JP2001233318A - Pulp mold container, and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulp mold container excellent in strength at a mouth edge portion of the container as a flange cut portion in a pulp mold, and excellent in appearance and touch. SOLUTION: In this pulp mold container and a cureing method including at least two pressing steps, a section of the mouth edge portion of the container has a substantially circular curled portion using a cut flange portion of the container obtained via a paper-making step and a drying step. The curling is implemented by laminating a synthetic resin film on at least one surface of the container surfaces obtained by this curling method. A plug adapted to an inner shape of the container may be used in the curling step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulp mold container formed by using a pulp material such as waste paper pulp or virgin pulp, and a method for producing the same.

[0002]

2. Description of the Related Art Styrofoam materials, pulp mold materials, and the like are used as cushioning materials for packaging home appliances, precision instruments, foods, and the like. Among them, the pulp mold material is mainly used for the packaging of small electric appliances and the packaging of foods such as eggs, and in recent years, has attracted attention as a substitute for styrofoam due to its effect on the environment. In addition, attention has been paid to buffering properties and heat insulating properties, which are characteristics of pulp molds, and application to fields where paper containers such as so-called paper cups have conventionally been used has been desired.

[0003]

The pulp mold container is prepared by dispersing waste paper pulp, virgin pulp, or the like as a raw material in water to form a pulp slurry, and then dewatering by vacuum suction to form a pulp component using a drawing mold. After the pulp is removed, the pulp component is suction-dehydrated and then formed into a predetermined shape. After the forming process, the pulp component is manufactured through a drying process of drying by heat. Because of the necessity of (1), the container has a flat flange portion continuously at the edge of the container. Therefore, when such a flange portion is not necessary, such as a paper cup shape,
After molding, it was necessary to cut the flange from the edge of the container to obtain the final product.However, if the cut surface of the mold was exposed at the edge of the container, not only the appearance was poor, but also the edge The strength of the part becomes weak. In addition, when such a mold container is directly used as tableware, the feel when the mouth edge of the mold container contacts the lips during eating and drinking is not preferred. When the contents are filled in a mold container having the flange, and the container is sealed with a lid made of a single-layer film or a film laminate material on the flange portion, the lid is peeled off and opened. In this case, since the adhesive strength exceeds the interlayer strength of the pulp mold, peeling may occur at the flange portion of the mold.

[0004]

Means for Solving the Problems The present inventor has studied the following curl processing on the edge of the mold container in order to solve the above-mentioned problems. That is, the present invention is a pulp mold container, which has a curl portion having a substantially circular cross section at an edge of the container.

[0005] The present invention is also a mold container according to claim 1, wherein a synthetic resin layer is provided on at least one surface of the surface of the pulp mold container.

Further, the present invention provides an upper mold having a convex portion inscribed in a pulp mold container opening edge, a curl groove capable of curling the upper end of the lip portion outward, and a lower portion having a shape corresponding to the outer shape of the pulp molding container. A method for manufacturing a pulp mold container, characterized in that a container lip of a pulp mold container is subjected to press processing a plurality of times by a mold, and the cross section of the container lip is curled into a substantially circular shape.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described more specifically. The pulp mold container has a flat portion having a width of about 10 mm, which is called a flange portion, on the outer periphery of the container edge regardless of the shape of the container due to the necessity in the papermaking process. If this flange part is finally unnecessary, after the pulp mold is formed, this part is further cut and trimmed by a punching machine or the like.

In the present invention, a pulp mold container having a thickness of about 1 mm is obtained through a papermaking and molding step and a drying step which are usually used, and the flange portion is formed to have a thickness of about 1 to 3 m.
After the trimming is performed with about m remaining, the edge of the container is curled by the method described below. First, a pulp mold container is inserted into a lower mold having a shape corresponding to the outer shape of the container, and a convex portion inscribed in the lip of the pulp mold container and an upper mold having a curl groove capable of curling the upper end of the lip outward. Then, the pulp mold container is pressed up and down. By this pressing, the edge of the container slightly curls outward along the curl groove of the upper mold, and a state called precurl is obtained. continue,
The pulp mold is pressed in a similar manner by means of an upper mold, which is different from the above-mentioned upper mold and has a deeper curled groove. As a result, outward curling of the container edge further proceeds. By repeating the above steps at least twice,
The curl of the rim of the container is gradually advanced, and finally a pulp mold container having a curl portion in which the cross section of the rim of the mold container is substantially circular can be obtained.

The reason why the pressing process is performed twice or more is as follows.
Pulp mold containers have lower rigidity than paper cups made of paperboard, so if a high pressure is applied to perform curling by a single press, the containers may be crushed. This is because it is necessary to cause the curl to progress. In addition, pulp mold differs from paperboard in that the material is low-density and thick, so that problems arise with the rotary curling method. Furthermore, in the present invention, a plug having a shape corresponding to the internal shape is inserted into the inside of the pulp mold container at the time of pressing for curling treatment, thereby supporting the container from the inside at the time of pressurization, resulting in insufficient pulp mold container rigidity. It is also possible to supplement. If necessary, it is desirable to spray a small amount of paraffin oil on the mold in order to improve the slip between the mold and the pulp mold container during pressing.

[0010]

<Example 1> A bleached chemical pulp similar to that used as a raw material for ordinary cup base paper is used as a raw material, and is manufactured through a normal papermaking and molding process and a drying process. It was cut to 1 mm or less to obtain a pulp mold container having a tapered cup shape having a container diameter of 80 mm, a height of 60 mm, and a thickness of about 1 mm. Next, the pulp mold container M was inserted into the lower mold a set in the air press, and the upper mold b-1 fixed to the upper part of the air press was lowered and pressed to perform curl processing. (FIG. 1-1) A small amount of paraffin oil is sprayed on the upper mold in order to make the lip of the pulp mold container slippery at the time of pressing. Next, the upper die of the air press was replaced with b-2, and the same press was performed to further curl the edge of the container (FIG. 1-2). Next, the upper die of the air press was replaced with b-3, the press was performed in the same manner, and the edge of the container was further curled (FIG. 1-3). Through the above steps, the cross section of the edge portion of the mold container was curled into a substantially circular shape.

<Example 2> The mold container obtained in Example 1 was further laminated with a polypropylene resin on the inner surface of the container. Next, the pulp mold container was inserted into the lower mold a set in the air press, and the upper mold b-1 fixed to the upper part of the air press was lowered and pressed to perform curl processing. (Fig. 1-1) Next, the upper die of the air press was replaced with b-2, and the elongation characteristics at the time of curling between the polypropylene resin on the surface and the mold were different. After the heat treatment for 0.5 second, the same press was performed to further curl the edge of the container (FIG. 1-2). Next, the upper die of the air press was replaced with b-3, the press was performed in the same manner, and the edge of the container was further curled (FIG. 1-3).
Through the above steps, the cross section of the edge portion of the mold container was curled into a substantially circular shape.

<Embodiment 3> Except for inserting a plug c having a shape corresponding to the inner shape of the inside of the mold container at the time of pressing and then performing the press working, the edge of the mold container is exactly the same as the embodiment 1. (See FIG. 2-1).
~ 3). The cross section of the edge of the mold container was curled into a substantially circular shape.

[0013]

According to the present invention, it is possible to obtain a pulp mold container excellent in the strength, appearance and touch feeling of the edge by subjecting the edge of the container to curl processing.

[Brief description of the drawings]

FIG. 1 is a curl processing step of Examples 1 and 2.

FIG. 2 is a curl processing step according to a third embodiment.

[Explanation of symbols]

 a: Lower mold b-1, b-2, b-3: Upper mold c: Plug M: Mold container

Claims (3)

[Claims] 1. A pulp mold container comprising a curl portion having a substantially circular cross section at the edge of the container. 2. The mold container according to claim 1, further comprising a synthetic resin layer on at least one surface of the surface of the pulp mold container. 3. An upper mold having a convex portion inscribing the lip of the pulp mold container, a curl groove capable of curling the upper end of the lip in an outward direction, and a lower mold having a shape corresponding to the outer shape of the pulp mold container. A method for producing a pulp mold container, comprising press-treating the container rim of the pulp mold container a plurality of times to curl the cross-section of the container rim substantially circularly.