JPH0243622B2 - - 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, a rectangular body member having ruled lines is wound into a cylindrical shape on a mandrel having a polygonal cross section with each side constituting the polygon slightly curved inward, and the overlapping parts are glued together. After fixing a gap-closing member to the open end of the mandrel, vacuum is applied using a suction hole provided in the mandrel, thereby recessing the body member to match the cross-sectional shape of the mandrel and forming a polygonal shape. It is suitable as a method for manufacturing paper containers for high-temperature filling.

Conventionally, in paper containers for high-temperature filling such as J-use, the body has a regular shape to prevent the container from denting or irregularly deforming due to negative pressure phenomenon caused by cooling of the filling after filling and sealing. The idea of providing ruled lines is known. However, even in the case of containers with ruled lines on the body, they do not necessarily deform into a regular shape (concave) 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 section provided with the above-mentioned 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 and the body is concave. 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 Fig. 1, a body member is made of a laminated material made of a combination of at least two of paper, synthetic resin, and metal foil, and has a rectangular shape with vertical ruled lines l, l... at regular intervals. 1 to Figures 2 to 4.
As shown in the figure, each side of an arbitrary polygonal shape is concave inward to form a curved surface 3, and the boundary between adjacent curved surfaces 3 and 3 is a protrusion 4, so that it has a cross-sectional shape similar to a starfish. , and a mandrel M having an appropriate number of small holes 6 communicating with a suction hole 5 provided in the axial direction in the center on the surface of each curved surface 3, and a presser foot 8 provided at the upper end with a packing material 7 interposed therebetween. The mandrel M is rotated and wound by clamping its end with a clamp (not shown) provided in the upper protrusion 4,
Next, the overlapping parts are glued together using ultrasonic sealing or the like to form a cylinder, and a closing member 2 is attached to one open end of the cylinder.
After that, a vacuum 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 performs vacuum suction through the small hole 6 to remove the body member 1 from the mandrel. Concave along the curved surface 3 of M. As a result, the body member 1 has a ridge line 10 at the point where it hits the protrusion 4 of the mandrel M.
As shown by diagonal lines in FIG. 3, a polygonal columnar (hexagonal in this embodiment) body 11 matching the cross-sectional shape of the mandrel M is formed.

The polygonal columnar body 11 thus completed
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) 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 jig is moved by vacuum suction. Since the force is applied to the entire body member at the same time, it is possible to take a long time to shape the shape, and it is possible to form the shape into an accurate polygonal shape.

[Brief explanation of the drawing]

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 opening ends of a rectangular cylindrical body, a body member with ruled lines at regular intervals is shaped by recessing each side of an arbitrary polygon inward. It has a cross-sectional shape of a curved surface, and a small hole communicating with the central suction hole is formed on the surface formed by each of the sides and protrudes to a width that is approximately the same as the width of the ruled line provided on the curved surface and the protrusion. The body is wound into a cylindrical shape on a mandrel on which the tip of the body has been formed, the overlapping parts are glued together, and a closing member is fixed to one open end.The body is then vacuum-suctioned through the small hole using the suction hole of the mandrel to attach the body to the mandrel. The rectangular tube is recessed to match the cross-sectional shape of the tube, and then compressed air is sent from the small hole through the suction hole to separate the body from the mandrel, and a closing member is provided at the other open end. A method for manufacturing a shaped container.