JP2003175980A - Assembled structural body of molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cushioning body for packaging which is friendly to environment and is lightweight and inexpensive and has excellent characteristics. <P>SOLUTION: A structural body is obtained by removing water as a slurry medium from small holes of a mold with a number of the small holes on the wall face and thereby piling up an ingredient which can not pass through the small holes in the slurry in the mold to form a molded article under a wet condition and thereafter, connecting a plurality of molding members obtained by drying the molded article in the mold or out of the mold through connecting members. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning material for packaging which is environmentally friendly, lightweight, low cost and has excellent characteristics.

[0002]

2. Description of the Related Art Styrofoam, which has been conventionally used as a cushioning material for packaging, has excellent shock-absorbing properties, can be easily processed into any shape, is inexpensive, lightweight, and has a good appearance. It has the characteristics of However, in recent years
As the interest in environmental issues has increased, as with other so-called plastic products, there is a growing concern over post-use treatment. In other words, it has been pointed out that when incinerated after use, damage to the furnace due to generation of high temperature and generation of toxic gas. Further, when the landfill treatment is performed, it is not decomposable and further bulky, which is considered to be one of the causes of the shortage of the treatment plant.

As a solution to the problems in the processing of the Styrofoam, recently, pulp in the slurry is deposited on a mold having a large number of small holes on the wall surface while suctioning and dehydrating, and then dried. The obtained pulp mold has been attracting attention because it has no problem in either incineration or landfill treatment, and is increasingly used as a substitute for Styrofoam.

However, in the case of the conventional pulp molding method using low drainage pulp as a raw material, as pulp is deposited on the mold, the adhesion of pulp fibers to each other progresses and water drainage deteriorates, and the pulp is deposited at an early stage. Therefore, it is impossible to obtain a molded product having a thick deposited layer. Therefore, when the object to be buffered (the product to be wrapped) is relatively lightweight, it exhibits excellent buffering characteristics, but when the object to be buffered is a heavy object, the buffering characteristic is insufficient. It was As a solution to this problem, the inventors of the present invention prior to the application of the present application said, "By removing water, which is the medium of the slurry, from the small holes of the mold having a large number of small holes on the wall surface, A method of depositing a non-pore passing component in a mold, wherein a slurry having a Canadian Standard Freeness (CSF) of a slurry composition of 550 ml or more is used to form a wet molded product, and the molded product is then molded in the mold or A method for producing a molded product obtained by drying outside the mold ", and a low-density molded product (trade name: Green Pal: manufactured by Oji Bag Co., Ltd.) that is thick and has excellent buffering properties obtained by this method.
Has made various proposals.

[0005]

However, in the case of the above-mentioned wet-walled thick molded body, it is not sufficient, and there is a problem that the density is considerably higher and heavier than the Styrofoam because the amount of air retained in the deposited layer is small. Was there. In addition to the increase in raw material cost unlike the thin pulp molded product, there is the problem that the thicker the wall, the more energy is required to remove the water that is the medium and drying, which increases the manufacturing cost. It was As a way to reduce the weight and reduce the manufacturing cost, it is conceivable to form a molded product by hollowing out the part that does not affect the performance, but when trying to obtain it as an integrally molded product, the molding die used However, the wet method has a problem in that it is difficult for the raw material to enter the details, so that voids are included in the molded product and the resulting cushioning material tends to be inferior. An object of the present invention is to provide a cushioning material for packaging, which has a wet molding method similar to that of pulp molding, is environmentally friendly, is lightweight, has low cost, and has excellent performance.

[0006]

Means for Solving the Problems As a result of intensive studies made by the present inventors in view of the current situation, it is possible to realize excellent performance as a cushioning material by using a molded body to form a structure, which is lightweight and low cost. The inventors have found out what can be done and have completed the present invention. That is, according to the present invention, by removing water, which is the medium of the slurry, from the small holes of the mold having a large number of small holes on the wall surface, the small pore non-passing component in the slurry is deposited in the mold and the wet state And a plurality of molded members obtained by drying the molded product inside or outside the mold and then connecting the molded members through a connecting member. Among them, the Canadian Standard Freeness (CSF) of the slurry composition is preferably 550 ml or more. The molding member is a concave mold whose one surface is open as a mold having a large number of small holes on the wall surface,
It is preferable that a molded product in a wet state having an unnecessary portion is formed on the open portion of the molding die, and then the unnecessary portion of the molded product is cut off in a dry or wet state. Further, the thickness of the molded member is preferably 10 mm or more. Further, it is preferable that the molded member has a flat shape. Further, the connecting member removes water, which is the medium of the slurry, from the small holes of the forming die having a large number of small holes on the wall surface, thereby depositing the small hole non-passing component in the slurry in the forming die. It is preferable that it is obtained by drying the molded product in a mold or outside the mold after the molded product is obtained. Among them, the Canadian Standard Freeness (CSF) of the slurry composition is preferably 550 ml or more. Further, the connecting member is a mold having a large number of small holes on the wall surface, and a concave mold having one open surface is used to form a wet molded product having an unnecessary portion at the open part of the mold, and thereafter, Particularly, it is preferably obtained by cutting off the unnecessary portion of the molded product in a dry or wet state. Further, the thickness of the connecting member is preferably 10 mm or more. Moreover, it is preferable that the connecting member has a flat shape. Further, it is preferable that the molding member and the connecting member have a fitting structure.

The cause of the success of the present invention cannot be achieved when the conventional integral molding is performed by adopting a method of separately molding and assembling a plurality of members when manufacturing the cushioning material by the wet molding method. It has been found that it is possible to achieve a high level of low density, low cost, and high performance. Further, it has been found that a higher level of low density, low cost, and high performance can be achieved by devising the thickness, shape, and manufacturing method of the member.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described with reference to the drawings, but the present invention is not limited thereto. In addition, although pulp slurry is used in the description here, the raw material of the present invention is not limited to this. FIG. 1 is a perspective view showing an integrally molded type L-shaped pad 11 obtained by a conventional method, and FIG. 2 is a perspective view showing an L-shaped pad 12 manufactured by the method of the present invention. The L-shaped pad 12 of FIG. 2 is obtained by connecting three members 13 obtained by wet molding with three connecting members 14 obtained by similar molding.
FIG. 3 is a front view seen from the direction of the arrow in FIG. Figure 4
FIG. 6 is a perspective view showing a member used for manufacturing an L-shaped pad. FIG. 5 shows a concave mold 15 used for manufacturing the member.
FIG. 6 is a perspective view of FIG. 6, and FIG. 6 is a cross-sectional view taken along the line AA of the concave mold 15 shown in FIG. The mold of FIG. 6 is
As shown in the figure, it is an upper open system concave shape consisting of a double wall of an inner wall 17 and an outer wall 18, and has a large number of small holes 16 for dehydration on the bottom surface of the inner wall. A suction chamber 19 is formed by inner and outer double walls, and a suction port 20 is attached to the bottom of the outer wall.

7 to 10 are sectional views showing steps of forming the molding member of the present invention using the concave molding die 15 shown in FIG. As shown in FIG. 7, after the slurry reservoir surrounding frame 21 is attached to the upper part of the mold 15,
A pulp slurry 23 having a good drainage property is supplied from a guide 22 into a cavity formed by the molding die 15 and the slurry storage enclosure 21. Next, as shown in FIG. 8, the pulp deposit 25 is formed in the molding die by suction dewatering from the suction port 20 in the lower portion of the molding die 15. At that time, the pulp is piled up so as to protrude from the open surface of the mold and rise as shown in the figure.
Reference numeral 24 indicates a water droplet that has exuded by suction.

Next, as shown in FIG. 9, an unnecessary portion that is piled up on the open surface of the forming die is swelled up and the tip saw 2 is used.
Cut and trim the surface with 6. At that time, the suction from the suction port 20 is continued. Subsequently, as shown in FIG. 10, the drying device 27 is set up, and while sucking from the suction port 20, hot air is sent from the hot air port 28 to be discharged from the small holes 29 and pass through the pulp accumulation layer for drying. . FIG. 11 shows
It is a molded product taken out from the mold after drying. (A perspective view is shown in FIG. 4.) The thus obtained two kinds of members shown in FIG.
The L-shaped pad 1 shown in FIG. 2 is prepared and assembled.
Got 2. What is obtained by the present invention is not limited to the L-shaped pad. For example, by replacing one piece of the member 13 of FIG. 4 with the member 30 of FIG. 12 and assembling, a corner member 31 as shown in FIG. 13 is obtained. You can

As a main raw material of the slurry composition, a natural organic polymer fiber having a high surface strength and an interlayer strength and having excellent performance and having degradability and being environmentally friendly is preferably used. However, the present invention is not limited to this, and may include coarse powder / fine particles made of a natural organic polymer which is also an environmentally friendly material, and can be appropriately selected depending on the application. . These raw materials are used alone or in combination.

The present invention will be described in more detail below by taking a natural organic polymer fiber-containing system as an example, but the present invention is not limited thereto. Examples of natural organic polymer fibers include:
(1) Unbleached or bleached chemical pulp obtained by converting softwood or hardwood into kraft pulp, sulfite pulp, alkali pulp, or mechanical pulp such as GP or TMP (thermo-mechanical pulp), or cotton pulp, linter Pulp, waste paper pulp which has been treated with at least one of water repellency, water resistance and curing described in Japanese Patent Application No. 10-032920, liquid ammonia treated pulp, mercerized pulp, curled fiber ( Product name: HBA-FF, NHB405, NH
B416), cellulosic fibers such as hemp fibers described in Japanese Patent Application No. 10-377923, (2) protein fibers such as wool, silk thread and collagen fibers, (3) chitin / chitosan fibers and alginic acid fibers. And the like. Among them, cellulosic fibers are particularly preferable because they are excellent in performance and easy to procure. The natural organic polymer fiber is usually 20% by dry weight with respect to the slurry composition.
It is mixed in the range of 100%.

In the slurry composition, appropriate materials are selected and blended according to the required characteristics of the molded product. When it is desired to increase the interlaminar strength of the molded product, a cellulose-based fine fiber having a number average fiber length of 0.01 to 0.80 mm or a polyethylene fiber obtained by fibrillating the above-mentioned cellulose fiber with a sand grinder or the like. It is effective to blend thermoplastic synthetic fibers such as polypropylene fiber, polyethylene-polypropylene sheath-core fiber, and biodegradable aliphatic polyester fiber. These may be used alone or in combination of two or more. Among them, the one in which the cellulose-based fine fiber and the thermoplastic synthetic fiber are used in combination is particularly preferable because a molded product having little deformation and excellent surface smoothness can be obtained. As the thermoplastic synthetic fiber, a short fiber having a number average fiber length of 2 to 20 mm, which is easy to disperse in preparing a slurry, is particularly preferable. The cellulosic fine fibers or thermoplastic synthetic fibers may be used alone or in combination of two or more kinds, and are usually blended in the range of 2 to 40% by dry weight with respect to the composition.

The strip-shaped waste paper described in Japanese Patent Application No. 2000-105555 is excellent in performance and is preferable as a material used in combination with the above natural organic polymer fibers. In addition, rice husks and crushed products thereof are also preferable as materials to be used in combination. These are usually blended in the range of 5 to 80% by dry weight with respect to the composition.

In the slurry composition, an adhesive, a water-proofing agent, a water repellent, a dye, a pigment, a drainage improver, a pH adjuster, a slime control agent, a thickener, and the like may be appropriately added to the slurry composition.
Antiseptic, antifungal agent, antibacterial agent, flame retardant, rodenticide, insecticide, moisturizer, freshness-retaining agent, deoxidizer, foaming agent, surfactant, electromagnetic shielding material, antistatic agent, rust preventive, aromatic agent ,Deodorants,
Thermoplastic resin powder, expandable thermoplastic resin powder, various microcapsules having expandability and aromaticity, etc. can be selected and blended. These may be used in combination.

The slurry is usually prepared by blending the above-mentioned materials, and the most preferable one is prepared so that the Canadian standard freeness (CSF) of the slurry composition is 550 ml or more. Freeness 550
A material having a good drainage of not less than ml can efficiently produce a thick member preferable as the member of the present invention. Incidentally, in the present invention, the Canadian standard freeness of the slurry composition was measured by the method based on JIS-P-8121.

Water is usually used as the medium of the slurry, but a mixed solution of water and alcohol (such as methanol or ethanol) may be used. The concentration of the slurry is usually adjusted so that the dry solid content is in the range of 0.05 to 5% by weight, but it is preferably in the range of 0.05 to 3% by weight in terms of the dispersed state.

A mold known in the pulp mold industry is used for manufacturing the molded body. Among them, the concave mold having one open surface is excellent in that the slurry component is likely to enter the details of the mold, and as a result, a molded product is unlikely to have whiskers and a uniform product is easily obtained. As the material of the mold,
Iron, aluminum, wood, chemical wood, synthetic resin,
Various plywood and the like are used alone or in combination. As the molding die, 15 to 2 is formed on the inner wall surface of the die having a large number of small holes.
A wire mesh of 00 mesh is usually used. As the small holes of the molding die, generally circular holes having a diameter of 1 to 10 mm are used.

The injection of the slurry into the molding die is performed by a known method. As a method for removing the medium of the slurry from the small holes, there are, for example, a suction dehydration method, a gas pressure dehydration method, a mechanical pressure dehydration method, an electroosmotic dehydration method and the like, and these can be combined. Also, the dehydration conditions can be changed during the dehydration. The type of slurry used for injection is usually one type, but by dividing the injection of the slurry into two or more stages and changing the composition of the slurry used at that time, the deposition layers of different compositions are sequentially laminated. It is also possible to obtain a molded product.

The molded product can be subjected to a compression treatment before or after drying inside or outside the molding die. By this compression treatment, the density of the molded product is increased and at the same time the strength is increased.

As a drying method, methods known in the art such as hot air drying, infrared ray drying and microwave drying can be used. Above all, hot air aeration drying in which heated air is forcibly sent into the wet deposition layer to pass therethrough is effective. In particular, when the slurry composition has a Canadian standard freeness of 550 ml or more, it is highly effective because it has excellent air permeability. The hot air aeration drying method, for example,
Injecting heated air into the wet molded product, sucking from the opposite side of the molded product while supplying heated air, or injecting heated air into the wet molded product from the opposite side of the molded product, etc. A method can be mentioned. Further, it is also possible to adopt a method of irradiating the molded product with microwaves at the same time as flowing heated air by the above method. In the hot air aeration drying method, it is desirable to dry under the condition that heated air flows at a flow rate of 1 liter / cm ² · min or more in the deposited layer of the molded product. Particularly preferably, it is 5 liters / cm ² · min or more.

Among the molding members used in the present invention, a concave molding die having one open surface is used as a molding die having a large number of small holes on the wall surface, and molding in a wet state having an unnecessary portion in the open portion of the molding die. A product obtained by forming an object and then cutting off the unnecessary portion of the molded product in a dry or wet state has uniform density and strength and is excellent in dimensional accuracy. It is easy and preferable.

The thickness and shape of the molded member used in the present invention are not particularly limited, but those having a thickness of 10 mm or more are preferable in terms of performance as a cushioning material. In addition, a flat shape is preferable because a low cost can be expected because a molding die can be manufactured at low cost and the production efficiency of a molded product is good.

The connecting members used in the present invention include paper tubes (square paper tubes, hollow L paper tubes, round paper tubes, paper ring mats), assembled corrugated board, in addition to those obtained by the wet molding method as described above. Examples include laminated corrugated board, paper honeycomb structure, waste paper board, fiber board, particle board, wood, and the like. However, it is particularly preferable to use the above-mentioned wet molding method, which allows extremely simple production of an ideal shape.

Among the connecting members obtained by wet molding, a concave mold whose one surface is open is used as a mold having a large number of small holes on the wall surface, and a wet mold having an unnecessary portion in the open part of the mold is used. To form things, then
A product obtained by cutting off the unnecessary portion of the molded product in a dry or wet state has a uniform density and strength and is excellent in dimensional accuracy, and therefore is preferable because it can be easily assembled into a structure.

The thickness and shape of the connecting member used in the present invention are not particularly limited, but those having a thickness of 10 mm or more are preferable in terms of performance as a cushioning material. In addition, a flat shape is preferable because a low cost can be expected because a molding die can be manufactured at low cost and the production efficiency of a molded product is good.

Each member used in the present invention can contain the above-mentioned adhesive by means such as spraying, impregnation and coating in order to prevent the fibers from falling off and increase the strength. In addition, if necessary, waterproofing agents, water repellents, dyes, pigments, preservatives, antifungal agents, antibacterial agents, flame retardants, rodenticides, insect repellents, freshness-retaining agents, oxygen scavengers, electromagnetic shielding materials. An antistatic agent, a rust preventive agent, an aromatic agent, a deodorant agent, etc. can be incorporated by the same means.

A plurality of molded members obtained by the above-mentioned wet molding method are connected to each other via a connecting member to form a structure. The connecting of the molded member and the connecting member is usually performed by a fitting method or an adhesive method. Further, the fitting method and the adhesive method can be used together. Among them, the one in which the molded member and the connecting member are fitted into each other in a fitting structure is particularly preferable because the post-treatment after use is easy.

Examples of the adhesive include starch, modified starch,
Vegetable gum, gelatin, casein, PVA, CMC, hydroxyethyl cellulose, urea formaldehyde resin,
Vinyl acetate resin emulsion, acrylic ester resin emulsion, ethylene-vinyl acetate copolymer emulsion, styrene-butadiene copolymer emulsion, E
Examples thereof include a VA-based hot melt adhesive and an elastomer-based hot melt adhesive.

As the main raw material of the slurry composition of the present invention, environmentally friendly natural organic polymers are most commonly used, but in addition, fibers made of synthetic organic polymers, semi-synthetic organic polymers and inorganic substances are also used. The effect of the present invention can be expected in parts other than the environment even when coarse powder, fine particles, etc. are used as main raw materials.

The use of the assembled structure of the present invention is not limited to the cushioning material for packaging, and it can be expected to be used in fields other than the cushioning material. Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In Examples and Comparative Examples, "parts" and "%" mean "parts by weight" and "% by weight" unless otherwise specified.

<Example 1> Jute hemp bags were crushed by a crusher (Yamamoto Hyakuma Seisakusho, Atoms 14-1200 type),
Hemp fibers having a number average fiber length of 6 mm were obtained. The Canadian standard freeness of this fiber was measured to be 740 ml.
Also, a 1.5-liter sand grinder (simmar.com) in which 80% of glass beads having an average particle diameter of 2 mmΦ are filled with an aqueous slurry of corrugated cardboard pulp having a solid content concentration of 1%.
Made by Enterprises, Dyno Mill KDL-PILO
It was introduced into T) at 350 ml / min and passed through to obtain fine fibers having a number average fiber length of 0.30 mm. Next, 80 parts (dry weight) of the above-mentioned hemp fibers and 10 parts (dry weight) of fine fibers were further added to the copolymer polyester-polyethylene terephthalate sheath-core fiber (manufactured by Teijin, TSF.TJ04CN2.
Water was added to a mixture of 10 parts (dry weight) of 2 × 5) to adjust the solid content concentration to 1%, and the mixture was sufficiently stirred to obtain a slurry. The Canadian standard freeness of this slurry composition was 687 ml. Next, a concave mold shown in the perspective view of FIG. 5 (cross-sectional view of FIG. 6) for manufacturing the L-shaped pad member is prepared, and as shown in FIG. 7, a hopper is placed on the mold. After attachment, the suction chamber was first filled with water, and then the slurry was fed into the hopper from the guide. Next, as shown in FIG. 8, the fibers were deposited by suction and dewatering from a suction port provided in the lower part of the mold so as to bulge on the open surface of the mold. Then remove the hopper,
Subsequently, as shown in FIG. 9, unnecessary portions deposited so as to rise on the open surface of the mold were cut off with a tip saw. Next, as shown in FIG. 10, a drying device was set in close contact with the cut surface of the wet molded product, and hot air was blown from the hot air port while sucking from the suction port to dry. An L-shaped pad was obtained by combining the members thus obtained.

[0033]

As described above, according to the present invention, by removing the water of the slurry medium from the small holes of the forming die having a large number of small holes on the wall surface, the small hole non-passing component in the slurry is kept in the forming die. Since it is possible to obtain a molded product in a wet state by depositing it on a substrate and then dry the molded product inside or outside the mold by connecting a plurality of molded members through a connecting member, light weight, low cost, excellent It becomes a cushioning material having excellent characteristics.

[Brief description of drawings]

FIG. 1 is a perspective view showing an integrally molded type L-shaped pad according to a conventional method.

FIG. 2 is a perspective view showing an L-shaped pad manufactured by the method of the present invention.

FIG. 3 is a front view of the L-shaped pad viewed from the direction of the arrow in FIG.

FIG. 4 is a perspective view showing a member used for manufacturing an L-shaped pad.

FIG. 5 is a perspective view showing a concave mold used for manufacturing a member.

FIG. 6 is a cross-sectional view taken along the line AA of the concave mold of FIG.

FIG. 7 is a cross-sectional view showing a state in which a hopper, which is a surrounding frame for storing slurry, is attached on the concave mold of FIG. 6 and slurry is supplied from an upper guide.

FIG. 8 is a cross-sectional view showing a state in which fibers are deposited in a mold by suction dehydration.

FIG. 9 is a cross-sectional view showing a state in which unnecessary portions deposited on the open surface of the molding die are removed.

FIG. 10 is a cross-sectional view showing a state in which hot air is injected into a molded product in a wet state to dry it.

FIG. 11 is a cross-sectional view showing a dry-molded product thus obtained.

FIG. 12 is a perspective view showing a replacement member.

FIG. 13 is a perspective view of a corner member obtained by replacing the member of FIG.

[Explanation of symbols]

11: L-shaped pad of the conventional method, 12: L-shaped pad of the present invention, 13: Member obtained by molding, 14: Connecting member obtained by molding, 15: Concave mold used for manufacturing member , 16: small holes, 17: inner wall, 18: outer wall, 19: suction chamber, 20: suction port, 21: hopper, 22: guide, 2
3: Pulp slurry, 24: Water drop, 25: Pulp deposit, 26: Chip saw, 27: Drying device, 28: Hot air outlet, 29: Small hole, 30: Replacement member, 31: Corner material.

Claims (11)

[Claims] 1. A small-pore-passing component in the slurry is deposited in the molding die by removing water, which is a medium of the slurry, from the small-pores of the molding die having a large number of small holes on the wall surface. An assembled structure of a molded body, which is obtained by connecting a plurality of molded members obtained as a molded product and then drying the molded product inside or outside the mold through a connecting member. 2. The assembly structure of a molded article according to claim 1, wherein the slurry composition has a Canadian Standard Freeness (CSF) of 550 ml or more. 3. The molding member is a mold having a large number of small holes on the wall surface, and a concave mold having one open surface is used.
The molded product obtained by forming a wet molded product having an unnecessary part in the open part of the mold and then cutting off the unnecessary part of the molded product in a dry or wet condition. A structure for assembling the described molded article. 4. The thick molded body according to claim 1, wherein the molded member has a thickness of 10 mm or more. 5. The assembly structure of a molded body according to claim 1, wherein the molded member has a flat shape. 6. The connection member removes water, which is a medium of the slurry, from the small holes of the mold having a large number of small holes on the wall surface, thereby depositing the small hole non-passing component in the slurry in the mold. 6. The molded structure assembly structure according to any one of claims 1 to 5, which is obtained by forming a wet molded product, and then drying the molded product inside or outside the mold. 7. The molded assembly structure according to claim 6, wherein the slurry composition has a Canadian Standard Freeness (CSF) of 550 ml or more. 8. A concave forming mold having one open surface, wherein the connecting member is a forming mold having a large number of small holes on a wall surface,
The molded product is obtained by forming a wet molded product having an unnecessary part in the open part of the mold and then cutting off the unnecessary part of the molded product in a dry or wet condition. A structure for assembling the described molded article. 9. The thick-walled molded product according to claim 6, wherein the thickness of the connecting member is 10 mm or more. 10. The connecting member has a flat shape.
10. A structure for assembling the molded body according to any one of 9 to 9. 11. The assembly structure of a molded body according to claim 1, wherein the molded member and the connecting member have a fitting structure.