Tube container and method of manufacturing the same

Abstract

To provide a tube container that can eliminate burning of a paper mixture layer in a laminate sheet due to heat of a heater in molding and also improve production efficiency, and a method of manufacturing the same.SOLUTION: There is provided a tube container that has a head part 2 having a mouth cylindrical part 3 raised at a shoulder part 4, a trunk part 5 connected to the shoulder part 4, and a bottom part 6 formed by thermally melting an opening end 5a of the trunk part 5. The trunk part 5 is formed of a laminate 10 having a paper mixture layer 13 arranged between an inner layer 11 and an outer layer 12, and at the opening end 5a of the trunk part 5, the paper mixture layer 13 is coated with the inner layer 11.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tube container and a method for manufacturing the same. [Background technology]

[0002] In order to reduce the amount of plastic used, a tube container is known that is molded using a laminated sheet in which a paper blend layer is arranged between an inner layer side laminated film and an outer layer side laminated film in the body portion (for example, Patent Document 1). In the tube container described in Patent Document 1, both ends of the laminated sheet are covered in advance so that they are not exposed, and then the circumferential ends of the cylindrical laminated sheet are overlapped and heat-sealed together, so that the ends of the paper blend layer arranged inside the body are not exposed from both circumferential ends. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-026738 Summary of the Invention [Problem to be solved by the invention]

[0004] In the tube container of Patent Document 1, the end of the paper-containing layer is not exposed from both circumferential ends, but the paper-containing layer is exposed at the opening end in the height direction of the sleeve-cut body. Therefore, when the body is filled with contents and then heat is applied to the opening end of the body with a heater to form a bottom by thermal welding, there is a problem that the end of the paper-containing layer exposed from the opening end is burned by the heat of the heater.

[0005] Furthermore, the manufacturing method of the tube container in Patent Document 1 requires first forming a laminated sheet that covers both ends, and then molding the laminated sheet into a cylindrical shape to form the body, leaving room for improvement in terms of production efficiency.

[0006] The present invention aims to solve the problems of the conventional technology described above by creating a tube container and a manufacturing method thereof that prevents the paper blend layer in the laminated sheet from being burned by the heat of the heater during molding and that improves production efficiency. [Means for solving the problem]

[0007] Among the means for solving the above problems, the first means of the present invention is: A tube container having a head portion with a neck portion standing upright on a shoulder portion, a body portion connected to the shoulder portion, and a bottom portion formed by heat welding the open end of the body portion. The body is formed of a laminate in which a paper blending layer is disposed between an inner layer and an outer layer, At the open end of the body, the paper blend layer is covered with the inner layer. In the first main means of the present invention, the paper blending layer can be configured not to be exposed at the open end of the body, thereby preventing the paper blending layer from being burned by the heat of the heater during thermal welding.

[0008] In addition, the second means of the present invention is the main means of the present invention, and further includes a means in which the paper blend layer is covered by folding the inner layer radially outward. In this way, the paper composition layer can be easily coated.

[0009] In addition, the third means of the present invention is any one of the above means, and further comprises the addition of a means in which the bottom is sealed by heat welding the inner layers arranged opposite each other at the open end of the body portion that has been flattened. In the above-mentioned method, the inner layers disposed opposite to each other at the open end of the body are heat-sealed to each other, thereby reliably sealing the bottom.

[0010] The fourth aspect of the present invention is A method for manufacturing a tube container according to the first or second means, Using an apparatus including a split mold having a cavity and a plug provided so as to be able to advance and retreat with respect to the cavity, an extrusion step of extruding a molten parison, in which a paper blend layer is laminated between a resin inner layer forming an inner layer and a resin outer layer forming an outer layer, into the cavity and sandwiching the layers therebetween; a plug setting step of lowering the plug and setting it in the cavity; a cutting and covering step in which the parison is clamped and fixed between the lowered plug and the cavity, and the parison is cut by being sandwiched between a step formed on the side surface of the plug and an inclined upper surface provided on the split die, and the paper blend layer is covered with a resin inner layer that forms the inner layer and is bent approximately horizontally toward the radially outward direction by the lowered step; a filling step of filling the body portion with a content; The method is characterized by including a heat welding process in which the inner layers arranged opposite each other at the upper end of the body are overlapped to form a flattened shape, and then the open end of the body is crushed and heat welded to form the bottom. In the second main means of the present invention, productivity can be improved by cutting the body portion connected to the shoulder portion of the head portion, and at the same time, the end of the body portion can be covered to prevent the internal paper composition layer from being exposed, thereby preventing scorching. [Effects of the Invention]

[0011] In the present invention, the upper end of the paper blend layer at the end of the body can be covered and not exposed, so that when the end of the body is heated with a heater to heat-seal the bottom, it is possible to prevent the internal paper blend layer from burning. Furthermore, deterioration of the paper blending layer due to water or the like can be prevented, so that the appearance can be maintained in good condition. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a partial cross-sectional view showing a tube container according to an embodiment of the present invention and a portion thereof in an enlarged scale. [Figure 2]FIG. 2 is a partial cross-sectional view showing an enlarged view of the open end of the tube container immediately after molding. [Figure 3] FIG. 4 is an enlarged partial cross-sectional view showing the bottom of the tube container after heat welding. [Figure 4] FIG. 1 is a partial cross-sectional view showing the relationship between a split die and a plug as an example of a tube container manufacturing apparatus. [Figure 5] FIG. 2 is an enlarged cross-sectional view of the split die and the plug, showing the state before cutting the parison. [Figure 6] FIG. 10 is an enlarged cross-sectional view of the split die and plug showing a state in the middle of cutting the parison. [Figure 7] FIG. 10 is an enlarged cross-sectional view of the split die and the plug, showing the state when the parison is cut. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view showing an enlarged portion of a tube container according to an embodiment of the present invention, FIG. 2 is a partial cross-sectional view showing an enlarged portion of the open end of the tube container immediately after molding, and FIG. 3 is a partial cross-sectional view showing an enlarged portion of the bottom of the tube container after heat welding. In the following description, the direction along the container axis O passing through the center of the tube container 1 will be referred to as the axial direction, vertical direction, or height direction, and the direction perpendicular to the container axis O will be referred to as the radial direction.

[0014] As shown in Figure 1, the tube container 1 of the present invention is configured to have a synthetic resin head portion 2 in which a cylindrical neck portion 3 having a male thread 3a formed on the outer periphery is integrally provided upright on a tapered cylindrical shoulder portion 4, a cylindrical body portion 5 connected to the upper part of the shoulder portion 4, and a bottom portion 6 which is heat-welded to the open end 5a of the body portion 5 in a flattened state. A cap (not shown) can be attached to the neck portion 3.

[0015] As shown in the enlarged view in Figure 1 and Figure 2, the body 5 is formed of a laminate 10 consisting of an inner layer 11 formed of a synthetic resin such as polyethylene (PE) and having a single-layer or laminated structure, an outer layer 12 having a similar structure, and a paper-blended layer 13 of a predetermined structure laminated between them.

[0016] As shown in Fig. 3, the bottom 6 is formed by flattening and sealing the open end 5a of the cylindrical body 5 through heat welding. As shown in Fig. 2, the open end 5a before heat welding covers the upper end 13a of the paper blending layer 13 in a state in which the upper end of the inner layer 11 is bent radially outward (towards the end of the outer layer 12) approximately horizontally, and the end of the inner layer 11 and the upper end of the outer layer 12 are welded together, so that the end 13a of the paper blending layer 13 provided at the open end 5a of the body 5 is covered over the entire circumference.

[0017] Next, a method for manufacturing a tube container will be described, focusing on a method for covering the end portion 13a of the paper blending layer 13 with the inner layer 11 and the outer layer 12. The tube container 1 having the above-described configuration can be formed by an EBM molding method using a tube container manufacturing apparatus 20 as described below, using a molten parison 10A formed into a three-layer structure, for example, having a resin inner layer forming the inner layer 11, a resin outer layer forming the outer layer 12, and a paper blend layer 13 disposed therebetween.

[0018] Here, Figure 4 is a partial cross-sectional view showing the relationship between the split die and the plug as an example of a tube container manufacturing device, and Figures 5 to 7 are enlarged cross-sectional views of the split die and the plug, with Figure 5 showing the state before cutting the parison, Figure 6 showing the state during cutting of the parison (while the plug is descending), and Figure 7 showing the state at the time of cutting the parison (after the plug has descended). 4, the tube container manufacturing device 20 is mainly configured to have a split mold 21 and a plug 25 arranged above the split mold 21 so as to be movable up and down along the container axis O. A cavity 22, a cavity bottom 23, etc. are provided within the split mold 21, and a step 27 formed so as to protrude radially outward is provided on a side surface 26 of the plug 25.

[0019] The tube container 1 is produced by extruding a molten parison 10A into a cylindrical shape from an extrusion molding machine (not shown) through a die (not shown) into a cavity 22 (extrusion process). At this time, air is supplied from an air supply unit (not shown) to directly blow-mold the parison 10A. At the same time, a head portion 2 is formed at the lower end of the cavity 22.

[0020] Next, the plug 25, which has been waiting at an upper position, is lowered and inserted into the cavity 22 to set it (plug setting process). At this time, as shown in FIG. 5, the parison 10A is sandwiched and fixed between the side surface 26 of the plug 25 and the cavity inner surface 22A. Furthermore, as shown in FIG. 6, the parison 10A is sandwiched between a step portion 27 formed on the plug 25 and an inclined upper surface 24 provided above the cavity inner surface 22A. At this time, the descending step portion 27 can push and spread the resin inner layer forming the inner layer 11 radially outward (to the right in FIG. 6). Then, by lowering the plug 25, the paper blend layer 13 can be covered with the resin inner layer forming the inner layer 11, which is naturally folded radially outward substantially horizontally.

[0021] At the same time, as shown in Fig. 7, the step portion 27 comes into contact with the inclined upper surface 24, and the parison 10A is cut to a predetermined length, thereby forming a cylindrical body portion 5. At this time, the end of the resin inner layer that forms the inner layer 11 folded approximately horizontally is welded to the upper end of the resin outer layer that forms the outer layer 12. Therefore, as shown in Fig. 2, at the opening end 5a of the body portion 5 after cutting, the end 13a of the paper blending layer 13 is covered with the inner layer 11 and is not exposed (cutting and covering process).

[0022] The tube container 1 that has undergone the cutting and covering process is delivered to a customer (such as a manufacturer of various products) with the open end 5a of the body 5 open, and the contents are filled into the body 5 at the customer's factory (filling process). After filling, the inner layers 11 arranged opposite the opening ends 5a are overlapped and flattened, and then the opening end 5a of the body 5 is crushed and heated from above with a heater (not shown) to heat-seal the end, thereby completing the tube container 1 with the bottom 6 sealed (see Figure 3) (heat-sealing process).

[0023] In this way, in the heat welding process, the end of the laminate 10, in which the upper end of the paper blend layer 13 has been covered by the inner layer 11 in the previous cutting and covering process, is heated by a heater, thereby preventing the internal paper blend layer 13 from burning.

[0024] Furthermore, in the tube container 1 of the present invention, the bottom 6 is covered and the paper blend layer 13 is not exposed, which makes it possible to prevent deterioration of the paper blend layer 13 due to water, etc., and maintain a good appearance.

[0025] Furthermore, in the manufacturing method of the tube container of the present invention, the extruded parison 10A can be cut to form the body 5 and the paper blend layer 13 can be coated at the same time, and there is no need to first form a laminated sheet with both ends coated, as in the conventional method, and then mold the laminated sheet into a cylindrical shape to form the body, thereby improving production efficiency.

[0026] The configuration and effects of the present invention have been described above in accordance with the examples, but the present invention is not limited to the above examples. For example, in the above embodiment, the EBM molding method for extruding the parison 10A is used as the method for manufacturing the tube container, but other molding methods may also be used. [Industrial Applicability]

[0027] The present invention can be used in a wider range of applications in the field of tube container manufacturing. [Explanation of symbols]

[0028] 1: Tube container 2: Head section 3: Mouth tube part 3a: Male thread 4:Shoulder 5: Torso 5a: Open end 6: Bottom 10: Laminate 10A: Parison 11: Inner layer 12: Outer layer 13:Paper compound layer 13a: End 20: Tube container manufacturing equipment 21: Split mold 22: Cavity 22A: Inner surface of cavity 23: Bottom of cavity 24: Inclined top surface 25: Plug 26: Side 27: Step O: Container axis

Claims

1. The tube container has a head portion (2) with a neck portion (3) standing upright on a shoulder portion (4), a body portion (5) connected to the shoulder portion (4), and a bottom portion (6) formed by heat welding the open end (5a) of the body portion (5). The body (5) is formed of a laminate (10) in which a paper blending layer (13) is disposed between an inner layer (11) and an outer layer (12), A tube container characterized in that the paper blend layer (13) is covered with the inner layer (11) at the open end (5a) of the body (5).

2. 2. The tube container according to claim 1, wherein the inner layer (11) is folded radially outward to cover the paper blend layer (13).

3. 3. The tube container according to claim 1, wherein the bottom portion (6) is sealed by heat welding the inner layers (11) arranged opposite the open end (5a) of the body portion (5) that has been flattened.

4. A method for manufacturing the tube container according to claim 1 or 2, Using an apparatus including a split mold (21) having a cavity (22) and a plug (25) provided so as to be able to advance and retreat with respect to the cavity (22), an extrusion step of extruding a molten parison (10A) in which a paper blending layer (13) is laminated between a resin inner layer forming an inner layer (11) and a resin outer layer forming an outer layer (12) into the cavity (22) and sandwiching the layers therebetween; a plug setting step of lowering the plug (25) and setting it in the cavity (22); a cutting and covering step in which the parison (10A) is sandwiched between a step (27) formed on the side of the plug (25) and an inclined upper surface (24) provided on the split die (21) and cut, and the paper blending layer (13) is covered with a resin inner layer that forms the inner layer (11) bent approximately horizontally toward the radially outward direction by the descending step (27); a filling step of filling the body portion (5) with a content; and a heat welding step of flattening the inner layers (11) arranged opposite each other at the upper end of the body portion (5) by overlapping them together, and then crushing and heat welding the open end (5a) of the body portion (5) to form the bottom portion (6).

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