JPH0215379B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a container including a body having a polygonal (triangular or larger) cross-sectional shape.
In particular, by pasting fan-shaped, rectangular, etc. body members into a cylindrical shape,
After fixing the closing member to one of the upper and lower opening ends, it is fitted into a mandrel that has a polygonal cross section and each side of the polygon is slightly curved inward to utilize the suction hole provided in the mandrel. The method is characterized in that the body member is concave to a polygonal shape according to the cross-sectional shape of the mandrel by vacuum suction, and is suitable as a method for manufacturing paper containers for high-temperature filling such as youth products.

Conventionally, paper containers for high-temperature filling such as J-use have regularly-shaped ruled lines on the body to prevent the container from denting or irregular deformation due to negative pressure phenomenon caused by cooling of the filled material after filling and sealing. The idea of establishing a However, even in the case of containers with ruled lines on the body, they do not necessarily deform (deform) into regular shapes due to negative pressure phenomena, and may deform ungainly regardless of the ruled lines, resulting in poor quality and appearance. A problem arose in that it was damaged.

In order to solve this problem, a method has been considered in which the body with upper ruled lines is indented in advance along the ruled lines before filling. A conceivable method is to fit the body into a mandrel with a polygonal cross-section and press the body from the outside by some mechanical means, but in the present invention, the body is sucked from the inside of the mandrel to create a recess. I thought of a model that would let me do it.

The present invention will be explained in detail based on the embodiments shown in the drawings. First, as shown in Figure 1, it is fan-shaped, rectangular, etc.
The opposite ends of a body member 1 made of a laminated material made of a combination of at least two of paper, synthetic resin, and metal foil are overlapped to form a cylindrical shape, and a closing member 2 is provided at either the upper or lower open end. The body member 1 is fixed by a general method used in molding a co-tip, and the body member 1 is formed into a curved surface by recessing each side of an arbitrary polygon inward as shown in FIGS. 2 to 4. 3,
The boundary between adjacent curved surfaces 3, 3 is a protrusion 4,
It has a starfish-like cross-sectional shape, so to speak, and the surface of each curved surface 3 is provided with an appropriate number of small holes 6 that communicate with the suction hole 5 provided in the axial direction at the center, and a packing material 7 is provided at the upper end. (Depending on the type of molding machine, the direction of insertion is horizontal to the mandrel arranged horizontally, or vertical to the mandrel arranged vertically.) After that, a vacuum suction source (not shown) communicating with the suction hole 5 through the hole 9 provided in the center of the presser foot 8 of the mandrel M applies vacuum through the small hole 6 to remove the body member. 1 is recessed along the curved surface 3 of the mandrel M. As a result, the portion of the body member 1 that hits the protrusion 4 of the mandrel M forms a ridge line 10, and as shown by the inclined line in FIG. ) is formed.

The polygonal columnar body 11 thus obtained
The assembly of the container C is completed by filling the container C with juice or the like at about 90° C. from the other open end which is not closed, and then fixing another closing member 12.

It should be noted that if small holes 6' are provided not only on the curved surface 3 but also on the protrusion 4 of the mandrel M, the ridgeline 10 of the body member 11 can be formed more clearly.

Since the present invention is configured as described above, it has the following excellent practical effects.

(b) Unlike the conventional method of pressing the body member from the outside on a mandrel by mechanical means, the body member is pressed from the inside of the mandrel by vacuum suction without any other jig or the like coming into contact with the body member. Since it is designed to be recessed, the surface of the body member will not be damaged or wrinkled, and it can be accurately formed into a polygonal shape without damaging its appearance.

(b) Since there is no need to provide ruled lines on the body member as in the past, the number of steps can be reduced, and there is no need to align the body member when inserting it into the mandrel. Therefore, the operation is simple and the work efficiency is high.

(c) In the conventional pressing method, creases are created in the body member by moving the jig, so if you focus on one point on the body member, the jig passes only once, whereas in the method of the present invention, the body member is folded by vacuum suction. Since the force is applied to the entire body member at the same time, the shaping time can be increased, and an accurate polygonal shape can be formed.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Figure 1 is a developed plan view of a container body member according to the present invention, Figure 2 is a perspective view of a mandrel used in the present invention, and Figure 3 is a perspective view of a mandrel used in the present invention.
The figures are a cross-sectional view of the mandrel, FIG. 4 is a longitudinal cross-sectional view thereof, and FIG. 5 is a perspective view of a paper container manufactured according to the present invention. 1... Trunk member, 2... Bottom member, 3... Curved surface,
4...Protrusion, 5...Suction hole, 6,6'...Small hole,
7... Packing, 8... Presser foot, 9... Hole, 10
...Ridge, 11...Body, 2, 12...Closing member.

Claims (1)

[Claims] 1. In manufacturing a container in which closing members are provided at the upper and lower open ends of a rectangular cylindrical body, the opposing ends of the body are overlapped and glued together to form a cylindrical shape, and a closing member is attached to one open end. The fixed object has a cross-sectional shape of a curved surface by recessing each side of an arbitrary polygon inward, and a small hole communicating with the central suction hole is provided in the surface formed by each of the sides. Then, the body is recessed to match the cross-sectional shape of the mandrel by vacuum suction through the small hole using the suction hole of the mandrel, and compressed air is then sent from the small hole through the suction hole. A method for manufacturing a rectangular cylindrical container, characterized in that the body is separated from a mandrel and a closing member is provided at the other open end.