JP2003326619A - Paper-made molding and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper-made molding which can be molded without the occurrence of breakage of high elongation paper since the paper stretches locally as the shape of the molding approaches the shape of a mold in a molding process, because the elongation of the paper during molding converges on a region not contacting the mold, and to provide a method for manufacturing the paper- made molding. <P>SOLUTION: In manufacturing the paper molding, the high elongation paper is used, and the inside of a collar is deformed plastically without applying ruled line processing. In the method for manufacturing the paper molding, the molding is manufactured by multistage molding with the use of at least two molds different in shape. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional structure using high elongation paper, that is, a tray, a blister pack for store display, a container such as a squeezing container, and a paper product used for a purpose other than a container for storing articles. The present invention relates to a molded body and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a paper molded product is a plate-shaped product made by pressing a waterproof paperboard with a pair of concavo-convex molds, and a waterproof paperboard made by ruled lines is formed by the same method. However, the depth and the overlapping portion of the paper have problems such as poor sealing performance, and thus it cannot be used for the purpose of circulating liquid.

[0003]

Recently, as a countermeasure against this problem,
There is a container formed by attaching a thermoplastic resin layer or the like to a high elongation paper as described in Japanese Patent Publication No. 11-509276, water-resistant, and then molded without applying a ruled line.

However, high elongation paper is formed by press forming using a pair of concave and convex molds and pressure forming using a concave mold. With this method, a molded product can be obtained in one step, but it is temporarily contacted with the mold. There is almost no elongation of the formed part, and the elongation from that part concentrates on the part where the paper elongation during molding does not contact the mold.

As a result, during the molding process, the shape of the molded product locally expands as it approaches the shape of the mold, resulting in unreasonable elongation, and a molded product that can be molded without tearing the high elongation paper. The shape could not fully utilize the elongation of high elongation paper.

For example, referring to the drawings shown in FIGS. 4 and 5, an example of pressure molding will be described. FIG. 4 is a sectional view during molding.

The high-performance paper 4 is being stretched in conformity with the mold 2 in the molding section, and also in the stretching section, a portion 5 in contact with the mold and a portion 6 not yet in contact with the mold. The portion 5 that is in contact with the mold is not further deformed, whereas the portion 6 that is not in contact with the mold is still in contact with the mold 2. Continues to grow until

If this is shown by the transition of the lower surface of the high-performance paper 1 in FIG. 5, the initial lower surface 21 is gradually increased by increasing the contact portion with the mold, that is, the portion which is not further deformed, while the lower surfaces 22 and 23. , 24, 25 are molded. On the lower surface 26 before the completion of molding, there is almost no further elongation except the bottom corner portion 4, and the molding proceeds only at this small portion.

An object of the present invention is to solve the above problems and to provide a three-dimensional molded article that maximizes the elongation of the high elongation paper.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, that is, the invention according to claim 1 is a molded paper product formed by three-dimensionally molding a high elongation paper. In the above, the paper molded article is characterized in that the three-dimensional molded section is molded reasonably.

According to a second aspect of the present invention, in a method for producing a paper molded body formed by three-dimensionally molding a high elongation paper, multi-stage molding is performed by using at least two molds having different shapes. It is a method for manufacturing a molded body.

According to the third aspect of the invention, among the molds used for multistage molding, the mold used for the second and subsequent moldings has a smaller aperture ratio than the shape of the molded product of the mold used for the preceding process. 3. The method for producing a paper molded body according to claim 2, wherein the depth is large or at least one of the depths is large.

According to a fourth aspect of the present invention, in a paper molded body formed by three-dimensionally molding a high elongation paper, multi-stage molding is performed in the same molding machine by using a mold having a variable depth. And a method for producing the same.

According to a fifth aspect of the present invention, in a method for producing a paper molded body formed by three-dimensionally molding a high elongation paper, at least one of press molding, simple pressure molding, and vacuum molding is used. The method for producing a paper molded article according to any one of claims 2 to 4.

According to a sixth aspect of the present invention, in the paper molded article according to the first aspect, the high elongation paper has a structure in which a paper portion and a thermoplastic resin layer are provided on at least one surface of the paper portion. It is a paper molded article characterized by being.

The invention according to claim 7 is the invention according to claims 2 to 5.
In the method for producing a paper molded product according to any one of claims 1 to 3, the high elongation paper is a laminated product having a configuration in which a thermoplastic resin layer is provided on a paper portion and at least one surface thereof. It is a manufacturing method of a form.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments will be described below as examples of the present invention, but the present invention is not limited thereto.

The paper molded product of the present invention relates to a paper molded product obtained by three-dimensionally molding a high elongation paper using a high elongation paper.

Particularly, trays, blister packs, containers such as squeezing containers, cushioning materials, and other molded articles having a collar portion that is not substantially involved in molding are suitable for fixing high-stretch paper.

Therefore, all may be three-dimensionally molded parts, but those having a collar part are preferred.

When articles are to be stored, a mount or a thermoplastic resin film is adhered to the content storage side of the collar portion of the paper molded body, if necessary, and the above-mentioned molded body, mount or thermoplastic resin is used. If necessary, the resin film may be provided with a window so that the stored product can be viewed by the naked eye.

Various types of paper can be used for the paper molded product of the present invention depending on the application, but high elongation paper, that is, those having a tensile elongation at break of 10% or more is preferable.

In particular, it is preferable to use a high elongation paper having a basis weight of 100 g / m ² or more as the high elongation paper body.

The high elongation paper body used is generally one in which the paper is contracted in the lengthwise direction and the widthwise direction in the papermaking process and the post-process. For example, the method described in Japanese Patent Publication No. 11-509276 can be used. It is possible to use the one manufactured by the method of.

The high elongation paper may be only the high elongation paper body,
Due to the water resistance of the molded product and the protection of the stored items, the layer structure is from the outside, thermoplastic resin layer / high elongation paper body, high elongation paper body / thermoplastic resin layer, thermoplastic resin layer / high elongation paper body / It is also possible to use a high elongation paper having a thermoplastic resin layer.

Examples of the material of the thermoplastic resin layer include polypropylene, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, ethylene vinyl acetate copolymer, propylene homopolymer,
Binary or ternary copolymers of propylene and other olefins, polyolefins such as modified products thereof, polyester resins typified by polyethylene terephthalate resins, and polyamide resins can be used alone or in a laminate. .

If necessary, an ethylene vinyl alcohol resin layer may be arranged in the intermediate layer of the thermoplastic resin layer on the content storage side to suppress gas permeation. When biodegradable, polyhydroxybutyrate, microbial synthetic aliphatic polyester typified by polyhydroxybutyrate / valylate, polybutylene succinate,
Polybutylene succinate / adipate, polyethylene succinate, polyesteramide, polybutylene succinate / carbonate, polylactic acid, chemically synthesized aliphatic polyester typified by polycaprolactane, polybutylene adipate / terephthalate, modified polyethylene terephthalate, etc. A chemically-synthesized aliphatic aromatic polyester typified by the above can be used alone or as a laminate to form a resin layer.

Printing can be applied to the paper molded body,
The surface of the high elongation paper before three-dimensional molding, the front and back surfaces of the thermoplastic resin layer bonded to the high elongation paper, the surface of the mount, the well-known printing method on the front and back surfaces of the thermoplastic resin layer bonded to the mount, that is, It can be done with gravure, offset, flexo, silkscreen, pads and more. Further, it is also possible to perform printing by a known method after three-dimensionally molding the high elongation paper.

The method for molding the paper molded article is the well-known pressure molding method, the vacuum molding method, the press molding method using a pair of concave and convex dies used for thermoplastic resin sheets, the molding method, and the combination of the above. It is also possible to perform molding while heating, if necessary, such as when a thermoplastic resin layer is attached to high elongation paper.

The pressure molding is a molding method in which pressurized air is applied to the high elongation paper from the side opposite to the mold to mold it into the cavity shape of the mold. Press molding is a concave or convex molding material. The vacuum forming is a forming method in which the inside of the mold cavity is vacuumed and the high elongation paper is formed into the mold cavity shape.

However, the behavior of the paper during molding is shown in FIG.
As shown in (3), the high elongation paper 1 is almost completely stretched at the portion in contact with the mold, and the periphery thereof is sequentially stretched.

Therefore, even if the expansion of the molded product is set in accordance with the maximum elongation of the high elongation paper except for the hemisphere in one molding step, no matter how high the elongation paper is, its corners, that is, In a container, for example, a break occurs in the vicinity of the bottom corner portion 2, and only a shape that can be actually formed can be manufactured that is significantly smaller than the value calculated from the elongation rate of the high elongation paper.

Even if the state of breakage does not occur, cracks and cracks are likely to occur because the vicinity of the bottom corner portion 2 is weakened or becomes extremely thin due to unreasonable elongation.

On the other hand, in the paper molded product of the present invention, not only the collar portion 11 but also the molded portion 12 is unreasonably stretched due to local elongation at any portion, for example, the bottom corner portion. It became a molded part due to no elongation.

As described above, the molding in which the three-dimensional molding portion is reasonably formed means elimination of local elongation due to one molding, and the local molding generated in each molding step when the molding is divided into a plurality of moldings. Elongation does not enter into excessive molding.

For example, even in the case of two-stage molding, the position of the bottom corner is different, or the expansion to other parts can be sufficiently escaped, so that the expansion is not applied to that position. Various means can be used as long as they are molded by the method.

As a result, the first-stage molding is carried out to a shape capable of forming the high-strength paper shown in FIG. 3 without tearing, and the intermediate compact 32 is obtained. A paper-molded article having a molding section that has a natural elongation in which the elongation rate of the high-strength paper is maximized is obtained by adding elongation to a small portion, that is, the side wall portion 42 successively.

As a method of imparting elongation to the side wall portion 42, which is a portion having a small elongation, of the intermediate formed body 32 shown in FIG. 2 formed by pressure forming, vacuum, press forming with a pair of concave and convex molds, etc. The side wall portion 42 is changed to the side wall portion 44 by following the mold having the opening shape b smaller than the opening portion a by pressure air, vacuum, press molding with a pair of concave and convex molds.

Alternatively, as a method of imparting elongation to the side wall portion 41 of the intermediate compact 31 shown in FIG. 2 which is a portion having little elongation, compressed air or vacuum is applied to a mold having a depth d larger than the depth c of the intermediate compact 31. Then, the side wall portion 41 is changed to the side wall portion 43 by following it by press molding or the like using a pair of concave and convex molds. After the intermediate molded body 31 is obtained, the bottom of the mold may be moved in the depth direction to set the depth to d.

[0040]

EXAMPLES Examples of the present invention will be specifically described below, but the present invention is not limited thereto.

(Example 1) When the silk screen printing is printed on the side opposite to the product storage side, the elongation of the paper in the papermaking direction is 25%,
High-strength paper with a elongation of 15% in the perpendicular direction is used as a base material. High density polyethylene (HDPE) with a density of 0.956 from the storage side is 100 μm / high-strength paper 300 g / m ² (Nippon Paper Industries Co., Ltd. Company: Product name NPI Malt Paper 15
0g / m ² 2 sheets laminated product) / density 0.923 low density polyethylene (LDPE) 20μm / printing laminated body is heated at 130 degrees, and the papermaking direction of the paper is formed by pressure air forming with a pressure of 0.5 MPa. Molded so as to be in the short direction of the body, the opening size is 150 mm × 110 mm, the angle between the side wall and the bottom is 130 ° and R30 mm, and the outside size of the collar is 170 mm.
An intermediate molding having a collar portion having a size of mm × 130 mm and a depth of 25 mm was obtained.

After heating the intermediate molded body again, the opening size becomes 1
A paper mold 3 was obtained by covering a convex mold having a size of 20 mm × 80 mm and a depth of 25 mm with a pressure of 0.5 MPa so as to follow the convex mold from the side opposite to the product storage side.

The obtained molded product has an angle between the side wall and the bottom of 11
R20mm at 5 °, outside dimension of the collar 170mm × 130m
A paper molded body having a flange portion of m and a depth of 25 mm was obtained without ruled line processing.

This paper molded product has a small amount of elongation in a portion which is considered to be in early contact with the concave mold, and an angular portion (bottom corner portion) formed by the side wall and the bottom which is considered to be in slow contact with the concave mold. It can be confirmed by a microscope that the fiber condition is high.

However, it is a molded article within a range in which the three-dimensional molded section as a whole, particularly the corner portion (bottom corner section) formed by the side wall and the bottom is reasonably molded, and the fiber state is No damage such as tearing occurred.

Further, when room temperature water was poured into the inside so as to be filled with water, there was no leakage of water even after left for 120 minutes.

(Example 2) A molded product similar to that of Example 1 was molded from the same high elongation paper by pressure molding under the same conditions so that the papermaking direction of the paper was the short dimension direction of the molded body, and the opening was formed. The dimensions are 120mm x 80mm, and the angle between the side wall and the bottom is 115 °.
R10mm, outside dimension of the collar is 170mm × 130mm,
An intermediate molded body having a collar portion having a depth of 15 mm was obtained.

When the angle between the side wall and the bottom is 115 °, R20m
It was placed in a concave mold having a depth of 25 mm and a depth of 25 mm, and a compressed air of 0.5 MPa was applied from the product storage side to follow the concave mold to obtain a paper molded body.

This paper-made compact has little elongation in the portion which is considered to come into early contact with the concave mold, and the corner portion (bottom corner portion) formed by the side wall and the bottom which seems to come into slow contact with the concave mold. It can be confirmed by a microscope that the fiber condition is high.

However, as a whole, the molded product is a molded product within a range in which it is reasonably molded even in the three-dimensional molded part, particularly in the corner portion (bottom corner part) formed by the side wall and the bottom. No damage such as tearing occurred.

In addition, when room temperature water was poured into the inside so that it would be filled with water, there was no leakage of water even after left for 120 minutes.

(Comparative Example) A molded article similar to that of Example 1 was pressed from the same high elongation paper with the same convex and concave shapes as in Example,
A molded paper product 3 was obtained.

The obtained molded product has an angle between the side wall and the bottom of 11
R20mm at 5 °, outside dimension of the collar 170mm × 130m
It was a paper molded product having a m-shaped portion and a flange portion having a depth of 25 mm, and was the same in dimensions as the paper molded product of the example.

However, it was recognized from the direction of the fibers, etc. that elongation was particularly recognized at the corners (bottom corners) formed by the side walls and the bottom among the three-dimensional molded parts.

Since such an unreasonable molding is performed,
Fiber rupture occurred, and many breakages such as tears occurred at the bottom corners, and particularly at the bottom corners in the direction perpendicular to the papermaking direction, a paper molded product was obtained which was extremely continuous and continuous.

Further, when normal temperature water was injected into the inside, water leaked immediately before the water was full.

[0057]

EFFECTS OF THE INVENTION Since the paper molded article of the present invention is stretched while being dispersed at the time of molding, the elongation of the high-strength paper is dispersed, and the paper molded article such as a container is reasonably stretched. It is a molded product.

According to the present invention, even after the thermoplastic resin layer or the like is attached to the high elongation paper and the waterproof treatment is performed,
It becomes possible to make a molded container without applying crease processing, and it is possible to maintain its performance.

As a result, unlike the conventional paper-molded product which has been forced to stretch, it is possible to perform the molding by making the most of the elongation of the high-stretch paper.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a paper molding according to the present invention.

FIG. 2 is a cross-sectional view showing a manufacturing process of a paper molded body according to the present invention.

FIG. 3 is a cross-sectional view showing a process for manufacturing a paper molded body according to the present invention, which is different from FIG.

FIG. 4 is a cross-sectional view showing a manufacturing process of a conventional paper molded body.

FIG. 5 is a cross-sectional view showing the manufacturing process of the conventional paper molded body of FIG. 4 in a transition of the lower surface of the high elongation paper.

[Explanation of symbols]

1 Paper molded body 2 mold 3 High elongation paper 4 bottom corner 5 Parts in contact with the mold 6 Part not in contact with mold 11 Tsuba 12 Molding section 21-26 Lower surface of high elongation paper 31, 32 Intermediate molded product 41-44 Side wall

Continued front page    F term (reference) 3E033 AA08 BA10 BA13 BB08 CA09                       CA20 DD01 FA01 GA03                 3E075 AA07 BB02 CA01 DA32 DC18                       DC43 FA05 GA03                 4F100 AK01B AK01C BA02 BA03                       BA06 BA07 BA10A BA10B                       BA10C DG10A GB15 JK08

Claims (7)

[Claims] 1. A paper molded product obtained by three-dimensionally molding a high elongation paper, characterized in that a three-dimensional molded portion is molded without difficulty. 2. A method for producing a paper molded article, which is obtained by three-dimensionally molding a high elongation paper, which comprises multi-stage molding using at least two molds having different shapes. 3. Among the molds used for multi-stage molding, whether the mold used for the second and subsequent moldings has a smaller opening ratio or a larger depth than the shape of the molded product of the mold used for the preceding process. And at least one of them, the method for producing a paper molded product according to claim 2. 4. A paper molded body formed by three-dimensionally molding a high elongation paper, characterized in that multi-stage molding is carried out in the same molding machine by using a mold having a variable depth. Production method. 5. The method for producing a paper molded product obtained by three-dimensionally molding a high-stretch paper, wherein at least one of press molding, simple pressure molding and vacuum molding is used. A method for producing a paper molded body according to claim 2. 6. The paper molded article according to claim 1, wherein the high elongation paper is a laminate having a paper part and a thermoplastic resin layer provided on at least one surface thereof. Paper molded body. 7. The method for producing a paper molded article according to claim 2, wherein the high-elongation paper comprises a paper portion and a thermoplastic resin layer provided on at least one surface thereof. And a method for producing a paper molded body.