding c. Thereafter, a mold release operation is performed in synchronization with the intermittent conveyance of the sheet 10.

In the above description, it should be noted that firstly, when heating the pocket forming portion of the multilayer laminate sheet, the heating mode shown as "multi-heating" in FIG. 5 was adopted. That is, sheet 1
With the number of tacts (nt) synchronized with intermittent conveyance of 0, the core temperature T _p of the intermediate PE layer of the sheet is raised to the saturation temperature T, that is, a temperature T _o close to the temperature of the hot plate, as shown by the solid curve in the figure. It heats up quickly through heat conduction. Sheets that do not have an intermediate PE layer do not require such consideration, as the moldable temperature range is wide, and for example, a heating mode unrelated to the saturation temperature, as shown by the curved line in the figure, is sufficient. . On the other hand, the second point of note is that during the molding process, the non-pocket portion of the multilayer laminate sheet is efficiently cooled to at least prevent its temperature from rising. Molding molds for sheets without an intermediate PE layer do not require such considerations, so the cooling medium passages have usually been located at a distance from the molding recesses.

[Effect] In the above embodiment, in accordance with this heating mode,
By controlling the heating operation and setting the time and length of the object for 3 takts (n=3), assuming that the molding operation is 1 takt, T _o can actually be reduced to T
was able to match.

In other words, by ensuring that the length of the object in the forming station is at least three times the length of the object in the preparatory station, 2.9
This enables high-speed molding at m/min (standard pocket 100 rows/min). In addition, during the forming process, the recess of the metal female mold and the plug receiving/receiving part of the plug guide top plate are
By arranging the cooling medium passage close to the through holes, it is possible to efficiently cool the non-pocketed parts of multiple laminated sheets and prevent excessive temperature rise, thereby ensuring stable conveyance at high speeds. made possible.

As described above, the industrial effects of the present invention are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view to comprehensively show the main parts of an apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view of a preheating hot plate, and FIG. 3 is a FIG. 4 is a longitudinal sectional view of the main part of the forming station, and FIG. 4 is an enlarged schematic diagram for explaining the forming operation step by step, and FIG. 5 is a diagram showing the heating mode. 10...Sheet, 12... ...intermittent conveyance path, 14
... Pocket, 20 ... Spare station, 21
... Temperature sensor, 22, 24 ... Heat plate, 23, 2
5... Convex surface for heating, 26, 28... Bracket,
27... Drive device, 29... Buffer spring, 30...
... Molding station, 31 ... Recess, 32 ... Metallic solid female mold, 33, 34 ... Cooling medium passage, 3
6...Cam, 38...Cam follower, 41...
Plug receiving/through hole, 42...Plug guide,
43, 44...Cooling medium passage, 45...Side wall, 4
6... Bracket, 48... Pressurized air supply pipe, 4
9...Bottom plate, 50...Plug, 52...Plug
Base, 54... Operating cylinder, 56... Heater, 58... Temperature sensor, 60... Feed roller, 62... Recess, 64... Idler,
70... Forced air cooling plate, 72... Pressurized air supply pipe.

Claims (1)

[Scope of Claims] 1. A method for forming a PTP pocket on a multi-layer laminate sheet containing at least one intermediate high-density polyethylene layer, characterized by comprising the following sequential steps: (a) sheet; A process of locally and selectively heating the pocket-forming portion of the original fabric until its core temperature reaches 124°C to 132°C, (b) converting the locally and selectively heated sheet fabric into a metal sheet; A step of cooling the non-pocket forming part to 30°C or less by sandwiching it between the female die and the top plate of the corresponding plug guide; (c) Under this cooling state, the pocket forming part of the original sheet is A plug heated to 100°C to 120°C is pressed against the specified part of the sheet to 70% of the volume of the female recess.
(d) supplying pressurized air to the inflated portion through the gap between the plug and the plug guide, and forming the expanded portion until its outer surface aligns with the inner surface of the female mold recess; (e) removing the metal female mold, the plug and the plug guide; 2 The selective heating of the pocket-forming portion causes the sheet material to be sandwiched between a pair of hot plates provided with convex surfaces corresponding to the pocket-forming portions facing each other, and the core temperature of the sheet material is increased by heat conduction. The method according to claim 1, characterized in that the temperature is raised to a saturation temperature. 3. The method of claim 1, further comprising selectively heating the pocket forming region to about 127°C. 4. The method according to claim 1, characterized in that the pocket-free portion is cooled to about 24°C. 5. A method according to claim 1, characterized in that the temperature of the plug is about 110°C. 6. The method according to claim 1, wherein the multi-layer laminate sheet has a three-layer structure with an outer layer of polypropylene. 7. The method according to claim 1, wherein the multi-layer laminate sheet has a five-layer structure with polyvinylidene chloride layers on both sides of a high-density polyethylene middle layer and a polypropylene outer layer. . 8 It is arranged at two adjacent stations among the plurality of stations on the intermittent conveyance path of the PTP sheet raw material, and is characterized by a correlated combination of the following means.
PTP pocket forming equipment: (a) Placed in the first station and to be formed
The convex surfaces corresponding to the PTP pockets are provided to face each other, and the sheet material is sandwiched between them, and the core temperature of the sheet material can be raised to the saturation temperature by heat conduction, and at least one of the (b) a pair of hot plates that can be moved back and forth in a direction perpendicular to the conveyance path in synchronization with the intermittent conveyance of the original sheet;
(c) A solid female mold made of metal, which is provided with a recess that corresponds to the PTP pocket, has a cooling medium passage adjacent to the recess, and is capable of reciprocating motion in a direction orthogonal to the conveyance path; (c) corresponds to the recess; A plug is provided with a number of plug receiving/through passages, a cooling medium passage adjacent to the through passages, and a top plate capable of sandwiching an original sheet between the solid female mold and the plug.
(d) a guide, in which a number of plugs corresponding to the through passages of the top plate of the plug guide are installed, and is equipped with heating and temperature maintaining means, and the conveying passage is synchronized with the operation of the metal solid female mold; a plug base capable of reciprocating in a direction orthogonal to the plug base, each of the plugs acting on a pocket forming portion of the PTP sheet material sandwiched between the female die and the top plate of the plug guide; (e) the pre-expanded PTP through the gap between the plug and the plug guide; A means for supplying pressurized air to the pocket forming portion of the original sheet.