JP3331211B2 - Pulp molded product - 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 molded article having a screw portion and having a good sealing property with a cap. More specifically, the present invention relates to a pulp molded article having a screw portion on which the shape of a molding surface of a mold is faithfully transferred.
The present invention also relates to a method for producing the pulp molded article.

[0002]

2. Description of the Related Art As a pulp container having a thread portion formed thereon, there is known a pulp container in which a thread portion is formed in a paper cylinder by a calender press. However, in the calendar press, the shape of the screw and the shape of the container formed by the method are restricted, so that the sealing property with the cap is low, and the contents may leak out during use. Also, the strength of the paper cylinder itself is low,
Low durability against repeated opening and closing operations of the cap.

[0003] Japanese Patent Application Laid-Open No. 8-302600 discloses a pulp molded article having a convex portion such as a screw portion on the surface of the molded article. The convex portion is separately attached by, for example, an adhesive in a later step, or is formed in a drying step of the molded body. In the method of forming the projections in the drying step, the step of manufacturing the projections and the step of attaching the manufactured projections can be included in the molding step, so that a molded article can be efficiently produced. However, when a convex portion is formed in the drying step, the shape of the concave portion on the molding surface of the mold is not faithfully transferred depending on the shape of the convex portion, and each shape is rounded, the surface is roughened, or the convex portion is formed. In some cases, sufficient strength could not be obtained without increasing the density.

[0004] Accordingly, an object of the present invention is to provide a pulp molded article having a screw portion and having a good sealing property with a cap. Another object of the present invention is to provide a pulp molded article having a thread portion and having high durability against repeated opening and closing operations of the cap. It is a further object of the present invention to provide a pulp molded article in which the shape of a concave portion of a molding surface of a mold is faithfully transferred, and on which a thread portion having sufficient strength is formed.

According to the present invention, a screw portion is formed on the outer surface of the mouth and neck, and the cap having the screw portion is screwed onto the mouth and neck to measure the connection between the mouth and neck and the cap. and the overrun torque 1N · m or more, the open end of the mouth and neck, a pulp molded article in which the peripheral edge of the open hole edge has a flange portion formed is wound about a rotating ,
The pulp molded article is used as a papermaking mold.
The sheet corresponding to the screw portion in the rup molded article
A screw part is formed at the part of the paper making surface of the paper mold.
And the pulp mold is used as a heating mold
A screw portion is formed at a position corresponding to the screw portion in the molded body.
Using the pulp mold body
Under the pressing condition of the inserted expandable and contractible hollow core
Pulp molding formed by heating and drying
The object has been achieved by providing a body .

According to the present invention , a screw portion is formed on the outer surface of the mouth and neck.
And a cap having a screw portion is attached to the mouth and neck.
Between the mouth and neck and the cap measured in the screwed state
The overrun torque is 1 N · m or more,
At the open end, the periphery of the open end is formed by being wound about one turn.
Of pulp molded article having broken flange
A method for making a papermaking mold, the method comprising:
A screw portion is formed at a portion of the surface corresponding to the screw portion.
And the paper making using the paper making mold.
Pulp molding in which the screw portion is formed on the outer surface of the mouth and neck
Molded pulp molded article
Corresponds to the screw portion in the pulp molded article
Into the heating mold where the threaded part is formed
And then the expansion and contraction inserted into the pulp mold
An object of the present invention is to provide a method for producing a molded pulp molded article which is heated and dried under a state of being pressed by a hollow core .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. FIG. 1 is a perspective view of the pulp molded article 1, and FIG. 2 is an enlarged sectional view of the mouth and neck. FIG. 3 shows a partially cutaway perspective view of a pulp molded article 1 ′ having a form different from that of FIG. 1. The molded body 1, 1 'has a mouth and neck portion 2, 2' opened at an upper portion thereof, and further has a trunk 3,
It has a 3 'and bottoms 4, 4' and is cylindrical. The diameter of the mouth and neck 2, 2 'is smaller than the diameter of the trunk 3, 3'.

The molded bodies 1, 1 'have body portions 3, 3' formed at right angles to the bottom portions 4, 4 '. That is, the taper angles of the body portions 3 and 3 'are 0 degrees. In addition, the molded bodies 1 and 1 ′ have an overall height of 50 mm or more, preferably 100 mm or more. In addition, the molded object 1, 1 '
In some applications, the body parts 3, 3 'may not be formed at right angles to the bottom parts 4, 4'.

[0009] The molded articles 1 and 1 'do not have a seam or a thick portion due to bonding. Thereby, the strength of the molded bodies 1 and 1 'is increased, and the molded body has a good appearance impression.

In the molded article 1 shown in FIG.
A first mouth and neck 2a located on the tip side of the mouth and neck 2,
The first mouth and neck 2a has a larger diameter than the first mouth and neck 2a.
And a second mouth and neck portion 2 b located between the body and the torso 3. The first neck and neck 2a and the second neck and neck 2b are connected to the first step 7a.
Are articulated through. The second mouth and neck 2b is connected to the trunk 3 via a second step 7b. As a result, the mouth and neck 2 has a stepped shape. On the other hand, in the molded body 1 ′ shown in FIG. 3, the mouth and neck 2 ′ has a cylindrical straight shape.

The first neck portion 2a of the neck portion 2 of the molded body 1 shown in FIG. 1 has a flange portion 8 formed by winding the periphery of the opening end outward by about one turn. The flange portion 8 enhances sealing between the mouth and neck portion 2 and a top surface of a cap described later. Also, as shown in FIG.
A resin film 9 is laminated on the inner surface of the molded body 1 to impart water resistance to the molded body 1. The laminate of the resin film and the above-described flange portion 8 make the molded article 1 particularly suitable for containing a liquid.

The moldings 1, 1 'are formed using pulp as a main raw material. Of course, it may be formed from 100% pulp. When using other materials in addition to pulp,
The compounding amount of the material is 1 to 70% by weight, particularly 5 to 50% by weight.
It is preferable that Other materials include inorganic substances such as talc and kaolinite, inorganic fibers such as glass fiber and carbon fiber, synthetic resin powder such as polyolefin, synthetic fiber,
Non-wood or vegetable fibers, polysaccharides and the like.

[0013] The second mouth and neck 2 of the molded body 1 shown in FIG.
b has a screw portion formed of a spiral screw thread 5 on its outer surface. On the other hand, a screw portion having a spiral screw thread 5 'is also formed on the outer surface of the mouth and neck portion 2' in the molded body 1 shown in FIG. Screws 5,
Caps (not shown) each having a thread portion formed of a thread complementary to 5 ′ are screwed together.

Examples of the shapes of the screw threads 5, 5 'include a trapezoidal screw, a triangular screw, a square screw, a round screw, and the like. The strength of the mouth and neck 2, 2' and the productivity of the molded bodies 1, 1 '( For example, ease of drying and shaping of the threads 5, 5 ')
An appropriate shape is selected according to the conditions. For example, when the ease of opening and closing the cap is important or when the number of times of opening and closing of the cap is large, it is preferable to use a round screw or a triangular screw, and when it is desired to tighten the cap with a large torque, the cap is unlikely to be loosened. If it is desired to increase the pull-out strength of the cap, a trapezoidal screw is preferable. As shown in FIG. 5, the shape of the thread in the molded bodies 1 and 1 'is a trapezoidal screw having a trapezoidal cross section.

In the molded articles 1, 1 ', the mouth and neck 2,
The overrun torque between the mouth and neck 2, 2 'and the cap measured with the cap screwed on the 2' is 1N ·
m, preferably 1.2 Nm or more, more preferably 5 Nm or more. Thereby, the mouth and neck 2,
The sealing property between the cap 2 'and the cap is improved, and the cap is less likely to loosen due to vibrations during transportation or the like, and leakage of the contents accommodated in the molded articles 1, 1' is effectively prevented. In particular, in the molded body 1 shown in FIG. 1, since the flange 8 is formed at the opening end as described above, the sealing performance with the cap is further improved. If the value of the overrun torque is 1 Nm or more, the larger the value, the better the sealing performance between the mouth and neck 2, 2 'and the cap is improved. In normal use, if the overrun torque value is 5 N · m, no overrun occurs. In consideration of the manufacturing method of the molded bodies 1 and 1 ′ and the composition of the molded bodies 1 and 1 ′, the upper limit of the overrun torque that can be achieved by the current technology is about 10 N · m. A detailed method of measuring the overrun torque will be described in an example described later.

As shown in FIG. 5, the peripheral length in the width direction of the threads 5, 5 'is S (mm), the width in plan view is W (mm), and the thickness In the embodiment, when the thickness of the mouth and neck is set to t (mm), the screw threads 5 and 5 ′ may satisfy the relationship of the following Expression (1) and Expression (2) or Expression (3). preferable.

1 <S / W ≦ 1.5 (1) 0 <W ≦ 10t (mm) (2) 0 <W ≦ 10 mm (3)

In the above formula (1), if the S / W is more than 1.5, the thread 5 may break during dehydration or drying,
Alternatively, the surface of the threads 5, 5 'cannot be smoothed, and the density of the threads 5, 5' cannot be increased. In the above formulas (2) and (3), when W is more than 10 t (mm) and more than 10 mm, respectively, the pulp fiber is deposited along the concave shape of the papermaking mold. Considered, it is not easier than space. In addition, it is not easy to perform positioning when the molded body is taken out of the papermaking mold and loaded into the heating mold.

A screw thread 5 having a shape corresponding to the concave shape of the mold;
5 'is formed faithfully, preventing breakage of thread 5,5',
The surface of the threads 5, 5 'is further smoothed, and
From the viewpoint of further increasing the density of 5 ′, the formula (1) is preferably represented by the following formula (1) ′.

1 <S / W ≦ 1.3 (1) ′

In this embodiment, the width W of the thread (that is, the length of the base of the trapezoid) is 0.5 to 10 mm, particularly 2 to 10 mm.
It is preferable that the thickness is 6 mm from the viewpoint of generating a sufficient tightening force and the degree of freedom of the size and shape of the molded body 1.

The thickness of the molded articles 1 and 1 '(ie, the mouth and neck 2,
An appropriate value is determined for the thickness 2 (thickness 2 ′) t (mm) according to the use of the molded articles 1 and 1 ′, etc., but a general range is 0.1 mm.
It is preferably from 2 to 10 mm, particularly preferably from 0.4 to 2 mm. Within this range, the sealing performance between the mouth and neck 2, 2 'and the cap is further improved, and the durability when the cap is frequently opened and closed is further improved.

When the rising angle θ (see FIG. 5) of the mouth and neck portions 2 and 2 ′ at the screw thread 5 ′ from the basal plane B exceeds 90 °, the follow-up due to the expansion of the core described later becomes insufficient,
The temperature is preferably more than 0 degree and less than 90 degrees from the point that the pressing of the molded body by the core becomes insufficient.

Also, a corner 5a of the portion where the screw threads 5, 5 'stand up from the basal plane B of the mouth and neck 2, 2' (see FIG. 5).
Is preferably rounded in order to facilitate the transfer of a concave shape of a heating mold described later, and specifically, the curvature R of the corner 5a is 0.1 mm or more, particularly 0.3 mm. ~ 5m
m is preferable. In addition, the screw thread 5 shown in FIG.
The curvatures of the two corners 5a, 5a in 5 'may be the same or different. For example, when the cross-sectional shape in the width direction of the threads 5, 5 'is not a trapezoidal shape of an equal leg as shown in FIG. Often have different curvatures. But,
In any case, it is preferable that the curvatures of the two corners 5a, 5a are both in the above-mentioned range.

The height H of the threads 5, 5 'from the base surface 2a.
Are easy to form the threads 5,5 'and the threads 5,5'
An appropriate value is determined in consideration of the tightening force between the screw and the cap. Generally, the height H of the threads 5, 5 'is 0.3 mm or more, especially 0.3 to 10 mm, especially 0.5 to 4 mm, so that a sufficient tightening force is generated, and opening and closing is easy. It is preferable from a certain point.

Although it has been difficult to produce a pulp molded article having a thread portion having the above-described shape and dimensions by a conventional method, it can be easily produced by using a preferred method described later.

The effective number of turns of the screw portion is preferably 0.75 or more. If the effective number of turns is less than 0.75, the cap withdrawal strength of the screwed cap may be low, and the tightening force of the cap may be weak, so that sufficient sealing properties may not be obtained. Also, put the cap on the mouth and neck 2,2 '
The difference between the tightening torque when screwing into the cap and the opening torque when removing the screwed cap is measured under the same conditions (the same shape and dimensions of the container and cap). It is smaller than when the mouth and neck of the main body and the plastic cap are used. That is, so-called torque loss is reduced. This means that if the container body is made of pulp mold, the cap is less likely to loosen even with a small tightening torque, and the cap can be sealed without spilling the contents even with a small force compared to using a plastic container body. Can be done, which means higher security.

The number of threads is determined to be 2 to 64 threads / 25.4 mm, particularly 4 to 12 threads / 25.4 mm, according to JIS standard dimensions. It is preferable from the viewpoint of mountain durability. Although it is possible to improve the sealing property by increasing the number of threads, if the number of turns until the tightening is completed is too large, the usability when attaching and detaching the cap may be reduced.

[0029] The second mouth and neck 2 of the molded body 1 shown in FIG.
In the vicinity of the connecting portion between the b and the second step portion 7b, the screw thread 5 constituting the thread portion of the mouth and neck portion 2 and the thread thread constituting the thread portion of the cap are prevented from being screwed by a predetermined amount or more. A screw stopper rib 6 is formed. On the other hand, the compact 1 ′ shown in FIG.
A screw stopper rib 6 'is also formed near the connection between the mouth and neck 2' and the trunk 3 'in the mouth and neck 2'. The screw stopper ribs 6, 6 'may be of a type in which the cap is stopped by abutting on the end face of the threaded portion of the cap, or a type in which the threaded portion of the cap moves over the cap to stop the cap. In the molded articles 1 and 1 ', the screw threads are four, so the screw stopper ribs 6,
In the cross section of the mouth and neck 2, 2 ', four 6' are formed at intervals of 90 degrees. This state will be described with reference to FIG. 4 taking the molded body 1 'as an example. As shown in FIG. 4, the screw stopper rib 6 ′ has a first surface 6 parallel to a normal to an outer surface of the mouth and neck 2 ′ in a cross section of the mouth and neck 2 ′.
a and the second surface 6 that smoothly connects the first surface 6a and the outer surface of the mouth and neck 2 ′ in the screwing direction C of the cap.
b. By providing the screw stopper ribs 6, 6 ', overrun when the cap is mechanically tightened is effectively prevented. As a result, the torque value when mechanically tightening the cap can be further increased. If the torque value can be increased sufficiently, the screw stopper rib 6,
6 'may not be provided.

The center line average roughness Ra (JIS B 0601) of the mouth and neck portions 2 and 2 'including the threads 5 and 5' is preferably 50 μm or less, more preferably 25 μm or less, and further preferably 10 μm or less. The sealing performance between the mouth and neck 2, 2 'and the cap is further improved. Mouth and neck 2,2 '
In order to obtain such a highly smooth state, for example, a method of performing a predetermined polishing process can be mentioned. In particular, when a manufacturing method described later is used, the mouth and neck portion 2, 2 ′ can be formed without performing such a polishing process. Can be in a highly smooth state. The smaller the value of the center line average roughness, the better the sealing property between the mouth and neck 2, 2 'and the cap is improved, but the lower limit achievable with the current technology is 0.1 μm. It is about. In addition, it is preferable that the maximum height Ry (JIS B 0601) of the mouth and neck portions 2 and 2 ′ including the screw threads 5 and 5 ′ is 500 μm or less for the same reason.

In addition, the mouth and neck 2, including the threads 5, 5 '
Wax pick method (JIS P81) as a measure of 2 'surface strength [hardness of surface peeling (hardness of peeling), difficulty of fluffing during use, and difficulty of strength reduction of mouth and neck]
When the measurement value of 29) is preferably 5 A or more, more preferably 10 A or more, and still more preferably 16 A or more, the durability against repeated opening and closing operations of the cap increases,
Further, fluffing of pulp fibers, peeling of paper, falling off of paper powder, and the like are prevented, and deterioration of the appearance of the molded articles 1, 1 'is prevented.

In order to obtain a surface hardness at which the measured value of the wax pick method is equal to or more than the above value, a synthetic resin or a natural resin is externally added to the mouth and neck portions 2 and 2 ′ including the screw threads 5 and 5 ′. There is a method of adding internally. Examples of the method of externally adding these resins include a method of laminating a resin film on the mouth and neck portions 2 and 2 ′ including the threads 5 and 5 ′, a method of coating a resin liquid, and a method of impregnating the resin liquid. Examples of the internal addition method include a method in which a resin is added in advance to a pulp slurry as a raw material of the molded bodies 1 and 1 ′. Examples of the resin film include a polyolefin film and a polyester film, and it is particularly preferable to use a polyester shrink film. As the resin previously added to the resin liquid or pulp slurry used for the coating or impregnation, acrylic resin, styrene resin, polyester resin, polyolefin resin, synthetic rubber resin, vinyl acetate resin, polyvinyl alcohol resin Resin, wax resin, polyacrylamide resin, polyamide epichlorohydrin resin, starch resin, gum resin, viscose resin,
Epoxy resin, melamine resin, phenolic resin,
Examples include a liquid containing a urea-based resin, a polyurethane-based resin, a fluorine-based resin, a silicon-based resin, and the like, and a single or a mixture of two or more of them may be used.

In the molded articles 1 and 1 ', caps are screwed to the mouth and neck portions 2 and 2', and the engagement amount of the thread of the screw portion in each of the mouth and neck portions 2 and 2 'and the cap is reduced. When the pull-out strength of the cap measured under a condition of 0.5 mm and one turn is preferably 5 N or more, more preferably 10 N or more, and still more preferably 20 N or more, The sealing property between the cap 2 'and the cap is further improved, the leakage of the contents contained in the compact 1, 1' is more effectively prevented, and the compact 1, 1 'is grasped only by the cap. Even when lifted, the cap does not come off and leakage of the contents is prevented. Similar to the above-described overrun torque, the larger the value of the pull-out strength is, the better the sealing performance between the mouth and neck 2, 2 'and the cap is improved. Although the upper limit of the pull-out strength is about 700 N, it is practically sufficient, though it depends on the composition of the molded articles 1 and 1 ′. A detailed method of measuring the pull-out strength will be described in Examples described later.

The mouth and neck 2,2 'including the threads 5,5'
Its density is 0.4-2.0 g / cm ^Three, Especially 0.6-
1.5g / cm^ThreeIs a point of durability and sealing property.
Is preferred. Density is any size from mouth and neck 2,2 '
Cut off the slices, measure the weight of the slices,
It was determined from measurement of the size (area) and thickness of the section.
Calculated from volume.

The mouth and neck 2,2 'including the threads 5,5'
It is preferable that the side surface compressive strength is 20 N or more, especially 30 N or more from the viewpoint of preventing buckling of the mouth and neck portions 2 and 2 ′.
If the upper limit of the lateral compressive strength is about 500N, it is practically sufficient. For the same reason, the vertical compressive strength of the mouth and neck portions 2 and 2 ′ is preferably 100N or more, particularly preferably 300N or more, and an upper limit of about 700N is practically sufficient. These compressive strengths are measured at a compression speed of 20 mm / min using a Tensilon tensile tester. Furthermore, the drop strength of the mouth and neck 2, 2 '(JIS Z 1
703) is preferably such that cracking and deformation do not occur in one drop from a height of 1.2 m. In measuring the drop strength, the molded bodies 1, 1 'are dropped such that the mouth and neck portions 2, 2' hit the falling surface.

The mouth and neck 2, including the threads 5, 5 '
2 ′ has a moisture permeability (JIS Z 0208) of 100
g / (m ² · 24 hr) or less, especially 50 g / (m ² · 2
4 hr) or less is preferable from the viewpoint of preserving the contents (for example, preventing caking which hardens due to the powder detergent absorbing moisture).

The compacts 1, 1 'of the present embodiment preferably have a compressive strength in the vertical direction of 100 N or more, particularly 300 N or more, from the viewpoint of preventing buckling of the compacts 1 and 1'.
If the upper limit of the vertical compressive strength is about 700N, it is practically sufficient. The method for measuring the vertical compressive strength is as described above. Also, the drop strength (JISZ
1703) is preferably such that cracking and deformation do not occur in a single drop from a height of 1.2 m in any of the upright, inverted and side states. When measuring the drop strength, the molded bodies 1 and 1 'are filled with the contents (basically filled with water, and in the case of a commercial product, the contents are filled with a specified amount). 'Is sealed with a cap.

Next, a preferred method for producing the molded article of the present invention will be described with reference to the production of the molded article 1 'shown in FIG.
This will be described with reference to FIG. It goes without saying that the molded body 1 shown in FIG. 1 can be manufactured by the same method.

In the present manufacturing method, a papermaking mold having a threaded portion at a site on the papermaking surface of the papermaking mold corresponding to the threaded portion of the molded product 1 'is used. A molded body 1 'having a screw portion formed on the outer surface of the mouth and neck portion 2' is formed by papermaking using a mold.

More specifically, first, as shown in FIG. 6A, a papermaking metal comprising two split molds 11, 11 and having a cavity 12 of a predetermined shape formed by combining the split molds. A mold 10 is prepared. On the inner surface of the cavity of the papermaking mold 10, a screw thread (hereinafter referred to as a corresponding screw thread) 16 is formed at a portion corresponding to the screw thread 5 'of the molded body 1'. The corresponding thread 16 preferably satisfies the relationship of (4) and (5) described later.

Cavity 12 in papermaking mold 10
Communicates with the outside of the papermaking mold 10 through a slurry injection port 15 opened to the outside. Cavity 12
Is covered by a papermaking net (not shown) having a mesh of a predetermined size. Each of the split dies 11, 11 is formed with a plurality of communication passages 13 communicating from the inside (that is, the inner surface of the cavity 12) to the outside. Each communication path 13 is connected to suction means (not shown) such as a suction pump.

In this state, a filling nozzle 17 is inserted into the slurry inlet 15, and a predetermined amount of pulp slurry is injected into the cavity 12 through the filling nozzle 17. The pulp slurry concentration at this time is generally 0.1 to 5% by weight. Also, the pulp slurry may or may not be heated. Specifically, the temperature of the pulp slurry can be in the range of 0 to 90 ° C, more preferably 10 to 70 ° C, and even more preferably 40 to 40 ° C. Heating the pulp slurry to a high temperature is preferable because the dewatering efficiency increases.
Along with the injection of the pulp slurry, the inside of the cavity 12 is sucked under reduced pressure through the communication path 13 toward the outside of the papermaking mold 10 to suck moisture in the pulp slurry and to form a pulp fiber on the papermaking net covering the inner surface of the cavity 12. Is deposited. As a result, a water-containing pulp molded article 1 'formed by depositing pulp fibers is formed on the papermaking net. At this time, a predetermined amount of water (diluting water) is pressurized and injected into the cavity 12 to dilute the concentration of the pulp slurry in the cavity 12 at an initial stage and / or an end stage of the formation of the molded body 1 ′. Uneven thickness of the body 1 'can be effectively suppressed. The initial stage of formation is cavity 1
2 means that the pulp supplied into the pulp is 30% or less, particularly 20% or less of the whole pulp required for molding. The term "end of formation" refers to a state in which the pulp supplied into the cavity 12 accounts for 70% or more, particularly 80% or more of the entire pulp required for molding. The supply amount of the dilution water is preferably such that the concentration of the pulp slurry is reduced to 80% or less, particularly 20 to 60%.

The filling nozzle 17 is used as a means for supplying pulp slurry and a pressurized fluid described later. The filling nozzle 17 includes a driving plate 17a, a nozzle 17b vertically penetrating the driving plate, a three-way valve 17c attached to the upper end of the nozzle 17b, a slurry supply pipe 17d connected to the three-way valve 17c, and a pressurized fluid supply, respectively. A tube 17e is provided. By switching the three-way valve 17c, the nozzle 17b is alternatively connected to the slurry supply pipe 17d and the pressurized fluid supply pipe 17e. When the pulp slurry is injected into the cavity 12, the nozzle 17b is connected to the slurry supply pipe 17d.
Connected to. Further, the driving plate 17a is inserted into the slurry inlet 15 so that the slurry inlet 15 is closed.

The formed molded body 1 'is subjected to a dehydration step. First, as shown in FIG. 6B, the papermaking mold 10 is sucked from the inside to the outside through the communication path 13.
Under this condition, while the filling nozzle 17 is fixed at the position at the time of papermaking, the three-way valve 17c is switched to connect the nozzle 17b to the pressurized fluid supply pipe 17d, and a pressurized fluid supply source (not shown) Supplies a predetermined pressurized fluid into the cavity 12. As described above, the slurry injection port 15 is
7a is closed, so that the inside of the cavity 12 is airtight. Here, the air-tight state does not mean a state in which the inside of the cavity 12 is completely air-tight, but means that the inside of the cavity 12 is air-tight so that the pressure inside the cavity 12 becomes equal to or higher than a pressure described later by blowing a pressurized fluid. . The blown pressurized fluid passes through the molded body 1 ′ and is discharged to the outside through the communication passage 13.

As the pressurized fluid, for example, steam or superheated steam (hereinafter, both are collectively referred to as steams) can be used, and it is particularly preferable to use superheated steam. By blowing the steam, the temperature of the water contained in the molded article 1 'instantaneously rises due to the condensation heat transfer by the steam, the viscosity and surface tension of the water can be reduced, and the molded article 1' Moisture is instantaneously blown off very efficiently. As a result, the dewatering efficiency can be improved. Since this dehydration method does not mainly involve heat exchange, it is a very energy-efficient method. In addition, since the dehydration is completed instantaneously, the dehydration time can be reduced. Since a core made of an elastic material used in a heating and drying step described later is not used for dehydration, a machine time for inserting the core into the cavity is not required, and the machine time can be reduced. Further, since the blowing pressure is lower than the pressure for press dewatering, there is an advantage that a trace of the papermaking net is hardly formed on the surface of the obtained molded body 1 ', and a molded body having a good appearance can be obtained.

When the pressure in the cavity 12 is 98
kPa or more, especially 196 kPa or more, especially 294 k
It is preferable that the pressure is blown so as to be Pa or more. The pressure in the cavity 12 due to the blowing is preferably higher as long as the value is equal to or higher than the above value, but the degree of water removal gradually becomes saturated with an increase in the blowing pressure.
The economically viable upper limit of the pressure is about 980 kPa. The pressure in the cavity 12 refers to a difference between an inlet pressure and an outlet pressure of vapors into the cavity 12.

The above-mentioned dilution water supplied into the cavity 12 when the slurry remains in the cavity 12 or at the end of the formation of the molded body 1 ′ remains in the cavity 12 when the steam is blown. It is preferable to carry out from the time. As a result, the water in the cavity 12 is forcibly discharged out of the mold, and the drainage time is reduced. The time for blowing the steam is preferably about 2 to 20 seconds, particularly about 3 to 15 seconds, and the dehydration is completed in a very short time. By this dehydration, for example, a molded body having a water content of 75 to 80% by weight before dehydration is dehydrated to about 40 to 70% by weight.

When using superheated steam as steam,
It is sufficient that the superheated steam is heated so that the internal pressure of the mold becomes equal to or higher than the above-mentioned value and the steam is not condensed until just before the steam is blown into the mold. The steam may be sufficiently heated, but the dewatering effect does not change significantly.

As the pressurized fluid used for dewatering the molded body 1 ', compressed air can be used in addition to the above-mentioned steams. By blowing compressed air, moisture is instantaneously removed from the wet compact 1 ′ by a physical mechanism that does not mainly perform heat drying by heat exchange. The compressed air has a pressure in the cavity 12 of 196 kP.
It is preferable that the gas is blown at a pressure of at least a, especially at least 294 kPa. The upper limit of the pressure is about 1471 kPa for the same reason as in the case of steams. The blowing time of the compressed air is preferably 10 to 60 seconds, particularly preferably 15 to 40 seconds. The pressure (original pressure) of the compressed air is not particularly limited as long as the mold internal pressure is equal to or higher than the above-described value. Regarding the points which are not particularly described in the compressed air, the description in detail regarding the steams is appropriately applied.

Either one of the steam and the compressed air may be used, but preferably both are used in combination from the viewpoint of dehydration efficiency. In particular, it is preferable to blow compressed air after blowing steam. The reason for this is that if the blowing time of steam is long, there may be a large difference in the distribution of moisture content in the vertical direction of the molded body 1 ′. This is because it is effective to blow compressed air after sufficiently raising the temperature of the water contained in the molded body. When steam and compressed air are blown in this order, the pressure of the steam is 98 kPa or more, particularly 196 kPa or more, particularly 294 kPa or more, and the blowing time is preferably 2 seconds to 20 seconds, particularly 3 seconds to 15 seconds. Air pressure is 196 kPa or more, especially 2
At 94 kPa or more, the blowing time is 2 to 25 seconds, especially 5
It is preferably for about 20 seconds. It is preferable that the blowing of the steam and the compressed air be continuous from the viewpoint of dehydration efficiency.

When the molded body 1 'has been dehydrated to a predetermined moisture content, the supply of the pressurized fluid is stopped, and the filling nozzle 17 is taken out of the papermaking mold 10 as shown in FIG. Next, the papermaking mold 10 is opened, and the molded body 1 'dehydrated to a predetermined moisture content is taken out using a predetermined handling means. Threads are formed at the mouth and neck of the obtained molded body 1 '. In this case, the water content of the mouth and neck after the pressure dehydration was 4
0-90% by weight, especially 70-90% by weight (based on dry weight)
By doing so, it is possible to form a screw thread having excellent sealing properties and other properties.

The molded article 1 'taken out is then subjected to a heating and drying step. 7 (a) to 7 (c) sequentially show a heating and drying step, FIG. 7 (a) shows a core inserting step, FIG. 7 (b) shows a heating and drying step, and FIG. ) Is a step of opening the heating mold.

First, a heating mold 20 in which a cavity 22 having a shape corresponding to the outer shape of a molded body 1 ′ to be molded is formed by combining a pair of split molds 21 and 21 is prepared separately. The mold is heated to a predetermined temperature. In the present embodiment, the cavity shape of the heating mold and the cavity shape of the papermaking mold are the same. Into the heated cavity of the heating mold, a water-containing molded body 1 'dehydrated to a predetermined water content is loaded by using a predetermined handling means. No net is arranged on the inner surface of the cavity 22. Each of the split molds 21 and 21 is formed with a plurality of communication passages 23 communicating from the inside (that is, the inner surface of the cavity 22) to the outside. Each communication path 23 is connected to suction means (not shown) such as a suction pump.

On the inner surface of the cavity of the heating mold, a screw thread 26 (hereinafter referred to as a corresponding screw thread) satisfying the following equations (4) and (5) is formed on the screw thread 5 'of the molded body 1'. It is formed at the corresponding site.

The corresponding thread 26 has a circumferential length in the width direction of s.
(Mm), and when the width in plan view is w (mm), the following formulas (4) and (5) are satisfied. Heating mold 20 having corresponding threads 26 satisfying such a relationship
Is used, the screw thread 5 'having a shape corresponding to the shape of the corresponding screw thread 26 is faithfully formed, breakage of the screw thread 5' is prevented, the surface of the screw thread 5 'becomes smooth, and the screw thread 5' is formed. The density of 5 'is increased.

1 <s / w ≦ 1.5 (4) 0 <w ≦ 10 mm (5)

More preferably, the corresponding thread 26 satisfies the following relationship. 1 ≦ s / w ≦ 1.3 (4) ′

The angle θ ′ of the corresponding thread 26 corresponding to the rising angle θ of the thread 5 ′ is preferably more than 0 degree and less than 90 degrees corresponding to the rising angle θ. Furthermore, the corner of the corresponding screw thread 26 corresponding to the corner 5a of the screw thread 5 '(that is, the portion where the corresponding screw thread 26 falls from the inner surface of the mold corresponding to the base surface B of the mouth-neck portion 2' of the molded product). The curvature R ′ of the corner portion) is preferably 0.1 mm or more, particularly preferably 0.3 to 5 mm.

Next, as shown in FIG. 7 (a), the expandable and contractible hollow core 24 is placed in the contracted state while the heating mold 20 is sucked from the inside to the outside. Insert into the molded body 1 '. In the present invention, the expansion and contraction means the core 24
The case where the volume changes due to expansion and contraction of the core and the case where the core 24 itself does not expand and contract but the volume changes by supplying fluid to or removing fluid from the interior are included. Examples of the former include a core made of an elastic material such as natural rubber, urethane, fluorine-based rubber, silicone-based rubber or elastomer, and examples of the latter include plastic materials such as polyethylene and polypropylene, and plastic materials such as these. And a core formed of a flexible material such as papers and cloths, a film in which aluminum or silica is vapor-deposited on the above film, a film in which aluminum foil is laminated on a film of these plastic materials. In the present embodiment, a bag-shaped (balloon-shaped) core made of a stretchable elastic material is used as the core 24.

Next, as shown in FIG.
The core 24 is expanded by supplying a predetermined fluid into the inside, and the hydrated molded body 1 ′ is heated by the expanded core 24 by the heating mold 2.
0, that is, toward the inner surface of the cavity 22. As a result, the drying of the molded body 1 'proceeds, and the inner surface shape of the cavity 22 is transferred to the molded body 1'. In this case, the corresponding screw thread 26 formed in the heating mold 20
Satisfies the above-described relations of Expressions (4) and (5), so that the width of the pile of pulp fibers deposited in the corresponding screw thread 26 becomes the circumferential length of the corresponding screw thread 26 in the width direction. s, and even when the stack is given a convex shape, the stack is sufficiently pressed without breaking, and the corresponding thread 2
6 is faithfully transferred, and the density in the corresponding thread 26 is sufficiently increased. As a result, the thread 5 'in the obtained molded body 1' becomes a sufficiently transferred shape of the corresponding thread 26, and the surface of the thread 5 'becomes smooth. Further, the strength of the thread 5 'is improved.

As the fluid used to expand the core 24, for example, air (pressurized air), hot air (heated pressurized air), superheated steam, oil (heated oil), and other various liquids are used. Is done. In particular, it is preferable to use air, hot air, or superheated steam from the viewpoint of operability and the like. The pressure for supplying the fluid is preferably 0.01 to 5 MPa, particularly preferably 0.1 to 3 MPa.

In particular, by improving the exhaustability (exhaustability of water vapor generated by heating) at the portion corresponding to the mouth and neck in the heating mold 20, a screw thread having excellent sealing properties and other characteristics is provided. 5 ′ can be formed.

When the molded body 1 ′ is sufficiently dried, FIG.
As shown in (c), the fluid in the core 24 is drained, and the core 24 is reduced and taken out. Further, the heating die 20 is opened, and the molded body 1 'is taken out by a predetermined handling means. The mouth and neck 2 'of the molded article 1' thus obtained
The thread 5 'in the above formula satisfies the above-described formula (1), (2) or (3), and the shape of the concave portion in the heating die is faithfully transferred. Also thread 5 '
Has a smooth surface, higher density and higher strength.

Next, another preferred method for producing the molded article of the present invention will be described. With respect to the present manufacturing method, only the points different from the above-described manufacturing method will be described, and as for the same points, the detailed description regarding the above-described manufacturing method will be appropriately applied.
In the present production method, a pulp slurry is supplied into the cavity of a papermaking mold in which a cavity having a predetermined shape is formed by combining a pair of molds and combining the molds. After forming a water-containing molded body on the (molding surface), a scalable hollow core is inserted into the molded body, and then a predetermined fluid is supplied into the core to expand the core. Then, the molded body is pressed toward the cavity inner surface (molding surface) by the expanded core to dehydrate.

The structure of the papermaking mold in the present manufacturing method is the same as that shown in FIG. 6 (a), and a portion corresponding to the thread of the molded product on the inner surface of the cavity of the papermaking mold is
A corresponding thread is formed. As the core for pressing and dewatering the molded body, the same one as shown in FIG. 7A can be used. The fluid used to expand the core and the supply pressure thereof can be the same as in the above-described manufacturing method.

When the molded article can be dewatered to a predetermined moisture content and the shape of the inner surface of the cavity is sufficiently transferred to the molded article,
Drain the fluid in the core and reduce it. Next, the reduced core is taken out of the molded body, the papermaking mold is opened, and a water-containing molded body having a predetermined water content is taken out by a predetermined handling means. Threads are formed at the mouth and neck of the obtained molded body.

The molded product taken out is then subjected to a heating and drying step. In the heating and drying step, substantially the same operation as the above-described pressure dehydration step using a core is performed, except that the papermaking and dehydration are not performed and the heating mold is used in a state heated to a predetermined temperature. . That is, first, a heating mold in which a cavity having a shape corresponding to the outer shape of a molded body to be molded is formed by combining a pair of molds is separately prepared, and the heating mold is heated to a predetermined temperature. Keep it. Then, a water-containing molded body dehydrated to a predetermined moisture content is loaded into the heated cavity of the heating mold by a predetermined handling means.

Next, another core having a different shape and / or material from the core used in the pressure dehydration step is inserted into the molded body, and a fluid is supplied into the core to remove the core. The molded body is expanded and the molded body is pressed toward the inner surface of the cavity by the expanded core. The material of the core and the supply pressure of the fluid can be the same as in the pressure dehydration step. The molded body is heated and dried under this condition. Thereafter, the same operation as in the above-described manufacturing method is performed.

The present invention is not limited to the above embodiment. For example, a pulp molded article that satisfies the relations of the formulas (1) and (2) or (3) can be manufactured by a method other than the above-described manufacturing method. For example, in the above-described manufacturing method, the above formulas (4) and (5) are pressed by a core.
The pulp fiber was completely filled in the corresponding screw thread satisfying the relationship of (1) to form a screw thread. Alternatively, a corresponding screw thread that satisfies the expression (5) but is deeper than the corresponding screw thread is used. By using a heating mold having, and by appropriately adjusting the degree of pressing of the pulp fiber to form the thread in a state where the pulp fiber is not completely filled in the corresponding thread,
A molded article having a thread having a shape satisfying the relationship of (1) and (2) or (3) can be manufactured.

[0070]

The present invention will be described in more detail with reference to the following examples. However, it goes without saying that the scope of the present invention is not limited to such an embodiment.

Example 1 A pulp molded article was manufactured by the method shown in FIGS. 6 (a) to 6 (c) and FIGS. 7 (a) to 7 (c). Pulp slurry is NBKP / LBKP
= 50% by weight / 50% by weight, to which a paper strength agent, aluminum sulfate, a sizing agent, a retention aid and the like were added to make the total concentration 1% by weight. Table 1 shows the shapes and dimensions of the threads at the mouth and neck of the obtained molded article.

Examples 2 to 5 In Example 2, a polyester shrink film was laminated on the mouth and neck of the molded product. In Example 3, the mouth and neck of the molded article was coated with an emulsion of an acrylic resin. In Example 4, an acrylic resin emulsion and a melamine resin emulsion were added to the mouth and neck of the molded body at 50% by weight /
The blend blended at 50% by weight was impregnated. In Example 5, a pulp slurry containing 30% by weight of polyethylene synthetic resin fibers was used. Except for these, a pulp molded article was manufactured in the same manner as in Example 1. Table 1 shows the shapes and dimensions of the threads at the mouth and neck portion 2 of the obtained molded body.

Comparative Example 1 A paper tube (manufactured by Shofudo Co., Ltd., outer diameter φ70 mm, number of thread turns 1.25, number of threads 6.23 m)
m, screw thread width 3.5 mm).

[Evaluation of Performance] The obtained molded body was measured for overrun torque, pull-out strength, center line average roughness of the mouth and neck, surface strength by durometer and durometer hardness by the following methods. . Further, the measurement of the side compressive strength and the density was performed by the above-described method. Furthermore, the sealability between the mouth and neck and the cap and the degree of fluffing of the mouth and neck after repeated opening and closing of the cap were measured by the following methods. Table 1 shows the results.

<Overrun torque> Torque gauge (TO
The measurement was performed using MECHANICAL TORQUE METER 2-TM75 manufactured by HNICHI. The cap used was a wide height cap manufactured by Kao Corporation. This cap was manually tightened to measure the torque over the cap (tightening torque).

<Pull-out Strength> A jig to be attached to a tensile tester was attached to the cap, and the molded product and the cap were tightened to a torque of 3 N · m with the above-mentioned torque gauge. It was pulled at a speed of 20 mm / min, and the force when the cap was pulled out of the molded body was measured.

<Center Line Average Roughness of the Mouth and Neck> The surface roughness was measured using a surface roughness profile measuring machine [Surfcom 120A, Tokyo Seimitsu Co., Ltd.].

<Surface Strength of Neck and Neck by Wax Pick Method> The surface strength was measured according to JIS P8129. After the wax is fused to the surface of the mouth and neck and allowed to cool, the wax is peeled off from the surface of the mouth and neck, and the wax number (2A to 20A) that does not damage the surface of the mouth and neck is defined as the surface strength. The higher the wax number, the higher the surface strength. However, the surface strength could not be evaluated for a molded article coated with a thermoplastic resin or a molded article impregnated with a large amount of the thermoplastic resin.

<Durometer Hardness of Mouth and Neck> The durometer hardness is a measure of the difficulty of crushing the measurement target site, and here is a measure of the difficulty of reducing the strength of the mouth and neck.
Durometer hardness was measured according to JIS K7215. Rubber hardness tester [GS-809 manufactured by Teclock Corporation]
Shore A type] was used. The hardness calculation formula is as the following formula (A). 100-40 × h (A) In the formula, h represents the depth of the depression (mm). Measuring method: The molded body was erected, the hardness meter was held by hand and moved horizontally, and the outer peripheral surface of the mouth and neck portion where the thread was formed was pressed by the indenter portion of the rubber hardness meter. Within 1 second after the pressing, the depth h (mm) of the depression was measured, and the average value calculated from the above formula (A) with the number of measurements n = 10 was defined as the durometer hardness.
If the thickness of the compact is thin and soft, JIS K72
A test piece was cut out from the molded body in accordance with No. 15 and the measurement was performed by pressing the test machine while the test piece was placed on a glass plate. Also,
If necessary, a D-type testing machine was used, or when the test pieces were thin and difficult to measure, several test pieces were superposed and measured.

<Sealing Property of Mouth and Neck and Cap> The molded product was filled with Kao Corporation's powder bleach Wide Hiter (trade name), and the cap was set to about 1.
It sealed until it became 47 N * m (15 kgf * cm).
Next, the molded body was turned upside down and shaken up and down 10 times, and then erected again to remove the cap. The presence or absence of powder on the outer surface of the mouth and neck of the molded body and the threaded portion of the inner surface of the cap and the like was visually determined.

<Degree of Fluff on Mouth and Neck after Repeated Opening and Closing of Cap> After repeating the opening and closing of the cap, the degree of fluff on the mouth and neck was visually determined.

[0082]

[Table 1]

As is clear from the results shown in Table 1, it can be seen that the pulp molded products of Examples 1 to 5 (products of the present invention) have high sealing properties between the mouth and neck and the cap. In particular, in the molded articles of Examples 2 to 5 in which the resin was externally or internally added to the mouth and neck, it was found that the fluffing of the mouth and neck after repeated opening and closing operations of the cap was suppressed to a low level.

Example 6 A plastic molded article having the same shape and dimensions as in Example 1 was molded. Each of the pulp molded article of Example 1 and the plastic molded article was screwed with a plastic cap (cap of Wide Height Co., Ltd. manufactured by Kao Corporation) and 2.0 Nm (20 kgf) using a torque gauge. (Cm). Immediately thereafter, the opening torque was measured. The opening torque of the pulp molded article of Example 1 was 1.96 to 2.
45Nm, torque cross 0.49 ~ 0.98N
M (16 to 30%). On the other hand, the opening torque of the plastic molded body is 0.98 to 1.47 N.
・ M, and the torque loss is 1.47 to 1.96 N ・ m
(50-66%).

[0085]

According to the pulp molded article of the present invention, the sealability with the cap is improved. Further, according to the pulp molded article of the present invention, durability against repeated opening and closing operations of the cap is increased. Further, according to the pulp molded article of the present invention, the shape of the concave portion on the molding surface of the mold is faithfully transferred, and the strength of the screw portion is sufficiently increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a pulp molded article of the present invention.

FIG. 2 is an enlarged sectional view of a mouth and neck in the pulp molded article shown in FIG.

FIG. 3 (a) is a partially cutaway perspective view showing another embodiment of the pulp molded article of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a cross-sectional view of a thread in a width direction.

6 (a) is a pulp slurry injection step, FIG.
FIG. 6B shows a dehydration step by supplying a pressurized fluid, and FIG. 6C shows a step of opening a papermaking mold.

7 (a) shows a core inserting step, FIG. 7 (b) shows a heating drying step, and FIG. 7 (c) shows a heating mold opening step.

[Explanation of symbols]

 Reference Signs List 1, 1 'pulp molded article 2, 2' mouth and neck 3, 3 'trunk 4, 4' bottom 5, 5 'thread 6, 6' screw stopper rib 7a, 7b step 8 flange 9 resin film

Continuation of the front page (56) References JP-A-8-302600 (JP, A) JP-A-5-139433 (JP, A) JP-A-55-8139 (JP, A) Jpn. , U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B65D 1/00-1/48 D21J 3/00-3/12

Claims (9)

(57) [Claims] 1. A screw portion is formed on an outer surface of a mouth and neck portion, and an overrun between the mouth and neck portion and the cap is measured when a cap having a screw portion is screwed into the mouth and neck portion. The torque is 1 Nm or more, and at the open end of the mouth and neck,
A pulp molded article having a flange formed by winding the periphery of the opening end about one turn , wherein the pulp molded article is used as a papermaking mold.
The sheet corresponding to the screw portion in the rup molded article
A screw part is formed at the part of the paper making surface of the paper mold.
And the pulp mold is used as a heating mold
A screw portion is formed at a position corresponding to the screw portion in the molded body.
Using the pulp mold body
Under the pressing condition of the inserted expandable and contractible hollow core
Pulp molding formed by heating and drying
Body . 2. The height of a thread of said screw portion is 0.3 mm.
2. The effective number of turns is 0.75 or more.
The pulp molded article according to the above. 3. The molded pulp molded article according to claim 1, wherein a pull-out strength of the cap measured in a state where a cap having a threaded portion is screwed to the mouth and neck portion is 5 N or more. 4. The pulp molded article according to claim 1, wherein a center line average roughness of the mouth and neck portion including the screw portion is 50 μm or less. 5. The pulp molded article according to claim 1, wherein a resin is externally or internally added to the mouth and neck portion including the screw portion. 6. The pulp molded article according to claim 1, wherein a side compressive strength of the mouth and neck is 20 N or more. To wherein said port neck, any claim 1-6 in which the screw stopper rib is formed to prevent a predetermined amount or more of screwing the screw portion of the cap and the screw portion of the mouth and neck A pulp molded article according to any one of the above. 8. The neck and neck, a first neck and neck located on the tip side of the neck and neck, a second neck and neck having a diameter larger than the first neck and neck, and both necks and necks. And a step portion connecting the first and second portions.
The pulp molded article according to any one of claims 1 to 7. 9. A screw portion is formed on an outer surface of the mouth and neck portion.
And a cap having a screw portion was screwed to the mouth and neck portion.
Overlap between the mouth and neck and the cap measured in a state
Torque is 1 Nm or more, and at the open end of the mouth and neck,
A flange formed by winding the periphery of the open end about one turn
The method for producing a pulp molded article having a part
Thus, as a papermaking mold, the papermaking mold in the papermaking surface
A screw portion is formed at a portion corresponding to the screw portion.
Of the mouth and neck by papermaking using the papermaking mold.
A pulp molded product having the screw portion formed on the outer surface
Molding and molding the pulp molded body,
In the part corresponding to the screw part in the
It is loaded into the heating mold where the thread is formed, and then
Scalable hollow inserted into the pulp molded body
Pulp molding that is heated and dried under the pressing condition of a core
Manufacturing method of molded body.