JP2007176551A - Pulp molded body and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a pulp molded body capable of clearly forming, on at least one of surfaces, a three-dimensional indication made of a protrusion projecting from a surface. <P>SOLUTION: An intermediate pulp molded body molded from pulp fiber slurry through the use of a paper-making mold made of a mesh having a detachable molding face is released from a mold together with the mesh and dried. Thereafter, the intermediate pulp molded body removed from the mesh is compressed by a female die 21 and a male die 22 serving as a pair of compression molds to have the body thickness reduced, and in addition the three-dimensional indication made of the protrusion 5a is formed on at least one of surfaces. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a pulp mold molded body using pulp fibers as a raw material and a pulp mold molded body.

  Since the pulp mold molded body is made of pulp fiber, it does not generate harmful gas even when incinerated, and is used for environmentally friendly disposable containers and packaging materials. The conventional example of the manufacturing method of a pulp mold molded object is demonstrated.

  Patent Document 1 discloses a method for producing a precisely shaped pulp mold molded body. In this production method, a papermaking mold having a molding surface made of a mesh body is immersed in a pulp fiber slurry, and water is sucked and removed through a suction hole of the papermaking mold. To make a pulp mold intermediate molded body. Next, an after press method is disclosed in which the pulp mold intermediate molded body released from the papermaking mold is heated and pressed from both sides by a pair of press molds.

In addition, in Patent Document 2, a metal plate provided with a punch hole corresponding to a character or the like is attached to a molding surface made of a papermaking mold net, and the papermaking mold is immersed in a pulp fiber slurry to supply water. By removing by suction, the thickness of the pulp fiber at the part corresponding to the punched hole is made thicker than other parts.
Japanese Patent Laid-Open No. 9-296397 JP 2005-133232 A

  All of the above conventional techniques have the following problems.

  The after-press method disclosed in Patent Document 1 can form a three-dimensional display portion composed of fine irregularities such as characters, with the mesh on one side having a mesh to which a papermaking type mesh is transferred remaining. Can not.

  On the other hand, the method disclosed in Patent Document 2 has a limitation on the thickness of the metal plate and the hole area of the punched hole, and the thickness of the display portion composed of fine uneven portions is reduced to produce a strong molded body. I can't. In addition, there is a mesh on the tip surface of the convex portion corresponding to the punched hole portion, and it is difficult to form the display portion clearly.

  The present invention has been made in view of the above-described problems, and produces a pulp mold molded body having a smooth surface and having a clear three-dimensional display portion including a convex portion protruding from the surface on at least one surface. The purpose is to be able to.

  In order to achieve the above object, a method for producing a pulp mold molded body according to the present invention is a method for producing a pulp mold molded body having a three-dimensional display portion consisting of convex portions on at least one surface, and the molding surface is detachable. A paper making step for adsorbing the pulp mold intermediate formed body made of pulp fibers separated from the pulp fiber slurry to the net body using a paper making mold made of a simple net body, and releasing the pulp mold intermediate formed body together with the net body. A drying step of drying and a compression step of removing the dried pulp mold intermediate molded body from the net body and compressing it with a pair of compression molds to reduce the thickness, and comprising the convex portion The three-dimensional display unit is formed by a three-dimensional display unit forming unit including a concave portion provided in at least one of the compression molds in the compression step.

  In the compression step, the thickness of the pulp mold intermediate molded body is reduced to a thickness within a range of 60 to 80%.

  Furthermore, the said convex part may be characterized by the ratio of the height which protrudes from a surface being within the range of 20 to 90% of the average thickness of the said pulp mold molded object.

  Since this invention is comprised as mentioned above, there exists an effect as described below.

  It is possible to produce a precise pulp mold molded body having a smooth surface in which the mesh formed by the mesh body generated in the pulp mold intermediate molded body has disappeared.

  In addition, the three-dimensional display part which consists of a convex part can be clearly formed in the at least one surface of a pulp mold molded object.

  An embodiment of a method for producing a pulp mold product according to the present invention will be described with reference to the drawings.

  1A and 1B show a pulp mold container manufactured by a manufacturing method according to the present invention, in which FIG. 1A is a schematic top view, and FIG. 1B is a schematic cross-sectional view taken along line AA in FIG.

  The pulp mold container 1 is bent upward from the outer peripheral edge of the bottom wall 2, and has a peripheral side wall 3 whose diameter increases as it goes upward, and a flange bent outward from the upper end peripheral edge of the peripheral side wall 3. The outer peripheral edge portion of the collar portion 4 is a clean cut surface without a beard.

  And the intensity | strength of the collar part 4 is increased by forming in the radial direction intermediate part of the collar part 4 the cyclic | annular protrusion part 4a which curves and protrudes in a semicircular arc shape toward upper direction.

  The three-dimensional display unit 5 including the convex portions 5a may be any of numbers, characters, lines such as graphics, and combinations thereof.

  If the ratio of the height which the convex part 5a protrudes from the surface of the bottom wall 2 is within the range of 20 to 90% with respect to the average thickness of the pulp mold container 1, a clear three-dimensional display part is obtained. . If the ratio of the height to the average wall thickness is less than 20%, the three-dimensional display part becomes difficult to see. On the other hand, if it exceeds 90%, the convex portion 5a is easily bent, and the three-dimensional display portion is blurred.

  In the present invention, a non-wood-based or wood-based pulp raw material can be used. Non-wood pulp raw materials include native plants (bamboo, bamboo, esparto, weeds, etc.), fiber crops (kenaf, cotton linter, aqaba, sisal, jute, flax, kozo, mitsumata etc.), agricultural crops Waste (sugar cane, straw, rice straw, palm palm, banana, etc.). In addition, wood-based pulp raw materials are birch (such as oak) and conifer (such as cedar and cypress).

  Next, a method for producing a pulp mold molded body according to the present invention will be described by taking as an example a method for producing a pulp mold container in which the housing recess shown in FIG. 1 is formed from a bottom wall and a peripheral side wall.

  The method for producing a pulp mold molded body according to the present invention supplies a raw material liquid (pulp fiber slurry) in which pulp fibers are mixed and dispersed to a paper making apparatus, and adsorbs the pulp mold intermediate molded body on a molding surface made of a net. (Paper making) paper making process, drying step of releasing the mold molded pulp mold on the net together with the net, and drying, removing the dried pulp mold intermediate molded body from the net and the compression device And compressing the female mold and the male mold to reduce the wall thickness and smooth the surface, and at the same time, form a three-dimensional display portion consisting of convex portions on at least one surface. And if necessary, a deburring process for cutting off unnecessary portions connected to the outer peripheral edge of the collar portion is performed by a deburring device.

  As shown in FIG. 2, the papermaking apparatus used in the papermaking process of the present embodiment has a papermaking mold 11 having a large number of liquid passage holes (not shown) disposed in the papermaking tank 13, and is below the papermaking mold 11. A drainage chamber 14 is formed in the drainage chamber 14, and a drainage port 15 communicates with the drainage chamber 14. The papermaking mold 11 has a papermaking recess 11a having a shape that regulates one surface of the pulp mold intermediate molded body, and a mesh body 12 made of a metal mesh, a plastic net, or the like is detachably disposed on the surface of the papermaking recess 11a. It is installed. For this reason, when a predetermined amount of pulp fiber slurry 16 is supplied above the net body 12 of the papermaking mold 11 and sucked through the discharge port 15, the pulp mold intermediate molded body 10 remains on the net body 12 of the papermaking recess 11a, Only water falls into the drainage chamber 14 through the fluid passage hole and is discharged from the discharge port 15 to the outside.

  As shown in FIGS. 3 and 4, the compression mold used in the compression process includes a female mold 21 having a cavity surface 21 a shaped to regulate the outer surface (one surface) of the pulp mold container 1, and the pulp mold container 1. And a male die 22 having a cavity surface 22a having a shape for regulating the inner surface (the other surface) thereof, and are configured to approach or separate from each other by an actuator such as a fluid pressure cylinder or an electric cylinder (not shown).

  The cavity surface 21a of the female die 21 has a three-dimensional display portion forming portion including a concave portion 21b for forming the three-dimensional display portion 5 described above. Further, the cavity surface 22 a of the male mold 22 has a 3D display portion forming portion including a recess 22 b for forming the 3D display portion 5.

  (1) A predetermined amount of pulp fiber slurry 16 is supplied above the mesh body 12 placed on the papermaking mold 11 of the papermaking tank 13, and then water is sucked from the discharge port 15, whereby the pulp fibers in the pulp fiber slurry 16 are supplied. Is left on the net body 12, and only water is dropped into the drainage chamber 14 and discharged to the outside through the discharge port 15. As a result, the pulp mold intermediate formed body 10 (see FIG. 2) made of pulp fibers is adsorbed (made by paper) onto the net body 12.

  (2) After the above (1), the pulp mold intermediate molded body 10 is released from the papermaking mold 11 together with the net body 12, and after heating and drying in a drying chamber (not shown), the net body 12 is removed.

  (3) After the above (2), as shown in FIG. 3, the pulp mold intermediate molded body 10 is placed on the cavity surface 21a of the female die 21 of the compression device, and as shown in FIG. And the female mold 21 and the male mold 22 are brought close to each other to compress the pulp mold intermediate molded body 10 to reduce the wall thickness. As a result, the pulp mold container 1 having a smooth outer surface is press-molded, and at the same time, the three-dimensional display portion forming portion including the concave portion 21b of the female mold 21 and the three-dimensional display portion forming portion including the concave portion 22b of the male mold 22 are transferred. Then, the three-dimensional display portion 5 including the convex portions 5 a is formed on the outer surface and the inner surface of the bottom wall 2 of the pulp mold container 1.

  In the compression step of the present invention, by compressing with a compression mold to reduce the thickness of the pulp mold intermediate molded body, the mesh formed by one side of the pulp mold intermediate molded body disappears and is smooth. A surface is formed, and a three-dimensional display portion including convex portions is clearly formed.

  In the present invention, when the average thickness of the pulp mold molded body is reduced within the range of 60 to 80% with respect to the average thickness of the pulp mold intermediate molded body, the pulp mold intermediate molded body is formed on one surface. As the mesh disappears, a three-dimensional display portion composed of convex portions is clearly formed. If it is less than 60%, the mesh may remain, and if it exceeds 80%, the average thickness of the pulp molded product becomes too thin, and there is a possibility that a reduced strength portion may occur.

  (4) After (3) above, the female mold 21 and the male mold 22 are separated from each other, and the pulp mold container 1a with burr is released.

  (5) After the above (4), as shown in FIG. 5, the pulp mold container 1a with burr is placed on the receiving surface 31a of the lower pressing jig 31 of the deburring device, and the upper pressing jig 32 is used. In a state where the collar portion 4 is pressed and held, the cutter frame 33 having the edge 33a is slid relative to the lower pressing jig 31 in the downward direction in the figure, whereby the burr 1b on the outer peripheral edge of the collar portion 4 is obtained. Disconnect.

  In embodiment mentioned above, the three-dimensional display part 5 which consists of the convex part 5a is formed in the outer surface and inner surface of the bottom wall 2 of the pulp mold container 1. However, the present invention is not limited to this, and it is possible to manufacture a pulp mold container in which a three-dimensional display portion forming portion including a concave portion 21 b is provided only on the cavity surface 21 a of the female mold 21 and a three-dimensional display is formed only on the outer surface of the bottom wall 2.

  In addition, in contrast to the three-dimensional display portion forming portion formed of the concave portion 21b of the cavity surface 21a of the female mold 21, a three-dimensional display portion forming portion of a different image including the concave portion 22b is provided on the cavity surface 22a of the male die 22. Thereby, the pulp mold container which formed the different three-dimensional display part 5 in the inner surface and outer surface of the bottom wall 2 can be manufactured.

The pulp mold container manufactured with the manufacturing method of the pulp mold molded object which concerns on this invention is shown, (a) is a schematic top view, (b) is a schematic cross section along the AA line of (a). In this invention, it is a schematic cross section of the papermaking apparatus used for a papermaking process. In this invention, it is a schematic cross section which shows the state which mounted the pulp mold intermediate molded object on the female type | mold in a compression process. In this invention, it is a schematic cross section which shows the state which compressed with the female type | mold and male type | mold in a compression process, and shape | molded the container made from a pulp mold. It is a schematic cross section of the deburring apparatus which shows the state which cut | disconnected the burr | flash in the deburring process in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulp mold container 2 Bottom wall 3 Peripheral side wall 4 Brim part 5 Three-dimensional display part 5a Convex part 10 Pulp mold intermediate molded body 11 Paper making type 12 Net body 13 Paper making tank 14 Drainage chamber 15 Discharge port 16 Pulp fiber slurry 21 Female type 21a, 22a Cavity surface 21b, 22b Recess 22 Male mold 31 Lower presser jig 32 Upper presser jig 33 Cutter frame

Claims (5)

A method for producing a pulp mold molded body having a three-dimensional display portion consisting of convex portions on at least one surface,
A paper making step for adsorbing a pulp mold intermediate formed body made of pulp fibers separated from pulp fiber slurry using a paper making mold made of a net body having a detachable molding surface to the net body;
A drying step of releasing the pulp mold intermediate molded body together with the mesh body and drying;
A compression step of removing the dried pulp mold intermediate molded body from the net body and compressing it with a pair of compression molds to reduce the wall thickness,
The three-dimensional display part which consists of the said convex part is formed by the three-dimensional display part formation part which consists of a recessed part provided in at least one of the said compression type | mold in the said compression process, The manufacturing method of the pulp mold molding characterized by the above-mentioned.   2. The method for producing a pulp mold molded body according to claim 1, wherein in the compression step, the thickness of the pulp mold intermediate molded body is reduced to a thickness within a range of 60 to 80%.   The pulp mold molded body according to claim 1 or 2, wherein the convex portion has a height ratio protruding from a surface within a range of 20 to 90% of an average thickness of the pulp mold molded body. Manufacturing method.   A pulp mold molded article produced by the method for producing a pulp molded molded article according to any one of claims 1 to 3.   The pulp mold molded body according to claim 4, wherein the pulp mold molded body is a tray-shaped container made of a pulp mold in which an accommodation recess is formed from a bottom wall and a peripheral side wall.

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