JP2000118571A - Covering type low density molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dust from occurring, enable use for a water-sensitive cushioning object-to-be, prevent support performance from dropping due to moisture absorption and improve shock absorbability by completely or partially covering tightly an entire surface of a block-shaped low density molded object comprising a biodegradable material with a flexible material or the like. SOLUTION: A thermoplastic upper film 3 which has been heated to the vicinity of a softening point is brought close from above a biodegradable pulp- based low density molded object 2, and the film is sucked from below the object 2 to tightly cover the upper film 3 on an upper face of the object 2. Subsequently, a lower film 4 is placed under the low density molded object 2, the upper film 3 and the lower film 4 along a periphery of the object 2 are overlaid and fused with heat applied, thereby obtaining a covering type low density molded object 1. An aliphatic polyester, poly lactic acid, acetyl cellulose, starch or the like are especially preferable as the film to be used for covering since such biodegradable films can be disposed of at compost equipment without need for decomposing the film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-density molded article, and more particularly, to a coated low-density molded article coated with a block-shaped low-density molded article made of a biodegradable natural material.

[0002]

2. Description of the Related Art Conventionally, a styrofoam block-shaped molded article has a high impact strength and is hard to be crushed, so that the generation of dust is extremely small and the shock absorbing property is excellent. It has been widely used as a material, but in recent years, as interest in environmental issues has increased, a biodegradable buffer material made from a natural material has attracted attention as an alternative.

[0003] As one of them, molded articles by the pulp molding method have been widely used. This is a relatively thin and dense pulp deposit having a thickness of several millimeters. In addition, the provision of ribs and furns provided cushioning to the molded structure, so that the cushioning against impact upon use after the second use was extremely low and was not suitable for packaging heavy objects.

[0004] On the other hand, various types of solid block-shaped low-density bodies similar to styrene foam have been proposed. For example, as shown in JP-A-7-258453 and JP-A-9-94901, a rose-shaped buffer material, which is a starch-based closed-cell foam, and a large number of small pieces obtained by pulverizing the same, are assembled in a block shape. Bonded molded product or Japanese Patent Application No. Hei 10-3292
No. 0 and Japanese Patent Application No. 10-49985 are pulp-based low-density molded articles produced by a wet method.

[0005]

However, the biodegradable block-shaped low-density molded articles made of these natural materials have several problems. The first is the generation of dust. For example, fallen wood fibers or broken pieces of foamed starch enter gaps in the buffered material, and thus are not suitable as cushioning materials for precision equipment and the like that dislike dust.

[0006] The second is the hygroscopicity of natural materials. In the case of the pulp-based low-density compact, the raw material may absorb moisture under high-humidity conditions and transfer moisture to the material to be buffered. Further, when the buffer material of the starch foam absorbs moisture, there is a problem that the volume of the buffer material is reduced and the buffer material cannot be fixed sufficiently, in addition to a phenomenon of transferring moisture to the buffer material.

Third, there is a shortage of buffer performance. Since Styrofoam is a closed-cell foam, countless closed cells generate elasticity, and when a certain impact is received, it receives the distortion that occurs and quickly recovers, thereby absorbing the impact. In fact, in the starch-based foam molded article, there are actually many air passages between the crushed pieces that are collectively bonded, and the pulp-based low-density molded article naturally has a structure. However, it has high air permeability, so that a good cushioning performance such as that of polystyrene foam cannot be obtained.

Therefore, a first object of the present invention is to provide a block-shaped low-density molded product made of a biodegradable material free of dust generation. A second object of the present invention is to provide a block-like low-degradable material made of a biodegradable material that can be used for a buffer material that is sensitive to moisture and that does not decrease in volume due to moisture absorption and the support performance of the buffer material does not decrease. An object of the present invention is to provide a density molded body.

A third object of the present invention is to increase elasticity,
An object of the present invention is to provide a block-shaped low-density molded product made of a biodegradable material having improved shock absorption.

[0010]

Means for Solving the Problems As a result of investigations to solve the above problems, the present inventors have found that after forming a block-shaped low-density molded body made of a biodegradable material, the entire surface of the low-density molded body is formed. Can be solved by completely or partially adherent coating with a flexible material or the like, and have completed the present invention. The present invention includes the following inventions.

(1) The entire surface of a block-shaped low-density molded body made of a biodegradable material is completely or partially adhered with at least a part of the coating material using a coating material using a film material. Coated low density molded article. (2) The coated low-density molded article according to (1), wherein the entire surface of the biodegradable block-shaped low-density molded article having high air permeability is coated with the coating material.

(3) Canadian Standard Freeness (CSF) is 5
A slurry containing 50 ml or more of a fibrous or non-fibrous material as a main raw material is deposited on a mold having a large number of small holes while sucking and dewatering, and then dried to obtain the entire surface of the low-density molded body, A coated low-density molded product, characterized in that at least a part of the coating material is completely or partially adhered by using a film.

(4) Water is added to a material containing starch as a main component such as high amylose starch, and the surface of a rose or a crushed material obtained by evaporating and foaming is wetted to be tacky and adhered collectively. A coated low-density molded product, wherein the entire surface of a block-shaped low-density molded product is completely or partially adhered to a part or all of a coating material using a film.

(5) The coating-type low-density molding according to any one of the above (1) to (4), wherein the film used for coating is a film having thermoplasticity or heat melting property that can be softened by heating. body. (6) The film used for coating is a film further having biodegradable and / or water-soluble properties, (4) or
The coated low-density molded product according to (5).

(7) The coating mold according to (6), wherein the coating of the block-shaped low-density molded body made of a biodegradable material is a complete adhesion coating layer with a film on the entire surface of the block-shaped low-density molded body. Density molded body.

(8) The heat-softened coating film is brought into close contact with the low-density molded body while sucking air through a gas-permeable block-shaped low-density molded body made of a biodegradable material. A method for producing a coated low-density molded article.

(9) Canadian Standard Freeness (CSF) is 5
50 ml or more of a slurry composed mainly of a fibrous or non-fibrous material is deposited on a mold having a large number of small holes while sucking and dewatering, and then air is passed through a low-density molded body obtained by drying. A method for producing a coating-type low-density molded article, wherein a heat-softened coating film is adhered to the low-density molded article by suction while sucking.

(10) Water is added to a starch-based material such as high amylose starch and the like, and the surface of a rose-like product or a crushed product obtained by evaporating and foaming is humidified to have tackiness and collective adhesion. A method for producing a coated low-density molded product, wherein a heat-softened coating film is brought into close contact with the low-density molded product while sucking air through the block-shaped low-density molded product.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The block-shaped low-density molded product made of a biodegradable material used for the coated low-density molded product of the present invention includes: (a) a fiber-based material having a Canadian standard freeness (CSF) of 550 ml or more. Alternatively, a slurry containing a non-fibrous material as a main material is deposited on a mold having many small holes while sucking and dewatering, and then dried to obtain a low-density compact, or (b) starch as a main component. Or a block-like low-density molded product obtained by humidifying the surface of a pulverized material and adhering them to form a collective adhesive. Other examples include (c) a pulp-based low-density molded product made by a dry method. Of these, the molded articles (a) and (b) have high air permeability, so that the processing efficiency of the film coating is better than that of the molded article (c), and the effect of improving the buffer property by the film coating is improved. It is particularly preferred because it is large.

Examples of the fibrous or non-fibrous material having a Canadian standard freeness (CSF) of 550 ml or more used in the production of the low-density molded product (a) include, for example, kraft pulping of softwood and hardwood, and sulfite pulp. Unbleached or bleached chemical pulp obtained by sintering, alkali pulping, etc., or mechanical pulp such as GP, RMP, TMP, CTMP, or cotton pulp, linter pulp, hemp fiber, bamboo fiber, sawdust, chaff, soybean meal Cellulose coarse powder obtained by roughly pulverizing pulp, wood, bagasse, rice straw, coconut shell, etc. which have been subjected to at least one of water repellency, water resistance, hardening, and curling. And those having a Canadian Standard Freeness (CSF) of 550 ml or more. In addition, as a material, a synthetic polymer material, an inorganic material, or the like can be used. In addition, a recycled product such as used paper can be used as the above material.

Other materials can be added to the slurry composition used in the production of the low-density molded article (a) as necessary for improving the performance and imparting functions. For example, in order to improve the interlayer strength, it is effective to add cellulose-based fine fibers (for example, those obtained by wet-treating cellulose-based fibers with a sand grinder or the like), synthetic polymer fibers, and the like.

As the starch used in the production of the low-density molded article (b), starch obtained from corn starch, wheat flour, tapioca, potato, etc. can be used, and high amylose starch containing at least 45% by weight of amylose It is preferable to use a foamed one. The present invention can also be applied to those in which a thermoplastic resin, a water-soluble polymer, or the like is added in addition to starch.

Examples of the film used for coating the block-shaped low-density molded product made of a biodegradable material include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, aromatic polyester, aliphatic polyester, and polylactic acid. , Acetyl cellulose, ionomer, ethylene vinyl acetate copolymer (EVA),
Examples include ethylene vinyl acetate, nylon, polyvinyl alcohol, and starch. Above all, biodegradable films such as aliphatic polyesters, polylactic acid, acetylcellulose, starch, etc. are reused as fertilizers and soil conditioners by treating coated low-density molded products in a compost facility without separating them from the films. It is particularly preferable because it is possible. Further, a water-soluble film such as polyvinyl alcohol is particularly preferable because the coated molded body can be easily converted into a raw material or discarded. That is, when the low-density molded product is a pulp-based product or the like, the pulp slurry can be obtained simply by dispersing in water without being separated from the film, and can be used as a papermaking raw material.

As the coating film, a film to which an inorganic pigment, starch particles, pulp fiber, coconut shell fiber and the like are added can be used. The film may be a laminate of two or more types,
The film may be bonded to a material other than the film, such as paper, cloth, or nonwoven fabric. The film may be coated with an adhesive, a pressure-sensitive adhesive, a heat-sensitive adhesive, or the like. Further, the film may be a gas permeable film having holes provided in the film. Such a film is inferior in preventing moisture absorption of the low-density molded product, but is sufficiently effective in other aspects. As a material other than the film used for the surface coating, for example, paper, cloth, nonwoven fabric and the like can be mentioned, and those which are easily fused to the above film by heat or the like are preferable.

The film is usually selected from the range of 3 to 100 μm according to the purpose, but is not particularly limited. The film covering the surface of the molded body,
Partially different ones may be used. It is preferable that the film and the surface of the molded body are in an adhesive state.

[0026]

The coated low-density molded article of the present invention covers the entire surface of the block-shaped low-density molded article made of a biodegradable material, thereby removing fine components such as pulp or starch-based foam. The effect of preventing dust such as broken pieces from adhering to the buffer is achieved.

[0027] Further, when the molded article is a low-density molded article in which fine components such as pulp are deposited, the molded article is given an aptitude for moisture-sensitive material to be buffered. Is achieved. Further, when the molded body is a foam of a material containing starch as a main component,
The effect of preventing a decrease in volume due to moisture absorption and a decrease in the function of supporting and fixing the buffer object is achieved. Further, in the case of a material having a high air permeability such as the above low-density molded body, the covering film seals air inside, or the molded body is given elasticity in order to suppress the air permeability, thereby absorbing shock. The effect of improving the performance is achieved. In addition, the impact strength of these molded articles can be significantly improved.

Further, when the low-density molded article has an uneven portion, particularly when it has a concave portion, a gap is easily formed between the molded article and the film, and it is difficult to form a complete close contact state. When having high air permeability such as a density molded body, a film softened by heating is arranged on an uneven surface, and the air permeable low density molding is performed from a surface other than the uneven surface (in particular, the opposite surface is preferable). The method of bringing the film into close contact with the uneven surface while sucking air in the body, specifically, a method known as a skin pack or the like, enables extremely efficient close contact coating.

[0029]

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. FIG. 1 is a perspective view of a coated low-density molded product 1 of the present invention. FIG. 2 shows A of the coated low-density molded product 1 of FIG.
It is sectional drawing which follows the -A line. FIG. 3 shows a state at an initial stage of the film coating process. 4 is a sectional view showing a state in a stage following FIG. 3, FIG. 5 is a sectional view showing a state in a stage following FIG. 4, and FIG. 6 is a sectional view showing a state in a stage following FIG.

In the figure, reference numeral 2 denotes a pulp-based low-density molded product (hereinafter referred to as a low-density molded product), 3 denotes an upper film, and 4 denotes a lower film. As shown in FIGS. 1 and 2, the upper surface of the low-density molded body 2 has irregularities for receiving an object to be buffered, and the lower surface is a flat surface. First, as shown in FIG. 2, a thermoplastic upper film 3 is disposed above the low-density molded body 2, and is heated to a temperature near the softening point by a suitable heating means (not shown). Next, when air is sucked from the bottom surface of the low-density molded body 2 using suction means (not shown) while bringing the upper film 3 close to the low-density molded body 2, as shown in FIG. As shown in FIG. 5, the upper film 3 adheres to the upper surface of the low-density molded body 2, that is, the uneven surface in contact with the buffer, and the uneven surface of the low-density molded body 2 is heated. It is tightly covered with the softened upper film 3.

Subsequently, as shown in FIG. 6, a lower film 4 is laid under the low-density molded body 2 whose upper surface is already tightly covered with the upper film 3, and the upper film 3 on the peripheral edge of the low-density molded body 2 is formed. And the lower film 4 are superposed and fused by applying heat to obtain a coated low-density molded product 1 shown in FIGS.

In addition, a breathable film is selected as the lower film 4, and the lower film 4 is applied to the bottom surface of the low-density molded body 2 when coating with the upper film 3. If the inside air is sucked, the covering of the low-density molded body with the upper film 3 and the lower film 4 and the fusion of the film on the periphery of the low-density molded body can be performed without time loss.

As another method of tightly covering the low-density molded product with a film, a gas-permeable low-density molded product is placed in a bag-shaped film, and the air inside the bag is heated while heating the film. It is also effective to use a means for tightly covering the entire surface of the low-density molded product with a softening film by extracting the material through the air-permeable low-density molded product.

By a method similar to the method for coating a pulp-based low-density compact described above, water is added to a material containing high amylose starch as a main component, and the rose-like material obtained by evaporating and foaming or the pulverized material thereof is obtained. The block-shaped low-density molded body having the surface humidified to have tackiness and collectively adhered was coated with a film to produce a coated low-density molded body.

The coated low-density molded article of the present invention produced as described above is used not only as a cushioning material for protecting an object to be buffered, but also in a field where styrene foam or the like is used, that is, for a building material, a tatami core material or the like. Can be widely used in the field.

[0036]

According to the coated low-density molded article of the present invention, since the entire surface of the block-shaped low-density molded article made of a biodegradable material is covered, a separated material of fine components such as pulp or the like can be obtained. It is possible to prevent dust such as broken pieces of starch-based foam from adhering to the buffer.

Furthermore, the molded articles do not absorb moisture,
When the molded body is a low-density molded body in which fine components such as pulp are deposited, the molded body is given aptitude for an object to be subjected to buffering sensitive to moisture. Further, when the molded body is a foam of a material containing starch as a main component, the transfer of moisture of the buffer object itself is blocked by the coating film, and the low-density molded body due to moisture absorption from the outside. No reduction in volume occurs, and the function of supporting and fixing the buffer object is maintained for a long time.

Further, as a result of air being sealed inside the coated low-density molded article or suppression of air permeability between the inside and outside of the low-density molded article, the molded article has elasticity and improved shock absorption. As a result, the impact strength of these low-density compacts is remarkably improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a coated low-density molded product according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view showing a state at an initial stage of a film covering step, as viewed from a cross section taken along line AA of FIG. 1;

FIG. 4 is a sectional view showing a state in a stage following FIG. 3;

FIG. 5 is a cross-sectional view showing a state in a stage following FIG. 4;

FIG. 6 is a sectional view showing a state in a stage following FIG. 5;

[Explanation of symbols]

 1: coated low density molded article 2: low density molded article 3: upper film 4: lower film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shunsuke Shioi 4-7-5 Ginza, Chuo-ku, Tokyo Inside Oji Paper Co., Ltd. (72) Inventor Tadao Masuda 2-24-8-2 Iizuka 2-chome, Kawaguchi City, Saitama Prefecture F term (reference) 3E066 AA01 AA61 BA01 CA03 CA05 CA08 CB03 DA01 KA08 LA02 LA07 MA01 NA41 4F100 AJ02 AK03 AR00A AT00B AT00C BA03 BA06 BA10B BA10C CB00 DD31 GB90 JA15A JB07 JC00A JK10 JK11

Claims (2)

[Claims] 1. A low-density molded block made of a biodegradable material, wherein the entire surface of the low-density molded article is tightly coated with a coating material using a film material on at least a part of the coating material. Density molded body. 2. The coated low-density molded article according to claim 1, wherein the block-shaped low-density molded article made of a biodegradable material has high air permeability.