JP2001055217A - Hollow pulp molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the strength of an opening part, to heighten the sealability, to reduce the manufacturing cost, and to reduce the volume of the refuse by continuously or discontinuously forming m thick wall part which is thicker than a body part over a whole periphery of an area from an upper end face at the opening part to a specified depth. SOLUTION: A thick wall part 6 which is thicker than a body part 3 or a bottom part 4 is continuously formed over the whole periphery of an opening part 2 in an area from an upper end face 5 of the opening part 2 to a specified depth(d). The thick wall part 6 is expanded inward of a molded body 1 so that the mechanical strength of the opening part 2 can be sufficiently ensured in applications and shapes of the molded body. The overhang (x) in the horizontal direction from an inner wall of a part having no thick wall part 6 is 0.5 to 5.0 mm. By providing the thick wall part 6, a tab for sticking in sealing the upper end face 5 of the opening part 2 by a sealing paper or the like can be increased, and the adhesive strength of the upper end face 5 to the sealing paper or the like can be increased thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulp mold hollow molded article having a thick opening and a papermaking mold used for the production thereof.

[0002]

2. Description of the Related Art Plastic materials are generally used as raw materials for hollow containers such as containers having a lid and bottles because they have excellent moldability and are advantageous in terms of productivity. ing. However, since plastic has various problems in disposal, a hollow container made of pulp can be considered as an alternative. The hollow container made of pulp is economically excellent because it is easy to dispose and can be manufactured using waste paper as a raw material.

[0003] However, hollow containers made of pulp are inferior in strength, dimensional accuracy and surface properties as compared with plastic containers, and therefore, particularly when it is necessary to securely seal or when the container is repeatedly opened and closed. Although a plastic member for reinforcement is attached to a portion where a load is particularly applied during use, for example, an opening, a foreign substance other than pulp is generated at the time of disposal, and there is a disadvantage that it takes time to dispose and reuse the container. .

Accordingly, an object of the present invention is to provide a pulp molded hollow molded article having an improved strength of an opening.

[0005]

The present invention has an opening, a body, and a bottom, and the thickness of the body is smaller than the thickness of the body over the entire periphery of the opening from the upper end surface to a predetermined depth. The above object has been achieved by providing a pulp mold hollow molded body mainly formed of pulp, in which a thick portion having a large thickness is formed continuously or discontinuously.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a pulp mold hollow molded article of the present invention will be described based on preferred embodiments with reference to the drawings. FIG. 1 is a perspective view of a pulp mold hollow molded article (hereinafter simply referred to as a molded article) 1 according to a first embodiment of the present invention. The molded body 1 has an opening 2 formed in a cylindrical shape extending in a vertical axis direction at an upper portion thereof, and further has a body portion 3 and a bottom portion 4 and has a cylindrical shape. The diameter of the opening 2 is smaller than the diameter of the body 3.

In the opening 2, a thick portion 6 which is thicker than the thickness of the body 3 and the bottom 4 is formed in a region from the upper end surface 5 to a predetermined depth d. The thick portion 6 is formed continuously over the entire circumference of the opening 2.

[0008] As shown in FIG.
In a region from the upper end surface 5 to a predetermined depth d. Although the depth d depends on the use and shape of the molded body, it is generally 0.5 d.
~ 50mm (accuracy ± 1.0mm), preferably 5.0 ~
30 mm (accuracy ± 1.0 mm) is sufficient. The thick portion 6 can be formed from the upper end surface 5 of the opening 2 to the entire region in the depth direction.

As shown in FIG. 1, the thick portion 6
Overhangs inward. The degree of the overhang is determined from the viewpoint of ensuring the mechanical strength of the opening 2 sufficiently.
The amount x (see FIG. 1) of the opening 2 in the horizontal direction from the inner wall of the portion where the thick portion 6 is not formed is 0.
It is preferably 5 to 5.0 mm (accuracy ± 0.5 mm), and more preferably 1.0 to 3.0 mm (accuracy ± 0.5 mm). In addition, by providing the thick portion 6 in this manner, the area of the upper end surface 5 of the opening 2 is increased, and a margin for sealing the upper end surface 5 with a paper seal or the like can be increased. The adhesive strength between the end face 5 and the paper seal or the like can be increased.

The depth d of the thick portion 6 and the overhang amount x are such that the value of d / x is 0.1 to 100, preferably 1 to 30.
(The value of x / d is 10 to 0.01, preferably 1 to 1 /
If 30), the mechanical strength of the opening 2 can be sufficiently ensured. Further, as shown in FIG. 1, in the portion deeper than the depth d from the upper end surface 5 of the opening 2, the amount X of projection may be gradually reduced, and the inner wall of the opening 2 may be inclined. . Specifically, a tapered portion 6 a whose diameter gradually expands downward from the lower end (depth d) of the thick portion 6 is formed, and the thickness of the opening 2 is reduced by the thickness of the thick portion 6. From the thickness, the thickness of the body 3 is gradually approached through the tapered portion 6a. By forming such a tapered portion 6a, for example,
When the inner surface of the molded article 1 is provided with an inner layer such as a plastic layer or a coating layer to enhance the strength and leakproofness of the molded article, or to provide decoration, good adhesion between the inner surface of the molded article and the inner layer is obtained. be able to. When the molded body is used as a powder container, all the powder can be taken out through the tapered portion 6a. Furthermore, while obtaining such an effect, sufficient mechanical strength can be ensured by preventing stress concentration.

The mechanical strength of the opening in the molded article of the present invention
The degree of pressing of the outer peripheral surface of the opening is 10 to 1000 N (JIS
 Vertically set the nozzle opening from the side according to P8126.
(Value at 4 mm displacement measured at 3 ± 3 mm / min)
Preferably. Also, the specific compression strength in the height direction of the opening
Degree is 2N ・ m^Two/ G (measured according to JIS P8126)
Or more, preferably 10 to 200 Nm^Two/ G
(Value measured according to JIS P8126). Ma
In addition, the mechanical strength of the opening is repeated strength and sufficient sealing
In order to obtain the property, it should be larger than the mechanical strength of the
Is preferred. The mechanical strength of the molded body
2Nm in the specific compressive strength in the height direction of the part ^Two/ G (JIS
 Value measured according to P8126) or more, preferably 1
0 to 200 Nm^Two/ G (according to JIS P8126)
Measured value). The hardness of the opening is durable,
From the standpoint of obtaining a repellency, 85 to 95 (JIS K721
5 (measured according to Example 5)
preferable.

The opening 2 has a predetermined smoothness on at least one of the upper end surface 5, the inner peripheral surface 60 of the thick portion 6, and the outer peripheral surface 61 of the thick portion 6 in order to improve the sealing performance. It is preferable to have. The degree of such smoothness is such that the center line average roughness (Ra) is about 30 μm or less (a value measured in accordance with JIS B 0601) and the maximum height (Ry) is 30 or less.
When the thickness is about 0 μm or less (a value measured in accordance with JIS B0601), sufficient hermeticity is ensured. The surface roughness was measured using Surfcom 120A (manufactured by Tokyo Seimitsu Co., Ltd.), and the measurement conditions were cutoff: 0.8.
mm, measurement length: 10 mm, filter: 2CR, measurement magnification: 500, inclination correction: linear, polarity: standard. In order to smooth the upper end surface, the inner peripheral surface and the outer peripheral surface of the thick portion, a post-treatment such as polishing these surfaces by a predetermined means after manufacturing the molded body 1 is used. Preferably, by producing a molded body using a papermaking mold described later, sufficient smoothness can be obtained on these surfaces without performing the above-mentioned post-treatment.

In addition, from the viewpoint of more reliably improving the sealing performance, in addition to the above-mentioned conditions, a plastic lid body provided with each of the outer ring, inner ring, and contact ring corresponding to the form of the opening. Is preferably attached. In the case of mounting such a lid, since the angle of a seal portion such as an inner ring is restricted in the manufacturing method of the lid, at least one of the inner peripheral surface and the outer peripheral surface of the thick portion of the opening, in particular, ± 20 ° to vertical axis (accuracy ±
1 °), preferably ± 5 ° (accuracy ± 1 °), more preferably ± 2 ° (accuracy ± 0.5 °). By setting the form of the thick portion to such accuracy, the value of the high sealing property, that is, the sealing property measured according to JIS Z0208 (see the following example) is 1 m at 40 ° C., 90% RH and 24 hours. ^The amount of water vapor that passes per ² is 0.5-0.8g
It is made possible to obtain the hermeticity.

By forming the opening in each of the above forms, it is possible to provide another member made of plastics or the like for obtaining durability and airtightness that can withstand repeated opening and closing of the cap in the opening. When a lid body (not shown) is used which is unnecessary and has a contact ring contacting the upper end surface, an inner ring contacting the inner peripheral surface of the thick portion, and an outer ring contacting the outer peripheral surface. In addition, the attachment and detachment can be performed smoothly, and a high sealing property can be obtained.

As shown in FIG. 1, a thread 7 for screwing with a cap is formed on the outer peripheral surface of the opening 2.
The thread 7 has a trapezoidal vertical section. still,
The longitudinal cross-sectional shape of the thread 7 is not limited to a trapezoidal shape, but depends on the strength of the opening 2 and the productivity of the molded body 1 (for example, the ease of drying the thread 7 and the ease of imparting the shape). It may be a triangle or a rectangle. When the cap is frequently opened and closed, a trapezoidal shape is more preferable.

As shown in FIG. 1, the molded body 1 has a body 3 formed at right angles to a bottom 4. That is, the taper angle of the trunk 3 is 0 degree. The molded article 1 of the present embodiment has an overall height of 50 mm or more, preferably 1 mm or more.
It is set to be at least 00 mm. Depending on the use of the molded body 1, the body 3 may not be formed at right angles to the bottom 4.

The outer surface and the inner surface (excluding the opening) of the molded body 1 are made smooth. Thereby, for example, when a plastic layer is formed on the outer surface and / or the inner surface, the adhesion between the two is improved, and printing on the outer surface can be performed easily and clearly. Further, the appearance impression is further improved. The degree of smoothness of the outer and inner surfaces is
The center line average roughness (Ra) is 50 μm (JIS B 06
01 or less, and the maximum height (R
y) is about 500 μm (a value measured according to JIS B 0601) or less. The measurement of the surface roughness was performed by the above-described apparatus under the same conditions as above.

In particular, unlike the conventional pulp hollow container manufactured by laminating two splitters, the molded body 1 of the present embodiment does not have a seam and a thick portion due to lamination. Thereby, the strength of the molded body 1 is increased and a container having a good external appearance is obtained.

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

In the molded body 1 formed from the above-mentioned raw material, the density (ie, the density of the meat portion of the container) is set to 0.4 to 0.4.
By setting it to 2.0 g / cm ³ , mechanical properties such as tensile strength and compressive strength are satisfied, and a container having appropriate rigidity as a hollow container can be obtained. When the density is more preferably 0.6 to 1.5 g / cm ³ , a container having excellent usability can be obtained.

In the molded article 1, the JIS
The moisture permeability based on the ^{Z0208 100g / (m 2 · 24hr} )
When the content is 50 g / (m ² · 24 hr) or less, moisture in the atmosphere is hardly absorbed, and a container having appropriate rigidity as a hollow container can be obtained. Can be a container that is not damaged by moisture absorption.

Next, a preferred method for producing the molded article of the present invention will be described with reference to FIGS. The molded body 1 of the above embodiment is manufactured by a pulp molding method, and is particularly preferably manufactured by depositing pulp on the inner surface of a cavity of a mold having a cavity therein.

FIG. 2 is an exploded perspective view of the mold. The mold is provided with a plurality of communication passages for communicating the outside and the inside. A pair of split dies 11 and 12 each having a cavity corresponding to the outer shape of the molded body 1 to be molded, and being inserted into the cavity from the outside to form a contact with the inner surface of the cavity. And a retention portion forming mold 17 between which a space in which the slurry can be retained is formed. FIG. 2 shows one split mold 1.
Although the inner surface of 2 is not shown, it has the same configuration as the inner surface of the other split mold 11.

As shown in FIGS. 2 and 3, the split mold 11 is
The split mold 11 includes a paper making section 11A and a manifold section 11B, and the paper making section 11A is inserted into the manifold section 11B. By this insertion, a manifold 11C is formed between the paper making section 11A and the manifold section 11B. The inner surface of the paper making section 11A may be covered with a net having a mesh of a predetermined size. The inner surface has a plurality of communication holes 14, 14,.
・ Drilled regularly. This communication hole 14 communicates with the manifold 11C. Further, a plurality of suction holes 11D are formed in the left and right side surfaces of the manifold portion 11B.
A communication path from the outer surface of 1B to the inner surface of the paper making section 11A is formed.

As shown in FIG. 3, when the split halves 11 and 12 abut each other, a cavity 13 having a shape corresponding to the outer shape of the molded body to be molded is formed therein. A portion of the cavity 13 corresponding to the opening 2 of the molded body (hereinafter, this portion is referred to as an opening-corresponding cavity).
Has an opening that opens to the outside, and the slurry retaining wall 1 of the retaining portion forming mold 17 described later is formed in this portion.
7B is inserted. Although not shown, a screw groove having a shape corresponding to the screw thread 7 is formed on the inner surface of the cavity corresponding to the opening.

As shown in FIGS. 2 and 3, the retaining portion forming mold 17 includes a rectangular top plate 17A and a cylindrical slurry retaining wall 17B hanging down from a substantially central portion of the lower surface of the top plate 17A. Have been. The inside of the slurry retaining wall 17 </ b> B is a columnar cavity penetrating the retaining portion forming mold 17 in the vertical direction. This cavity becomes the slurry inflow path 17 </ b> C in the mold 10. Then, the slurry retaining wall 17B of the retaining portion forming mold 17 is inserted into the cavity corresponding to the opening, and the lower surface of the top plate 17A and the upper end surfaces of the split dies 11 and 12 come into contact with each other. Is formed.

The diameter of the outer surface of the slurry retaining wall 17B is smaller than the diameter of the cavity corresponding to the opening. As a result, when the slurry retaining wall 17B is inserted into the cavity corresponding to the opening, an annular space 18 in which the slurry can remain can be formed between the outer surface of the slurry retaining wall 17B and the inner surface of the cavity corresponding to the opening. It is formed. In the case where a tapered portion is provided at the opening of the formed body, the thickness of the pulp layer is adjusted by appropriately controlling the suction pressure near the outer surface of the slurry retaining wall 17B, or the shape of the slurry retaining wall is changed to the tapered portion. The mold 17 has a corresponding undercut, and the slurry retaining portion forming mold 17 is also formed of a split mold that can be divided into several pieces such as a slide.

FIGS. 4A to 4D show such a mold 10.
The papermaking process of the process of manufacturing the molded body 1 by using is shown in order, specifically, (a) is a papermaking process, (b)
Is a core insertion step, (c) is a pressurization / dehydration step, and (d) is a step of opening a mold and taking out an intermediate of a molded body. still,
In FIG. 4, the mold 10 is illustrated with a part thereof omitted for the sake of simplicity.

First, as shown in FIG. 4 (a), an injection pump (not shown) is started to suck up pulp slurry from a pulp slurry storage tank (not shown), and a mold is fed through a slurry inflow passage 17C. The pulp slurry is pressure-injected into 10. Next, the inside of the cavity 13 is depressurized by sucking from the outside of the split dies 11 and 12, the moisture in the pulp slurry is sucked, and the pulp fibers are deposited on the inner surface of the cavity 13. At this time, the slurry wraps around and fills the annular space 18 formed by the outer surface of the slurry retaining wall 17B and the inner surface of the cavity corresponding to the opening, so that the slurry is more likely to stagnate. Even a large amount of pulp fiber is deposited. Further, the pulp slurry is injected into the cavity 13 under pressure, so that the cavity 1
The pressure of the pulp slurry in 3 is the same at any position, and the pulp slurry sufficiently spreads to the annular space 18. As a result, on the inner surface of the cavity 13, the pulp layer 1 in which the thickness of the portion corresponding to the vicinity of the opening upper end surface of the obtained molded body is larger than the other portions.
5 are formed. The thickness of the large thickness portion corresponds to the thickness of the annular space 18 described above.

After the pulp layer 15 having a predetermined thickness is formed,
The injection of the pulp slurry is stopped, and the inside of the cavity 13 is completely sucked and dehydrated. Subsequently, as shown in FIG. 4B, the inside of the cavity 13 is suctioned and decompressed, and the elastic, elastic, and hollow core 16 is inserted into the cavity 13. The core 16 is inflated like a balloon in the cavity 13 to press the pulp layer 15 against the inner surface of the cavity 13, thereby imparting the inner surface shape of the cavity 13 and promoting the pressure dehydration of the pulp layer 15. used. The core 16 is formed of urethane, fluorine-based rubber, silicone-based rubber, elastomer, or the like, which is excellent in tensile strength, rebound resilience, elasticity, and the like.

Next, as shown in FIG.
A pressurized fluid is supplied to the inside to expand the core, and the expanded core 16 presses the pulp layer 15 against the inner surface of the cavity 13. Then, the pulp layer 15 is pressed against the inner surface of the cavity 13 by the expanded core 16, and the inner surface shape of the cavity 13 is transferred to the pulp layer 15, and dehydration further proceeds. Thus, since the pulp layer 15 is pressed against the inner surface of the cavity 13 from the inside of the cavity 13, the shape of the inner surface of the cavity 13 is accurately transferred to the pulp layer 15 even if the shape of the inner surface of the cavity 13 is complicated. Will be done. Also, the obtained molded body 1
, The strength of the thick portion 6 near the upper end 5 of the opening 2 is sufficiently increased. In addition, unlike the conventional manufacturing method, there is no need to use a bonding step, and thus the obtained molded article 1 has no joints and thick portions due to bonding.
As a result, the strength of the obtained molded body 1 is further increased and the appearance impression is improved. As the pressurized fluid used to expand the core 16, for example, compressed air (heated air), oil (heated oil), and other various liquids are used. The pressure for supplying the pressurized fluid is 0.01 to 5 MPa,
In particular, it is preferable to make it 0.1 to 3 MPa.

When the shape of the inner surface of the cavity 13 is sufficiently transferred to the pulp layer 15 and the pulp layer 15 can be dehydrated to a predetermined moisture content, as shown in FIG. Pull out. Then, the core 16 automatically shrinks and returns to its original size. Next, the contracted core 16 is taken out of the cavity 13, and the mold 10 is further opened to take out a wet intermediate body 15 'having a predetermined moisture content.

The removed intermediate 15 'is then subjected to a heating and drying step. In the heating / drying step, the same operation as the paper making step shown in FIG. 4 is performed except that the paper making / dewatering is not performed. That is, first, a mold in which a cavity having a shape corresponding to the outer shape of a molded body to be molded is formed by abutting a pair of split molds is heated to a predetermined temperature, and wetted in the heated mold. The intermediate in state is charged.

Next, a core similar to the core 16 used in the paper making process is inserted into the intermediate body, and a pressurized fluid is supplied into the core to expand the core. The intermediate is pressed against the inner surface of the cavity. The material of the core and the supply pressure of the pressurized fluid can be the same as in the papermaking process. In this state, the intermediate is dried by heating. When the intermediate is sufficiently dried, the pressurized fluid in the core is drained, and the core is shrunk and taken out. Further, the mold is opened, and the molded article 1 is taken out.

As described above, the molded body 1 manufactured as described above has a thick portion which is thicker than the thickness of the body portion 3 and the bottom portion 4 in the region from the upper end face 5 to the predetermined depth in the opening 2. 6 is formed. In addition, the upper end surface 5, the inner peripheral surface 60 and the outer peripheral surface 61 of the thick portion 6 are made smooth, and can withstand repeated attachment / detachment of the lid at the opening without any special post-processing. A pulp mold hollow molded article having excellent strength and high hermeticity can be obtained.
In addition, since a plastic member for reinforcement is not particularly necessary, the production cost is low, and it can be reused or incinerated after use, which leads to a reduction in waste.

FIG. 5 (a) shows a second embodiment of the pulp molded hollow molded article of the present invention. It should be noted that the points that are not particularly described in the second embodiment are appropriately described in the first embodiment. The hollow pulp molded article 1 of the second embodiment is a carton-shaped hollow container suitable for accommodating contents such as a powdery substance and a granular substance, and has an opening 2 at an upper portion thereof, and further has a trunk. 3 and bottom 4
have.

As shown in FIG. 5B, the opening 2 is formed on the upper end face 5 as in the molded body 1 of the first embodiment.
To a predetermined depth d, and a thick portion 6 having an overhang amount x in the horizontal direction is formed continuously over the entire circumference of the opening 2. A tapered portion 6a is formed at the lower end of the thick portion 6 as in the first embodiment.

The opening 2 includes a contact ring 101 that contacts the upper end surface 5, an inner ring 102 that contacts the inner peripheral surface 60 of the thick portion 6, and an outer ring 103 that contacts the outer peripheral surface of the opening 2. When the cover 100 is attached, the contact ring 101 and the inner ring 10 are attached to the upper end surface 5, the inner peripheral surface 60 and the outer peripheral surface 61 of the thick portion 6.
The outer ring 103 and the outer ring 103 have smoothness so as to reliably contact each other, so that they can be smoothly attached and detached and high sealing performance can be obtained.

The body 3 and the bottom 4 are connected to each other via a curved surface 40, so that the impact strength of the molded body 1 is enhanced. It is preferable that the curvature of the curved surface portion 40 is 0.5 mm or more, particularly 5 mm or more from the viewpoints of improvement of impact strength, improvement of drying efficiency, improvement of surface finish of a molded body, and the like.
The shape of the cross section of the molded body 1 is substantially the same over the height direction of the molded body 1, and has a rectangular shape with four rounded corners. This also increases the impact strength of the molded body 1. The curvature at the four corners is preferably 0.5 mm or more, particularly 5 mm or more for the same reason as in the case of the curved surface portion 40.

According to the molded article 1 of the second embodiment, as in the case of the molded article of the first embodiment, the mounting of the lid at the opening is performed.
A pulp molded hollow molded article having strength enough to withstand repeated desorption and high hermeticity can be obtained. In addition, since a plastic member for reinforcement is not particularly necessary, the production cost is low, and it can be reused or incinerated after use, which leads to reduction of waste. In addition, when an inner layer such as a plastic layer or a coating layer is attached to the inner surface of the molded body 1 to enhance the strength and leakproofness of the molded body, or when decoration is added, good adhesion between the inner surface of the molded body and the inner layer is provided. Can be obtained. In addition, while obtaining such an effect, it is possible to prevent stress concentration and secure sufficient mechanical strength.

The present invention is not limited to the embodiments described above, but can be appropriately modified. For example, the thick portion 6 may be formed discontinuously over the entire circumference of the opening 2.
In addition, the thick portion 6 may project inward and outward. The thick portion that protrudes outward is used, for example, as a projection for fitting with a cap that is used as needed. In addition, a plastic layer or a coating layer is provided on the outer surface and / or inner surface of the molded body 1, at least on the outer surface and / or inner surface of the opening 2, to further increase the strength and effectively prevent leakage of the contents. Or may be decorated. Further, the molded article of the present invention may be applied not only to a hollow container used for housing contents but also to an object such as an ornament.

[0042]

EXAMPLES The pulp molded hollow molded article of the first embodiment was manufactured by the procedure according to the above-mentioned manufacturing method, and the hardness evaluation and the sealing property were evaluated by the following procedures. The evaluation results are shown in [Table 1].

[Evaluation of Hardness] Durometer Hardness Measurement method based on JIS K7215 Tester: Rubber hardness tester GS-709 Shore, manufactured by Teclock Corporation
A type Hardness calculation formula: 100-40 × h h: Depression depth (m
m) Measuring method: Invert the pulp mold hollow molded body, hold the hardness meter by hand, and move it horizontally to measure the hardness of the outer peripheral surface of the opening, which is the part where the screw thread is formed, using the indenter part of the rubber hardness meter. It was pressed with a force of 10N. The average value calculated as the number of measurements n = 10 from the depth h (mm) depressed within 1 second after pressing was defined as hardness. If the thickness of the container is thin and soft, use JIS K7
A test piece was cut out from the molded body in accordance with 215, and the measurement was performed by pressing the tester with the test piece placed on a glass plate. In addition, a D-type testing machine was used as necessary, or when the test pieces were thin and hard to measure, several test pieces were superposed and measured.

[0044]

[Table 1]

As shown in Table 1, the hardness of the pulp molded hollow molded article of the example is higher than the hardness of the commercially available pulp container, and the resin bottle (a wide-height extra-large bottle container manufactured by Kao) is used. ) Hardness (97-98) on the outer surface of the cap top surface and the outer peripheral surface of the bottle container opening
It was confirmed that the hardness was equivalent to.

[Evaluation of Hermeticity] The body of the molded body was cut so that the outer diameter of the opening was 36 mm, the outer diameter of the body was 82 mm, the outer surface area was 700 cm ² , and the volume was 1 L. All the side walls were covered with aluminum foil so as not to cover the ring, and the specimen was used. The test piece was placed in a bottomed cylindrical cup, the lower end opening of the test piece was sealed with a wax sealing agent, and the opening was closed with a resin cap to be used for the test. Before sealing with a wax sealant, 10 g of calcium chloride was placed on a dish and placed in the test body. Then, 24 hours in a storage room at 40 ° C. and 90% RH.
After standing time, by measuring the increase in weight of calcium chloride having a dish (g), in terms of the amount of water vapor passing per 1 m ^2, measures how water vapor extent pass through at the opening upper end of the molded body did.

As shown in [Table 1], the pulp mold hollow molded article of the example shows a high hermeticity compared to the hermeticity of a commercially available pulp container, and is made of a resin container (Kao wide-higher extra-large size). Bottle container) value (0.2-0.
4 g / 24 hr · m ² ).

[0048]

According to the present invention, the mounting of the lid at the opening is performed.
A pulp molded hollow molded article having strength enough to withstand repeated desorption and high hermeticity can be obtained. Since such a molded article does not particularly require a plastic member for reinforcement, the production cost is low, and since it can be reused or incinerated after use, it leads to reduction of garbage. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a pulp mold hollow molded body according to the present invention.

FIG. 2 is an exploded perspective view of a mold.

FIG. 3 is a vertical cross-sectional view of the mold cut at the abutting surface and viewed.

4 (a) to 4 (d) are process diagrams sequentially showing a paper making process in a process of manufacturing the pulp mold hollow molded article of the embodiment shown in FIG. 1.

FIG. 5 is a diagram showing a second embodiment of the present invention;
(A) is a fragmentary sectional view of a main part, and (b) is an enlarged view of a main part of (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pulp mold hollow molded body 2 Opening part 3 Body part 4 Bottom part 5 Upper end surface 6 Thick part 6a Tapered part 60 Inner peripheral surface 61 Outer peripheral surface 7 Thread

Claims (6)

[Claims] 1. A thick portion having an opening, a body, and a bottom, and having a thickness greater than the thickness of the body over the entire periphery of a region from an upper end surface to a predetermined depth in the opening. A pulp mold hollow formed body formed mainly of pulp, which is formed continuously or discontinuously. 2. The pulp mold hollow molded article according to claim 1, wherein the thick portion projects inward. 3. The pulp mold hollow molded article according to claim 1, which is obtained by depositing pulp fibers on an inner surface of a cavity of a mold having a cavity therein. 4. The method according to claim 1, wherein the upper end surface of the opening and any one of the inner peripheral surface and the outer peripheral surface of the thick portion have a predetermined smoothness for enhancing the sealing performance with the sealing portion of the lid. The pulp mold hollow molded article according to any one of the above. 5. The thickness d of the thick portion is 0.5 to 50.
mm, the extent of the overhang of the thick portion is 0.5 to 5.0 mm, the amount x of overhang in the horizontal direction from the inner wall of the portion of the opening where the thick portion is not formed, and The pulp mold hollow molded article according to any one of claims 1 to 4, wherein a value of a ratio d / x between the depth d and the overhang amount x is 0.1 to 100. 6. The hollow pulp molded article according to claim 1, wherein a tapered portion is provided at a lower end of the thick portion.