JPH07304012A - Method and plant for manufacturing buffering material - Google Patents

Abstract

PURPOSE:To contrive to shorten production time and to remarkably improve performance as buffering material by a method wherein paper cotton, which is produced by dry-splitting paper into the form of cotton, is hot-pressed with steam-spraying. CONSTITUTION:A steam spraying press 9 consists of two layers of laminates or an upper side laminate mainly consisting of a cooling plate 10, a heat insulating material 11, a hot plate 12 and a spraying platen 13 piled up in the order named, and a lower side laminate mainly consisting of a spraying platen 13, a hot plate 12, a heat insulating material 11 and a cooling plate 10 piled up in the order named. Hot-pressed material is set between the upper side laminate and the lower side laminate. The steam lead in the respective laminates are firstly fed to the spraying platens 13 respectively so as to be radiately sprayed to the material inserted between the spraying platens from the spraying platens 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning material manufacturing method and a cushioning material manufacturing plant. The cushioning material produced by the method of the present invention is suitably used as a cushioning material for packing various products such as electric equipment and precision equipment.

[0002]

2. Description of the Related Art A cushioning material is used for packing many products from factory products such as electric equipment and precision equipment to packaged foods, etc., and absorbs shocks generated during transportation and handling. Prevents product damage. As the cushioning material, for example, the following materials have been used, but they have the problems described together.

(I) Synthetic resin materials such as expanded polystyrene and expanded polyethylene: Expensive, the above materials are not decomposed by bacteria and microorganisms, and remain semi-permanently and accumulate in soil or water to bring about environmental pollution. Or may have a harmful effect on marine animals (when marine organisms mistakenly eat the above materials for food, or eat with food, etc., these materials accumulate in the body and die. ), Burning waste products of the above materials in the furnace not only causes air pollution, but also raises the combustion temperature and makes the furnace wall of the combustion furnace brittle, causing damage and shortening the life of the combustion furnace. It (Ii) Waste paper that is used as it is without being pressure-molded (waste paper is simply rolled, waste paper is finely cut with a shredder, etc., and packed in a vinyl bag. The same problem as (i) above due to the synthetic resin material contained in the vinyl bag or adhesive, which has a low cushioning capacity. (Iii) Paper cotton obtained by wet defibration of paper: Since wet defibration requires the installation of a wastewater treatment device, the device becomes large and equipment cost increases.

[0004]

Therefore, as an alternative to the above-mentioned conventional cushioning material, paper cotton obtained by dry defibration of used paper is formed by mechanical compression and sprayed with water to put it into the used paper. Wet the filler originally included
A method for producing a cushioning material by drying and adhering the paper cotton is disclosed (Japanese Patent Application No. 5-98895).
issue). However, simply spraying water as in this method makes it difficult for water to sufficiently penetrate into the inside of the paper cotton, which takes time. A method of using an alcoholic aqueous solution or the like for the purpose of increasing the permeability of water into the paper cotton and a method of immersing the paper cotton in the aqueous solution can be considered, but as a result, the paper cotton contains a large amount of water. It will be. In this way, when the water content in the paper cotton is increased, the adhesive may flow out, it takes time to cure with the thermosetting resin, and when the water content is 12% or more, it may be There are problems such as poor shape retention.

The method of the present invention has been made for the purpose of further improving the above method to shorten the production time and greatly improve the performance as a cushioning material. The present invention provides a novel method for producing a cushioning material and a plant for producing a cushioning material, which uses paper cotton made into a cotton shape.

[0006]

The method of manufacturing a cushioning material according to the present invention is characterized in that hot-press molding is performed by steam injection of paper cotton which is defibrated by dry defibrating the paper. . In a preferred embodiment, the steam is sprayed at a temperature of 120 ° C. or higher. In a more preferred embodiment, a thermosetting resin is added as a binder. The manufacturing plant of the cushioning material of the present invention includes a device for dry defibrating paper to produce paper cotton, a device for mixing the paper cotton and a binder, and a hot pressing device by steam injection. It has a gist.

[0007]

In the production method of the present invention, as a raw material, dry defibrated cotton wool (hereinafter abbreviated as paper cotton) is used. Paper cotton, which is made by dry defibrating paper into cotton, is a cotton-like material in which short fibers are entangled with each other.Although short fibers have a relatively long fiber length, they are entangled with other materials. In addition to having the property of being easy, it also has properties useful in manufacturing a cushioning material, that is, elasticity and lightness, and a press-molded paper cotton is a very good cushioning material. obtain.

The paper used in the method of the present invention is not particularly limited, and newspapers, telephone books, magazines, advertising papers, publications, cardboard papers, OA papers, computer papers, etc. can be used.
It is recommended to use these waste papers in order to reduce manufacturing costs and use resources effectively. The production method of the present invention basically uses the above-mentioned paper as a raw material, but in addition, the following materials (i) to (iii) are also used.

(I) Fiber: Natural fibers such as cotton (egibutto cotton, rice cotton, etc.), hemp (cannabis, jute, Manila hemp, cho linen, flax, bow hemp, sisal, kenaf, ramie, etc.), suhu, etc. Half-finished goods (used clothes,
Scraps, ear pieces, etc.), plant fibers (coconut fiber, coconut fiber, sugar cane fiber, etc.) and animal fibers (wool, cashmere, alpaca, rabbit hair, etc.) other than those mentioned above that have not been conventionally used as paper materials. As synthetic fibers, polyamide-based, polyester-based, polyacrylic-based, polyvinyl alcohol-based, polyvinyl chloride-based, polyvinylidene chloride-based, polyolefin-based (eg polypropylene-based, polyethylene-based etc.), polyurethane-based, fluororesin-based (eg poly-based Fibers such as tetrafluoroethylene type).

It is preferable that such a fiber is a fiber (several centimeters) having an average fiber length longer than the average fiber length (about 0.1 to 3 mm) of the above-mentioned paper cotton. The fibers having such an average fiber length act as a tie when mixed with the above-mentioned cotton, and when they are entangled with each other, the entanglement between the fibers becomes strong and the dispersion becomes difficult. Therefore, it is possible to efficiently manufacture a cushioning material having excellent moldability and shape retention, and it is also possible to reduce the amount of the binder to be added required when manufacturing the cushioning material as much as possible. Among the above fibers, since it is a natural material, it has high biodegradability and is less likely to be accumulated in soil or the like. Therefore, it is recommended to use from the viewpoint of environmental protection.

(Ii) Binder: As a natural material, starch paste (wheat flour, barley flour, rye flour, corn starch, tapioca starch, guar mannum,
Degreased soybeans, glue paste, etc.) and thermosetting resins (phenolic resins, urea resins, melamine resins, urea resins, epoxy resins, unsaturated polyester resins, etc.).

The paper used as the raw material of the present invention often contains a filler such as starch paste from the beginning, and the solidifying action of this filler is expected, but the moldability and shape retention are further improved to some extent. When it is desired to manufacture a cushioning material having the above strength, it is recommended to add the above binder.

Among the above binders, natural materials represented by starch paste and the like are useful for improving the shape retention of the cushioning material. This natural material has the advantages that it is cheaper than a thermosetting resin, the manufacturing cost can be reduced, and since it is a natural component, it is highly biodegradable and less likely to be accumulated in soil or the like. Moreover, the thermosetting resin is useful for increasing the strength of the cushioning material.

(Iii) As other materials, antiseptics, antifungal agents, flameproofing agents, flame retardants, etc .: By adding these materials, a buffer material having the characteristics of each material can be obtained. The range of utilization of the material can be further expanded.

By the way, in the method of the present invention, (i) a paper made of wood or the like having a small thermal conductivity is used as a raw material, and (ii) the paper is dry defibrated,
A large amount of air will be contained between the paper cotton and these (i
) And (ii), the paper cotton used in the present invention has a very small thermal conductivity. Therefore,
If this is attempted to be thermoformed without any means, the following inconveniences will occur. That is, a material having a low thermal conductivity generally has a drawback that it is difficult to press-mold. Such a drawback is more noticeable when manufacturing a low-density cushioning material. For example, when the above paper cotton is hot press molded using a thermosetting resin, the thermosetting resin is rapidly cured on the surface of the paper cotton contacting the hot platen, but the inside of the paper cotton is not cured. It is difficult to occur and it takes time for the entire paper cotton to cure. Specifically, when using paper cotton and melamine resin to heat the curing temperature of the melamine resin (140 ° C or higher) to produce a cushioning material having a density of 0.3 and a thickness of 20 mm, It takes about 10 minutes for the temperature to reach the curing temperature of the melamine resin. In this way, it takes a long time for heat to be evenly conducted to the entire paper cotton, which causes uneven curing due to the thermosetting resin, resulting in uneven hardness in the manufactured cushioning material. There is a problem such as a decrease in In addition, such a cushioning material has a low cushioning ability, and when this cushioning material is used for packaging a synthetic resin product or the like, it causes an adverse effect such as a scratch on the surface of the product or a decrease in surface gloss. Therefore, the product value may be reduced.

In order to prevent such a problem due to thermal conductivity, it is possible to raise the temperature of the hot plate during hot pressing, but there is a risk that the surface of the cushioning material will be burned depending on the processing temperature. As a result, temperature control becomes very difficult.

Therefore, the present invention proposes a new method of hot press forming by steam injection using the above materials. By performing hot press molding by such a method, it has become possible to efficiently manufacture a cushioning material excellent in elasticity, moldability and shape retention in a short time for the first time.

The reason is as follows (a)
The effect of (c) is to increase the thermal conductivity of paper cotton. (A) Steam penetrates the inside of the cotton by the steam injection. (B) A portion of the steam condenses inside the cotton and becomes water, which is absorbed by the cotton, which increases the water content of the cotton. (C) When the water content of the paper cotton is increased, the binder is uniformly dispersed, and the solidification or curing of the binder can be quickly achieved even with a small amount. A heating method using pressurized hot air may be considered instead of the steam heating method, but the effects of (a) to (c) above are not as remarkable as in the case of steam injection.

The hot press forming by steam injection used in the method of the present invention is a very useful method for increasing the thermal conductivity of the cotton and making the temperature rising rate of the entire cotton uniform. By using such a method, the manufacturing time can be shortened and the quality of the cushioning material can be improved.

The manufacturing method of the present invention will be described in detail below. (A) Dry defibration of paper. As a method of dry defibrating the above-mentioned paper, it is preferable to put the paper previously cut into strips by a cutting machine such as a shredder into the dry defibration machine for processing. The cutting machine used is not limited to a shredder, and for example, paper may be cut into small pieces by hand.
Alternatively, depending on the size of the paper, it is possible to directly insert the paper into the defibrating machine without cutting it. Examples of the dry defibrating machine used in the present invention include the dry defibrating device described in Japanese Patent Application No. 5-265895, AFT fiber riser (manufactured by AFT), turbo mill (manufactured by Turbo Industry), Jacobison mill (Shinko Pantech). It is recommended to use a product manufactured by the company.
The paper cotton obtained by dry defibrating the paper in this manner is a cotton-like material that is easily entangled with each other. In that case, when the above-mentioned fibrous material is present, the entanglement and the overlap with the paper cotton are further increased.

(B) If necessary, a binder is applied to cotton and then mixed. Examples of the method of applying the binder to the paper cotton include the following methods. Binder is blown off under compressed air and spread on cotton wool. The binder is dissolved in water and sprayed under compressed air. In the above and above, the pressure of the compressed air is preferably about 5 kg / cm ^{2 in} terms of instrument air pressure. Use a rotating brush or a splashing disperser to splash the binder off and spread it on paper. The entire cotton wool is impregnated with the binder solution. As the binder used in this step, it is recommended to use a thermosetting resin in order to effectively exhibit the action of hot press molding.

As a method for mixing these materials after applying the binder to the paper cotton, it is preferable to use a mixer such as a mixer, a blender or a fluidized bed. Other than paper cotton,
When the above-mentioned materials such as fiber, antiseptic agent, antifungal agent, flameproofing agent and flame retardant are also used, these are mixed in the same manner. In order to increase the mixing ability of these materials, before the materials are put into the mixing machine, they are cut into strips in advance with a cutting machine such as a shredder, or when fibers are used, further dry defibration is performed after cutting. Recommended to process. When mixing a plurality of types of materials, they may be simultaneously mixed in the same mixer or may be put in separate mixers and mixed.

When fibers are used, the mixing ratio of the fibers is appropriately changed depending on the field of use of the cushioning material, but in order to secure moldability and shape retention, the ratio is 5% or more, and 30
% Or less is preferable. If the ratio of the fibers is less than 5%, the entanglement of the fibers becomes insufficient, the strength and elasticity of the cushioning material become weak, and the handling becomes difficult. On the other hand, if the mixing ratio of the fibers exceeds 30%, the manufacturing cost increases, which is not preferable.

The content of the binder is appropriately changed depending on the field of use of the cushioning material, but is 5% with respect to the total amount of the material.
As described above, it is preferable that the content is 25% or less.
If the content of the binder is less than 5%, the strength is insufficient to maintain the shape as a cushioning material.
%, Which is not preferable because the manufacturing cost exceeds%.

(C) These mixed materials are hot press molded by steam injection. The method of hot press molding is
It is not particularly limited except that it is performed by steam injection, but from the viewpoint of increasing the thermal conductivity of paper cotton and efficiently performing the above treatment, first, the above mixed material is continuously pressed or belt pressed before hot press molding. It is recommended to fill it in a forming machine such as a formula and compress it to a predetermined density.

Table 1 shows the results of measuring the densities of the compression-molded articles at the respective surface pressures when the material was compression-molded using the belt press type forming machine, and FIG. 1 shows the relationship between them. Is shown as a graph.

[0027]

[Table 1]

As is apparent from Table 1 and FIG. 1, when the surface pressure is increased, the density of the compression molded body is increased and the surface pressure is about 10 k.
With gf / cm ² , a compression molded body of about 0.5 g / cm ³ is obtained. In this way, the material is compressed to some extent to increase the density, and then steam is supplied using the steam injection device.

FIG. 2 shows the structure of the steam injection device used in the present invention. In the figure, first,
Steam supplied from a steam generator such as a boiler (not shown) is introduced into the steam inlet 1. The introduced steam is sequentially passed through the strainer 2, the cyclone separator trap 3, and the pressure reducing valve 4, whereby impurities such as dust are separated and removed. The steam cleaned in this way is connected to a branched header (dispersor) 5,
6 is introduced into the steam injection press 9 through the stop valve 7 and the solenoid valve 8, respectively. The outlet sides of the headers 5 and 6 are connected to a conventional stop valve and drain. The steam injection press 9
The upper laminated body is constituted by stacking a cooling plate 10, a heat insulating material 11, a heating plate 12, and a spray board 13 in this order, and the lower stacked body is mainly a spray board.
13, a heat plate 12, a heat insulating material 11, and a cooling plate 10 are stacked in this order. The material to be press-molded is set between the upper laminate and the lower laminate (that is, between the sprayers). The steam introduced into each laminated body is first supplied to the jet board 13 and is radially jetted from the jet board 13 to the material inserted between the jet boards. The heat insulating material 11 and the cooling plate 10 provided above or below the heat plate 12 prevent heat distortion in the steam injection press and prevent heating of a hydraulic cylinder in a hydraulic device that drives the press. belongs to.

FIG. 3 shows the arrangement of the steam introduction passages arranged in the spray board. The figure (a) is the left side view, the figure (b) is the front view, and the figure (c) is the right side view. In the figure, length 500 mm x width 500 mm
B. In the spray board having a thickness of 50 mm, the steam introduction paths 14 are formed in parallel, six from the left side and five from the right side of the spray board. A large number of injection holes 15 having an inner diameter of 2 mm are installed in communication with each of the steam introduction passages 14.
Steam is sprayed at the same time.

The injection temperature of steam is controlled by the pressure reducing valve 4. This injection temperature is preferably selected appropriately according to the type of binder used, and when a thermosetting resin is used, it needs to be raised to a temperature at which the resin is cured. For example, when a phenol resin and an epoxy resin are used as the thermosetting resin, a urea resin is 1
It is preferably 10 ° C or higher, and 115 ° C or higher in the case of a melamine resin. At that time, the steam injection temperature is set to 120
If you raise the moisture content of steam by raising it above ℃,
Since a high molecular compound such as lignin contained in paper cotton also gels and exerts an adhesive action, it is possible to reduce the amount of the binder added, and it is possible to efficiently manufacture the cushioning material. In this way, the material is heated and humidified to solidify or cure the binder, and then the material is compressed to a desired thickness of the cushioning material and held for a certain period of time to obtain a cushioning material having a predetermined density.

The production plant of the present invention is basically an apparatus for dry defibrating paper to produce cotton, an apparatus for mixing the dry defibrated cotton with a binder, and a steam jet. Hot pressing apparatus according to the present invention. FIG. 4 shows an embodiment of the cushioning material manufacturing plant of the present invention. First, the shredder device 16 communicates with the raw material storage hopper 17 via a belt conveyor. Next, the raw material storage hopper 17, the FS mill 18, the defibrated paper cotton storage hopper 19, the mixer 20, and the forming machine 21 are connected in this order via feeders. Further, this forming machine 21, inspection machine 22, cutting machine 23, steam injection device 24, humidity control chamber 25, stacker 26, feeder 2
7, sander (thickness adjusting machine) 28, cutting machine (horizontal dimension) 29,
A cutting machine (longitudinal dimension) 30, an inspection machine 31, and a stacker 32 are connected in this order via a belt conveyor. A control room 33 is installed in a place apart from these devices.

The manufacturing process of this embodiment will be described below with reference to the manufacturing plant shown in FIG. (1) Cut the paper with the shredder device 16. (2) The cut paper is put into the raw material storage hopper 17. (3) Using the FS mill 18, the cut paper is dry defibrated to produce paper cotton. (4) The dry defibrated paper cotton is defibrated Paper cotton storage hopper 19
Throw in. (5) A binder is added to the paper cotton and mixed with the mixer 20. (6) The mixed material is compressed by the forming machine 21 to a predetermined density. (7) The compressed material is inspected by the inspection machine 22. (8) Cut into a predetermined size with the cutting machine 23. (9) The cut material is hot press molded by the steam injection device 24. (10) The obtained molded body is put into the humidity control chamber 25 to cure the molded body. (11) Stack the cured molded product into a stacker 26 and a feeder 27.
And carry it to Thunder 28. (12) Adjust the thickness with the sander 28. (13) Further, the cutting machine 2 is formed so as to have predetermined horizontal and vertical dimensions.
Cut the molded product at 9, 30. (14) The cut molded body is inspected by the inspection machine 31. (15) Place it on the stacker 32 and carry it to the designated place. In these manufacturing processes, the room temperature and humidity are controlled by the control room 33.

As described above, the method for producing the cushioning material of the present invention is such that the content of paper cotton or fiber, the kind and addition amount of the binder are changed, or the steam injection temperature, the pressure and the pressure during hot press molding are applied. By changing the time, the density of the cushioning material can be changed.

Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited to this, and any modification or implementation of the present invention is possible without departing from the spirit of the above and the following. It is included in the technical scope.

[0036]

【Example】

Example 1 Waste paper was cut into 3 × 12 mm with a shredder and dry defibrated with an FS mill to obtain paper cotton. 15% by weight of melamine resin was added to the obtained paper cotton, and they were mixed with a mixer. Next, after being compressed by a forming machine to a density of 0.1 g / cm ³ , it was installed in the steam injection device shown in FIG. 2 and the steam injection temperature was set to 1
A buffer material having a density of 0.1 g / cm ³ was manufactured by raising the temperature to 20 ° C. and performing hot press molding.

The buffering capacity of the buffering material was evaluated by applying various compressive forces to the buffering material thus manufactured and measuring the shrinkage ratio of the buffering material under each compression with a caliper. The shrinkage ratio in the present embodiment means the volume (V _i ) under various compressive forces with reference to the volume (V ₀ ) of the cushioning material under a certain compressive force (0.2 kg / cm ² ).
Is expressed by the following equation. Shrinkage rate = (V ₀ −V _i ) / V ₀

FIG. 5 is a graph in which the contraction rate under each compressive force is plotted in a semilogarithmic graph. As is clear from the figure, the cushioning material manufactured in this example has an excellent elastic force because the contraction rate increases almost proportionally as the compression force increases. Therefore, the cushioning material produced by the method of the present invention is capable of absorbing the shock generated when transporting electric equipment products and the like, and exerting a cushioning effect of softening the damage of the products.

[0039]

Since the manufacturing method of the present invention is configured as described above, it is possible to efficiently manufacture a cushioning material excellent in moldability, shape retention and elasticity in a short time. Further, since the cushioning material having various densities can be manufactured by adjusting the kind and amount of the material, the temperature at the time of hot press molding, etc., the cushioning material can be used in a wide range of fields.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the surface pressure and the density of a compression-molded body during compression molding by a forming machine.

FIG. 2 is a schematic diagram showing a configuration of a steam injection device used in the present invention.

FIG. 3 is a schematic view showing an arrangement of steam introduction paths arranged in an injection plate.

FIG. 4 is a schematic view showing an embodiment of a cushioning material manufacturing plant of the present invention.

FIG. 5 is a graph showing the relationship between compressive force and contraction rate in Example 1.

[Explanation of symbols]

 1 Steam inlet 2 Strainer 3 Cyclone separator trap 4 Pressure reducing valve 5,6 Header 7 Stop valve 8 Solenoid valve 9 Steam injection press 10 Cooling plate 11 Insulation material 12 Hot plate 13 Injection plate 14 Steam introduction path 15 Injection hole 16 Shredder device 17 Raw material Storage hopper 18 FS mill 19 Defibrated paper cotton storage hopper 20 Mixer 21 Forming machine 22 Inspection machine 23 Cutting machine 24 Steam injection device 25 Humidity control chamber 26 Stacker 27 Feeder 28 Thunder 29 Cutting machine (horizontal dimension) 30 Cutting machine (vertical dimension) ) 31 Inspection machine 32 Stacker 33 Control room

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Go Aimoto 2-3-1, Niihama, Arai Town, Takasago City, Hyogo Prefecture Kobe Steel Works Takasago Works

Claims (4)

[Claims] 1. A method for producing a cushioning material, characterized in that hot-press molding is performed by steam jetting paper cotton, which is obtained by dry defibrating paper into a cotton shape. 2. The manufacturing method according to claim 1, wherein the steam is injected at a temperature of 120 ° C. or higher. 3. The method according to claim 1, wherein a thermosetting resin is added as a binder. 4. A cushioning material manufacturing plant comprising a device for dry defibrating paper to produce cotton, a device for mixing the cotton with a binder, and a hot pressing device by steam injection.