JP4834260B2 - Liquid storage container and method for manufacturing the container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a container for storing a liquid, a method for manufacturing the container, and a mold used for the manufacturing method, and more particularly to a liquid supply destination formed by multilayer blow molding and supplying liquid to the outside. The present invention relates to a liquid storage container having a liquid supply part connected to a given supply part, a method for manufacturing the container, and a mold used in the manufacturing method.
[0002]
[Prior art]
In recent years, as a liquid storage container, a container formed by multilayer blow molding has been widely used. Blow molding involves extruding a thermoplastic resin as a tube-shaped parison, sandwiching the parison with a mold from the side, blowing air into the bag-shaped parison, inflating the parison, and contacting the inner wall of the mold. How to get a product.
[0003]
When a container is formed by blow molding, a welded portion between thermoplastic resins called a pinch-off portion is formed at an end portion in the axial direction of the parison. If the seal strength of the welded part is weak, cracks will occur in the welded part due to external impacts, etc., especially when storing ink or chemicals, from the viewpoint of safety, the impact strength of the welded part, It is important to have excellent sealing performance.
[0004]
Conventionally, in order to improve the welding strength of a pinch-off portion of a liquid container (hereinafter referred to as a blow container) formed by blow molding, as shown in FIG. A blow container 100 in which the welding strength is improved by increasing the welding area in the portion 101 is known.
[0005]
By the way, as shown in FIG. 9, in the case of the blow container 100 having a general multilayer structure composed of the outer layer 100a, the intermediate layer 100b, and the inner layer 100c, the welding strength is divided between the three layers. Of course, it is determined by how the inner layers 100c are welded to each other. Therefore, the intermediate layer 100b and the inner layer 100c remain without changing the thickness up to the tip of the pinch-off part 101 simply by protruding the pinch-off part 101 outward, and the welding area increases, but the welding strength is Not much improvement.
[0006]
In order to solve this, a blow container 110 as shown in FIG. 10 has been proposed (see Japanese Patent Laid-Open No. 7-88943).
[0007]
That is, the blow container 110 has a structure in which the pressing recesses 112 and 113 are formed in steps on both side surfaces from which the pinch-off portion 111 protrudes. The pressing recesses 112 and 113 are formed by blow molding using a mold having left and right pinch-off portion molding surfaces provided with ridges facing each other in a stepwise manner. Thereby, with the mold closing operation of the mold, the intermediate layer 110b and the inner layer 110c are pushed up by the protrusions of the mold, and the welding area of the outer layers 110a at the pinch-off portion 111 is increased.
[0008]
As described above, in a multi-layered liquid storage container formed by blow molding, the pinch-off portion protrudes outward to improve the impact strength and sealing performance of the container.
[0009]
On the other hand, among liquid storage containers formed by multilayer blow molding, it is a multilayer laminated structure consisting of an outer layer having shape retention and an inner layer having pressure deformability, and even in a container that can be peeled between these layers, In order to increase the welding area between the inner layers, it has been proposed to project the pinch-off portion outward (see Japanese Patent Laid-Open No. 5-310265).
[0010]
[Problems to be solved by the invention]
However, the above-described conventional structure has a structure in which the pinch-off portion protrudes in any case, so that it may interfere with other objects when the container is used, and may satisfy a necessary function in some cases. Sometimes it was impossible. Further, if the pinch-off portion is formed at a position directly held by the user's hand, there is a possibility that the handling becomes unstable or the hand is damaged. Furthermore, such a protruding pinch-off part is not preferable in appearance.
[0011]
For containers that can be peeled between layers, even if the pinch-off part protrudes outward to increase the welding area between the inner layers, the outer layer and inner layer can be peeled, so the impact strength of the container itself Also, the sealability could not be satisfied.
[0012]
An object of the present invention is to provide a liquid container having improved impact strength and sealability without causing a pinch-off portion formed by blow molding to substantially protrude outward.
[0013]
Another object of the present invention is to provide related inventions such as a manufacturing method of the liquid container and a mold used in the manufacturing method.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the liquid storage container of the present invention comprises an outer wall constituting a housing,
It has an outer surface with the same shape as the inner surface of the outer wall The Store liquid inside Flexible inner wall When,
The weld end of the inner wall is exposed to the outside of the outer wall and pinched off In a liquid storage container comprising a pinch-off unit,
The inner wall is The wall thickness region has a wall thickness region in which the wall thickness is relatively increased across the welding end, and is formed so as to be peelable from the inner surface of the outer wall except for the welding end. The outer surface of the area in front Record Wall thickness Corresponding to the region Said Between the inner surface of the outer wall In the sky A gap is formed.
[0018]
In addition, the method for manufacturing a liquid storage container according to the present invention includes an outer wall constituting the housing and an outer surface having a shape equivalent to the inner surface of the outer wall. The Store liquid inside Flexible inner wall And the inner wall The welding end for closing the pin is exposed to the outside of the outer wall and pinched off In a manufacturing method of a liquid storage container comprising a pinch-off unit,
Providing a mold having a cavity having the same shape as the outer surface of the liquid storage container, a first parison for a cylindrical outer wall having a smaller diameter than the mold, and a second parison for an inner wall;
A step of sandwiching the first and second parisons with the mold and pushing a resin forming the first and second parisons outside the mold into a portion of the mold where the pinch-off portion is formed; ,
Air is introduced into the interior, the first and second parisons are inflated to conform to the mold, and the outer wall and the inner wall are connected to each other. Peeling A process that can be formed;
The wall thickness of the inner wall having a wall thickness region formed so as to be peelable from the inner surface of the outer wall excluding the weld end and having a relatively thick wall across the weld end. Between the outer surface of the region and the inner surface of the outer wall corresponding to the wall thickness region Forming a void portion.
[0020]
In the present specification, the “root portion” and the “tip portion” of the pinch-off portion mean the root portion and the tip portion in the pinch-off portion in the direction from the inner surface to the outer surface of the liquid storage container.
[0021]
In addition, “multilayer blow molding” in the present invention means so-called coextrusion multilayer blow molding in which a co-extruded multilayer parison is sandwiched between divided molds and a pressurized fluid is introduced into the parison and expanded. To do.
[0022]
Further, the “liquid” in the present invention is used to include a sol-like viscous fluid.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0024]
(First embodiment)
FIG. 1 is a schematic perspective view of an ink storage container according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the ink storage container shown in FIG.
[0025]
The ink storage container 1 of the present embodiment has a substantially polygonal column shape (each ridge line and apex portion is formed by an ink supply port 4 for supplying ink to the outside protruding from one end and a handle 3 protruding from the other end. A hollow container (having a minute curved surface shape), which is used by being detachably attached to a holder (not shown). The ink supply port 4 is provided with a plug member (not shown) for making an inner bag 12 (to be described later) into a sealed container. When the ink storage container 1 is attached to the holder, the holder is inserted through the plug member. And the space in the inner bag 12 are coupled, and the ink in the ink storage container 1 is consumed through this coupling portion. The handle 3 is a part that the user puts on when removing the ink container 1 attached to the holder from the holder.
[0026]
As shown in FIG. 2, the ink container 1 is formed by multilayer blow molding, and has a cross-sectional structure of an outer wall that forms the casing 11, an inner layer of the outer wall, and an inner surface of the casing 11. And an inner wall forming an inner bag 12 having an equivalent or similar outer surface.
[0027]
The inner bag (inner wall) 12 has flexibility and can be peeled off from the housing (outer wall) 11. Therefore, only the inner bag 12 can be deformed without the housing 11 being deformed with the derivation of the ink stored in the ink storage portion inside the inner bag 12. The thickness of the inner bag 12 is from the central region of each surface to the periphery so that the portion constituting the corner portion (including a curved surface shape) is thinner than the central region of each surface of the substantially polygonal columnar shape. It gradually decreases and has a convex shape on the ink storage portion side. In other words, the convex direction is the same as the deformation direction of the surface, and has the effect of promoting the deformation of the ink storage portion. With such a configuration, as described in JP-A-9-267483 As the liquid is led out, it is possible to generate a negative pressure optimum for the ink jet field at the ink supply port 4. FIG. 2 mainly shows the layer structure of the ink container 1 and does not show the actual thickness of each layer.
[0028]
In addition, at the end of a pinch-off portion 13 described later of the ink storage container 1, the ink storage container 1 is formed with an outside air communication port 14 formed by a gap between the housing 11 and the inner bag 12. Thereby, outside air can be introduced between the housing 11 and the inner bag 12 from the outside air communication port 14, and the inner bag 12 can be easily deformed as the ink in the ink storage portion is consumed.
[0029]
Further, the inner bag 12 is composed of three layers in which an ink-resistant liquid contact layer 12c, an elastic modulus dominating layer 12b, and a gas barrier layer 12a excellent in gas barrier properties are laminated in order from the inside. Function is separated by state. The elastic modulus dominating layer 12b is such that its elastic modulus is kept almost constant within the operating temperature range of the ink storage container 1, that is, the elastic modulus of the inner bag 12 is within the operating temperature range of the ink storage container 1. The elastic modulus dominating layer 12b is kept almost constant. In the inner bag 12, as long as the liquid contact layer 12c is the innermost layer, the positions of the elastic modulus dominating layer 12b and the gas barrier layer 12a may be interchanged, and the elastic modulus dominating layer 12b is the outermost layer and the gas barrier layer. 12a may be an intermediate layer.
[0030]
By configuring the inner bag 12 in this way, the inner bag 12 can sufficiently perform the functions of the respective layers with few layers, ie, the liquid contact layer 12c, the elastic modulus dominating layer 12b, and the gas barrier layer 12a. Thus, the influence on the temperature change such as the elastic modulus of the inner bag 12 is reduced.
[0031]
In the present embodiment, polypropylene is used as the material of the innermost liquid contact layer 12c constituting the inner bag 12, cyclic olefin copolymer is used as the material of the middle modulus controlling layer 12b, and EVOH is used as the material of the outermost gas barrier layer 12a. (Saponified product of EVA (ethylene vinyl acetate copolymer resin)) is used. The casing 11 is made of the same polypropylene as the innermost layer of the inner bag 12.
[0032]
Here, the adhesive strength between the three layers constituting the inner bag 12 is sufficiently larger than the adhesive strength (peeling strength) between the housing 11 and the inner bag 12. Therefore, when the ink container 1 is used, the casing 11 and the inner bag 12 can be easily separated from each other, and the layers constituting the inner bag 12 are not separated.
[0033]
As described above, since the ink storage container 1 is formed by multilayer blow molding, the ink supply port 4 side and the opposite end, that is, the end on the side where the handle 3 is provided are provided. And a pinch-off portion 13. In the state shown in FIG. 2, the pinch-off portion 13 is formed from the portion serving as the handle 3 at the rear end of the ink storage container 1 toward the bottom. The pinch-off portion 13 on the ink supply port 4 side is not shown in FIG.
[0034]
A cross-sectional structure of the pinch-off portion 13 will be described with reference to FIG. FIG. 3 is a cross-sectional view of the vicinity of the pinch-off portion of the ink container shown in FIG. 2 cut in a direction crossing the pinch-off portion.
[0035]
As shown in FIG. 3, the pinch-off portion 13 does not have a tip protruding from the surrounding portion in the outer surface structure of the ink storage container 1, and is viewed from the outer surface of the ink storage container 1. Thus, substantially the same surface as the periphery of the pinch-off portion 13 is formed. By using the flat pinch-off portion 13, it is possible to stabilize the handling of the ink storage container 1, and to prevent a problem that the hand is cut from the safety aspect. Further, the appearance of the ink storage container 1 is not damaged.
[0036]
Such a structure, for example, as a mold for molding the ink storage container 1, is specially provided in a mold that does not have a recess that serves as a resin reservoir for the resin that can be cut off in the pinch-off portion 13, or a recess that serves as a resin reservoir. It can be formed using a mold having a simple structure. When the parison that forms the base for forming the ink storage container 1 is sandwiched between the molds, the casing 11 and the inner bag 12 are pushed up inward by the intrusion of the resin that cannot escape into the resin reservoir in the pinch-off portion 13. Thereby, on both sides of the portion where the wetted layers 12c of the inner bag 12 are welded to each other, the casing 11 and the inner bag 12 are thicker than the surrounding portions. The convex part 21 and the convex part 22 by the inner bag 12 are formed.
[0037]
Here, the formation of the convex portions 21 and the convex portions 22 using a mold having a special structure in the concave portion serving as a resin reservoir will be supplemented with reference to FIG. FIGS. 8A and 8B are cross-sectional views for explaining a method for manufacturing the ink tank shown in FIG. 1, wherein FIG. 8A is a state in which mold clamping is in progress, and FIG. 8B is a state in which mold clamping is completed. Is shown.
[0038]
The mold 30 has a cavity having substantially the same shape as the outer surface of the ink container 1 (see FIG. 1) to be manufactured. As shown in FIG. A dam 30b is formed as a parison narrow pressure region for pressurizing a co-extruded parison described later. An outer wall resin layer (first parison) that forms the casing 11 and serves as a molding base of the ink storage container, and an inner wall gas barrier layer 12a that forms the inner bag 12, an elastic modulus dominating layer 12b, and liquid contact When sandwiching the cylindrical parison 40 having a smaller diameter than the mold 30 in which the resin layer (second parison) composed of the layer 12c is concentrically arranged on the inner side thereof, first, the mold facing the protrusion 30a. The parison 40 is sandwiched between the mold ends 30d. Here, in the parison 40, the resin 40a (a part of the resin outside the mold) in a region where it cannot escape into the resin reservoir 30e that is an open space outside the mold is pushed into the dam 30b. At this time, as the gap between the protrusion 30a and the end portion 30d decreases, the resin 40a in the dam 30b moves in the direction of the arrow in the drawing, that is, in the mold (from the outside of the case housing to the inside of the inner bag). It is pushed into the area where the pinch-off part 13 is formed.
[0039]
When the mold 30 is closed and the interior of the parison is inflated with a fluid such as air, as shown in FIG. 8B, the resin 40a is pushed into a region where it cannot escape into the resin reservoir 39e. The convex part 21 of a body and the convex part 22 of an inner bag are formed. In the region of the mold 30 where the pinch-off portion 13 is formed, the end 30c of the dam 30b is configured so that a gap 30f is formed with the mold 30 closed, as shown in FIG. In this state, a pressed parison exists in the gap 30f, and the pinch-off portion 13 and the resin 40a in the dam 30b are continuous. This part is removed from the mold, and then deburred with reference to the outer wall surface of the housing, so that the pinch-off part 13 can be formed substantially on the same plane as the periphery as described later. It can be formed so that the part where the inner walls are integrated is exposed to the outside. This is more desirable in forming the voids described later.
[0040]
In the present embodiment, as described above, the parting lines of the mold 30 facing each other when the mold clamping is completed are in contact with each other except for the parting line of the pinch-off portion 13 where the parison 40 is sandwiched. The parting line of the pinch-off part 13 between which the pinch-off part 13 is sandwiched has a slight gap 30f, that is, both end parts 30c of the mold 30 forming the pinch-off part 13 are not in contact with each other and have a minute slit-like gap 30f. desirable. This is because the clearance 30f allows the aforementioned resin 40a to be pushed into the mold more reliably until the mold clamping is completed. As a result, since the resin larger than the volume of the dam 30b at the end of mold clamping is not held in the dam at the end of mold clamping, productivity is improved.
[0041]
Moreover, the thickness of the convex part 21 of a housing | casing and the convex part 22 of an inner bag is determined by the quantity of the resin 40a in a parison narrow pressure area | region, and the viscoelastic characteristic of the resin of a plasticization state. In the present embodiment, when using a resin having the same viscoelastic property, when it is desired to increase the thickness, the protrusion amount of the protrusion 30a is increased, the amount of resin pushed into the dam 30b is increased, or the volume of the dam 30b is increased. Is reduced so that a large amount of resin flows into the mold.
[0042]
The protrusion 30a is not limited to this shape as long as the resin 40a that cannot escape into the opened resin reservoir 30e can be pushed into the dam 30b. Specifically, in the cross-sectional view shown in FIG. 8A, the distance between the protrusion 30a and the end 30d before clamping is shorter than the distance between both ends 30c of the mold 30 forming the pinch-off portion 13. It only has to be.
[0043]
Moreover, the dam 30b as a pinching area | region should just push back the resin which forms the parison 40 outside a type | mold to the part in which the pinch-off part 13 in a type | mold is formed. Specifically, instead of providing the protrusions 30a and the like, a gap as in the present embodiment is provided in a portion where the pinch-off portion of the mold is formed to increase the thickness of the mold, and the gap is opened to the outside of the mold. It may be adapted to extend to the formed resin reservoir. However, it is preferable to provide the resin reservoir 30e with a protrusion 30a that does not allow the resin to escape, as in this embodiment, because the resin can be pushed into the mold more reliably.
[0044]
As described above, the casing 11 and the inner bag 12 can be peeled off. That is, the housing 11 and the inner bag 12 are not welded to each other, and the inner bag 12 is held between the convex portions 21 of the housing 11 and held by the housing 11 in the pinch-off portion 13. Thus, since the holding | maintenance area | region of the inner bag 12 by the housing | casing 11 becomes large because the inner bag 12 is pinched | interposed between the convex parts 21 of the housing | casing 11, the housing | casing 11 and the inner bag 12 are welded. Even if it does not exist, it can suppress that the inner bag 12 remove | deviates from the housing | casing 11 in the pinch-off part 13. FIG. In addition, even if the inner bag 12 is temporarily detached when it is peeled off, the inner bag 12 is difficult to be detached from the housing 11, and as a result, irregular deformation of the inner bag can be suppressed.
[0045]
Incidentally, the outside air communication port 14 (see FIG. 2) is formed by peeling the housing 11 and the inner bag 12 as shown in FIG. However, since the proportion of the area where the casing 11 and the inner bag 12 constituting the outside air communication port 14 are separated from each other is small in the pinch-off portion 13, the holding force of the inner bag 12 by the casing 11 is limited to the outside air. The effect of the communication port 14 is small.
[0046]
On the other hand, by forming the convex portion 22 on the inner bag 12, the thickness of the liquid contact layer 12c, the elastic modulus dominating layer 12b, and the gas barrier layer 12a is increased, and the inner bag 12 at the root portion of the pinch-off portion 13 is increased. Strength can be improved. Further, the formation of the convex portion 22 on the inner bag 12 also increases the welding area between the inner walls forming the inner bag 12 and improves the welding strength between the inner walls forming the inner bag 12 at the pinch-off portion 13. Is effective. In order to obtain this effect, according to the experiments by the present inventors, for the inner bag 12, the thickness of the convex portion 22 as the thick region is larger than the average thickness of the other regions of the inner bag 12. Is preferably in the range of 1.5 to 4 times.
[0047]
Further, a gap 20 a is formed between the housing 11 and the inner bag 12 in the portion where the convex portions 21 and 22 are formed. Here, the gap portion 20a may be formed between the outer surface of the convex portion 22 formed by the inner bag 12 and the inner surface of the housing 11 corresponding thereto, and the convex portion 21 is not necessarily required.
[0048]
As a method for forming the gap portion 20a, (1) the pinch-off portion is pressed or pressed vertically inward from the outer surface of the container, and (2) from an outside air communication port provided at an arbitrary portion of the casing. By introducing outside air between the housing and the inner bag, the boundary surface between the housing and the inner bag is once peeled off to allow the outside air to enter the pinch-off portion. (3) The container body is pressed or pressurized and deformed. There are methods such as allowing outside air to enter the pinch-off part.
[0049]
Hereinafter, the function of the gap 20a will be described with reference to FIG. FIG. 5 is a cross-sectional view of the pinch-off portion for explaining the behavior of the pinch-off portion when an external impact is applied to the ink storage container shown in FIG.
[0050]
For example, when an impact force is applied to the ink storage container 1 from the outside by dropping or the like, the impact force is transmitted from the housing 11 to the inner bag 12. Here, in the pinch-off portion 13, since the gap portion 20 a is formed between the housing 11 and the inner bag 12 on both sides of the root portion, the gap portion 20 a serves as a damper that absorbs impact, The impact force transmitted to the inner bag 12 can be reduced.
[0051]
Further, since the gap portion 20a exists on both sides of the pinch-off portion 13, when the impact force is transmitted to the inner bag 12, as shown in FIGS. 5 (a) and 5 (b), in the direction in which the impact force is applied. Accordingly, the inner bag 12 can swing in the left or right direction or both the left and right directions to absorb the impact. Thereby, damage applied to the welded portion of the inner bag 12 in the pinch-off portion 13 is suppressed, and damage such as tearing of the pinch-off portion 13 is prevented, so that ink leakage from the pinch-off portion 13 can be prevented.
[0052]
Moreover, since the housing | casing 11 and the inner bag 12 are separable, in the part of the inner bag 12 pinched | interposed into the convex part 21 of the housing | casing 11, when an impact force is added, the housing | casing 11 and the inner bag are only momentarily. A gap 20 b is formed between While the gap 20b is formed, the impact force applied to the housing 11 is substantially blocked by the gap 20b. Therefore, the impact force transmitted from the outside to the inner bag 12 in the pinch-off portion 13 becomes smaller, and damage to the pinch-off portion 13 due to the impact force from the outside can be more effectively prevented.
[0053]
In addition, since formation of the space | gap part 20b is a moment, the inner bag 12 does not remove | deviate from the housing | casing 11 by forming the space | gap part 20b. Also, as shown in FIGS. 5A and 5B, after the inner bag 12 is shaken, the inner bag 12 returns to the state shown in FIG. 3 and is held by the housing 11.
[0054]
As described above, the inner bag 12 can be prevented from being damaged at the pinch-off portion 13 when an external impact force is applied by the action of each of the gap portion 20a and the gap portion 20b. Of course, the fact that the outer shape of the ink container 1 is flat at the site where the pinch-off part 13 is formed also makes it difficult for the impact force to be directly applied to the pinch-off part 13, greatly contributing to preventing damage to the pinch-off part 13. . Further, these two types of gaps 20a and 20b may be allocated in advance so as to be effective in the direction of receiving a higher impact with a higher probability due to the outer shape and weight distribution of the ink storage container 1. This is possible, and by doing so, damage to the pinch-off portion 13 can be prevented.
[0055]
(Second Embodiment)
FIG. 6 is a schematic perspective view of a liquid storage container according to the second embodiment of the present invention. FIG. 7 is a cross-sectional view of the main part of the pinch-off part cut in a direction crossing the pinch-off part of the liquid container shown in FIG.
[0056]
The liquid storage container 50 of the present embodiment has a housing and an inner bag separable from the housing, as in the first embodiment described above. The inner bag may be a shampoo or a rinse, for example. A pump member 51 having a spout 52 at the end is provided in the mouth 53. A cylindrical portion 55 connected to the pump member 51 and used to take out the liquid inside extends to the inside of the liquid storage container 50, and its open end 55 a is positioned near the bottom surface 56 of the liquid storage container 50. is doing. Similar to the first embodiment, the bottom surface 56 is provided with a pinch-off portion 58. The outer surface of the thick wall region of the inner wall (the convex portion 60 of the inner bag 59 shown in FIG. 7) and the housing A gap 57 is formed between the inner surface and the inner surface. In the present embodiment, the outside air communication port 54 is drilled in the mouth portion 53 of the liquid storage container 50 by an arbitrary processing means.
[0057]
The structure in the vicinity of the pinch-off portion 58 will be further described in detail with reference to FIG.
[0058]
Also in this embodiment, the gap portion 57 is formed between the convex portion 61 of the housing 62 and the convex portion 60 of the inner bag 59 as in the first embodiment. In the present embodiment, unlike the first embodiment described above, the inner bag 59 has a laminated structure of an inner layer 59a such as polypropylene to which an adhesive resin is added and a barrier layer 59b such as EVOH. Of course, depending on the type of contents, the inner bag may be a single layer instead.
[0059]
The casing 62 of the present embodiment is made of polypropylene. Regarding the bottom surface 56, the outer peripheral portion of the liquid storage container 50 forms the mounting surface 56b, whereas the inner region of the casing 62 is formed. 56a protrudes relatively toward the inner bag 59 side. A pinch-off portion 58 is provided in the recess formed by the placement surface 56b and the inner region 56a so as to protrude to the outside, and the outer wall outer surface of the housing 62 corresponding to the pinch-off portion 58 has the projection 56c. Forming. Even in such a container, the pinch-off portion 58 can be protected when an impact is applied from the outside by providing the gap portion 57 described above.
[0060]
Such a liquid storage container is suitable as a container for storing viscous foods such as mayonnaise and ketchup, foamy viscous cosmetics such as shaving cream, liquid detergents, jelly-like facial cosmetics, etc. in addition to shampoo and rinse. Available. Moreover, according to those contents, a pump as shown in this embodiment may be used, or a simple opening may be used.
[0061]
【The invention's effect】
As described above, according to the present invention, between the inner wall and the outer wall in the thick region of the inner wall in the pinch-off portion of the liquid storage container formed by blow molding, which is configured in a multilayer laminated structure and in a delaminated state. By forming a gap in the gap, the gap functions as a damper, and it is possible to prevent damage to the pinch-off part when an impact force is applied to the liquid storage container from the outside, and thus leakage of liquid from the pinch-off part. . In addition, as a result, the pinch-off portion can be configured to be substantially flush with the periphery of the pinch-off portion when viewed from the outer surface of the housing, and various problems due to the protruding pinch-off portion can be prevented. Furthermore, by increasing the thickness of the casing at the pinch-off part, the strength of the casing and inner bag at the pinch-off part can be improved, and the welding area between the inner bags also increases, so the pinch-off part The welding strength can be improved. In addition, the liquid storage container in which various problems in the pinch-off portion are eliminated as described above can be manufactured by using the liquid storage container manufacturing method and the mold according to the present invention.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of an ink storage container according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the ink container shown in FIG. 1 along the formation direction of a pinch-off portion.
3 is a cross-sectional view of the vicinity of the pinch-off portion of the ink container shown in FIG. 1 cut in a direction crossing the pinch-off portion.
4 is a cross-sectional view of the ink storage container shown in FIG. 1 at an outside air communication port cut in a direction crossing a pinch-off portion.
FIG. 5 is a cross-sectional view of the pinch-off portion for explaining the behavior of the pinch-off portion when an impact is applied to the ink storage container shown in FIG. 1 from the outside.
FIG. 6 is a schematic perspective view of a liquid storage container according to a second embodiment of the present invention.
7 is a cross-sectional view of the main part of the pinch-off part cut in a direction crossing the pinch-off part of the liquid container shown in FIG. 6. FIG.
FIGS. 8A and 8B are cross-sectional views for explaining a manufacturing method of the ink tank shown in FIG. 1, wherein FIG. 8A is a state in which mold clamping is in progress, and FIG. 8B is a state in which mold clamping is completed. Indicates.
FIG. 9 is a cross-sectional view in the vicinity of a pinch-off portion of an example of a conventional liquid storage container formed by blow molding.
FIG. 10 is a cross-sectional view in the vicinity of a pinch-off portion of another example of a conventional liquid storage container formed by blow molding.
[Explanation of symbols]
1 Ink storage container
3 Handle
4 Ink supply port
11,62 housing
12,59 inner bag
13, 58 Pinch-off part
14,54 Open air communication port
20a, 20b, 57 gap
21, 22, 60, 61 Convex
30 mold
30a protrusion
30b Dam
30f clearance
40 Parison
50 Liquid container
51 Pump member
52 Outlet
53 mouth
55 Tube
56 Bottom
56b Placement surface
56c protrusion

Claims (9)

An outer wall constituting the housing;
A flexible inner wall for accommodating the liquid therein having an inner surface and an outer surface of the same shape of the outer wall,
In a liquid storage container comprising: a welding end for closing the inner wall exposed to the outside of the outer wall and pinched off .
The inner wall has a wall thickness region in which the thickness of the wall is relatively increased across the welding end, and is formed so as to be peelable from the inner surface of the outer wall except for the welding end. liquid container and forming an air gap portion between the inner surface of the outer wall corresponding to the outer surface prior Symbol wall thickness region of the wall thickness region.   The liquid storage container according to claim 1, wherein the pinch-off portion forms the same surface as the periphery of the pinch-off portion when viewed from the outer surface of the housing. The liquid container according to claim 1, wherein the wall thickness region of the inner wall protrudes toward a space for storing the liquid formed by the inner wall. 2. The liquid storage according to claim 1, wherein a thickness of the inner wall in a wall thickness region is 1.5 to 4 times as large as a thickness of another region constituting the inner wall. container. Wherein the outer wall constituting the housing, a liquid container according to claim 1, characterized in that it comprises a fresh air passage for introducing external air between the outer wall and the inner wall. Space for accommodating the liquid to be formed by the inner wall is substantially polygonal shape, the thickness of the inner wall, towards the portion constituting the corner portion is thinner than the central region of each surface constituting the substantially polygonal shape The liquid container according to claim 5 . Wherein said liquid container has a liquid outlet portion for leading the liquid in which they are housed in the outside, the inside wall, characterized in that for generating a negative pressure by the deformation caused in connection with the derivation of the liquid Item 2. A liquid container according to Item 1. An outer wall constituting the housing;
A flexible inner wall for accommodating the liquid therein having an inner surface and an outer surface of the same shape of the outer wall,
In a manufacturing method of a liquid storage container, comprising a pinch-off portion that is pinched off by exposing a welding end portion for closing the inner wall to the outside of the outer wall ,
Providing a mold having a cavity having the same shape as the outer surface of the liquid storage container, a first parison for a cylindrical outer wall having a smaller diameter than the mold, and a second parison for an inner wall;
A step of sandwiching the first and second parisons with the mold and pushing a resin forming the first and second parisons outside the mold into a portion of the mold where the pinch-off portion is formed; ,
Introducing air into the interior, inflating the first and second parisons, along the mold, and forming the outer wall and the inner wall so as to be peelable ;
The wall thickness of the inner wall having a wall thickness region formed so as to be peelable from the inner surface of the outer wall excluding the weld end and having a relatively thick wall across the weld end. Forming a gap between the outer surface of the region and the inner surface of the outer wall corresponding to the wall thickness region . The mold is a pair of left and right, and a pinch-off portion forming surface in each mold is used to push the resin forming the first and second parisons outside the mold into the mold when clamping. While having a parison clamping part that holds a part of the resin,
The step of pushing the resin forming the first and second parisons into the portion of the mold where the pinch-off portion is formed includes holding the resin in the parison clamping portion and placing the held resin in the mold. The method for producing a liquid container according to claim 8 , wherein the method is performed by pushing.

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