JP3260926B2 - Tube container manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a tube container.

[0002]

2. Description of the Related Art Generally, tube containers for foods and the like which require gas barrier properties are manufactured by a blow molding method. That is, first, a parison is formed using an extruder, and this parison is set in a left and right split mold,
Compressed air is blown into the parison and molded by inflation.After that, the bottom is cut and opened, and after filling the contents from this opening, the cut portion is joined by welding or the like,
Manufactures tube containers.

[0003]

However, since the tube container manufactured by the blow molding method uses a split mold, a parting line appears on the surface of the manufactured tube container. With such a parting line, there is a problem that when printing is performed on the surface of the tube container, the printing becomes dirty.

[0004] The present invention has been made in view of such problems of the prior art, and has as its object to provide a method of manufacturing a tube container having no parting line on the surface.

[0005]

The present invention has the following features to attain the object mentioned above. In the method for manufacturing a tube container according to the present invention, the housing tubular portion of the tube container is manufactured by vacuum forming, pressure forming or press forming a resin sheet using a female mold. This female mold is provided with a cavity that has a shape substantially the same as the housing cylinder portion including the straight body portion, the shoulder portion, and the small cylinder portion of the tube container to be manufactured, and has a bottom corresponding to the mouth tube side of the tube container. Keep it.

A resin sheet in a softened state is placed in the female cavity opening. This resin sheet may be softened after being placed in the cavity opening, or may be placed in the cavity opening after being softened. Then, the softened resin sheet is sucked from the surface of the cavity, or is blown with compressed air from the outside of the resin sheet, or is pushed in with a plug, or is used in combination with the resin sheet. Pressure contact.

Then, the resin sheet pressed against the inner surface of the cavity is cooled and solidified to form a bottomed cylindrical body in which substantially the entirety of the housing cylindrical portion of the tube container to be manufactured is integrally molded.
The bottomed cylinder is released from the female mold, and the bottom of the bottomed cylinder corresponding to the mouth portion of the tube container to be manufactured (that is, a portion corresponding to the mouth portion side of the tube container to be manufactured). ) To open the spout-side connection port. Then, a barrel portion is formed and fixed to the connection port.

[0008] It is also possible to form the mouthpiece portion separately in a predetermined shape by injection molding or compression molding and insert and fix this mouthpiece portion to a connection port provided in the bottomed cylinder body. However, it is also possible to provide a mouthpiece at the connection port by the following method.

That is, a resin different from the bottomed cylinder is welded to the connection port of the bottomed cylinder to close the connection port. The first mold disposed inside the bottomed cylinder and the second mold disposed outside the connection port of the bottomed cylinder are formed by compression molding the resin that closes the connection port. Mold into In this way, the mouthpiece can be securely fixed to the bottomed cylinder (housing cylinder) in a sealed state.

The resin sheet may be a single-layer sheet or a laminated sheet. As a laminated sheet, polypropylene / adhesive polyolefin (Adma) / ethylene vinyl alcohol copolymer (EVAL)
/ Adhesive polyolefin (Adma) / polypropylene and the like.

[0011]

[Function] There is no parting line on the surface of the housing cylinder. The surface of the housing cylinder without the parting line can be printed neatly.

[0012] It is possible to reduce the thickness of the portion corresponding to the shoulder of the housing cylinder. In a tube container having an accommodating cylindrical body having a thin shoulder portion, when the content in the tube container decreases, the shoulder of the accommodating cylindrical body can be crushed and the contents can be poured out. The remaining amount of contents that cannot be used because they cannot be used can be reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, a tube container manufactured by the method of the present invention will be described with reference to FIG.
The tube container 1 includes a housing tube 2 formed by vacuum-forming a flexible resin laminated sheet, and a resin mouth tube 6 formed by compression-molding a resin. The accommodating tube portion 2 includes a straight body portion 3, a tapered shoulder portion 4, and a small tube portion 5. On the other hand, the mouthpiece 6 has a spout 7 at the tip and a male thread 8 on the outer peripheral surface.

Next, a manufacturing process of the housing cylinder 2 of the tube container 1 will be described with reference to FIGS. The housing cylinder 2 is manufactured using a female mold 10 and a plug 15 as shown in FIG. The female mold 10 has a shape in which the small tube portion 5 of the housing tube portion 2 of the tube container 1 is slightly extended, the end of the straight body portion 2 is slightly extended, and a step portion is provided at the tip end thereof. Cavity 11 is provided. In the cavity 11, the bottom 11 a corresponds to the small cylinder 5 side of the accommodation cylinder 2. The female die 10 is a female die for vacuum forming, and the female die 10 is provided with a number of intake holes (not shown).

On the other hand, the plug 15 has a similar shape to the cavity 11 of the female die 10 and can be inserted into and removed from the cavity 11. This plug 15 is also a plug for vacuum forming, and the plug 15 is provided with a number of holes for supplying compressed air (not shown). Although the plug 15 has a similar shape to the cavity 11 in the present embodiment, the plug 15 may not have the similar shape and may have a shape and a size such that a gap is formed between the plug 15 and the inner surface of the cavity 11.

A laminated sheet 20 made of resin is arranged above the opening 11b of the cavity 11 in the female mold 10,
It is softened by heating with a heater (not shown). Next, FIG.
As shown in FIG.
Then, the plug 15 is held between the upper surface of the housing 0 and the holding metal 19, and the plug 15 is lowered to enter the cavity 11. At the same time, the cavity 10 is evacuated by sucking the female mold 10 and the compressed air is supplied from the plug 15 so that the laminated sheet 2
0 is pressed against the inner surface of the cavity 11.

Next, the plug 15 is raised while the suction of the female die 10 is continued, and the laminated sheet 20 is cooled. Thereby, the laminated sheet 20 is formed into a shape along the inner surface of the cavity 11. After cooling, the formed laminated sheet 2
0 is released from the female mold 10 to obtain a bottomed cylinder 21 as shown in FIG.

Next, the bottom portion 21a and the upper portion 21b of the bottomed cylindrical body 21 are respectively taken along the line X--X and the line Y--Y in FIG.
By cutting along the Y line, a housing cylinder 2 of the tube container 1 as shown in FIG. 3B is obtained. The opening of the small cylinder part 5 in the storage cylinder part 2 serves as the spout-side connection port 5a.

Next, the process of fixing the mouthpiece portion 6 to the small tube portion 5 of the housing tube portion 2 will be described with reference to FIG. First, a cutting tool 30 shown in FIG. 4A is attached to the outer end of the small tube portion 5 of the housing tube portion 2, and a resin plate in a molten state is punched by using the cutting tool 30, and the cut resin plate is punched out. 40 is welded to the inner surface of the distal end of the small cylindrical portion 5. FIG. 4A shows this state, and the connection port 5 a of the small cylindrical portion 5 is closed by the resin plate 40.

Next, the cutting tool 30 is removed from the small cylinder portion 5,
As shown in FIG. 4B, a lower mold (second mold) 32 having a cavity 32 a having a shape corresponding to the outer shape of the mouthpiece portion 6 is arranged below the housing tube portion 2. Inside of part 2,
An upper die (first die) 31 having an outer shape corresponding to the inner surface shape of the mouthpiece portion 6 and having a punch portion 31a at the tip is arranged.

The resin plate 4 welded to the small cylinder 5
After the 0 is changed from the molten state to the softened state, the upper mold 31 is lowered, and the resin plate 40 is compression-molded by the upper mold 31 and the lower mold 32 as shown in FIG. At this time, the punch 31a of the upper die 31 pierces the spout 7 of the mouthpiece 6, and the lower die 32 forms the male screw 8 of the mouthpiece 6.

After completion of the compression molding, the upper mold 31 and the lower mold 32 are removed to complete the tube container 1 shown in FIG. In addition, a cap (not shown) is attached to the mouth tube portion 6 of the tube container 1 to fill the contents into the housing tube portion 2, and the opening end of the straight body portion 3 of the housing tube portion 2 is closed. The step of closing by means such as heat welding is the same as before.

In the tube container 1 manufactured as described above, since the housing cylinder 2 of the tube container 1 is formed by a single female mold 10 for vacuum forming, the housing cylinder 2 has a parting line. There is no. As a result, when printing is performed on the surface of the housing cylinder portion 2, it is possible to perform clear printing.

Further, since the housing cylindrical portion 2 is manufactured by the vacuum forming method, the thickness of the tapered shoulder portion 4 can be reduced, and the tapered shoulder portion 4 can be made extremely flexible. When the contents become less, the tapered shoulder 4 can be crushed and the contents can be poured out,
The remaining amount of unusable contents that cannot be poured out can be reduced.

[0025]

As described above, according to the present invention,
An excellent effect that a tube container having no parting line on the surface of the housing cylinder can be manufactured is exhibited. As described above, the surface of the housing cylinder having no parting line can be printed neatly, so that a tube container having high commercial value can be manufactured.

Further, according to the present invention, there is an effect that a tube container having a thin shoulder portion of the housing cylinder can be manufactured. When the thickness of the shoulder portion of the housing cylinder can be reduced in this manner, the remaining amount in the housing cylinder that cannot be poured out of the contents in the tube container can be reduced, so that the contents can be consumed without waste. The excellent effect that the tube container which can be manufactured can be manufactured is produced.

[Brief description of the drawings]

FIG. 1 is a view for explaining a manufacturing process of a housing cylinder in a manufacturing method of the present invention, and is a schematic configuration diagram showing a state before a plug is lowered.

FIG. 2 is a view for explaining a manufacturing process of a housing cylinder part in the manufacturing method of the present invention, and is a schematic configuration diagram showing a state after a plug is lowered.

FIG. 3A is a cross-sectional view of a bottomed cylinder manufactured by the method of the present invention, and FIG. 3B is a cross-sectional view of a storage cylinder obtained by cutting the bottomed cylinder. .

FIGS. 4A to 4C are schematic structural views each showing a process of providing a mouthpiece portion in a housing cylinder in the manufacturing method of the present invention.

FIG. 5 is a cross-sectional view of a tube container manufactured by the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube container 2 Housing cylinder 5a Discharge side connection port 6 Mouth cylinder part 10 Female type 11 Cavity 11a Bottom part 11b Opening part 15 Plug 20 Laminated sheet (resin sheet) 21 Bottomed cylinder 21a Bottom part 31 Upper mold (first) Mold) 32 Lower mold (second mold) 40 Resin plate

──────────────────────────────────────────────────の Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 51/08 B29C 69/02 B29D 23/20

Claims (3)

(57) [Claims] 1. A female having a cavity having substantially the same shape as a housing cylinder portion comprising a straight body portion, a shoulder portion, and a small cylinder portion of a tube container to be manufactured, and having a bottom portion on a side corresponding to a mouth tube portion side of the tube container. A mold is prepared, a resin sheet in a softened state is arranged at the cavity opening of the female mold, the resin sheet is pressed against the inner surface of the cavity of the female mold, and this is cooled and solidified to form the tube container to be manufactured. After forming a bottomed cylindrical body in which substantially the entirety of the housing cylindrical portion is integrally molded and releasing the bottomed cylindrical body from the female mold, the bottomed cylindrical body corresponds to the mouth cylinder side of the tube container to be manufactured. A method for producing a tube container, characterized in that a bottom portion to be cut is cut to open a spout side connection port, and a mouthpiece is formed and fixed to the connection port. 2. A first mold disposed inside the bottomed cylinder and a second metal disposed outside the connection port of the bottomed cylinder, wherein the connection port of the bottomed cylinder is closed by welding a resin. The method for manufacturing a tube container according to claim 1, wherein the resin that closes the connection port is compression-molded into a mouthpiece with a mold. 3. The method according to claim 1, wherein the resin sheet is a laminated sheet.