JP2023022744A - Preliminary peeling method of double container - Google Patents

Abstract

To provide a preliminary peeling method of a double container, by which preliminary peeling can be performed while suppressing damage of an inner bag.SOLUTION: According to the present invention, a preliminary peeling method of a double container provided with an outer shell and an inner bag comprises a peeling step. There is provided the peeling step as a step of peeling the inner bag from the outer shell by cracking a biting-off part provided at a bottom part of the outer shell in a state where an inside of the inner bag is made to be under negative pressure. According to the peeling step, the biting-off part may be crashed by applying force to a region displaced from the biting-off part at the bottom part. An inspection step may be further included therein. The inspection step may inspect whether or not a pin-hole is present in the inner bag, based on data obtained when increasing a pressure of the inside of the inner bag after the peeling step.SELECTED DRAWING: Figure 6

Description

The present invention relates to a pre-separation method for double containers.

Patent Literature 1 discloses a double container having an inner bag and an outer shell.

JP 2020-193023 A

An outside air introduction part is necessary for preliminary peeling of the inner bag. At the bottom of the outer shell, there is a cutout formed in the manufacturing process, and if this cutout is broken, an outside air introduction section can be formed. However, when the force that splits the cut portion is applied to the bottom of the outer shell, that force is also transmitted to the inner bag. While cracking the outer shell, we want to suppress damage to the inner bag.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a method for pre-separating a double container, which enables pre-separation while suppressing damage to the inner bag.

According to the present invention, there is provided a method for preparatory peeling of a double container having an outer shell and an inner bag, comprising a peeling step, wherein the outer shell is peeled off while the inside of the inner bag is under a negative pressure. A method is provided for peeling the inner bag from the outer shell by breaking a cutout provided in the bottom of the bag.

In the present invention, the cut portion can be split while the inner bag is about to shrink due to the negative pressure. Since the inner bag can be shrunk in response to the cracking of the cut portion and the introduction of outside air, preliminary peeling can be performed while suppressing damage to the inner bag.

Various embodiments of the present invention are illustrated below. The embodiments shown below can be combined with each other.
Preferably, in the peeling step, the cut portion is split by applying a force to a portion of the bottom portion shifted from the cut portion.
Preferably, an inspection step is further provided, wherein the inspection step inspects whether or not the inner bag has a pinhole based on data obtained when the pressure inside the inner bag is increased after the peeling step. .
Preferably, the diameter of the bottom of the shell is 14-25 mm.

1 is a side view of an example of a double container; FIG. FIG. 2 is a cross-sectional view taken along line AA of FIG. 1; It is a bottom view of a double container. It is a block diagram showing the structure of a preliminary|backup peeling apparatus. 1 is an exploded perspective view of an example suction head; FIG. FIG. 4 is a cross-sectional view showing a state in which the double container is set on the suction head and the amount of displacement of the contact portion is set; FIG. 10 is a cross-sectional view showing how the front end surface of the contact portion hits the bottom of the double container in the peeling process. FIG. 8 is an enlarged cross-sectional view showing an enlarged B dashed line area near the bottom of the double container in FIG. 7 ; FIG. 4 is a schematic cross-sectional view showing an example of how the inner bag shrinks in the peeling process. FIG. 10 is a cross-sectional view showing how the inner bag is put back after the peeling process and the leak inspection process is performed. 4 is a graph schematically showing the relationship between time and flow rate measured when the pressure inside the inner bag is increased. FIG. 11 is a cross-sectional view showing a modified example of the position of the contact portion (zero deviation amount); FIG. 10 is a cross-sectional view showing a modification (concave curved surface) of the contact portion; It is a cross-sectional view showing a modification (trapezoidal recessed portion) of the contact portion. FIG. 10 is a cross-sectional view showing a modification of the abutment portion (a convex curved surface that rises slightly inside the concave portion). FIG. 10 is a cross-sectional view showing a modified example of the contact portion (a deviating convex curved surface in the concave portion); FIG. 11 is an exploded perspective view of another example of a suction head; It is sectional drawing showing the state which set the double container to the other example of a suction head.

Embodiments of the present invention will be described below. Various features shown in the embodiments shown below can be combined with each other. In addition, the invention is established independently for each characteristic item.

1. Example of Double Container Subject to Preliminary Peeling A double container 1 to be preliminarily peeled will be described with reference to FIGS. 1 to 3. FIG. As shown in FIG. 1 , the double container 1 has a cylindrical shape with a bottom, and includes a storage portion 7 for storing contents and a mouth portion 9 for discharging the contents from the storage portion 7 . The housing portion 7 includes a trunk portion 7a and a bottom portion 7b.

FIG. 2 shows the AA cross section of FIG. The double container 1 is a double structure container having an outer shell 12 and an inner bag 14 . The inner bag 14 is arranged inside the outer shell 12 at a portion other than the mouth end of the double container 1 . The inner bag 14 is configured to be contractible away from the outer shell 12 as the contents are discharged. At this time, outside air is introduced into the intermediate space between the inner bag 14 and the outer shell 12 through an outside air introduction portion 15 (outside air introduction hole), which will be described later. maintained.

The double container 1 of the present embodiment is, for example, a resin container (cartridge) attached with a nebulizer as a sucking device for sucking out and spraying contents. In this embodiment, the content is a liquid (for example, a drug solution for treating asthma). After the contents are filled in the double container 1, a cap having a through hole is attached, and then the through hole is sealed with a film. The nebulizer has a hollow puncture needle, and after the puncture needle breaks through the film, it is inserted into the double container 1 through the through hole, and the contents are sucked out through the puncture needle.

The bottom portion 7b has a convex cross section projecting downward, and a cutout portion 7d is provided in the center of the bottom portion 7b. The cutout portion 7d closes the bottoms of the outer shell 12 and the inner bag 14, respectively. The cutout portion 7d is formed by crushing the parison with a pair of split molds when forming the double container 1 by direct blow molding. The bottom of the double container 1 is closed by welding the facing surfaces of the parison together at the cut portion 7d.

The cutout portion 7d is also illustrated in the bottom view of FIG. As shown in FIG. 3, the cutout portion 7d cuts through the bottom portion 7b while passing through the center point _C0 of the bottom portion 7b.

The material of the outer shell 12 preferably contains homopolypropylene from the viewpoint of increasing rigidity, preferably contains random polypropylene from the viewpoint of increasing impact resistance, and may contain both homopolypropylene and random polypropylene. preferable. From the viewpoint of enhancing flexibility, the material of the inner bag 14 preferably contains at least one of LDPE and LLDPE, and preferably contains LDPE. An intermediate layer (not shown) may be provided between the outer shell 12 and the inner bag 14 . The intermediate layer is composed of a resin that can be peeled off from one or both of the material of the outer shell 12 and the material of the inner bag 14 . The intermediate layer is preferably an EVOH layer containing EVOH (ethylene-vinyl alcohol copolymer) resin.

As an example, the double container 1 has a content of 1 to 20 mL. The content of the double container 1 is preferably 1-10 ml, more preferably 3-5 ml. Specifically, the contents of the double container 1 are, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, and 20. It may be within a range between two. The bottom diameter D ₀ of the double container 1 shown in FIG. 3 may be, for example, 14-25 mm, or 14-16 mm. Specifically, the bottom diameter _D0 is, for example, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 mm. may be within the range.

2. Configuration of Preliminary Stripping Device An example of the preliminary stripping device 2 used in the preliminary stripping method of the embodiment will be described with reference to FIGS. 4 to 6. FIG. Preliminary peeling means a step of peeling the inner bag 14 from the outer shell 12 before filling the inner bag 14 with contents. By performing the preliminary peeling, the inner bag 14 is separated from the outer shell 12 after filling the inner bag 14 with the contents, and the inner bag 14 is easily shrunk.

2-1. Block Configuration Diagram As shown in FIG. The suction device 3 includes a suction head 3a (see FIG. 5) and a stage 3b (see FIG. 6). The pipe 8 includes a pipe 8 a connecting the suction head 3 a and the solenoid valve 4 , a pipe 8 b connecting the decompression system 5 and the solenoid valve 4 , and a pipe 8 c connecting the pressurization system 6 and the solenoid valve 4 . By controlling the electromagnetic valve 4, it is possible to switch which of the decompression system 5 and the pressurization system 6 is connected to the suction head 3a. The decompression system 5 enables air to be sucked through the suction head 3a. Air can be blown through the suction head 3a by the pressure system 6. As shown in FIG.

The pressure reducing system 5 includes a regulator 53 and a vacuum pump 54 in order from the solenoid valve 4 side. The vacuum pump 54 reduces the pressure in the pipe 8b by discharging the air in the pipe 8b. The regulator 53 controls the flow rate of the air flowing through the pipe 8b or the pressure of the air inside the pipe 8b.

The pressurization system 6 includes a flow meter 64, a pressure gauge 65, a speed controller 61, a regulator 62, and a compressor 63 in order from the electromagnetic valve 4 side. The compressor 63 supplies compressed air into the pipe 8c. The regulator 62 controls the pressure of the air inside the pipe 8c. The speed controller 61 controls the flow rate of air flowing through the pipe 8c. A pressure gauge 65 measures the pressure of air in the pipe 8c. The flow meter 64 measures the flow rate of air flowing through the pipe 8c. The order of components included in the pressurization system 6 may be changed or omitted as appropriate.

The preliminary peeling device 2 further includes a drive mechanism 71 , a contact portion 72 and a control portion 73 . The drive mechanism 71 is an air cylinder as an example. The contact portion 72 is arranged at a position facing the suction head 3a (see FIG. 6). The drive mechanism 71 drives the contact portion 72 forward and backward toward the suction device 3 and stops the contact portion 72 at an arbitrary position. The control unit 73 controls the position of the contact portion 72 with respect to the suction head 3 a , the number of repetitions of advancing and retreating (that is, the number of reciprocations), and the moving speed of the contact portion 72 by controlling the driving mechanism 71 . As a result, the magnitude of the impact force and the pressing force applied to the contact partner of the contact portion 72 can be adjusted.

2-2. Configuration of Suction Head 3a The suction head 3a shown in FIG. The head base 31 and the packing 32 are provided with through holes 31a and 32a communicating with the inside of the pipe 8a, respectively. The packing 32 is arranged inside the housing recess 31 b of the head base 31 . The packing 32 is made of a material such as elastomer that can improve airtightness.

The insertion member 33 includes a rod-shaped portion 33a and a flange portion 33b radially protruding from the proximal end of the rod-shaped portion 33a. A through-hole 34a is provided in the packing 34, and the bar-shaped portion 33a is inserted through the through-hole 34a. The material of packing 34 is similar to that of packing 32 . The rod-shaped portion 33 a is a rod-shaped portion and is made thinner than the inner diameter of the mouth portion 9 of the double container 1 .

2-3. Configuration of Stage 3b and Abutting Portion 72 FIG. The suction head 3a is installed in the central concave portion 3b1 of the stage 3b. The suction head 3a is covered with the mouth portion 9 of the double container 1, and the mouth portion 9 is accommodated in the central recessed portion 3b1 of the stage 3b. The depth of the central recessed portion 3b1 may be, for example, a depth sufficient to surround the body portion 7a of the double container 1.

As shown in FIG. 6, a through hole 33c is provided inside the insertion member 33. As shown in FIG. The rod-shaped portion 33a is provided with a suction port 33d that communicates with the through hole 33c. 33 d of suction ports are provided in the front-end|tip 33a1 of the rod-shaped part 33a.

A contact portion 72 is arranged above the suction head 3a in FIG. 6 (in other words, above the bottom portion 7b). The contact portion 72 is connected to a drive mechanism 71 (not shown in FIG. 6) installed near the stage 3b. The contact portion 72 has a tip surface 72a. The tip surface 72a is positioned above the suction head 3a. In FIG. 6, the tip surface 72a of the contact portion 72 is a dome-shaped convex curved surface (hemispherical surface). There are various other structural examples of the contact portion 72, including those shown in FIGS.

Note that in FIG. 6, the amount of deviation _E1 is set in advance as an example. The amount of deviation _E1 will be described with reference to FIGS. 3 and 8. FIG. 3 is a plan view of the bottom portion 7b viewed along the central axis of the double container 1. FIG. A contact portion _F1 indicates a point where the tip end surface 72a and the bottom portion 7b contact within the area of the bottom portion 7b in plan view. The amount of deviation _E1 represents how much the contact portion _F1 deviates from the center point _C0 in plan view of FIG. When the amount of deviation _E1 is set, as shown in FIG. 8, when the abutting portion 72 is lowered, the tip surface 72a can be brought into contact with the portion displaced from the cutting portion 7d.

The base radius R ₀ is illustrated in FIG. 3, where R ₀ is 1/2 of D ₀ . With C ₀ as the origin and a coefficient k, the amount of deviation E ₁ may be defined by E ₁ =k×R ₀ . k may be, for example, 0.1 or less, 0.2 or less, or 0.5 or less, for example k=0.05 to 0.5. When k=0.5, the contact portion _F1 is displaced from the center point _C0 in the radial direction by exactly half of _R0 . Specifically, coefficient k may be, for example, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.40, 0.50, 0.60. may be within a range between any two of the numerical values exemplified in . As will be described in a modified example below, the deviation _E1 may be zero, in which case the coefficient k=0.

The contact portion _F1 varies depending on the shape and degree of curvature of the distal end surface 72a. When the tip surface 72a and the bottom portion 7b can be considered to be in point contact, the distance between the contact portion _F1 , which is the contact point, and the center point _C0 can be defined as the displacement amount _E1 . If the tip surface 72a and the bottom portion 7b are in surface contact over a relatively large range, for example, the center point of the area within the contact surface is regarded as the contact portion _F1 , and the distance between this center point and the center point _C0 is can also be taken as the amount of deviation _E1 .

3. Preliminary Stripping Method A preliminary stripping method according to the embodiment includes a stripping process and a leak inspection process.

3-1. Peeling Process As shown in FIG. 6, the double container 1 is set in the preliminary peeling device 2 . The head base 31, the flange portion 33b, and the end surface of the mouth portion 9 are in close contact with each other through packings 32 and . Due to this close contact, the inside of the inner bag 14 communicates with the outside only through the through holes 31a, 32a, 33c. The decompression system 5 or the pressurization system 6 can depressurize or pressurize the inside of the inner bag 14 .

Next, the decompression system 5 starts the suction of the suction head 3a. The pressure inside the inner bag 14 is reduced by the suction. A negative pressure inside the inner bag 14 creates a state in which the inner bag 14 tends to shrink. The timing of starting suctioning is set so that the inside of the inner bag 14 becomes negative pressure by the time the tip surface 72a contacts the bottom portion 7b at the latest.

Next, the contact portion 72 is lowered so that the tip surface 72a is brought into contact with the bottom portion 7b as shown in FIG. In the embodiment, the amount of deviation _E1 is set as an example, so that the tip surface 72a contacts the contact portion _F1 shifted from the cutout portion 7d of the bottom portion 7b. In the enlarged cross-sectional view of FIG. 8, the original bottom surface position 7b1 is illustrated with a dashed line. A vertically downward force acts on one side of the bottom portion 7b due to the contact of the tip surface 72a. As a result, the cut portion 7d is split to form the outside air introducing portion 15. As shown in FIG.

In the outer shell 12, the strength of the cutout portion 7d is particularly weak. Therefore, by applying a force to the outer shell 12, as shown in FIG. Along with the introduction of the outside air from the outside air introduction part 15, the force that causes the inner bag 14 to shrink (the force represented by the numerous arrows pointing downward in FIG. A peel gap _G1 is created. FIG. 8 schematically shows an example of the separation gap _G1 . Outside air can be introduced into the separation gap G ₁ between the outer shell 12 and the inner bag 14 through the outside air introduction part 15 .

Here, there are various variations in how to apply the force to the bottom portion 7b by the tip surface 72a. The contact portion 72 may be quickly lowered by the drive mechanism 71 to apply an impact force to the bottom portion 7b. The driving mechanism 71 may be used to relatively gently lower the contact portion 72 to apply the pressing force to the bottom portion 7b. The contact portion 72 may be reciprocated a plurality of times in the vertical direction to bring the tip surface 72a into contact with the bottom portion 7b a plurality of times. This "multiple times" may be, for example, two times, three times, or four times or more. may be assumed. In one to several times (specifically, the last time, for example) of the plurality of times of contact, the contact portion 72 is stopped at the lowered position for a certain period of time, and the state in which the bottom portion 7b is pushed down is maintained. You may If the area of the bottom portion 7b of the small double container 1 is small, it may be difficult to peel off with only one contact. In this case, the separation may be reliably caused by applying the impact force multiple times.

Although not shown in FIG. 8, the packings 32 and 34 may absorb to some extent the force that pushes the double container 1 downward when the contact portion 72 is brought into contact with the bottom portion 7b. In this case, the double container 1 may be displaced downward to some extent by contracting the packings 32 and 34 in the thickness direction when the contact portion 72 is brought into contact with the bottom portion 7b. Thereby, the impact force or pressing force applied to the shell 12 may be adjusted.

FIG. 9 schematically shows an example of how the inner bag 14 shrinks due to preliminary peeling. When the outside air introduction portion 15 is formed by breaking the cut portion 7d, the inner bag 14 can be quickly shrunk as shown in FIG. This is because the inside of the inner bag 14 is made to have a negative pressure by the suction, so that the cut portion 7d can be broken while the inner bag 14 is about to shrink due to the negative pressure. As a result, preliminary peeling can be performed while suppressing damage to the inner bag 14 .

After the preliminary peeling, the pressure system 6 blows air into the inner bag 14 through the suction head 3a. As a result, the inner bag 14 is inflated until it returns to its original position as shown in FIG.

3-2. Leak Inspection Process In the embodiment, as an example, the leak inspection process is performed following the preliminary peeling process. In the leak inspection process, it is inspected whether or not there is a pinhole in the inner bag 14 based on the data obtained when the pressure inside the inner bag 14 is increased after the peeling process.

Specifically, as shown in FIG. 10, the presence or absence of pinholes is checked with the flowmeter 64 while the inner bag 14 is inflated to its original state. If there is a pinhole, a flow rate will occur due to air leakage.

As shown in FIG. 11, after the start of pressurization, the flow rate of air measured by the flow meter 64 rapidly increases, but the flow rate gradually decreases as the inner bag 14 expands. If the inner bag 14 has no pinholes, the air flow rate becomes very small (almost zero) when the inner bag 14 is fully inflated. On the other hand, if the inner bag 14 has pinholes, air flows out of the inner bag 14 through the pinholes even if the inner bag 14 is fully inflated. More than if there were no pinholes in bag 14 . For this reason, after the elapse of a predetermined time T, based on the flow rate of air leaking from the inner bag 14 (more specifically, by confirming whether or not this flow rate exceeds the threshold value Th), the inner bag 14 It can be determined whether pinholes are present.

Further, when the inner bag 14 has a pinhole, the inside of the inner bag 14 is less tightly sealed, so that the inside of the inner bag 14 is less likely to be pressurized. Therefore, it is possible to determine whether or not there is a pinhole in the inner bag 14 based on the pressure detected by the pressure gauge 65 after the lapse of a predetermined time while the set pressure of the compressor 63 is set to the reference value. good. Furthermore, the presence or absence of pinholes may be determined based on data such as the expansion mode and expansion time of the inner bag 14, in addition to the flow rate and pressure. However, from the viewpoint of accuracy, the determination based on the flow rate is preferable.

According to the preliminary peeling method of the embodiment described above, the inner bag 14 can be shrunk as the cut portion 7d is cracked and the outside air is introduced. As a result, preliminary peeling can be performed while suppressing damage to the inner bag 14 . Moreover, it is efficient because the leak inspection can be performed after the preliminary peeling. Note that the double container 1 set in FIG. 6 may be, for example, immediately after molding. In other words, the peeling process may be performed immediately following the molding process for molding the double container 1 .

4. Modifications The configuration of the embodiment can be modified in various ways. A plurality of modifications described below may be applied singly or in combination.

For example, the leak inspection process of the embodiment may be omitted, or the leak inspection may be performed by another method after the peeling process.

As a modification, as shown in FIG. 12, the amount of deviation _E1 may be zero. Specifically, as shown in FIG. 12, the peeling process may be started with the central portion _C1 of the tip surface 72a positioned vertically above the cut portion 7d, and the tip surface 72a may be positioned at the center point _C0 of the bottom portion 7b. Center _C1 may be applied. In this case, the center portion _C1 , the center point _C0 , and the contact portion _F1 are aligned on the vertical line, so the deviation amount _E1 is zero.

The shape of the contact portion 72 can be variously modified. For example, variations illustrated in FIGS. 13-16 may be provided. As shown in FIG. 13, a concave surface (or an inverted dome shape) tip surface 72b may be provided. As shown in FIG. 14, tip surfaces 72c1 and 72c2 forming the side surface and bottom surface of the inverted trapezoidal recess may be provided. In the example of FIG. 14, force is applied to the bottom portion 7b by the planar tip surface 72c1. As shown in FIG. 15, the tip end face 72c1 of FIG. 14 may be replaced with a tip end face 72d of a convex curved surface slightly raised in the recess. As shown in FIG. 16, a convex curved tip surface 72e2 that is slightly raised and deviated in the recess may be provided in the concave curved tip surface 72e1. As another modification, the contact portion 72 may be made into a simple bottomed cylindrical shape by removing the tip surface 72c2 of FIG. In the examples of FIGS _. 13 to 15, the amount of deviation _E1 is zero as in the example of FIG. 12, and in the example of FIG.

The three-dimensional shape of the contact portion 72 in each of FIGS. 6 and 12 to 15 can be rotationally symmetrical about the central axis CL, but is not limited to this. As a modification, an extruded shape in which the outline of the contact portion 72 is extruded in the depth direction (thickness direction) of each drawing may be applied. 16 has an asymmetrical shape with respect to the central axis CL, and an extruded shape extruded in the depth direction of the drawing of FIG. 16 can be used.

The configuration of the bottom portion 7b of the double container 1 can also be modified in various ways. As an example, the bottom portion 7b may be modified to have a flat bottom surface. As another modification, the bottom portion 7b may be recessed toward the inside of the housing portion 7, in which case the bottom portion 7b is a concave curved surface. In these cases, the tip surface 72a preferably has a convex shape. Also, the height of the protrusion of the bottom portion 7b, that is, the degree of protrusion of the bottom portion 7b may be made smaller than that illustrated in FIG.

It is understood that there are many combinations of the shapes of the bottom portion 7b and the tip surface 72a according to the modified example. For convenience, when the combination of shapes is represented by "(shape of bottom portion 7b)/(shape of tip surface 72a)", at least "convex shape/convex shape (see FIG. 6)" and "convex shape/concave shape (see FIG. 6)" 13)”, “convex shape/planar shape (see FIG. 14)”, “planar shape/convex shape”, and “concave/convex shape”.

When both the bottom portion 7b and the tip surface 72a are curved convexly or concavely, the degree of curvature of both can be set variously. As an example, the convex shape of the bottom portion 7b may have a gentler curvature (that is, a smaller curvature) than the convex curved surface of the tip surface 72a, or vice versa. The degree of curvature may be compared using the radius of curvature, or if the cross section is not circular, the radius of curvature of the circumscribed circle may be used for comparison.

In addition, although force is applied only to one place of the bottom part 7b in embodiment, it is not limited to this. Alternatively, force may be applied to multiple locations simultaneously or sequentially in any order. A plurality of contact portions 72 may be provided with a plurality of convex end faces 72a. A plurality of regions to which force is applied may be set on both sides of the cut portion 7d.

In each of the modifications described above, the method of applying force (number of times, speed, strength) to the bottom portion 7b can be arbitrarily applied from various variations as described in the embodiment.

The suction head 3a can be variously modified. 33 d of suction ports may be provided in parts other than the front-end|tip of the rod-shaped part 33a. When the suction port 33d is provided on the peripheral surface of the rod-shaped portion 33a, it is preferably provided at a position where the inner bag 14 is unlikely to block the suction port 33d (for example, near the base of the rod-shaped portion 33a). The number of suction ports 33d may be two or more. As another modified example of the suction head 3a, the insertion member 33 and the packing 34 may be omitted as shown in FIG. In this case also, suction can be performed with the double container 1 set as shown in FIG.

The drive mechanism 71 is not limited to an air cylinder. Any other reciprocating mechanical element may be used instead of the air cylinder, and the contact portion 72 may be driven by any electromagnetic actuator.

Table 1 below shows the test results of the peeling process using several types (No. 1 to No. 6) of the contact portions 72 in the preliminary peeling device 2 of the embodiment. The several types of contact portions 72 have different tip surface shapes (contact surface shapes with the bottom portion 7d). Each test condition No. in Table 1. 1 to No. 6 differ in the shape of the tip surface (convex, concave, flat) and the presence or absence of deviation (whether or not there is a deviation amount _E1 ). An air cylinder was used as the drive mechanism 71, and the pressure of the air cylinder was set to 0.2 MPa. With this setting, the force applied by the contact portion 72 to the contacted portion was measured with a push-bull gauge and found to be 60N. The double container 1 used for the samples under each test condition has the same shape. Since the sample double container 1 had been cold for some time after molding, it was warmed lightly (about 5 seconds) with hot air before being used for the test. Test condition no. 1 to No. 6, the number of samples in the double container 1 was N=3.

Table 1 shows three grades of evaluation results (⊚, ∘, Δ) focusing on cracks in the cut portion 7d. Test condition no. Of the samples 1, 2, 5 and 6, all (three) of the samples showed good cracking at the cutout portion 7d and good peeling of the inner bag 14 (results ⊚). Test no. In the samples of the four conditions, the cutout portion 7d was cracked, but the degree of peeling was poor, and some samples peeled to some extent (results ◯). Test condition no. In sample No. 3, the cut portion 7d was cracked, but peeling was insufficient (result Δ). A convex shape was advantageous when compared with the tip surface shape.

Since the fragility of the cutout portion 7d also depends on the material and thickness of the outer shell 12, the shape of the bottom portion 7b, and the like, the tip surface shape may be selected according to the structural material of the double container 1. Further, for example, the peeling process of the embodiment can be applied immediately after molding of the double container 1, the magnitude and number of times of the force applied by the drive mechanism 71 can be increased, or the suction force of the suction device 3 can be increased to promote preliminary peeling. It is also possible to consider methods such as

Reference Signs List 1: Double container 2: Preliminary stripping device 3: Suction device 3a: Suction head 3b: Stage 3b1: Central concave portion 4: Solenoid valve 5: Decompression system 6: Pressurization system 7: Storage section 7a: Body section 7b: Bottom section 7b1 : Original bottom surface position 7d : Cutouts 8, 8a, 8b, 8c : Piping 9 : Mouth 12 : Outer shell 14 : Inner bag 15 : Outside air introduction part 31 : Head bases 31a, 32a, 33c, 34a : Through hole 31b : Receiving recess 32 : Packing 33 : Insertion member 33a : Rod-shaped portion 33a1 : Tip 33b : Flange 33d : Suction port 34 : Packing 53 : Regulator 54 : Vacuum pump 61 : Speed controller 62 : Regulator 63 : Compressor 64 : Flow meter 65 : pressure gauge 71 : drive mechanism 72 : contact portions 72a, 72b, 72c1, 72c2, 72d, 72e1, 72e2 : tip surface 73 : control portion C ₀ : center point C ₁ : center portion D ₀ : bottom diameter R ₀ : Bottom radius E ₁ : Deflection amount F ₁ : Contact part G ₁ : Separation gap T : Predetermined time Th : Threshold

Claims (4)

A method for pre-peeling a double container having an outer shell and an inner bag, comprising:
Equipped with a peeling process,
In the peeling step, the inner bag is peeled from the outer shell by breaking a cut portion provided at the bottom of the outer shell while the inside of the inner bag is under a negative pressure. 2. The method of claim 1, wherein
In the peeling step, a force is applied to a portion of the bottom portion shifted from the cut portion to crack the cut portion. A method according to claim 1 or claim 2,
In addition to the inspection process,
The inspecting step inspects whether or not there is a pinhole in the inner bag based on data obtained when the pressure inside the inner bag is increased after the peeling step. The method according to any one of claims 1 to 3,
The method, wherein the bottom of the shell has a diameter of 14-25 mm.

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