JP2001301064A - Method for producing contraction container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contraction container which is free from wrinkles by stable draw forming and has good dimensional precision and excellent appearance. SOLUTION: Especially in parts corresponding to the corners of the container 30 of a sheet 23 made of base paper, ruled line processing 24 is applied radially to an area outside the peripheral fringe of the sheet 23, and contraction processing is done with a part reaching an intermediate area in the lengthwise direction of the ruled line of the ruled line processing 24 pressed by a press plate 13.

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 drawn container, and more particularly to a method for forming a drawn container by drawing a sheet mainly composed of paper.

[0002]

2. Description of the Related Art A synthetic resin molded container is used as a tray-shaped container for storing various foods and the like for distribution. The molded container is formed into a shape that is aligned with the concave portion of the mold by vacuum forming or pressure forming a sheet-shaped resin material. Such a synthetic resin tray-shaped container is excellent in productivity and advantageous in cost, but causes a problem in treatment after use. In particular, incineration may generate harmful gases or damage the furnace.

In view of such problems, a drawing container is used which is formed by drawing a sheet mainly composed of paper into a tray shape, for example. This type of squeezing container obtains a molded product by sandwiching a sheet-like material between a pair of dies.

[0004]

When a base paper is sandwiched between a mold having a concave portion and a mold having a convex portion, and the drawing is performed, the base paper has a locally expanded portion and a compressed portion. Is generated. Then, when the paper is locally stretched beyond the breaking elongation of the base paper, the base paper is broken at the site and breakage occurs. Also, when compressed during drawing, a large number of wrinkles are formed inside the tray-like container, which deteriorates the appearance and results in a case lacking in cosmetics. In some cases, the commercial value of the tray may be lost.

Therefore, as shown in FIG. 10, a sheet-like base paper 1 is previously subjected to a ruled line, that is, a streak-like bending process 2. When such a sheet 1 is formed by drawing, it has a shape as shown in FIGS. Here, by trimming the portion corresponding to the outer peripheral edge of the container 4 at the cutting line 3, the container 4 having the concave portion 5 as shown in FIG. 13 can be obtained. When the base paper 1 is subjected to the ruled line processing 2 in this manner, the formability particularly at the corners of the container 4 is improved.

However, even in such a conventional drawing container, when wrinkles due to the ruled line processing 2 are drawn down along a gap between a pair of dies during drawing, strong friction occurs when the thickness of the wrinkles is large. The accompanying resistance acts, and the mutual resistance between the base paper 1 and the mold is prevented by such resistance, whereby the sheet 1 may be damaged.

[0007] Such a conventional squeeze container is shown in FIG.
As shown in FIG. 13, the upper surface of the completed container 4, especially at the corners thereof,
The ruled line 2 remains in the region reaching the peripheral portion of the tray, and the appearance of the tray-shaped container 4 is impaired by such a ruled line 2, resulting in lack of cosmetics.

The present invention has been made in view of the above problems, and provides a method of manufacturing a drawn container which is easy to form and does not leave wrinkles or ruled lines in the formed container. The purpose is to:

[0009]

According to one aspect of the present invention, there is provided a method for forming a drawn container by drawing a sheet mainly composed of paper, wherein the sheet is formed in a region outside an outer peripheral edge of the drawn container. The present invention relates to a method for producing a drawn container, which comprises drawing in a state where a radially creased line is formed.

[0010] A ruled line may be formed at a position corresponding to the corner portion of the drawn container formed here. The sheet may be formed by drawing while the outer peripheral portion of the sheet is pressed by a pressing plate. Further, a region on the outer peripheral side of the intermediate portion of the ruled line processing region may be pressed by a pressing plate. Further, the sheet may be paperboard in which a resin film or aluminum foil is laminated on at least one surface of paper. The drawing may be performed in a state where the sheet contains 8 to 25% by weight of water. The drawing may be performed while heating at a temperature within the range of 50 to 150 ° C.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIGS. 1 to 4 show an apparatus used for drawing of a drawn container according to an embodiment of the present invention. This apparatus is, as shown in FIG. It is composed of a mold 12 on the side and a pressing plate 13, and by drawing these in an overlapping manner, a drawn container can be obtained.

As shown in FIG. 1, a projection 17 is formed on the lower surface of the upper mold 11 at a substantially central portion thereof. As shown in FIG. 2, the lower mold 12 is provided with a concave portion 18 substantially at the center thereof, which substantially matches the shape of the container. On the other hand, as shown in FIG. 3, the holding plate 13 is formed of a frame having a relatively narrow width, and an opening 19 is formed at the center.

Next, a state in which a drawn container is formed by using the upper and lower dies 11, 12 and the holding plate 13 will be described. The base paper 23 used here may be a general base paper made of natural pulp or non-wood pulp. Alternatively, a base paper containing a fibrous resin may be used. Further, a sheet 23 made of a base paper in which a resin film is bonded to one or both surfaces of a base paper containing such natural pulp, non-wood pulp, or fibrous resin, or an aluminum foil is bonded may be used.

As shown in FIG. 5, the base paper 23 has a streak-like bent line at a position corresponding to a corner portion of the container 30 outside a region corresponding to the outer peripheral edge 35 of the container 30. The ruled line processing 24 consisting of the ruled line constituted by is performed. The edge of the inner side of the ruled line 24 of the ruled line processing 24 is made to substantially coincide with the outer peripheral edge of the container 30. Further, such ruled line processing 24 is performed by the pressing plate 13.
Is formed so that a portion corresponding to the inner peripheral edge 20 of the opening 19 intersects the middle position of the ruled line (see FIG. 6).

The sheet-like base paper 23 which has been subjected to the ruled line processing 24 in this manner has a water content within the range of 8 to 25% by weight.
More preferably, the moisture is adjusted to a moisture content within the range of 13 to 20% by weight, optimally around 15% by weight.

The sheet 23 conditioned to an appropriate moisture content in this manner is placed on the upper surface of the lower mold 12 shown in FIG.
Then, the periphery of the sheet 23 is pressed by the pressing plate 13.
The position of the inner peripheral edge of the opening 19 of the holding plate 13 at this time is shown in FIG.
As shown by the chain line 20, the ruled line processing 24 intersects the middle position in the length direction of the ruled line.

The upper and lower dies 11 and 12 are used to hold the sheet 23 in the range of 50 to 150 ° C., more preferably 60 ° C.
Heat to within -100 ° C. In such a state, the projection 17 of the upper mold 11 is replaced with the recess 1 of the lower mold 12.
Press molding is performed so as to conform to 8. As a result, the sheet 23 is drawn as shown in FIGS. By trimming the sheet 23 at a cutting line 35 corresponding to the outer peripheral edge of the sheet 23, the squeezing container 3 as shown in FIGS.
0 is obtained.

Such a drawn container 30 does not have any ruled line formed by the ruled line processing 24. That is, the ruled line processing 24
Is formed in a region outside the cutting line 35 that forms the outer peripheral edge of the container 30. Therefore, if the sheet 23 is punched at the cutting line 35, the ruled line 24 does not remain on the container 30 side. Therefore, since there is no unevenness due to the ruled line 24 in the narrow gap between the protrusion 17 of the upper mold 11 and the concave portion 18 of the lower mold 12, the base paper of the corner portion of the container 30 at the time of drawing processing is used. Can be moved, and the slippage between the sheet 23 and the molds 11 and 12 is not hindered by the abnormal frictional force, so that the paper is not damaged.

As described above, according to the drawing method of the container 30 of the present embodiment, the sheet 2 is formed on the outer peripheral side of the container 30 at a portion corresponding to the corner before drawing.
3 is subjected to the ruled line processing 24, and the ruled line processing 2
4 is pressed by the pressing plate 13 on the outer peripheral side of the sheet 23. Here, the portion pressed by the pressing plate 13 is set at a position where the inner peripheral edge 20 of the opening 19 intersects the intermediate position in the length direction of the ruled line 24. Then, drawing is performed by the upper and lower dies 11 and 12 in such a state to obtain the squeezed container 30 along the concave portion 18 of the lower dies 12.

Such a squeezed container 30 is formed by a ruled line processing 24 formed on a portion on the outer peripheral side of the sheet 23 and corresponding to a corner of the container 30.
No wrinkles occur. Therefore, a container having an excellent appearance and aesthetic appearance can be obtained. Also, the ruled line processing 24 is
Is provided outside the outer peripheral edge 35 of the container 3.
In forming the "0", the sheet 23 is not damaged particularly at the corner thereof, and the sheet 23 is stretched uniformly, thereby stabilizing the forming. Therefore, from this, the squeezing container 30 which is excellent in dimensional accuracy, has a good appearance, and has aesthetics is provided.

As shown in FIG. 9, a flange 31 is formed on the outer peripheral side of the container 30, and a step 32 is formed on the inner peripheral side of the flange 31. It has become. It should be noted that such a squeezed container does not necessarily have to have such a flange 31 or a step 32, and can be widely applied to squeezed containers of various shapes.

[0022]

As described above, the main invention of the present application is a method for forming a drawn container by drawing a sheet mainly composed of paper, wherein the sheet is radially formed in a region outside the outer peripheral edge of the drawn container. Is drawn and formed in a state where a ruled line processing is performed.

Therefore, according to such a method of manufacturing a drawn container, since the sheet is radially creased particularly in a region outside the outer peripheral edge of the drawn container, the corner portion is formed by such a crease processing. Is performed stably. Moreover, since the crease processing is not formed in the area inside the outer peripheral edge of the container, the product does not wrinkle and does not break. Therefore, this
A drawn container having stable molding, excellent dimensional accuracy, and aesthetic appearance can be obtained.

In particular, the outer peripheral portion of the sheet is pressed by the presser plate, and at this time, the area outside the middle portion of the ruled line processing area is pressed by the presser plate so that the drawing process is performed. The ruled line processing area in the area inside the set area and outside the outer peripheral edge of the container is more easily extended,
This stabilizes the molding and prevents the product from wrinkling and tearing.

[Brief description of the drawings]

FIG. 1 is a bottom view of an upper mold.

FIG. 2 is a plan view of a lower mold.

FIG. 3 is a plan view of a holding plate.

FIG. 4 is a longitudinal sectional view showing a state where the upper and lower dies and the presser plate are combined to perform drawing.

FIG. 5 is a plan view of a sheet to be subjected to drawing.

FIG. 6 is a plan view of a drawn sheet.

FIG. 7 is an external perspective view of a drawn sheet.

FIG. 8 is an external perspective view of a formed drawn container.

FIG. 9 is a front view in which a part of the drawing container is broken.

FIG. 10 is a plan view of a sheet for performing conventional drawing.

FIG. 11 is a plan view showing a state where the sheet is drawn.

FIG. 12 is an external perspective view of the drawn sheet.

FIG. 13 is an external perspective view of a conventional container obtained by drawing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet (base paper) 2 Ruled line processing 3 Cutting line (outer periphery) 4 Container 5 Concave part 11 Die (upper side) 12 Die (lower side) 13 Pressing plate 17 Protrusion 18 Depression 19 Opening 20 Inner perimeter 23 Sheet (base paper) 24 Ruled line 30 Container 31 Flange 32 Stepped portion 33 Recess 35 Outer edge (cut line)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E033 AA10 BA09 BA10 BA13 BB01 BB08 DD01 EA20 FA01 FA10 3E075 AA10 BA30 CA01 DB03 DB22 DC28 GA02 GA03

Claims (7)

[Claims] 1. A method for forming a drawing container by drawing a sheet mainly composed of paper, wherein the drawing is radially ruled on the sheet in a region outside an outer peripheral edge of the drawing container. A method for producing a drawn container, characterized by forming. 2. The method according to claim 1, wherein a ruled line is formed at a position corresponding to a corner portion of the drawn container to be formed. 3. The method according to claim 1, wherein the outer peripheral portion of the sheet is drawn while being pressed by a pressing plate. 4. The method according to claim 3, wherein an area on the outer peripheral side of an intermediate portion of the ruled line processing area is pressed by a pressing plate. 5. The method according to claim 1, wherein the sheet is a paperboard having a resin film or an aluminum foil laminated on at least one surface of the paper. 6. The method for producing a drawn container according to claim 1, wherein the drawing is performed in a state where the sheet contains 8 to 25% by weight of water. 7. The drawing process is performed while heating at a temperature in the range of 50 to 150 ° C.
3. The method for producing a squeezed container according to 1.