Pre-peeling method for double container

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

[Technical field]

[0001] The present invention relates to a method for preliminary peeling of a double container. [Background technology]

[0002] Patent Document 1 discloses a double container having an inner bag and an outer shell. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-193023 A Summary of the Invention [Problem to be solved by the invention]

[0004] An air intake is necessary for preliminary peeling of the inner bag. There is a cut in the bottom of the outer shell that is created during the manufacturing process, and if this cut is broken, an air intake can be formed. However, if force is applied to the bottom of the outer shell to break the cut, that force is also transmitted to the inner bag. While breaking the outer shell, it is desirable to minimize damage to the inner bag.

[0005] The present invention has been made in consideration of the above circumstances, and provides a method for preliminary peeling of a double-layered container, which can perform preliminary peeling while suppressing damage to the inner bag. [Means for solving the problem]

[0006] According to the present invention, there is provided a preliminary peeling method for a double container having an outer shell and an inner bag, comprising a peeling step, in which the inner bag is peeled off from the outer shell by breaking a cutting portion provided at the bottom of the outer shell while creating a negative pressure inside the inner bag.

[0007] In the present invention, the cutting portion can be broken when the inner bag is shrinking due to negative pressure. Since the inner bag can shrink as the cutting portion is broken and outside air is introduced, preliminary peeling can be performed while suppressing damage to the inner bag.

[0008] Various embodiments of the present invention will be described below. The embodiments described below can be combined with each other. Preferably, in the peeling step, the cut-out portion is broken by applying a force to a portion of the bottom portion shifted from the cut-out portion. Preferably, the method further comprises an inspection step, in which the inspection step checks whether or not a pinhole is present in the inner bag based on data obtained when the inside of the inner bag is pressurized after the peeling step. Preferably, the diameter of the bottom of the outer shell is 14 to 25 mm. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a side view of an example of a double container. [Diagram 2] FIG. 2 is a cross-sectional view taken along line A-A in FIG. [Diagram 3] FIG. [Figure 4] FIG. 2 is a block diagram showing a configuration of a preliminary peeling device. [Diagram 5] FIG. 2 is an exploded perspective view of an example of a suction head. [Figure 6] 11 is a cross-sectional view showing a state in which a double container is set on the suction head and the amount of displacement of the contact portion is set. FIG. [Figure 7] 10 is a cross-sectional view showing a state in which the tip surface of the contact portion comes into contact with the bottom of the double container in the peeling process. FIG. [Figure 8] 8 is an enlarged cross-sectional view of a region B indicated by a broken line in the vicinity of the bottom of the double container in FIG. 7. [Figure 9] 10A to 10C are schematic cross-sectional views showing an example of how the inner bag shrinks in a peeling process. [Figure 10] 11 is a cross-sectional view showing how the inner bag is replaced after the peeling step and a leak inspection step is performed. FIG. [Figure 11]13 is a graph showing a schematic representation of the relationship between time and flow rate measured when the pressure inside the inner bag is increased. [Figure 12] 13 is a cross-sectional view showing a modified example (zero deviation amount) of the position of the abutment portion. FIG. [Figure 13] FIG. 11 is a cross-sectional view showing a modified example (concave curved surface) of the contact portion. [Figure 14] FIG. 11 is a cross-sectional view showing a modified example (trapezoidal recess) of the abutment portion. [Figure 15] 13 is a cross-sectional view showing a modified example of the contact portion (a small protruding convex surface within a recess). FIG. [Figure 16] FIG. 11 is a cross-sectional view showing a modified example of the contact portion (a displaced convex curved surface within a recess). [Figure 17] FIG. 11 is an exploded perspective view of another example of the suction head. [Figure 18] FIG. 11 is a cross-sectional view showing a state in which a double container is set in another example of the suction head. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described. Various features shown in the following embodiments can be combined with each other. Also, each feature can be an invention independently.

[0011] 1. Examples of double-layered containers that can be pre-peeled The double container 1 to be subjected to the preliminary peeling will be described with reference to Figures 1 to 3. As shown in Figure 1, the double container 1 is cylindrical with a bottom, and includes a storage section 7 for storing the contents, and a spout 9 for discharging the contents from the storage section 7. The storage section 7 includes a body section 7a and a bottom section 7b.

[0012] Fig. 2 shows a cross section taken along line AA in Fig. 1. The double container 1 is a double-structure container having an outer shell 12 and an inner bag 14. The inner bag 14 is disposed within the outer shell 12 at a location other than the mouth end of the double container 1. The inner bag 14 is configured to be able to shrink away from the outer shell 12 as the contents are discharged. At that time, outside air is introduced into the intermediate space between the inner bag 14 and the outer shell 12 through an outside air introduction section 15 (outside air introduction hole) described later, so that the outer shell 12 does not shrink and maintains its original shape.

[0013] The double container 1 of this embodiment is, for example, a resin container (cartridge) to which a nebulizer is attached as an aspirating device that aspirates and sprays the contents. In this embodiment, the contents are liquid (e.g., a medicinal liquid for treating asthma). After the contents are filled into the double container 1, a cap having a through hole is attached, and the through hole is sealed with a film. The nebulizer has a hollow puncture needle, which is inserted into the double container 1 through the through hole after piercing the film, and the contents are aspirated through the puncture needle.

[0014] The bottom 7b has a convex cross section that protrudes downward, and a cutout 7d is provided in the center of the bottom 7b. The cutout 7d closes the bottom of each of the outer shell 12 and the inner bag 14. When forming the double container 1 by direct blow molding, the cutout 7d is formed by squeezing the parison with a pair of split molds. The bottom of the double container 1 is closed by welding the opposing surfaces of the parison to each other at the cutout 7d.

[0015] The cutout portion 7d is also shown in the bottom view of Fig. 3. As shown in Fig. 3, the cutout portion 7d passes through the center point C0 of the bottom portion 7b and cuts the bottom portion 7b vertically.

[0016] The material of the outer shell 12 preferably contains homopolypropylene from the viewpoint of increasing rigidity, and preferably contains random polypropylene from the viewpoint of increasing impact resistance, and preferably contains both homopolypropylene and random polypropylene. The material of the inner bag 14 preferably contains at least one of LDPE and LLDPE, and preferably contains LDPE, from the viewpoint of increasing flexibility. An intermediate layer (not shown) may be provided between the outer shell 12 and the inner bag 14. The intermediate layer is made of a resin that is peelable 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.

[0017] The double container 1 has a capacity of 1 to 20 mL, for example. The capacity of the double container 1 is preferably 1 to 10 ml, and more preferably 3 to 5 ml. The capacity of the double container 1 may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, or 20, and may be within a range between any two of the numerical values ​​exemplified here. The bottom diameter D0 of the double container 1 shown in FIG. 3 may be, for example, 14 to 25 mm, or 14 to 16 mm. The bottom diameter D0 may be, for example, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 mm, and may be within a range between any two of the numerical values ​​exemplified here.

[0018] 2. Configuration of preliminary peeling device An example of a preliminary peeling device 2 used in the preliminary peeling method of the embodiment will be described with reference to Figures 4 to 6. Preliminary peeling refers to a process of peeling the inner bag 14 from the outer shell 12 before filling the inner bag 14 with the contents. By performing preliminary peeling, the inner bag 14 is easily separated from the outer shell 12 and shrinks after the inner bag 14 is filled with the contents.

[0019] 2-1.Block diagram As shown in FIG. 4, the preliminary peeling device 2 includes a suction device 3, a solenoid valve 4, a decompression system 5, a pressurization system 6, and a pipe 8. 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 8a connecting the suction head 3a and the solenoid valve 4, a pipe 8b connecting the decompression system 5 and the solenoid valve 4, and a pipe 8c connecting the pressurization system 6 and the solenoid valve 4. By controlling the solenoid valve 4, it is possible to switch between the decompression system 5 and the pressurization system 6 to be connected to the suction head 3a. The decompression system 5 allows air to be sucked through the suction head 3a. The pressurization system 6 allows air to be blown through the suction head 3a.

[0020] The pressure reduction system 5 includes, in this order from the solenoid valve 4 side, a regulator 53 and a vacuum pump 54. The vacuum pump 54 exhausts air from the pipe 8b to reduce the pressure inside 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.

[0021] The pressurizing system 6 includes, in order from the solenoid valve 4 side, a flow meter 64, a pressure gauge 65, a speed controller 61, a regulator 62, and a compressor 63. The compressor 63 supplies compressed air into the pipe 8c. The regulator 62 controls the air pressure in the pipe 8c. The speed controller 61 controls the flow rate of air flowing through the pipe 8c. The pressure gauge 65 measures the air pressure in the pipe 8c. The flow meter 64 measures the flow rate of air flowing through the pipe 8c. The order of the components included in the pressurizing system 6 may be changed or omitted as appropriate.

[0022] The preliminary peeling device 2 further includes a driving mechanism 71, a contact part 72, and a control unit 73. The driving mechanism 71 is, for example, an air cylinder. The contact part 72 is disposed at a position facing the suction head 3a (see FIG. 6). The driving mechanism 71 drives the contact part 72 to move toward and away from the suction device 3, and stops the contact part 72 at any position. The control unit 73 controls the driving mechanism 71 to control the position of the contact part 72 relative to the suction head 3a, the number of times the contact part 72 moves back and forth (i.e., the number of times the contact part 72 moves back and forth), and the moving speed of the contact part 72. This makes it possible to adjust the magnitude of the impact force or pressing force applied to the contact part of the contact part 72.

[0023] 2-2. Configuration of suction head 3a The suction head 3a shown in Fig. 5 includes a head base 31, a packing 32, an insertion member 33, and a packing 34. The head base 31 and the packing 32 are provided with through holes 31a and 32a, respectively, that communicate with the inside of the pipe 8a. The packing 32 is disposed in the accommodation recess 31b of the head base 31. The packing 32 is made of a material that can increase airtightness, such as an elastomer.

[0024] The insertion member 33 includes a rod-shaped portion 33a and a flange portion 33b that protrudes in the radial direction from the base end of the rod-shaped portion 33a. The packing 34 is provided with a through hole 34a, and the rod-shaped portion 33a is inserted into the through hole 34a. The material of the packing 34 is the same as that of the packing 32. The rod-shaped portion 33a is a rod-shaped portion and is made thinner than the inner diameter of the mouth portion 9 of the double container 1.

[0025] 2-3. Configuration of stage 3b and contact portion 72 6 shows the state in which the double container 1 is set in the preliminary peeling device 2. The suction head 3a is placed in the central recess 3b1 of the stage 3b. The mouth 9 of the double container 1 is placed over the suction head 3a, and the mouth 9 is accommodated in the central recess 3b1 of the stage 3b. The depth of the central recess 3b1 may be, for example, deep enough to surround the body 7a of the double container 1.

[0026] 6, a through hole 33c is provided inside the insertion member 33. A suction port 33d communicating with the through hole 33c is provided in the rod-shaped portion 33a. The suction port 33d is provided at a tip end 33a1 of the rod-shaped portion 33a.

[0027] The contact portion 72 is disposed above the suction head 3a in Fig. 6 (in other words, above the bottom portion 7b). The contact portion 72 is connected to a driving 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 located 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. 13 to 16, and this point will be explained later in the modified examples.

[0028] In FIG. 6, the deviation amount E1 is set in advance as an example. The deviation amount E1 will be described with reference to FIG. 3 and FIG. 8. FIG. 3 is a plan view of the bottom 7b viewed along the central axis of the double container 1. The contact portion F1 is a point where the tip surface 72a and the bottom 7b contact each other, which is shown within the plan view area of ​​the bottom 7b. The deviation amount E1 represents how far the contact portion F1 is displaced from the center point C0 in the plan view of FIG. 3. When the deviation amount E1 is set, the tip surface 72a can be brought into contact with a portion displaced from the cutting portion 7d when the contact portion 72 is lowered, as shown in FIG. 8.

[0029] FIG. 3 illustrates the bottom radius R0, where R0 is 1 / 2 of D0. The deviation amount E1 may be defined as E1=k×R0 using a coefficient k with C0 as the origin. 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 part F1 is shifted from the center point C0 in the outer radial direction by exactly half of R0. The coefficient k may be, for example, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.40, 0.50, 0.60, or the like, or may be within a range between any two of the numerical values ​​exemplified here. As described in a modified example below, the deviation amount E1 may be zero, in which case the coefficient k=0.

[0030] The contact site F1 varies depending on the shape of the tip surface 72a and the degree of curvature. When the tip surface 72a and the bottom portion 7b can be regarded as being in point contact, the distance between the contact site F1, which is the contact point, and the center point C0 can be regarded as the deviation amount E1. When 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 contact surface area can be regarded as the contact site F1, and the distance between this center point and the center point C0 can be regarded as the deviation amount E1.

[0031] 3.Pre-peeling method The preliminary stripping method of the embodiment includes a stripping step and a leak inspection step.

[0032] 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 face of the mouth portion 9 are tightly attached via packings 32 and 34. This tight attachment results in the inside of the inner bag 14 being in communication with the outside only through the through holes 31a, 32a, and 33c. It becomes possible to reduce or increase the pressure inside the inner bag 14 by the pressure reduction system 5 or the pressure increase system 6.

[0033] Next, suction of the suction head 3a is started by the decompression system 5. The pressure inside the inner bag 14 is reduced by the suction. The pressure inside the inner bag 14 becomes negative, creating a state in which the inner bag 14 tries to shrink. The timing of starting the suction is set so that the pressure inside the inner bag 14 becomes negative at the latest before the tip surface 72a hits the bottom 7b.

[0034] Next, the contact portion 72 is lowered so that the tip surface 72a comes into contact with the bottom portion 7b as shown in FIG. 7. In the embodiment, the amount of deviation E1 is set as an example, so that the tip surface 72a comes into contact with the contact portion F1 that is shifted from the biting portion 7d of the bottom portion 7b. In the enlarged cross-sectional view of FIG. 8, the original bottom surface position 7b1 is shown by a dashed line. When the tip surface 72a comes into contact, a vertically downward force acts on one side of the bottom portion 7b. As a result, the biting portion 7d is cracked, and the outside air introduction portion 15 is formed.

[0035] The strength of the cutout portion 7d of the outer shell 12 is particularly weak. Therefore, by applying force to the outer shell 12, the cutout portion 7d can be opened to form the outside air introduction portion 15 as shown in Fig. 8. As outside air is introduced from the outside air introduction portion 15, a force that causes the inner bag 14 to shrink (force represented by multiple arrows pointing downward in Fig. 8) acts, generating a peel gap G1 between the inner bag 14 and the outer shell 12. Fig. 8 shows an example of the peel gap G1 diagrammatically. Outside air can be introduced into the peel gap G1 between the outer shell 12 and the inner bag 14 through the outside air introduction portion 15.

[0036] Here, there are various variations in the way the tip surface 72a applies force to the bottom 7b. The drive mechanism 71 may quickly lower the contact portion 72 to apply an impact force to the bottom 7b. The drive mechanism 71 may relatively gently lower the contact portion 72 to apply a pressing force to the bottom 7b. The contact portion 72 may be moved up and down multiple times to bring the tip surface 72a into contact with the bottom 7b multiple times. This "multiple times" may be, for example, two or three times, or may be four or more times, but may be, for example, three times in order to reliably split the biting portion 7d and to shorten the process time. Note that, in one or several times (specifically, for example, the last time) among the multiple times of contact, the contact portion 72 may be stopped at the lowered position for a certain period of time to hold the bottom 7b pressed down. If the area of ​​the bottom 7b is small in a small double container 1, it may be difficult to peel off only by one contact. In this case, the impact force may be applied multiple times to ensure peeling.

[0037] Although not shown in Fig. 8, the force with which the double container 1 is pressed downward when the contact portion 72 contacts the bottom portion 7b may be absorbed to some extent by the packings 32, 34. In this case, the packings 32, 34 may shrink in the thickness direction when the contact portion 72 contacts the bottom portion 7b, so that the double container 1 may be displaced downward to some extent. This may adjust the impact force or pressing force applied to the outer shell 12.

[0038] Fig. 9 shows a schematic example of how inner bag 14 shrinks due to preliminary peeling. When outside air introduction portion 15 is formed by splitting cut portion 7d, inner bag 14 can quickly shrink accordingly as shown in Fig. 9. This is because the inside of inner bag 14 is made negative pressure by suction, so cut portion 7d can be split while inner bag 14 is shrinking due to the negative pressure. This allows preliminary peeling to be performed while preventing damage to inner bag 14.

[0039] After the preliminary peeling, air is blown into the inner bag 14 through the suction head 3a by the pressurizing system 6. This causes the inner bag 14 to expand until it returns to its original position, as shown in FIG.

[0040] 3-2.Leak inspection process In the embodiment, as an example, the preliminary peeling step is followed by a leak inspection step, in which the presence or absence of pinholes in the inner bag 14 is inspected based on data obtained when the inside of the inner bag 14 is pressurized after the peeling step.

[0041] Specifically, with the inner bag 14 inflated to its original state as shown in Fig. 10, the presence or absence of a pinhole is checked using the flow meter 64. If a pinhole is present, a flow rate will occur due to air leakage.

[0042] As shown in FIG. 11, after the start of pressurization, the air flow rate measured by the flowmeter 64 increases rapidly, but as the inner bag 14 expands, the flow rate gradually decreases. If there is no pinhole in the inner bag 14, the air flow rate becomes a very small value (almost 0) when the inner bag 14 is fully inflated. On the other hand, if there is a pinhole in the inner bag 14, air will flow out of the inner bag 14 through the pinhole even when the inner bag 14 is fully inflated, so the flow rate of air sucked out of the inner bag 14 will be greater than when there is no pinhole in the inner bag 14. Therefore, it is possible to determine whether or not a pinhole is present in the inner bag 14 after a predetermined time T has elapsed based on the flow rate of air leaking out of the inner bag 14 (more specifically, by checking whether this flow rate exceeds the threshold value Th).

[0043] Furthermore, if a pinhole exists in inner bag 14, the degree of sealing inside inner bag 14 will be reduced, making it difficult to pressurize the inside of inner bag 14. For this reason, with the set pressure of compressor 63 set to a reference value, it may be determined whether or not a pinhole exists in inner bag 14 based on the pressure detected by pressure gauge 65 after a predetermined time has elapsed. Furthermore, in addition to flow rate and pressure, the presence or absence of a pinhole may be determined based on data such as the expansion mode and expansion time of inner bag 14. However, from the viewpoint of accuracy, a determination based on flow rate is preferable.

[0044] According to the preliminary peeling method of the embodiment described above, the inner bag 14 can be shrunk as the cut-off portion 7d breaks and outside air is introduced. This allows preliminary peeling to be performed while suppressing damage to the inner bag 14. In addition, it is efficient because a leak test can be performed following the preliminary peeling. The double container 1 set in FIG. 6 may be one immediately after molding, for example. In other words, the peeling process may be performed immediately following the molding process for molding the double container 1.

[0045] 4. Variations The configuration of the embodiment can be modified in various ways. The following modifications may be applied alone or in combination.

[0046] For example, the leak inspection process of the embodiment may be omitted, or a leak inspection may be performed by another method after the peeling process.

[0047] As a modified example, the deviation amount E1 may be set to zero as shown in Fig. 12. Specifically, the peeling process may be started by placing the center C1 of the tip surface 72a vertically above the cutting portion 7d as shown in Fig. 12, or the center C1 of the tip surface 72a may be brought into contact with the center point C0 of the bottom portion 7b. In this case, the center C1, the center point C0, and the contact portion F1 are exactly aligned on a vertical line, so the deviation amount E1 is zero.

[0048] The shape of the contact portion 72 may be modified in various ways. For example, the modified examples shown in Figs. 13 to 16 may be provided. As shown in Fig. 13, a concave (or inverted dome) tip surface 72b may be provided. As shown in Fig. 14, tip surfaces 72c1 and 72c2 constituting the side and bottom surfaces of an inverted trapezoid recess may be provided. In the example of Fig. 14, a force is applied to the bottom 7b by the planar tip surface 72c1. As shown in Fig. 15, the tip surface 72c1 of Fig. 14 may be replaced with a tip surface 72d of a convex curved surface that rises slightly into the recess. As shown in Fig. 16, a tip surface 72e2 of a convex curved surface that rises slightly into the recess and is offset may be provided within the tip surface 72e1 of the concave curved surface. As another modified example, the tip surface 72c2 of Fig. 14 may be removed to make the contact portion 72 simply a bottomed cylinder, and its bottom surface (i.e., tip surface 72c1) may be abutted against the bottom 7b. In the examples of FIGS. 13 to 15, the deviation amount E1 is zero as in the example of FIG. 12, while in the example of FIG. 16, the deviation amount E1 is provided due to the deviation of the tip end surface 72e2.

[0049] The three-dimensional shape of each of the contact portions 72 in Fig. 6 and Fig. 12 to Fig. 15 may be a rotationally symmetric shape about the central axis line CL, but is not limited to this. As a modified example, an extruded shape in which the contour of the contact portion 72 in each of these figures is extruded in the depth direction (thickness direction) of each figure may be applied. Note that the contact portion 72 in Fig. 16 has an asymmetric shape with respect to the central axis line CL, and an extruded shape extruded in the depth direction of Fig. 16 can be used.

[0050] The configuration of the bottom 7b of the double container 1 can also be modified in various ways. As one example, the bottom 7b may be modified to have a flat bottom surface. As another modification, the bottom 7b may be recessed toward the inside of the storage section 7, in which case the bottom 7b has a concave curved surface. In these cases, it is preferable that the tip surface 72a has a convex shape. Also, the convex height of the bottom 7b, i.e., the degree to which the bottom 7b protrudes, may be smaller than that illustrated in FIG. 6.

[0051] According to the above-described modified example, it is understood that there are many combinations of shapes of the bottom 7b and the tip surface 72a. For convenience, when the shape combination is expressed as "(shape of the bottom 7b) / (shape of the tip surface 72a)", there are at least a plurality of combinations of "convex shape / convex shape (see FIG. 6)", "convex shape / concave shape (see FIG. 13)", "convex shape / flat shape (see FIG. 14)", "flat shape / convex shape", and "concave shape / convex shape".

[0052] In addition, when both the bottom portion 7b and the tip surface 72a are curved convexly or concavely, the degree of curvature of the two can be set to various degrees. As an example, the convex shape of the bottom portion 7b may have a gentler curvature (i.e., a smaller curvature) than the convex curved surface of the tip surface 72a, or vice versa. The degree of curvature may be compared by the radius of curvature, but if the cross section is not circular, it may be compared by the radius of curvature of the circumscribed circle.

[0053] In the embodiment, the force is applied only to one point on the bottom 7b, but this is not limiting. As a modified example, the force may be applied to multiple points simultaneously or sequentially in any order. The multiple contact parts 72 may have multiple convex tip surfaces 72a. The multiple areas to which the force is applied may be set on both sides of the cutting part 7d.

[0054] In each of the above modified examples, the method of applying force to the bottom portion 7b (number of times, speed, strength) can be arbitrarily selected from the various methods described in the embodiment.

[0055] The suction head 3a can be modified in various ways. The suction port 33d may be provided at a location other than the tip of the rod-shaped portion 33a. When the suction port 33d is provided on the peripheral surface of the rod-shaped portion 33a, it is preferable to provide it 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 modification of the suction head 3a, the insert member 33 and the packing 34 may be omitted as shown in FIG. 17. In this case, suction is also possible with the double container 1 set as shown in FIG. 18.

[0056] The driving mechanism 71 is not limited to an air cylinder. Any other mechanical element that reciprocates may be used instead of the air cylinder, and the contact portion 72 may be driven by any electromagnetic actuator. EXAMPLES

[0057] Table 1 below shows the results of a test of the peeling process using several types (No. 1 to No. 6) of the contact portion 72 in the preliminary peeling device 2 of the embodiment. The several types of contact portion 72 have different tip surface shapes (shapes of the contact surface with the bottom portion 7d). Each test condition No. 1 to No. 6 in Table 1 differs in tip surface shape (convex, concave, flat) and the presence or absence of deviation (presence or absence of deviation amount E1). An air cylinder was used as the driving mechanism 71, and the air cylinder pressing force was set to 0.2 MPa. When the force applied by the contact portion 72 to the contacted portion with this setting was measured with a push-pull gauge, it was 60 N. The double container 1 used as the sample under each test condition had the same shape. Since the sample double container 1 had cooled down due to the passage of time after molding, it was lightly warmed with hot air (for about 5 seconds) before being used in the test. The number of samples of the double container 1 under each test condition No. 1 to No. 6 was N=3.

[0058] [Table 1]

[0059] Table 1 shows a three-level evaluation result (◎, ○, △) focusing on cracking of the cutting portion 7d. In the samples under test conditions No. 1, 2, 5, and 6, the cutting portion 7d cracked well in all (three) samples, and the inner bag 14 also peeled well (result ◎). In the sample under test condition No. 4, the cutting portion 7d cracked, but the degree of peeling was poor, and in some samples it peeled to a certain extent (result ○). In the sample under test condition No. 3, the cutting portion 7d cracked, but the peeling was insufficient (result △). When comparing the tip surface shapes, the convex shape was advantageous.

[0060] In addition, since the fragility of the cutting portion 7d depends on the material and thickness of the outer shell 12 and the shape of the bottom portion 7b, the shape of the tip surface may be selected according to the structural material of the double container 1. In addition, other methods are also conceivable, such as applying the peeling process of the embodiment immediately after molding the double container 1, increasing the magnitude or number of times of the force applied by the driving mechanism 71, or increasing the suction force of the suction device 3 to promote preliminary peeling. [Explanation of symbols]

[0061] 1:Double container 2: Pre-peeling device 3: Suction device 3a: Suction head 3b: Stage 3b1: Central recess 4: Solenoid valve 5: Pressure reducing system 6: Pressurized system 7: Storage section 7a: Torso 7b: Bottom 7b1: Original bottom position 7d: Cutting part 8, 8a, 8b, 8c: Piping 9: Mouth 12: Outer shell 14: Inner bag 15: Outside air intake section 31: Head base 31a, 32a, 33c, 34a: Through hole 31b: Recessed portion 32: Packing 33: Insertion member 33a: Rod-shaped part 33a1 :Tip 33b: Flange part 33d: Inlet 34: Packing 53: Regulator 54: Vacuum pump 61: Speed ​​controller 62: Regulator 63: Compressor 64:Flow meter 65: Pressure gauge 71: Driving mechanism 72: Contact part 72a, 72b, 72c1, 72c2, 72d, 72e1, 72e2: Tip surface 73: Control section C0: Center point C1: Center D0: Bottom diameter R0: Bottom radius E1: Displacement amount F1:Contact site G1: Peeling gap T: Predetermined time Th: Threshold

Claims

1. A method for pre-peeling a double-layered container having an outer shell and an inner bag, comprising the steps of: A peeling step is provided, The peeling step peels the inner bag from the outer shell by breaking a cutout portion provided at a bottom of the outer shell while maintaining a negative pressure inside the inner bag, The peeling step is a method in which the cutting portion is broken by applying force to a portion of the bottom portion that is shifted from the cutting portion.

2. 2. The method of claim 1 , Further comprising an inspection process; The inspection step inspects whether or not there is a pinhole in the inner bag based on data obtained when the inside of the inner bag is pressurized after the peeling step.

3. 3. The method of claim 1 or claim 2, wherein the diameter of the base of the shell is between 14 and 25 mm.

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