JPH0215380B2 - - 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, after pasting fan-shaped, rectangular, etc. body members with ruled lines into a cylindrical shape, and fixing a closing member to one of the upper and lower opening ends, the body members have a polygonal cross section, and each side of the polygon is turned inward. It is characterized by fitting into a slightly curved mandrel and applying vacuum suction using the suction hole provided in the mandrel, thereby recessing the body member to match the cross-sectional shape of the mandrel to form a polygonal shape. This method is suitable for manufacturing paper containers for high-temperature filling.

Conventionally, paper containers for high-temperature filling such as J-use have regularly-shaped ruled lines on the body to prevent dents and irregular deformation of the container due to the negative pressure phenomenon caused by the cooling of the filling 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 (indent) into a regular shape 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 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 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 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. The opposing ends of the body member 1 are overlapped to form a cylindrical shape, and the closing member 2 is fixed to either the upper or lower open end by a common method used in the molding of cots.
As shown in FIGS. 2 to 4, each side of a given polygon is concave inward to form a curved surface 3, and the boundary between adjacent curved surfaces 3 and 3 is a protrusion 4, so to speak. It has a starfish-like cross-sectional shape, and an appropriate number of small holes 6 are provided on the surface of each curved surface 3 that communicate with a suction hole 5 provided in the axial direction at the center, and a packing material 7 is provided at the upper end. Insert it into a mandrel M equipped with a presser foot 8 (depending on the type of molding machine, the direction of insertion is horizontal to a mandrel placed horizontally, or vertical to a mandrel placed vertically). Thereafter, 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 performs vacuum suction through the small hole 6 to remove the body member 1. is recessed along the curved surface 3 of the mandrel M via the broken line l. 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 diagonal lines in FIG. A body portion 11 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 degrees from the other open end which is not closed, and then fixing another closing member 12.

Note that if the mandrel M is provided with small holes 6' not only on the curved surface 3 but also on the protrusion 4, the ridgeline 10 of the body member 1 can be formed more clearly.

Further, the body member 1 may be fan-shaped like a general paper cup.

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, 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 the manufacture of containers in which closing members are provided at the upper and lower open ends of a rectangular cylindrical body, opposing ends of the body member with ruled lines at regular intervals are overlapped and glued together to form a cylindrical shape. , which has a closing member fixed to one open end, has a cross-sectional shape of an arbitrary polygon with each side concave inward to form a curved surface, and the surface formed by each of the sides has a center. The mandrel is inserted into a mandrel with a small hole that leads to the suction hole of A method for producing a rectangular cylindrical container, characterized in that compressed air is sent through the hole to detach the body from the mandrel, and a closing member is provided at the other open end.