JPH09316800A - Formation of pulp and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both a method for forming pulp and an apparatus therefor capable of controlling the weight of a product more precisely than a conventional pulp forming method and apparatus therefor. SOLUTION: A product 31 is formed from paper pulp by uisng a stationary mold part 2 equipped with a mold surface 3 for demarcating the shape of the product and a mold 1 equipped with a movable mold part 10 having a closed position to form a mold cavity 15 for enclosing the mold surface and an open position accessible to the mold surface 3. The movable mold part 10 is moved to the closed position and a predetermined fixed amount of pulp having a given concentration is injected to the mold cavity 15. The mold surface 3 is sucked through plural passageways in the stationary mold 2 so as to make the product 31 formed on the mold surface 3. The product 31 formed on the mold surface 3 is dried by injecting steam and then the mold cavity 15 is sucked and dried so as to remove remaining water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to molding or improvement of a product manufactured from pulp, particularly paper pulp. It also relates to a method and apparatus for shaping a product manufactured from pulp.

[0002]

Molded paper pulp has been conventionally used in the manufacture of egg containers. And, recently, the method for manufacturing an egg container has been improved so that it can be molded into a product having a complicated shape, and can be used as a protective container for a fragile product such as an egg.

Presently, the molding of paper pulp to produce products such as egg containers is done using either rotary molding equipment or reciprocating molding equipment. In both cases, the pulp solids are deposited on the mold surface of the mold by immersing the mold in a pool of pulp, and then suction force is applied to the mold surface to attract the pulp solids onto the wire mesh and cover the mold surface. I was trying to make it. Such equipment is widely used for mass production of egg containers and shaping of other pulp products.

[0004]

In this known method, the amount of pulp spread on the mold surface is non-uniform because of the time the mold is immersed in the pool of pulp and the concentration of pulp solids in the pulp liquid. . Therefore, the total amount of pulp spread on the mold surface is not uniform. That is, since the pulp is spread on the mold surface, the suction effect is reduced, and the amount of pulp spread on the mold surface becomes uneven. In addition, the pulp solids and liquid are withdrawn from the pool in a non-uniform manner, resulting in uneven pulp solids concentration on the liquid. That is, the weight of the molded product becomes non-uniform throughout the manufacturing process, and conventionally, the finished molded product has a wide range of weight.

It is an object of the present invention to provide a pulp molding method and apparatus capable of controlling the weight of a product more precisely than known pulp molding methods and apparatuses.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a fixed mold portion having a mold surface defining a shape of a product, and a movable mold, the movable mold wherein the movable mold is the fixed mold portion. A method of molding a product from pulp using a mold, having a closed position surrounding the mold surface and an open position allowing the mold surface to be accessible, for defining a mold cavity around the mold surface. The movable mold part is moved to the closed position, and a predetermined fixed amount of pulp containing a fixed concentration of pulp solids in the pulp liquid is injected into the mold cavity to form a molded product on the mold surface. To press the mold surface to dry the molded product on the mold surface of the mold cavity, By methods serial moving the movable mold to the open position consists in taking out the formed product from the mold, it has solved the problems.

The invention further provides an apparatus for molding a product from pulp having a fixed mold part having a mold surface defining the shape of the product and a movable mold part, wherein the movable mold part surrounds the mold surface. Means for moving the movable mold between a closed position surrounding the mold surface of the stationary mold portion to define a mold cavity therein and an open position for making the mold surface accessible, and a constant concentration in the pulp liquid. Means for injecting a predetermined fixed amount of pulp having pulp solids into the mold cavity, means for pressing the mold surface to form a molded product on the mold surface, and An apparatus comprising means for drying the molded product on the mold surface in the mold cavity is provided. To.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the pulp molding apparatus of the present invention includes a mold covered by a wire mesh 4 welded to a mold surface 3 defining the shape of a product molded from paper pulp. It comprises a metal mold 1 having a fixed mold part 2 which projects towards the surface 3. The fixed mold part 2 is installed in a suction chamber 5 which is connected to the mold surface 3 via a large number of passages (not shown) in the fixed mold part 2. The first outlet of the suction chamber 5 is connected to a vacuum source through a suction valve 6 and a suction line 7. The second outlet of the suction chamber 5 is connected to an atmospheric pressure collecting container (not shown) via an exhaust valve 8 and an exhaust line 9.

The movable mold part 10 is connected to a cylinder device 12 having a piston 11 of a pneumatic or hydraulic piston, a cylinder 14 in which the piston 11 moves. The fixed mold part 2 is a piston / cylinder device 1.
The action of 2 allows it to move between an open position and a closed position so that in the open position it is remote from the fixed mold part 2 and the mold surface is accessible, while in the closed position the movable mold part is molded. Engage with the stationary mold part 2 to surround the surface 3 and form a mold cavity 15 (see, eg, FIG. 2).

The movable mold part 10 passes through a pulp supply line 17 including a pulp supply valve 18 and a supply tank 1
It has a first suction port connected to the discharge port of No. 6. The second suction port of the movable mold part 10 is connected to a steam supply device through a steam line 19 including a steam valve 20. The outlet of the movable mold unit 10 is connected to a vacuum source through a vacuum line 21 including a vacuum valve 22.

The first suction port of the supply tank 16 is connected to the discharge port of the pulp storage tank 24 via a pulp supply line including a pulp supply valve 26. The second suction port of the supply tank 16 is connected to a compressed air source via a compressed air line 27 including a compressed air valve 28. The storage tank 24 contains a paper pulp source 29 whose concentration of pulp solids in the water is kept constant by an agitator 30. The supply tank 16 senses the level of pulp in the supply tank 16 that is received from the storage tank 24 through the pulp supply line 25, and the pulp level in the supply tank 16 is a predetermined pulp volume in the supply tank 16. Pulp feed valve 2 when the required level corresponding to
A level sensor 31 for closing 6 is provided.

A method of using the above-described apparatus for carrying out the pulp molding process of the present invention will be described below with reference to FIGS.
Further details will be described with reference to the various steps of the method described in.

Initially, the movable mold part 10 of the mold 1 is in the open position, and the valves 6, 8, 18, 20, 22, 26.
And 28 are each in the closed position.

Referring to FIG. 1, in the first step of the method, the pulp supply valve 26 is opened so as to supply a predetermined concentration of pulp from the storage tank 24 to the supply tank 16. The level sensor 31 detects the pulp level in the supply tank 16, and when this level reaches the required level,
The level sensor 31 operates to close the pulp feed valve 26 so that the feed tank 16 contains a predetermined volume of pulp, ie, a fixed amount, of paper pulp solids in the water having a predetermined concentration. Become.

Referring to FIG. 2, in the second step of the method, the compressed air valve 28 is opened to supply compressed air to the supply tank 16 through the compressed air line 27 for pressurization. The movable mold part 10 is also closed by the piston-cylinder arrangement 12 so as to actuate the piston 11 towards the fixed mold part 2 to define a mold cavity 15 surrounding the mold surface 3. Move.

In the third step of the method shown in FIG. 3, while the pulp discharge valve 18 is first opened and the compressed air valve 28 is opened, a certain amount of pulp in the feed tank 16 is filled in the mold cavity 15. And is brought into contact with the mold surface 3 of the fixed mold portion 2. The exhaust valve 8 is open during this step of the molding process. The pulp solids separate on the mesh 4 due to the pressure gradient effect across the mold surface and the water flows through the passages of the stationary mold part 2 into the collecting chamber.

In the fourth step of the molding method shown in FIG. 4, the pulp discharge valve 18 and the exhaust valve 8 are closed, and the suction valve 6 connects the vacuum source and the suction chamber 5 through the vacuum line 7. So open. Thus,
The suction force acts on the mold surface 3, the accumulated pulp is attracted to the mold surface 3, and all the water remaining in the mold cavity 15 through the passage of the fixed mold portion 2 is forcibly sucked and thus partially. , The pulp is dried.

The fifth step of the molding method shown in FIG. 5 begins as soon as the mold cavity 15 is empty. In this fifth step, the compressed air valve 28 is closed and the steam valve 20 is open for connection to the steam supply through the mold cavity 15 and the steam line. Thus, the steam discharged into the mold chamber 15 heats the mold 1, and further dries the molded pulp on the mold surface of the fixed mold part. Suction valve 6
Keeps opening during the process of this molding method, and the suction chamber 5
Remains connected to the vacuum source through the suction line 7.

In the sixth step of the molding method shown in FIG. 6, the vapor valve 20 is closed and the vacuum valve 2
2 is open to connect the vacuum source and the mold cavity 15 through the vacuum line 23. Therefore, both the suction chamber 5 and the mold cavity 15 are under the condition of being sucked, and all the remaining vapor and moisture are removed from the suction chamber 5 and the mold cavity 15. This step reduces the moisture of the molded pulp product to a level where the product retains its shape when removed from the mold surface.

In the seventh step of the method shown in FIG. 7, the suction valve 6 is closed and the exhaust valve 8 is opened while the vacuum valve 22 is opened. Therefore, a suction force acts on the product molded on the mold surface 3 from the mold cavity 15 side. Thus, from the mold surface 3,
The molded pulp product 31 is removed.

The piston / cylinder device 12 is used in the eighth step of the method shown in FIG.
0 is actuated to move to the open position. The exhaust valve 8 is kept closed and the vacuum valve 22 is kept open during this process. Therefore, since the suction force continues to work on the molded product, when the movable mold part 10 moves to the open position,
The product separates from the fixed mold part 2.

As shown in FIG. 9, in the ninth step of the molding method, the tray 32 is inserted into the opened mold part 1 and the vacuum valve 22 is closed so that the vacuum source and the movable mold part are not connected. . Then, the molded product 31 is dropped onto the tray 32, and the opened mold part 1
Then, the tray 32 is taken out together with the molded product 31.

Then, the present apparatus returns to the state shown in FIG. 1, and the cycle of operations constituting the molding method of the present invention is repeated.

[0024]

According to the present invention, in particular, a molded product having a uniform weight can be easily molded by using one male mold that defines the mold surface.

[Brief description of drawings]

FIG. 1 is a view of a pulp molding apparatus of the present invention in a first state for carrying out the first step of the pulp molding method of the present invention, in which the supply tank of the apparatus is full.

2 is a view of the apparatus of FIG. 1 in a second state for carrying out the second step of the pulp molding method, wherein the supply tank is pressurized and the movable mold part of the apparatus is in the closed position.

FIG. 3 is a view of the apparatus of FIG. 1 in a third state for performing the third step of the pulp molding method, with pulp being pushed from the supply tank into the mold cavity of the apparatus.

FIG. 4 is a view of the apparatus of FIG. 1 in a fourth state for performing the fourth step of the pulp molding process, while maintaining the pressure on the pulp taken into the mold cavity,
Suction is performed on the mold surface.

5 is a view of the apparatus of FIG. 1 in a fifth state for carrying out the fifth step of the pulp molding process, wherein steam is being introduced into the mold cavity while suction is being applied to the mold surface.

FIG. 6 is a view of the apparatus of FIG. 1 in a sixth state for carrying out the sixth step of the pulp molding step, with suction being applied to the mold cavity and the mold surface.

FIG. 7 is a diagram of the apparatus of FIG. 1 in a seventh state for performing the seventh step of the pulp molding step, showing a state in which suction is being performed into the mold cavity while exhausting air from the mold surface.

FIG. 8 is a view of the apparatus of FIG. 1 in a seventh state for performing the eighth step of the pulp forming step, in which suction is provided to the mold cavity while moving the movable mold section of the apparatus to its open position. It is in a state of being.

FIG. 9 is a view of the apparatus of FIG. 1 in a ninth state for performing the ninth step of the pulp molding process, in which the molded product has been removed from the mold section of the device.

[Explanation of symbols]

 1 Mold 2 Fixed Mold Part 3 Mold Surface 5 Suction Chamber 10 Movable Mold Part 11 Piston 12 Cylinder 14 Cylinder Device 16 Supply Tank 24 Pulp Storage Tank 31 Product

Claims (21)

[Claims] 1. A stationary mold part comprising a mold surface defining a shape of a product, and a movable mold, said movable mold comprising a closed position wherein said movable mold surrounds the mold surface of said fixed mold part and said movable mold. A method of molding a product from pulp using a mold, the mold surface having an open position where the mold surface is accessible, wherein the movable mold part is in a closed position to define a mold cavity around the mold surface. Is moved to inject into the mold cavity a predetermined constant amount of pulp containing a constant concentration of pulp solids in the pulp liquid, and to apply the mold surface to form a molded product on the mold surface. Press to dry the molded product on the mold surface of the mold cavity and place the movable mold in the open position. A method comprising transferring and removing the molded product from the mold. 2. Filling a supply tank from a pulp storage tank containing a fixed concentration of pulp with a fixed amount of pulp to a predetermined level of pulp, and filling the pulp in the filled supply tank into a mold cavity. The method of claim 1, wherein the pulp is injected into the mold cavity by draining. 3. The method of claim 2 including introducing compressed air into the supply tank to discharge the pulp in the filled supply tank to the mold cavity. 4. The method of claim 1, comprising evacuating the mold surface through passages in the stationary mold section while applying pressure to a predetermined fixed amount of pulp in the mold cavity. Method. 5. The method of claim 4 including applying pressure to the mold surface to dry the molded product and then aspirating the mold surface through passages in the stationary mold section. 6. A method according to any of claims 1 to 5, comprising drying the molded product on the mold surface by injecting steam into the mold cavity while aspirating the mold surface. 7. The method of claim 6 including shutting off the supply of steam to the mold and aspirating the mold cavity to remove water from the mold cavity. 8. The method of claim 7 including stopping suction on the mold surface to remove the dried molded product from the mold surface. 9. The method of claim 8 including continuing to aspirate the mold cavity while moving the moveable mold part to move it to the open position to separate the molded product from the mold surface. 10. A mold is opened between a mold surface and a molded product separated from the mold surface, a tray is inserted, suction to the mold is stopped to place the molded product on the tray, and the tray is removed from the mold. 10. The method of claim 9, comprising: 11. An apparatus for molding a product from pulp having a fixed mold part having a mold surface defining a shape of the product and a movable mold part, wherein the movable mold part forms a mold cavity around the mold surface. Means for moving the movable mold between a closed position surrounding the mold surface of the fixed mold portion for defining and an open position for allowing the mold surface to be accessible; and a concentration of pulp solids in the pulp liquid. Means for injecting a predetermined fixed amount of pulp into the mold cavity, means for applying pressure to the mold surface to form a molded product on the mold surface, and in the mold cavity An apparatus comprising means for drying a shaped product on a mold surface. 12. A pulp storage tank for storing a pulp containing a certain concentration of pulp solids in a pulp liquid, a supply tank, and for filling the supply tank with pulp from the storage tank to a predetermined level. The apparatus of claim 11 having means and means for draining pulp in a supply tank filled in the mold cavity. 13. The first inlet of the storage tank communicates with the outlet of the storage tank through a pulp supply line having a pulp supply valve that opens to fill the supply tank, the storage tank predetermining the supply tank. 13. The apparatus of claim 12 including a level sensor that closes the pulp feed valve when the level being filled is satisfied. 14. A second inlet of the storage tank communicates with a compressed air supply line to supply compressed air from the outlet of the storage tank to discharge the pulp in the storage tank filled into the mold cavity. 14. The device of claim 13, wherein: 15. A suction chamber including means for sucking the mold surface so as to dry a molded product, the suction chamber communicating with the mold surface through a passage in the fixed mold portion, and the suction port of the suction chamber through a suction valve. 15. An apparatus according to any one of claims 11 to 14 having a vacuum supply line. 16. An exhaust line communicating with the exhaust port of the suction chamber through a valve to remove air from the mold surface while pressure is applied to a quantity of pulp in the mold cavity. 15 devices. 17. A steam supply line communicating with the mold cavity through a steam valve for supplying steam to the mold cavity to dry the molded product on the mold surface. The device according to claim 16. 18. The apparatus of claim 17 including a vacuum source in communication with the mold cavity through a vacuum valve for aspirating the mold cavity to remove water from the mold cavity. 19. The apparatus according to claim 11, wherein the mold surface of the fixed mold portion has a wire mesh attached to the fixed mold portion. 20. Apparatus according to any of claims 11 to 19 comprising means having a piston and cylinder arrangement for actuating the movable mold part. 21. Movable into the open mold between the mold surface and the molded product separated from the mold surface by suctioning the movable mold part, stopping suction to the movable mold part. 21. Apparatus according to any of claims 11 to 20 having a reciprocating tray which is movable to exit the molded part together with the molded product.