JP3241574B2 - Pulp mold forming method, pulp mold forming method, and pulp mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulp mold formed from pulp slurry, a mold for molding the pulp mold, and a molding method.

[0002]

2. Description of the Related Art When a predetermined product or the like is transported, the product or the like is packed with a package or cushioning material having a recess corresponding to the shape of the product or the like. As such a packaging and cushioning material, expanded polystyrene or the like is usually used. However, it has recently become a serious problem that these materials cause environmental pollution upon disposal.

[0003] On the other hand, for the purpose of effective use of recovered resources and the like, packing materials are manufactured from waste paper pulp such as corrugated cardboard or newsprint, which is easy to dispose of.
Such packaging is called a pulp mold. Such a pulp mold usually uses a molding die having a molding surface of a corresponding shape and formed with a large number of suction holes opened in the molding surface, and the molding surface of the molding die is put into pulp slurry. The pulp is formed by sucking the pulp on the molding surface by sucking from the suction hole in a state of being immersed, and after the sucked pulp is suctioned and dehydrated, the water content is set to a level that can maintain the shape, and then It is manufactured by releasing from the mold and drying with hot air in a drying furnace.

[0004]

By the way, the suction holes opened on the molding surface of the above-mentioned mold are, for example, round holes having a diameter of about 3 mm, and are provided at a rate of about one per cm ² . . Therefore, if the pulp is directly adsorbed on the molding surface, the pulp slurry is sucked into the suction holes in a state of pulp slurry, so that a predetermined pulp mold is hardly formed, and the suction holes are easily clogged. Therefore, usually, when the above-mentioned molding die is used, a mesh such as a wire mesh of, for example, about # 40 formed according to the shape of the molding surface is fixed on the molding surface, and the pulp is adsorbed to the mesh. Have been.

However, even if the pulp is sucked through the mesh as described above, after the mesh and the pulp come into close contact with the molding surface, the opening of the suction hole and the mesh come into close contact with each other. Only the part facing the hole, i.e. only a small part of the area of the entire molding surface, is sucked exclusively. As a result, the suction force is insufficient at the portion not facing the opening of the suction hole, the pulp is not sufficiently adsorbed, and the desired thickness cannot be obtained. At the part facing the hole, the suction force is locally excessive, so the net-like body is dented to the suction hole side, and a large convex part that follows the shape is formed on the surface of the molded pulp mold. At the same time, the pulp is pulled through the mesh toward the suction hole side, and the pulp fibers are pulled into the suction hole side to produce protrusions of the pulp,
A desired surface shape cannot be obtained.

[0006] The occurrence of such pulp protrusions can be prevented, for example, by making the mesh body finer than about # 80. In this case, even if the pulp fibers are sucked by a relatively large suction force, the pulp fibers are not drawn into the suction holes through the net-like body, so that pulp projections are unlikely to occur. However, since the mesh diameter of the fine mesh is also reduced at the same time, the gap between the opening on the molding surface side of the suction hole and the mesh is further reduced, and the pulp is further reduced in the portion not facing the opening of the suction hole. It becomes difficult to be adsorbed, which causes a problem that the thickness of the entire pulp mold becomes more uneven.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a pulp mold having a desired surface shape, a molding die capable of obtaining the pulp mold, and a molding method. Is to do.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the pulp mold of the present invention is to provide a pulp mold having a large number of suction holes opened in a molding surface. Is sucked from the suction hole in a state covered with the mesh, the pulp in the pulp slurry is adsorbed on the mesh in the pulp slurry, and the pulp adsorbed outside the pulp slurry is formed on the molding surface. By dehydrating in the pulp mold for forming a pulp mold, (a) provided along the molding surface, the suction hole is opened in the inner surface, suction from the suction hole as seen including a large number of water passing grooves for maintaining a gap between the opening of the molding surface side of the suction hole and the mesh-like body when the, and
The suction hole opened on the inner surface of the water passage groove is provided on the molding surface.
A predetermined angle along the longitudinal direction of the water channel with respect to the normal direction
That is, it is provided to be inclined .

[0009]

According to the first aspect of the present invention, the mold for the pulp mold is provided along the molding surface, the suction hole is opened on the inner surface, and when the suction hole is sucked from the suction hole, the molding of the suction hole is performed. It is configured to include a number of water passage grooves for maintaining a gap between the opening on the surface side and the mesh body. Therefore, when the pulp is adsorbed on the molding surface and when the pulp is sucked and dehydrated, the depth of the water passage groove provided on the molding surface is formed between the opening of the suction hole on the molding surface side and the mesh body. The gap corresponding to the distance is maintained. Therefore, suction is performed through the water passage groove, and a sufficient suction force is obtained even in a portion not facing the opening of the suction hole, the pulp is adsorbed to a sufficient thickness, and the entire molding surface In this method, a substantially uniform pulp thickness is obtained, and only a part of a small area is locally suctioned as in the related art, thereby suppressing deformation of the mesh body, and corresponding to the suction hole on the surface of the pulp mold. No large convex portion is formed, and a pulp mold having a desired surface shape can be obtained. Moreover, the gap between the opening on the molding surface side of the suction hole and the mesh is maintained in the same manner even when a fine mesh is used. Can be prevented. Also, the suction direction by the suction hole is the length of the water channel.
The mesh is concave toward the suction hole because it is in the direction of the hand.
Is further suppressed and more uniform on the entire molding surface.
Pulp mold with better surface shape with suction force
Is obtained. In addition, dewater by suction outside the pulp slurry.
When dewatered from the pulp,
It becomes easier to flow and dehydration is promoted.
Shape retention after molding is improved.

[0010]

Preferably, at least a part of the water passage groove is provided in a pattern corresponding to a predetermined figure formed in a convex shape on the surface of the pulp mold.
By doing so, the pulp adsorbed on the molding surface is slightly protruded toward the water passage groove together with the net by being sucked from the suction hole. A minute convex portion corresponding to the water passage groove is formed, and the water passage groove is provided at least partially in a pattern corresponding to a figure (for example, a symbol or a pattern) formed on the surface of the pulp mold. From, by simply adsorbing the pulp mold on the molding surface and dewatering,
A desired figure is provided on the surface of the pulp mold by the formed minute projections.

Preferably, the width of the water passage groove on the molding surface is 0.2 to 2.0 mm. By doing so, the lower limit of the width of the water passage groove is sufficiently large, so that the pulp adsorption speed is sufficiently fast and sufficiently high molding efficiency is obtained, and the water generated by the suction dewatering is removed. While being efficiently discharged through the grooves, the upper limit is sufficiently small, so that the deformation of the mesh body is suppressed, and the height of the protrusions formed on the pulp mold surface with the deformation is sufficiently small. Is done.

[0013] Preferably, the suction hole has a cross-sectional area on the inner surface side of the mold larger than a cross-sectional area of the opening on the inner surface of the water passage groove. By doing so, the cross-sectional area of the suction hole can be made sufficiently large on the inner surface side of the mold, so that clogging due to pulp fibers or the like can be suppressed.

Preferably, the suction holes are provided at intervals of 200 mm or less in each of the plurality of water passage grooves. In this case, since the interval between the suction holes is sufficiently small, shortage of suction force due to pressure loss in the water passage groove is less likely to occur, and sufficiently high adsorption efficiency and dehydration efficiency can be obtained.

Preferably, the water passage grooves are provided at a pitch of 30 mm or less, more preferably 20 mm or less. In this case, since the interval is sufficiently small, the mesh and the pulp are in close contact with the molding surface, and suction cannot be performed. The occurrence of defects is further suppressed. In order to keep the rigidity of the molding surface sufficiently high, the area of the water passage groove is preferably about 1/15 to 1/2 of the whole molding surface, and the pitch is preferably 2 mm or more.

[0016]

According to a second aspect of the present invention, there is provided a method of forming a pulp mold from pulp slurry, the method comprising: (b) a plurality of suction holes opened in the molding surface, and a plurality of water passage grooves provided along the molding surface, the suction holes being opened in the inner surface , and the water passage grooves
The suction hole opened in the inner surface of the
With a predetermined angle along the longitudinal direction of the water channel
The provided mold is immersed in the pulp slurry in a state where the molding surface is covered with the mesh, and the pulp in the pulp slurry is adsorbed on the mesh by sucking from the suction hole. And (c) a dewatering step of dewatering the pulp adsorbed on the reticulated body on the molding surface thereof by sucking through the suction holes outside the pulp slurry.

[0017]

According to the second aspect of the present invention, a molding die provided along a molding surface and provided with a large number of water passage grooves having suction holes opened on the inner surface is provided with the molding surface covered with a net. By immersing the pulp in the pulp slurry and sucking it from the suction hole, the pulp in the pulp slurry is adsorbed on the mesh body, and by sucking the pulp from the suction hole outside the pulp slurry, the pulp is absorbed on the mesh body. And a dewatering step of dewatering the pulp on the molding surface.
Therefore, when suction is performed from the suction hole, that is, when the pulp in the pulp slurry is adsorbed and when the pulp is dewatered, a large number of holes are formed between the opening on the molding surface side of the suction hole and the mesh. The gap corresponding to the depth of the water passage groove is maintained. Therefore, in the adsorption step and the dehydration step, suction is performed through the water passage groove,
Sufficient suction force is obtained even in the part not facing the opening of the suction hole, the pulp is adsorbed to a sufficient thickness, a substantially uniform pulp thickness is obtained on the entire molding surface, and only a part of a small area is Deformation of the mesh body due to local suction is suppressed, and a large convex portion corresponding to the suction hole is not formed on the surface of the pulp mold, so that a pulp mold having a desired surface shape can be obtained. Moreover, the gap between the opening on the molding surface side of the suction hole and the mesh is maintained in the same manner even when a fine mesh is used. Can be prevented.

[0018]

A third aspect of the present invention for achieving the above object is a pulp mold according to the third aspect, which is formed by the pulp mold forming method according to the second aspect. There is to be.

[0019]

In this manner, the pulp mold is formed by the pulp mold forming method of the second invention. Therefore, a pulp mold having a desired surface shape that has a substantially uniform thickness as a whole and does not have a large convex portion corresponding to the suction hole is obtained. In addition, when a sufficiently fine mesh is used, a pulp mold having a desired surface shape and having no pulp projections can be obtained.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the appearance of a pulp mold forming die 10 according to one embodiment of the present invention. This mold 10
Is made of, for example, an epoxy resin or an aluminum alloy, and has a molding surface 12 having an uneven shape corresponding to the shape of the pulp mold to be molded. A large number of water passage grooves 14 having a plurality of suction holes 18 opened on the bottom surface are, for example, 2 to 20 mm.
At a predetermined center interval (pitch), a mesh 16 covering the entire molding surface 12 is fixed.

FIG. 2 is an enlarged view showing a part of the molding surface 12 of the molding die 10. The water passage groove 14 provided on the molding surface 12 has, for example, a U-shaped cross section perpendicular to the molding surface 12 and a width of 0.2 to 3.0 mm.
It is provided along the forming surface 12 to a size of preferably about 0.2 to 2.0 mm and a depth of about 0.5 to 10 mm, 1 to 5 times the width, preferably about 1 to 2.5 times the width. This water channel 14
Has a diameter of 0.5 penetrating in the thickness direction of the molding die 10.
A suction hole 18 of about 3.0 mm extends along its longitudinal direction,
The openings are provided at predetermined intervals of, for example, about 15 to 200 mm, including the relationship with the suction holes 18 provided in the surrounding water passage groove 14. The diameter of the suction hole 18 at the opening on the water passage groove 14 side is ± 0.5 mm with respect to the width of the water passage groove 14.
3, preferably about 0 to 0.5 mm larger, but as shown in FIG. 3, a cross section along the water passage groove 14 is shown on the inner surface side of the molding die 10, that is, on the back surface side of the molding surface 12. It is formed in a stepped hole shape so as to have a relatively large diameter. The relationship between the pitch and the width of the water passage groove 14 is preferably such that the total area of the water passage groove 14 is
It is set to be about 1/15 to 1/2 with respect to the whole 2.

Further, as shown in FIG.
The opening 8 has an elliptical shape as shown in FIG. 2 because the opening 8 is inclined at a predetermined angle of, for example, about 30 ° with respect to the molding surface 12. That is, the suction hole 18
Is inclined at a predetermined angle along the longitudinal direction of the water passage groove 14 with respect to the normal direction of the molding surface 12. In addition, the suction holes 18 are provided at intervals of 15 to 200 mm as described above in principle. However, as shown in FIG. Are all provided.

The above-mentioned suction hole 18 is formed in a portion of the molding surface 12 excluding the ridge within 20 mm from the ridge of the peripheral edge of the projection.
An elongate release purge hole 20 which is slightly larger than, for example, a diameter of 1 to 3 mm is formed. When the pulp mold molded on the molding surface 12 is released from the mold, the purge hole 20 is used to easily release the pulp mold by blowing air and prevent breakage at that time. When the pulp mold is used mainly as a packing material, it is formed by selecting a position that does not hit a product in the water passage groove 14. The reason why the pulp mold is formed on the periphery of the projection is to suppress deformation of the pulp mold when the mold is released. Therefore, it is not necessarily provided in all the water passage grooves 14, for example, 30 to 100 m
The distance is about m. If the distance is 100 mm or more, mold release failure may occur.
In the following, the man-hour will be increased without contributing to the improvement of the releasability. Also, it is preferable that the diameter is larger than the suction hole 18 so that the air amount is sufficient at the time of mold release. If the diameter is less than 1 mm, the air amount is insufficient. In such a case, the pulp mold has a convex shape.

The mesh 16 fixed to the molding surface 12 is, for example, a polyester non-woven fabric having a basis weight of about ²⁰ to 50 g / m ^2.
3, and is prevented from being peeled off from the peripheral edge by the mesh body holder 27 fixed to the peripheral edge as shown in FIG. The double use of the nonwoven fabric is for the purpose of sufficiently increasing the thickness of the mesh body 16, and for example, a polyester nonwoven fabric having a basis weight of about 100 g / m ² may be fixed. In FIG. 1 and the like, the mesh holder 27 is omitted.

FIG. 3 is a view schematically showing a state in which the molding die 10 is mounted in the pulp molding apparatus. In FIG. 3, a chamber 23 is fixed to the tip of a support arm 22. A base 24 to which the mold 10 is attached by bolts 26 is fixed to the flange surface 23a of the chamber 23 by bolts 25a and nuts 25b. As shown in the figure, the mold 10 has a thickness of, for example, about 2 cm and a molding surface 1.
2 has a recess 28 shaped along
And the chamber 23 form a closed space 30. Both the suction hole 18 and the purge hole 20 for release are opened in the recess 28. Therefore, at the time of molding the pulp mold, the purge hole 20 for release functions as a suction hole, while the suction hole 18 also functions as an air ejection hole for release. For this reason, the size of the release purge hole 20 is limited to 3 mm or less as described above.

A closed space 30 formed by the recess 28 and the chamber 23 is connected to a switching valve 34 via a hole 32 of the support arm 22. The switching valve 34 is switched between a suction position connected to a suction pump 38 via a drain tank 36 and an ejection position connected to a compressor 40 in accordance with the operation of a timer (not shown) or the like. Therefore, depending on the switching position, the suction pump 38
The inside of the closed space 30 is made negative pressure by the
Or air is blown out from the suction hole 18 by the compressor 40. The water stored in the drain tank 36 is appropriately discharged by a discharge pump 42.

FIG. 4 is a view schematically showing the overall configuration of a pulp molding apparatus to which the above-mentioned molding die 10 is attached. The pulp molding apparatus includes a rotation shaft 94 rotatably supported by a support device (not shown) about an axis perpendicular to the paper surface. The rotation shaft 94 has a pair of support arms 22 (22a, 22b). ) Are mounted at pivot angles different from each other by 180 °. Those support arms 2
Molds 10a and 10b are attached to tips of 2a and 22b, respectively. A liquid tank 98 storing pulp slurry 96 is provided below the rotating shaft 94. Molds 10a and 10b attached to the tips of the support arms 22a and 22b respectively have pulp slurry 9 at the lower end position.
6 to be immersed. That is, the molds 10a and 10b are provided on opposite sides of the rotating shaft 94, and are alternately positioned in the pulp slurry 96 by being rotated about the axis thereof. The pulp is adsorbed on the molding surface 12 by being sucked from the suction hole 18 while being immersed in the 96,
The pulp mold 100 is formed by suction dehydration outside the pulp slurry 96.

The pulp mold 100 on the molding surface 12 is movable above and below the rotating shaft 94 so as to be movable in the left-right direction in FIG. Release device 1 that adsorbs and transports
02 is provided. The pulp mold 100 dewatered on the molding surface 12 is released from the molds 10a and 10b by the mold release device 102 and sent to a drying step (not shown).

A method of forming the pulp mold 100 using the pulp mold forming apparatus having the above-mentioned structure will be described with reference to FIG. 4 and FIG. First, by rotating the rotating shaft 94 in the immersion step of the step 1, the upper mold 10a is rotated downward according to the arrow in FIG. 4 and the lower mold 10b is rotated.
Is turned upward. Next, in the suction step of step 2, during the rotation, the suction pump 38 is operated and the switching valve 34 connected to the molding die 10a is switched to the suction position, so that the suction hole 18 of the molding die 10a is pulled out. Start suction. The suction pump 38
Is already operated, the switching valve 34 is switched while continuing the operation.

Then, the mold 10a is further rotated and put into the pulp slurry 96 in the liquid tank 98, so that the pulp slurry 96 is kept in the pulp slurry 96 for a predetermined adsorption time in the adsorption step of step 3. Of the pulp is adsorbed on the molding surface 12. The predetermined suction time is set to a relatively short time, for example, about 2 seconds. After the predetermined time has passed,
In the pulling-up step of the step 4, the molding die 10a is taken out of the pulp slurry while the suction from the suction hole 18 is continued.
In the dewatering step, the pulp adsorbed on the molding surface 12 is dehydrated by continuing the suction for a predetermined time of, for example, about 10 seconds, and the pulp mold 100 is formed. In addition, since the suction from the suction hole 18 is continuously performed, the dewatering step is performed immediately after the mold 10a is taken out of the pulp slurry 96 in the pulling-up step.

At this time, the basis weight of the molding surface 12 is 100 g / m ^2.
Since the sufficiently fine mesh 16 made of non-woven fabric is fixed, the adsorbed pulp is not drawn into the suction hole 18 from the mesh 16.
In addition, since the water passage groove 14 is provided on the molding surface 12 and the suction hole 18 is opened in the water passage groove 14, the mesh body 16 and the adsorbed pulp can be kept in the suction hole even during the above-mentioned dehydration. 18 cannot be brought into close contact with the opening on the molding surface 12 side,
In the meantime, a gap corresponding to the depth of the water passage groove 14 shown by h in FIG. 2 is maintained. As a result, the mesh member 16 is brought into close contact with the opening of the suction hole 18, and the suction force at the opening becomes excessive while the suction force at the portion other than the opening does not become insufficient. Thus, a substantially uniform suction force can be obtained over the entire surface. Therefore, only the reticulated body 16 and a part of the pulp are locally sucked at the opening of the suction hole 18 to form a large convex portion in the pulp mold, or the pulp is sufficiently adsorbed at the portion separated from the opening. Insufficient thickness is suppressed. In addition, the dewatered water flows along the water passage groove 14 and is efficiently discharged from the suction hole 18.

After the dehydration is completed as described above, in the release step of step 6, the switching valve 34 is switched to the ejection position to eject air from the suction hole 18 and the release purge hole 20, and the release device 102 Pulp mold 100
Is adsorbed, released from the molding die 10a, transported to a drying step, and then dried by a predetermined drying device to obtain a dried product of the pulp mold 100. At this time,
As shown in the cross section in FIG. 6, a small ridge 104 having a height of 0.5 mm or less corresponding to the water passage groove 14 is formed on the surface (the surface on the molding surface 12 side) of the pulp mold 100 (and the dried product). No large protrusions corresponding to the suction holes 18 or protrusions of the drawn pulp (so-called fluff) are produced. In FIG. 6, the protrusions 104 are exaggerated for the sake of explanation.

By the way, the above-mentioned molding die 10 is, for example,
It is manufactured according to the process shown in FIG. First, FIG.
As shown in (a), a gypsum or wooden prototype (master mold) 44 having the shape of the molding die 10 is prepared, and one surface corresponding to the molding surface 12 is machined by, for example, an end mill or sand blast. Thus, a groove 45 having the dimensions and shape of the water passage groove 14 is formed. A silicone rubber 46 is applied to one surface of the mold 44 on which the groove 45 is formed, and after being cured, the silicone rubber 46 is removed from the mold 44 to form a ridge corresponding to the water passage groove 14 as shown in FIG. 48 inside 5
0 is obtained.

Next, the inner surface 50 of the duplication mold 52 is
Then, a surface layer having a thickness of, for example, about 2 to 10 mm is formed by a so-called gel coating method (lamination method) in which an epoxy resin is applied with a brush, and further used for backing the epoxy resin (for lamination).
By applying the above resin, an epoxy resin layer 54 having a thickness of, for example, about 10 to 30 mm is formed as shown in FIG. At this time, a groove corresponding to the ridge 48, that is, the water passage groove 18 is formed in the epoxy resin layer 54.
Further, as shown in FIG. 7D, for example, a reinforcing member 56 in which a plate made of FRP or the like is assembled in a lattice shape is fixed to the inner surface thereof, thereby reinforcing the epoxy resin layer 54 to form the duplication mold 52. After removing the suction hole 18 with a drill, etc.
The mold 10 is obtained by forming the mold release purge holes 20. In FIG. 3, the reinforcing member 56 is omitted.

When the molding die 10 is used, the mesh 16 must be attached to the molding surface 12. For example, the mesh 16 is made of a polyester non-woven fabric as described above. In this case, the polyester non-woven fabric is heated and pressed at about 120 to 150 ° C. on the molding surface 12 to form a shape following the molding surface 12 and bonded at several places with a cyanoacrylate adhesive or the like. It is fixed on the molding surface 12.

In this embodiment, the mold 10 of the pulp mold is provided along the molding surface 12 and has a suction hole 18 opened at the bottom surface. Opening of hole 18 on molding surface 12 side and net 1
6 and a large number of water passage grooves 14 for maintaining a gap between them. Therefore, even when the pulp is adsorbed on the molding surface 12 and the pulp is sucked and dehydrated, the depth of the water passage groove 14 is formed between the opening of the suction hole 18 on the molding surface 12 side and the mesh body 16. h (approximately 0.5 to 10 mm in the present embodiment) is maintained. Therefore, suction is performed through the water passage groove 14, so that a sufficient suction force is obtained even in a portion not facing the opening of the suction hole 18, the pulp is adsorbed to a sufficient thickness, and molding is performed. Face 1
(2) A substantially uniform pulp thickness is obtained on the entire surface, and the deformation of the reticulated body 16 due to the local suction of only a small area as in the related art is suppressed. Since a large convex portion corresponding to the hole 18 is not formed, a pulp mold 100 having a desired surface shape can be obtained. Moreover, the gap between the opening of the suction hole 18 on the molding surface 12 side and the mesh body 16 is similarly maintained even when a fine mesh body 16 is used as in this embodiment. In addition, it is possible to prevent the occurrence of pulp projections (fluffing) at the same time as obtaining the surface shape of.

Further, according to the present embodiment, the suction hole 18 opened on the bottom surface of the water passage groove 14 has a predetermined angle along the longitudinal direction of the water passage groove 14 with respect to the normal direction of the molding surface 12. For example, it is provided at an angle of about 30 ° with respect to the molding surface 12. With this configuration, the suction direction of the suction hole 18 is in a direction along the longitudinal direction of the water passage groove 14, so that the mesh 16 is further suppressed from being recessed toward the suction hole 18, and the entire surface of the molding surface 12 is suppressed. A more uniform suction force can be obtained, and the pulp mold 100 having a better surface shape can be obtained. In addition, when dewatering by suction outside the pulp slurry 96, the water dewatered from the pulp easily flows along the water passage grooves 14, thereby promoting dehydration, and increasing the dewatering rate, thereby maintaining the shape retention after release. Will be improved.

According to the present embodiment, the width of the water passage groove 14 on the molding surface 12 is 0.2 to 2.0 mm. By doing so, the lower limit value of the width of the water passage groove 14 is sufficiently large, so that the pulp adsorption speed is sufficiently high to obtain sufficiently high molding efficiency, and the water generated by suction dehydration is passed through. While the water is efficiently discharged through the water groove 14, the upper limit value is sufficiently small, so that the deformation of the mesh body 16 is suppressed, and the projections or ridges formed on the surface of the pulp mold 100 with the deformation. The height of 104 is made sufficiently small.

According to the present embodiment, the suction hole 18 is
The cross-sectional area on the concave 28 side, that is, the inner surface side of the mold 10 is made larger than the cross-sectional area of the opening on the bottom surface of the water passage groove 14. By doing so, the cross-sectional area of the suction hole 18 can be made sufficiently large on the inner surface side of the mold 10.
It is possible to suppress clogging due to pulp fibers and the like.

In this embodiment, the suction holes 18
Are provided at intervals of 200 mm or less in each of the plurality of water passage grooves 14. In this case, since the interval between the suction holes 18 is sufficiently small, shortage of suction force due to pressure loss in the water passage groove 14 is unlikely to occur, and sufficiently high adsorption efficiency and dehydration efficiency can be obtained. In the present embodiment, since the suction area is determined by the water passage groove 14, the number of the suction holes 18 must be reduced as compared with the related art within a range where a substantially uniform suction force can be obtained in the water passage groove 14. Is possible. Therefore, the man-hour for forming the minute suction holes 18 is made simpler than before, and the molding die 10 can be manufactured at low cost.

Further, according to the present embodiment, the water passage groove 14 is
It is provided at a pitch of 20 mm or less, and the interval is sufficiently small, so that the mesh 16 and the pulp are in close contact with the molding surface 12 and suction cannot be performed, and unevenness in the thickness of the pulp mold 100 and The occurrence of poor suction such as the formation of holes is further suppressed. Moreover, since the total area of the water passage grooves 14 is about 1/15 to 1/2 with respect to the entire molding surface 12 and the pitch is 2 mm or more, the molding surface 1
2 is kept sufficiently high.

In this embodiment, since the duplicating mold 52 for producing the molding die 10 is made of flexible silicone rubber, the molding die 10 is manufactured and released. Also, in the case of the duplication mold 52 including a so-called undercut shape that forms a negative angle with respect to the drawing direction, the molding die 10 can be easily released by deforming and duplicating the duplication mold 52. It is.

Further, in this embodiment, the molding die 10 provided with a large number of water passage grooves 14 provided along the molding surface 12 and having the suction hole 18 opened on the bottom surface is used.
The pulp in the pulp slurry 96 is immersed in the pulp slurry 96 in a state covered by the pulp slurry 6, and the pulp in the pulp slurry 96 is absorbed onto the mesh body 16 by sucking through the suction hole 18. The pulp mold 100 is formed by a step including a dehydration step of a step 5 of dehydrating the pulp adsorbed on the mesh body 16 on the molding surface 12 by sucking through the suction hole 18.

Therefore, when sucked through the suction hole 18,
That is, when the pulp in the pulp slurry 96 is adsorbed and when the pulp is dewatered, a large number of water passage grooves 14 are formed between the opening of the molding surface 12 side of the suction hole 18 and the mesh 16. A gap corresponding to the depth h is maintained. Therefore, in the adsorption step and the dehydration step, the suction is performed through the water passage groove 14, and the suction hole 1
In the portion not facing the opening 8, a sufficient suction force is obtained, the pulp is adsorbed to a sufficient thickness, a substantially uniform pulp thickness is obtained over the entire molding surface, and only a small part of the pulp is localized. The deformation of the reticulated body 16 due to the aspiration is suppressed, and the pulp mold 100
No large protrusion corresponding to the suction hole 18 is formed on the surface of the pulp mold 100, and the pulp mold 100 having a desired surface shape can be obtained. Moreover, the gap between the opening of the suction hole 18 on the molding surface 12 side and the mesh body 16 is similarly maintained even when a fine mesh body 16 is used as in this embodiment. It is possible to prevent the occurrence of pulp protrusions while obtaining the surface shape of the pulp.

Next, another embodiment of the present invention will be described. In the following description, portions common to the above-described embodiment will be denoted by the same reference numerals and description thereof will be omitted.

FIG. 8 shows a grid-shaped water passage groove 58 on the molding surface 12.
It is a figure which shows the principal part of the shaping | molding die 10 in which was provided. The water passage groove 58 is formed so that its cross section perpendicular to the molding surface 12 has a V-shape. Although not shown, the suction hole 18 and the release hole for release are formed at the V-shaped tip. 20 is opened. Even when such a lattice-shaped water passage groove 58 is provided, the close contact between the molding surface 12 and the mesh body 16 can be avoided as in the case where the above-described long water passage groove 14 is provided. Therefore, the same effect as in the above-described embodiment can be obtained.

The molding die 1 having the water passage groove 58 described above
0 is produced, for example, as follows. That is, as shown in FIG. 9A, for example, φ5 mm is formed on one surface 64 corresponding to the molding surface 12 of the concave mold 60 made of gypsum or the like.
A low melting point paraffin 62 formed into a roughly spherical shape is attached to the entire surface while being pressed, is cooled to a predetermined temperature of, for example, about 18 ° C., is cured, and then is released from the mold to produce a prototype. At this time, as shown in FIG. 9 (b), a cross section of the main part of the prototype 68 before release is shown in which the one surface 64 side of the spherical paraffin 62 attached to the concave mold 60 as a whole is one surface 64.
At the same time, a portion of the curved surface 65 of the spherical paraffin 62 on the one surface 64 side remains after being pasted, so that the molding surface on the one surface 64 side of the prototype 68 has the curved surface 65 , A lattice-shaped groove corresponding to the lattice-shaped water passage groove 58 is formed. That is, in this embodiment, instead of forming grooves in the original by machining or the like, spherical paraffin 62 is used.
Is adhered to the concave mold 60 and released, whereby the prototype 6
At the same time as the fabrication of 8, a lattice-shaped groove is formed in the prototype 68.

After the prototype 68 is formed as described above, the molding die 10 is formed in the same manner as in the embodiment shown in FIG.
Is obtained. Therefore, the molding surface 1 of the obtained molding die 10
2, the water passage grooves 58 having a V-shaped cross section perpendicular to the molding surface 12 are formed in a lattice shape as described above. As shown in the present embodiment, the cross-sectional shape of the water passage groove is U
The shape is not limited to a letter shape, and may be various shapes such as a V-shape. Further, a method of forming a prototype groove is not limited to machining.
As described above, it is also possible to use a method such as attaching the spherical paraffin 62 to the concave mold 60. In the case of the present embodiment, there is an advantage that the groove processing for the prototype 68 is unnecessary.

It should be noted that, in the above-described step of fabricating the prototype 68, as shown in FIGS.
When the radius of curvature of 0 is small, the shape cannot be transferred accurately if spherical paraffin 62 is directly attached. Therefore, when using the concave mold 60 having the bottom corner 70 having such a small radius of curvature, for example, as shown in FIG.
Preferably, the spherical paraffin 62 is attached as described above.

FIG. 11 is a view showing still another embodiment, in which a master for manufacturing a mold having stripe-shaped water passage grooves 14 similar to the mold 10 shown in FIG. 1 is manufactured. FIG. First, the ridges 4 have a shape obtained by inverting the molding die 10 with gypsum or the like, that is, an inner surface shape similar to the duplication mold 52 made of silicone rubber.
A concave mold 74 having no 8 is manufactured. Then, the concave mold 7
For example, over the entire surface 75 corresponding to the molding surface 12 of FIG.
2 ~ φ8mm rod-shaped thermosetting clay (for example,
An epoxy resin-based clay 76 is pressed and crushed incompletely so that the deformation ratio Δd / D is about 0 to 40% as shown in an enlarged view in FIG. In the drawing, the broken line indicates the cross-sectional shape of the thermosetting clay 76 before deformation. Then, by heating the clay at a predetermined temperature to cure the thermosetting clay 76, the mold is released to obtain the prototype. At this time, if release is difficult, a backing material for gel coating (for example, epoxy cloth mixed with glass cloth or glass fiber)
It is good to release after strengthening with etc.

As described above, FIGS.
As in the embodiment shown in FIG. 7, the curved surface 78 remains on the attached thermosetting clay 76, and the pair of curved surfaces 78, 78 of the adjacent thermosetting clay 76 forms the original mold. A groove 80 having a V-shaped cross section is formed on one surface corresponding to the molding surface 12.

FIG. 13 shows a pulp mold 10 to be molded.
FIG. 4 is a diagram showing a main part of a molding surface 82 of a molding die for forming a figure such as a predetermined symbol or pattern on the surface of a zero. In the figure, a water passage groove 84 is formed in the molding surface 82, and a part of the water passage groove 84 is, for example, a pulp mold 100.
Of the drawing (A112-R in the figure) is provided as a figure water passage groove portion 85 provided in an inverted shape, and several suction holes 18 are provided in the independent water passage groove 84 constituting each character. Is open. As described in the embodiment shown in FIG.
0 has a small ridge 1 having a shape corresponding to the water passage groove 84.
04 is formed, the pulp mold 100
Is formed in a convex shape on the surface of.

That is, in the present embodiment, the water channel 8
By properly setting the planar shape of the molding surface 82,
In order to improve the surface accuracy of the pulp mold 100 after molding, the surface of the mold is not subjected to so-called after-pressing, and the pulp is not subjected to surface processing of the figure pattern. This makes it possible to form a figure such as a product number on the surface of the mold 100. In the drawing, the suction holes 18 in the stripe-shaped water passage grooves 84 are omitted.

FIGS. 14A and 14B show water passage grooves 86 and 88 which are still another example of the shape of the water passage groove provided on the molding surface 12.
FIG. 3 is a diagram showing a cross-sectional shape perpendicular to a molding surface 12 of FIG. FIG.
In FIG. 11A, the water passage groove 86 is provided in a step shape, and in FIG. 11B, the water passage groove 88 is provided in a saw-tooth shape. Although these water passage grooves 86 and 88 do not have a clear groove shape, the virtual molding surface 9 shown by a dashed line in FIG.
0 (that is, the molding surface formed by the mesh body 16), a gap 92 is formed. Since the gap 92 has a function of guiding water to the suction hole 18 during suction dehydration, Even with the water passage grooves 86 and 88 having such a shape, the same effect as that of the above-described water passage groove 14 and the like can be obtained.

That is, in the present invention, the “water passage groove” is defined as a gap between the opening of the suction hole 18 on the molding surface 12 side and the mesh 16 when the molding surface 12 and the mesh 16 are in close contact with each other. The shape is not particularly limited as long as it can maintain and provide a sufficient suction area and a flow path of water generated by dehydration and substantially fulfill the function of a water passage groove.

While the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be embodied in still another embodiment.

For example, in the above-described embodiment, the water passage grooves 14 and the like are provided in the form of stripes or lattices on the molding surface 12 and the like, but a substantially uniform suction force can be obtained on the entire surface of the molding surface 12 and the like. If provided, for example, it may be provided in a curved shape. Therefore, as in the embodiment shown in FIG. 12, in order to form a predetermined figure on the surface of the pulp mold 100, the figure is formed in an inverted pattern, and the appearance is enhanced or the buffering action is enhanced. The water passage groove 14 and the like may be formed with various curves and the like so that various patterns such as a puddle are formed.

Further, in the embodiment, by machining, pasting of paraffin or thermosetting clay or the like,
Although grooves corresponding to the water passage grooves 14 and the like were formed in the prototype 44 and the like,
For example, a groove may be formed in the prototype 44 or the like with a marking needle or the like. In addition, when forming a groove | channel by the sticking method, not only paraffin and thermosetting clay but various thermoplastic resins, thermosetting resins, etc. can be used.

In the embodiment, the molding die 10 and the like are made of epoxy resin. However, aluminum and its alloys, metals such as stainless steel, other resins such as urethane and silicone, gypsum or the surface of gypsum are coated with resin or chemically. It may be composed of a plated material, a tree or a material in which the surface of a tree is similarly coated.

In the embodiment, a groove corresponding to the water passage groove 14 and the like is formed in the prototype 44 and the like, and silicone rubber is applied to the prototype 44 and the like to produce a replication mold 52, and the replication 52 is produced. The water flow grooves 14 and the like were formed at the same time as the molding die 10 made of the epoxy resin from the mold 52 by a gel coating method. For example, the water flow grooves 14 and the like were formed directly on the molding die 10 and the like by etching or machining. You may. For example, when the molding die 10 or the like is made of an aluminum casting or the like, the water passage groove 1 of the molding die 10 or the like is used.
It is also possible to form a water passage groove 14 or the like by coating a portion where no 4 or the like is formed with a resin or plating and chemically etching using a corrosive such as caustic soda.
When the mold 10 or the like is made of gypsum, wood, resin, or the like, it is also possible to directly form the water passage groove 14 or the like by machining or the like.

In the above-described embodiment, the molding die 1
0 etc. were made of epoxy resin,
The molding die 10 or the like may be manufactured by gel-coating the inner surface corresponding to the molding surface 12 with another thermosetting resin such as a phenol resin.

In the embodiment, the molding die 10 is provided with the purge hole 20 for release in addition to the suction hole 18. The hole 20 need not necessarily be provided.

In the embodiment, all the suction holes 18 are provided so as to open on the bottom surface of the water passage groove 14. However, the suction holes 18 may be provided so as to open on the side surface. Further, a part of the suction hole 18 may be provided in a part other than the water passage groove 14 on the molding surface 12.

In the embodiment, the suction hole 18 is formed as a stepped hole in which the area of the opening on the inner surface side of the molding die 10 is larger than the opening on the water passage groove 14 side. It may be formed in a conical shape in which the sectional area gradually increases from the groove 14 side toward the inner surface of the molding die 10. If clogging is unlikely to occur, the entire structure may have the same cross-sectional area.

In the embodiment, the nonwoven fabric made of polyester is used as the net 16. However, for example, other nonwoven fabrics made of polyester, polypropylene or tricot, or mesh made of resin, stainless steel or brass are used. Etc. may be used. When a mesh is used, the effect of suppressing pulp projections (fluffing) can be obtained with # 40 to # 400 (wire diameter 0.03 to 0.22 mm).
From the viewpoint of durability, it is preferable that the wire diameter of the mesh is 0.01 mm or more. Therefore, it is preferable to use a mesh having an opening coarser than about # 100, for example, a mesh of about # 80.

In addition, although not specifically exemplified, the present invention
Various changes can be made without departing from the spirit of the invention.

[Brief description of the drawings]

FIG. 1 is a view showing an entire pulp mold according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing a part of a molding surface of the molding die of FIG.

FIG. 3 is a diagram showing a mounting state of the molding die of FIG. 1 in a pulp molding apparatus by a cross section along a water passage groove.

FIG. 4 is a diagram schematically showing a configuration of a pulp molding apparatus using the molding die of FIG.

FIG. 5 is a process diagram illustrating a pulp molding method by the pulp molding device of FIG. 4;

6 is a diagram showing a cross-sectional structure of a pulp mold obtained by the process of FIG.

FIG. 7 is a diagram illustrating a manufacturing process of the molding die of FIG. 1;

FIG. 8 is a view showing a main part of a molding die according to another embodiment of the present invention.

9 (a) and 9 (b) are views for explaining a method of manufacturing the mold of FIG. 8;

10 is a view for explaining a method of processing a concave bottom corner in the manufacturing method of FIG. 9;

FIG. 11 is a view for explaining another example of a method for manufacturing a mold having a stripe-shaped water passage groove.

FIG. 12 is a view showing a cross section of a thermosetting clay which is stuck in a concave shape in the manufacturing method of FIG. 11;

FIG. 13 is a view showing another example of the planar shape of the water passage groove.

FIGS. 14A and 14B are diagrams showing other examples of the shape of the water passage groove, respectively.

[Explanation of symbols]

 10: Mold 12: Mold surface 14: Water passage groove 16: Net 18: Suction hole 96: Pulp slurry 100: Pulp mold

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Fumitaka Miwa 3-36 Noritakeshinmachi, Nishi-ku, Nagoya-shi, Aichi Prefecture Noritake Co., Ltd. Limited (72) Inventor Yoshinari Mizutani 3-chome, Noritake-shinmachi, Nishi-ku, Nagoya-shi, Aichi No. 1 No. 36 Noritake Co., Limited (56) References JP-A-8-49200 (JP, A) JP-A-57-191400 (JP, A) JP-A-7-69374 (JP, A) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) D21J 3/10 D21J 7/00

Claims (4)

(57) [Claims] 1. It has a number of suction holes opened in a molding surface,
Suction is performed through the suction hole while the molding surface is covered with the mesh, and the pulp in the pulp slurry is adsorbed on the mesh in the pulp slurry, and the pulp adsorbed outside the pulp slurry is removed. A pulp mold forming mold for forming a pulp mold by dewatering on the forming surface, wherein the suction hole is provided along the forming surface, the suction hole is opened on an inner surface thereof, and suction is performed from the suction hole. before opening the inner surface of the large number of water passing grooves only contains and vent water groove to maintain a gap between the molded surface side of the opening of the suction hole and the mesh-like body when it is
The suction hole is formed in the water passage groove with respect to a normal direction of the molding surface.
Provided at a predetermined angle along the longitudinal direction
Mold pulp mold, characterized in that it. 2. The mold according to claim 1, wherein at least a part of said water passage groove is provided in a pattern corresponding to a predetermined figure formed in a convex shape on the surface of the pulp mold. 3. A method for molding a pulp mold from pulp slurry, comprising: a plurality of suction holes opened in a molding surface; and a plurality of through holes provided along the molding surface and the suction holes opened in an inner surface thereof. A water groove , and the suction hole opened on the inner surface of the water groove,
Along the longitudinal direction of the water passage groove with respect to the normal direction of the molding surface.
The pulp in the pulp slurry is immersed in the pulp slurry in a state where the forming surface is covered with the mesh body, and is sucked through the suction hole. And a dewatering step of dewatering the pulp adsorbed on the reticulated material on the molding surface by sucking the pulp adsorbed on the reticulated material by sucking the pulp from the suction hole outside the pulp slurry. A pulp mold forming method characterized by the above-mentioned. 4. A pulp mold formed by the pulp mold forming method according to claim 3 .