JPH0615753A - Production of pulp foamed buffer material - Google Patents

Abstract

PURPOSE:To provide a pulp foamed buffer material easy to burn at the time of treatment after use, also susceptible to landfilling treatment, improved in the insufficiency of the buffer strength of a pulp mold and further having moldability. CONSTITUTION:Pulp foamed beads are obtained by kneading pulp containing regenerated pulp and a biodegradable thickener along with a foaming agent using water and molding the kneaded matter into granules and subsequently foaming and dying the same or by violently stirring both of them along with a surfactant using water to foam them and subsequently molding the obtained foamed mixture into granules to dry the granules. As the thickener used in the production of the pulp foamed beads, a thickener having adhesiveness is used. An aggregate is obtained by filling a molding frame with the pulp foamed beads before drying to dry the beads to subject the same to self-bonding or by coating the surfaces of the pulp foamed beads with an adhesive and filling the molding frame with the coated beads and curing the adhesive to bond the pulp foamed beads.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a foam cushioning material having a granular pulp molded product as a unit of a three-dimensional structure, and in particular, even after land use or incineration, waste pollution. For example, the present invention relates to a foamed cushioning material which does not cause the above and can be used as a cushioning material for electric appliances and food packaging.

[0002]

2. Description of the Related Art Styrofoam (polystyrene foam) conventionally used as a cushioning material is lightweight, inexpensive, and has stable properties. Also, bead foaming method,
In any of the foam molding methods, such as the extrusion foaming method, the moldability is good and the buffering capacity is also excellent.

However, in recent years, as interest in environmental problems has increased, there has been an increase in voices regarding the processability after use, as with other so-called plastic products. That is,
When incinerated after use, damage to the furnace due to generation of high heat and generation of harmful gas have been pointed out. In addition, when it is landfilled, it is not decomposable and is more bulky.
It is also considered to be one of the causes of the shortage of treatment plants.

As a solution to the problems in the processing of the Styrofoam, recently, a pulp mold has attracted attention as a cushioning material, and it has been increasingly used as a substitute. The pulp mold is manufactured from recycled pulp as a raw material, and its cushioning force and strength can be given by devising its shape, and both incineration and landfill treatment are easy.

However, the cushioning strength of the pulp mold is not sufficient, it is not suitable as a cushioning material for a heavy object, and the range of use is limited due to the restriction of the shape. Further, it is necessary to prepare a die having a complicated shape exclusively for designing and manufacturing the cushioning material, which takes time, and it is difficult to prototype and develop a new shape. Moreover, there was no moldability and workability.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to improve the drawbacks of the above-mentioned expanded polystyrene cushioning material and pulp mold. That is, the purpose of the treatment after use is to provide easy incineration, enable landfill treatment, improve buffer strength deficiency of the pulp mold, and impart moldability.

[0007]

In order to solve the above-mentioned problems, the present invention comprises kneading a pulp containing recycled pulp and a biodegradable thickener with water together with a foaming agent. The pulp-expanded beads obtained by granulating and then foaming and drying are obtained, or another is obtained by vigorously stirring with water and stirring with water, then granulating and drying to obtain pulp-expanded beads. The present invention provides a method for producing a pulp foam cushioning material, which is constituted as a unit of a dimensional structure, and is obtained as an aggregate of the pulp foam beads, and is also used as a thickener in the production of the pulp foam beads. Using a thickening agent having a property, the pulp foam beads before drying are filled in a molding frame and dried, and the pulp foam beads are self-adhered or an adhesive is applied to the surface of the pulp foam beads. After that, in the molding frame mold Hama, the adhesive is cured, is characterized in that to obtain an aggregate and either associates the pulp foam beads.

The present invention will be described in detail below. As the pulp containing the recycled pulp used in the present invention, recycled pulp derived from waste paper, old corrugated cardboard, old magazines and the like can be used, and also the cotton-like pulp produced in the process of paper processing and the like. Can also be used.

For pulp containing this recycled pulp, 7 to
Add 30 times the amount of water, suspend and knead.

Then, a biodegradable thickener is added to this and mixed. The addition amount varies depending on the additive substance or the strength of the pulp foaming cushioning material to be obtained later, but normally 0.5 to 20 parts by weight is added to 100 parts by weight of pulp.

As the biodegradable thickener, natural polysaccharides such as sodium alginate, starch, agar, mannan, chitin and chitosan, treated products of natural polysaccharides such as carboxymethyl cellulose, or synthetic polyvinyl alcohol. A water-soluble polymer or the like can be used.

In order to make this into a foam bead, 2
There are two ways. One is a method in which a foaming agent is added, and the mixture is molded into granules and then foamed. The other is a method in which a surfactant is added, and the mixture is stirred to cause foaming, and then formed into particles.

When a foaming agent is added, its amount is 10 to 20 parts by weight with respect to 100 parts by weight of pulp.
This may change depending on the strength. As the foaming agent, a heat-decomposition type foaming agent is specifically preferably used and has a diameter of 5 mm.
After being formed into particles of about 10 mm, it is heated and foamed at about 180 to 200 ° C. As such a foaming agent, for example, an inorganic foaming agent such as sodium bicarbonate or ammonium carbonate, or an organic foaming agent such as azodicarbonamide or benzenesulfonylhydrazide can be used.

If a surfactant is added, pulp 10
5 to 20 parts by weight is added to 0 parts by weight, but this may be changed depending on the desired degree of foaming. Specific examples of the surfactant include non-soap (higher fatty acid salt), tween (manufactured by Kanto Chemical Co., Inc., trade name) type and span (manufactured by Kanto Chemical Co., Ltd., trade name) fatty acid ester. Ionic surfactants, amphoteric surfactants, anionic surfactants such as sulfonates, cationic surfactants and the like can be used. These and the above-mentioned mixture are vigorously stirred to foam. The rate of foaming due to stirring can also be adjusted as desired. 5-12m of raw material containing this bubble
It is molded into m particles.

In order to use the pulp foam beads thus obtained as a pulp foam cushioning material, the pulp foam beads are put into a hermetically sealed frame mold prepared in a desired shape. This input amount can also be changed according to the strength design.

There are two methods for adhesion between the foamed beads. One is a method in which an adhesive thickener is used as the thickener, and the mixture is filled in a frame mold and self-adhesive at the same time as drying. After applying the adhesive solution, fill it in the frame mold,
This is a method of curing the adhesive.

As the thickener having adhesiveness, soluble starch solution, polyvinyl alcohol, carboxymethyl cellulose and the like can be used. Further, if the amount is small, the adhesiveness may be imparted by adding an ordinary adhesive solution.

Further, the same adhesive solution as described above can be used as the adhesive solution applied to the surface. Here, when a pyrolytic foaming agent is used to form the pulp foam beads, the raw material kneaded product is molded, then the adhesive solution is applied, and heated and foamed at 180 to 200 ° C. in the frame mold, Dry and cure the adhesive to make a pulp foam cushioning material. Similarly, when a surfactant is used, after foaming and molding, it is dried at 180 ° C., the adhesive solution is applied, filled in a frame mold, and then dried again.

[0019]

As described above, by using pulp including recycled pulp as a raw material, it is easily incinerated, and the gas generated by foaming is maintained in the structure by the biodegradable thickener, and the drying step is performed. After that, the structural unit itself having a property of being capable of being decomposed in the soil at the same time as giving strength to the structure and having a property of being capable of being decomposed at the time of landfilling, is obtained by the production method of the present invention, which also has a buffer property Moreover, even if a mold having a complicated shape is filled in the frame mold, it is possible to easily manufacture the mold.

[0020]

【Example】

<Example 1> Pulp: cotton-like pulp 100 parts by weight Thickener: sodium alginate 0.5% by weight solution 1000 parts by weight Foaming agent: azodicarbonamide 20 parts by weight After kneading the above, the mixture is formed into granules. It is immersed in a 2% solution of calcium chloride dihydrate. Since sodium alginate becomes insoluble calcium alginate, this stabilizes the shape. A 5% by weight solution of carboxymethylcellulose is applied as an adhesive to this surface, and then about 90% of the volume is put into a prepared frame mold. After sealing the container, heating was performed at 180 ° C. to start foaming to obtain pulp expanded beads, which was dried, and at the same time, adhesion between the pulp expanded beads was measured to obtain a pulp expanded cushioning material.

Example 2 Pulp: Cotton-like pulp 100 parts by weight Adhesive thickener: Polyvinyl alcohol 10% by weight solution 800 parts by weight Foaming agent: Sodium bicarbonate 20 parts by weight The above ingredients are kneaded into granules. After processing and molding, about 90% of the volume is put into the prepared frame mold. After sealing, 180
The pulp foaming beads were adhered to each other by heating and foaming at 0 ° C. and drying to obtain a pulp foaming cushioning material.

<Example 3> Pulp: 100% by weight of cotton-like pulp Thickener: 0.5% by weight solution of sodium alginate 3000 parts by weight Surfactant: Fatty acid ester ("Tween 80" manufactured by Kanto Chemical Co., Inc.) After stirring 5 parts by weight or more vigorously to cause foaming, calcium chloride 2
Drop into the wt% solution to give an insoluble calcium alginate gel. Dry the gel beads at about 140 ° C,
After obtaining the pulp expanded beads, a 5 wt% carboxymethylcellulose solution as an adhesive is applied to the bead surface.
Further, the pulp foaming cushioning material was filled in a frame mold and heated at about 180 ° C. to bind beads.

[0023]

EFFECTS OF THE INVENTION The present invention is as described above, and the pulp foam beads themselves, which are the constituent units of the pulp foam cushioning material obtained by the present invention, have a structure having fine air bubbles inside. Has appropriate elasticity and cushioning properties. The pulp cushioning material formed by binding the beads does not depend on the cushioning force due to a complicated structure unlike the pulp mold made of a similar material, and the lack of the cushioning strength of the pulp mold is improved.

Further, by adjusting the addition amount of the foaming agent and the thickening agent, it becomes possible to have a wide buffering force, and the buffering agent can be designed widely. Further, in the production, the pulp foam beads are used as a unit of the constitution, so that it is easy to handle even a complicated die, and the design and production of the die become easy, so that the production efficiency is improved as compared with the pulp mold.

Regarding the treatment after use, since the present invention uses a biodegradable thickener, landfill treatment is possible, and even incineration treatment is perfectly acceptable.

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[Procedure amendment]

[Submission date] April 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

For pulp containing this recycled pulp, 7 to
Add 35 times the amount of water, suspend and knead.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

Examples of the biodegradable thickener include sodium alginate, natural polysaccharides such as starch, agar and mannan, processed products of natural polysaccharides such as carboxymethyl cellulose, and synthetic water-soluble polymers such as polyvinyl alcohol. Can be used.

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Claims (4)

[Claims] 1. A pulp expanded bead obtained by kneading a pulp containing recycled pulp and a biodegradable thickener with water together with a foaming agent, molding the kneaded material into granules, then foaming and drying. A method for producing a pulp foam cushioning material, which is constituted as a unit having a three-dimensional structure and obtained as an aggregate of the pulp foam beads. 2. A pulp expandable bead obtained by pulping a pulp containing recycled pulp and a biodegradable thickener together with a surface active agent by vigorously stirring with water to form a granule and then drying. A method for producing a pulp foam cushioning material, which is constituted as a unit of a dimensional structure and obtained as an aggregate of the pulp foam beads. 3. The pulp foam cushioning material according to claim 1, wherein a thickener having adhesiveness is used as a thickener, and the pulp foam beads before drying are filled in a molding frame mold. Then, the pulp foam beads are self-bonded to obtain an aggregate, which is then obtained. 4. A method of applying an adhesive to the surface of the expanded pulp beads according to claim 1, filling the molding frame mold, and curing the adhesive to bond the expanded beads. A method for producing a foam cushioning material.