JP2000354748A - Kneading of powder and liquid and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently knead powder and liquid while dispensing with large power and a special mixing device by agitating and mixing the powder and the liquid in a tank and drawing out a part of the mixture by a pump to circulate and return it to the tank through a static mixer while keeping agitating and mixing. SOLUTION: The mixture 11 of the powder and the liquid is thrown into an agitating tank 10 with an agitator 20, which is operated intermittently to rotate an agitation blade 22 at low speed while keeping the tank at the prescribed temperature. A part of the mixture 11 is circulated through a circulating means 50, etc., after a cock B1 is opened and the pump 30 under the tank 10 and the static mixer 40 are operated while rotating the blade 22. After the preliminary kneading like this way is sufficiently carried out, the mixture 11 is supplied to a kneading/foaming container by opening another cock B2. The liquid component can be efficiently permeated into the powder component by agitating the mixture 11 at low speed and then settling it like this way and the kneading effect can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for kneading a powder and a liquid, and more particularly, to a method for mixing powder in the food industry and recycling used paper. The present invention relates to a method and an apparatus for kneading with a liquid.

[0002]

2. Description of the Related Art At present, instead of plastic-based cushioning materials represented by styrene foam, which are widely used, paper-based cushioning materials obtained by recycling used papers have been attracting attention for the purpose of recycling used papers. Examples of paper-based cushioning materials having excellent elasticity include those described in JP-A-10-152173. That is, the cushioning material is a foamed molded article obtained by mixing waste paper powder and a binder containing gelatin or alginic acid in an amount of 50% by weight or more. The foamed molded product is obtained by kneading waste paper powder obtained by pulverizing waste paper, a binder containing 50% by weight or more of gelatin or alginic acid, a crosslinking reaction accelerator, and a liquid component containing water and a softening agent. , Molded and dried by heating. In this case, the liquid component is preferably in a relatively small amount to facilitate drying.

[0003] An example of a kneading method conventionally used in the production of the above-mentioned foam molded article will be described with reference to FIG. FIG. 2 shows a kneading device (preliminary kneading device) that has been used conventionally. A stirring tank 10 having a high-speed stirrer 20 'capable of revolving paper powder, gelatin, a crosslinking reaction accelerator, and a liquid component containing water as a main component, which has been previously finely ground to about 2 to 5 mm. Put in. While maintaining a temperature of 50-60 ° C. with a jacket (not shown), FIG.
As shown in (2), the stirring blade 22 is rotated while the rotating shaft 21 revolves and moves in the stirring tank 10. At this time, the pump 30 is not operated. Start stirring blades 22 for 30 to 5
5 rpm for 10 minutes at a slow speed of 0 rpm, then 150-200 rpm
Pre-kneading is performed by rotating at a high speed of 300 rpm or more at a high speed of 300 rpm or more for 5 to 10 minutes.
At this time, the revolution of the rotating shaft 21 in the stirring tank is 10 to 20 times / minute. In the case of a stirrer that does not revolve,
Special stirring blades must be used. The pre-kneaded mixture 11 is kneaded by a pump 30 with a kneader (not shown).
Sent to and kneaded. The kneading is performed for 10 to 30 minutes with a special stirrer under a condition of about 50 to 70% of moisture using a jacketed stirring tank, and then molded and (heated) dried to obtain a foam molded article. .

By the way, when the paper powder is mixed with the liquid component containing water as a main component as described above, the paper powder and the liquid containing water as a main component are kneaded in a short time to form a paper powder. Since water repellency occurs (dilatancy phenomenon), the kneading requires a great deal of labor and requires a large-scale kneading apparatus. Normally, in order to mix paper powder and liquid uniformly in a short time, stirring by high-speed rotation of the rotating blade causes large holes inside the mixture when the amount of liquid is small and the viscosity is high, stopping the circulation of the mixture. Resulting in. In addition, in the case of stirring with a stirring blade, in the case of high viscosity, the mixture mainly adheres to the rotating blade and moves due to the viscosity, so that the mixture hardly flows at a position far from the rotating blade. In addition, dust rises and the working environment becomes worse. Therefore, in the prior art, a large power is required to finally stir the mixture of the paper powder and the liquid at a high speed, and the orbit inside the stirring tank can be rotated while rotating the stirring blade shown in FIG. It is necessary to use a stirrer 20 ′, a reversible stirrer, a stirrer having a stirring blade of a special shape, and the like, which increases capital investment costs. Furthermore, the operation is complicated and the working environment is poor, for example, the operation is performed by dividing the number of rotations into multiple stages, and much attention is required for automation of the kneading stage.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and a method for kneading powder and liquid which does not require a large power or a special stirring device. And an apparatus therefor.

[0006]

In order to achieve the above-mentioned object, the present inventor has proposed a method of kneading powder and liquid by mixing powder and liquid in a container to wet the powder. While stirring and mixing with a stirrer, a kneading method in which a part of the mixture is extracted and circulated through a container through a static mixer was found to be suitable, and the present invention was completed. The present invention is characterized in that, while stirring and mixing the powder and the liquid in the container with a stirrer, a part of the mixture is extracted by a pump and circulated through the container through a static mixer. The method of kneading. Also, the present invention
A kneading apparatus provided with a container, a stirrer provided in the container, a pump connected to the container and provided at a lower portion of the container, a static mixer connected to the pump, and a circulating means from the static mixer to the container. It is about.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is characterized in that, while stirring and mixing a powder and a liquid in a container with a stirrer, a part of the mixture is withdrawn by a pump and circulated to the container via a static mixer. And Examples of the powder include flour, starch, paper powder, and especially a mixture of pulp or paper powder or defibrated material. less than,
The kneading in the case where a paper powder and a liquid containing water as a main component are kneaded to obtain a foamed molded product will be described. Paper powder is obtained by pre-crushing waste paper with a turbo cutter in advance, using a continuous homogenizer, and finely pulverizing to 1 to 15 mm, more preferably about 2 to 5 mm at a high speed of 3,000 to 6,000 rpm. Or kneaded with water without pulverization.

In the preparation of the foamed molded product, the paper powder preferably contains a binder, a crosslinking reaction accelerator and the like. Binders are used to form good foams. Examples of the binder include gelatin, alginic acid, egg white, polysaccharides such as starch, and the like.
These may be used alone or in combination of two or more. The crosslinking reaction accelerator is used, if necessary, to stabilize the foamed shape. Examples of the crosslinking reaction accelerator include a crosslinking accelerator represented by transglutaminase, aldehyde compounds such as formalin, acetaldehyde, glutaraldehyde, and complex ions alum (aluminum potassium sulfate). These may be used alone or in combination of two or more.

In the preparation of a foamed molded article, the liquid of the present invention includes water, a softening agent and the like. As the water, industrial water, tap water, purified water, and the like can be appropriately used. Softeners are used to provide elasticity to the molded foam. Specific examples include glycerin, ethylene glycol, diethylene glycol, polyethylene glycol, triethanolamine, polyvinyl alcohol, and the like, or a mixture of any of these and sucrose. These may be used alone or in combination of two or more.

The method of mixing the powder and the liquid is such that, after mixing all of the paper powder in advance and mixing with the liquid, a part of the powder is mixed with the liquid and then the remaining powder is mixed. You may.
Further, a binder such as gelatin may be previously mixed with the powder, or may be mixed as an aqueous solution.
However, it is preferable that the binder, the crosslinking reaction accelerator and the softening agent are mixed with a powder or a liquid before foam molding. If necessary, additives such as a surfactant, an antibacterial agent, a fungicide coloring agent, a bleaching agent, an antioxidant, a weather (light) agent, and a filler are added to the mixture. You may.

FIG. 1 shows an example of a kneading apparatus (preliminary kneading apparatus) used in the present invention. The kneading device (preliminary kneading device) used in the present invention includes a container (stirring tank) 10
And a stirrer 20 provided in a container (stirring tank) 10;
A pump 30 connected to the container (stirring tank) 10 and provided at the lower part of the container, a static mixer 40 connected to the pump, and a circulating means 50 from the static mixer 40 to the container (stirring tank) 10 are provided. I have.

The following is applicable to a case where a foamed molded product is obtained by kneading a paper powder and a liquid containing water as a main component. The mixture is stirred and mixed with a stirrer, and a part of the mixture is extracted with a pump. An example of a kneading method of circulating the mixture in a container via a static mixer will be described with reference to FIG. 1, but the present invention is not limited to the following. A total of 100 kg of the mixture of the paper powder and the liquid (moisture content of the mixture; 50 to 7)
(5% by weight) 11 into a stirring tank 10 (capacity 200 liters) equipped with a stirrer 20 and a jacket (not shown).
The stirrer 20 is operated while maintaining the temperature at 50 to 60 ° C. At this time, the pump 30 is not operated. Start, 20-10
The stirring blade 22 is rotated at a low speed of 0 rpm for 5 to 10 minutes. Then, it is left still for 1 to 3 hours.

After standing, the stirring blades 22 of the stirrer 20 are again
Spin at a speed of 20-100 rpm for 5-10 minutes. At the same time, the cock B1 is opened, and the pump 30 and the static mixer 40 below the stirring tank 10 are operated. A part of the mixture 11 in the stirring tank 10 is
1. Return to the stirring tank 10 through the static mixer 40 and the circulation means 50. At this time, the pressure of the pump 30 is 1 to 5 kg / cm ² G, and the cock B2 is closed. After 5 to 10 minutes, after the preliminary kneading is sufficiently performed, the cock B2 is opened, and the mixture 11 is sent to a kneading and foaming device (not shown).

The kneading and foaming device (not shown) is a continuous mixer type homogenizer. For example, "Whip Zero One" manufactured by Mitsubishi Kakoki Co., Ltd. can be used. The kneading and foaming conditions are as follows: the pressure of the regulator at 50 to 60 ° C. to 5 kg / c.
m ² G or less, and the number of revolutions is 500 to 3,000 rpm.
The sufficiently kneaded and foamed mixture is molded and dried to form a foamed molded article. Examples of the molding method include injection molding and form molding. The drying method may be carried out in a mold, and examples thereof include heat drying, freeze drying, microwave irradiation, and natural drying. In the case of heating and drying, the temperature is 10
0-200 ° C.

At the beginning of the kneading operation, the mixture is stirred at a low speed and then allowed to stand, so that the liquid component permeates into the solid component,
The kneading effect increases, and high-speed stirring becomes unnecessary. For this reason, in the kneading method of the present invention, the maximum rotation speed of the stirring blade is sufficient at 300 rpm. Although the above example is of a batch type, premixing and kneading may be performed continuously. Further, the kneading effect is increased by changing the mixer type to a draft tube type, adding a surfactant to a liquid, and the like. The pre-kneading, kneading, and foaming operations need to be performed at 50 to 60 ° C., a temperature at which the binder such as gelatin does not solidify and does not deteriorate.

The above-mentioned stirrer 20 is a special mixer such as a high-speed stirrer, a stirrer that can revolve while rotating a stirring blade, a reversible stirrer, a stirrer having a stirring blade of a special shape, or a high-powered stirrer. There is no need to use a low-power, inexpensive slow-speed stirrer. As the pump 30, a positive displacement pump generally used for a high-viscosity mixture is preferable. For example, "Mono Pump NLS30RB" manufactured by Hyojin Equipment Co., Ltd. may be mentioned. As the static mixer 40, a generally used screw type element or the like may be used. Static mixer 4
The diameter of the circulation means 50 from 0 to the stirring tank 10 is not particularly limited, but is preferably 4 to 5 cm when the capacity of the stirring tank 10 is 50 to 200 liters.

As described above, in the present invention, the mixture of paper powder and liquid is gently stirred and mixed in a container, and then allowed to stand, so that the paper powder is sufficiently wetted. Kneading is possible only by circulation of the mixture through a line mixer (static mixer) and uniform stirring in the container. Although the working time is long due to the above-mentioned standing time, the kneading container is set to 2 in a continuous batch system.
In the case of alternate operation with more than two units installed, the kneading containers other than the operating kneading container are put on standby, so that a standing time may be taken during that period, and the working efficiency does not decrease.

[0018]

According to the present invention, the working process time is relatively short and efficient without requiring a large power or a special stirring device.
A method and apparatus for kneading powder and liquid are provided,
They are suitable for the production process of foamed molded articles of recycled paper. The obtained foamed molded article is useful as a substitute for a plastic buffer represented by styrene foam. Further, the method and apparatus for kneading powder and liquid of the present invention can be applied not only to kneading of paper powder and liquid, but also to kneading of powder in the food industry.

[Brief description of the drawings]

FIG. 1 is a schematic view of a kneading apparatus (preliminary kneading apparatus) of the present invention.

FIG. 2 is a schematic view of a kneading apparatus (preliminary kneading apparatus) according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Container (stirring tank) 11 Mixture 20 Stirrer 30 Pump 40 Static mixer 50 Circulation means

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jun Fukaishi 2-1 Okawa-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term (reference) 4M035 AA23 AB44 AB46 AC31 4G078 AB09 AB20 BA05 DA19 DB04

Claims (2)

[Claims] A powder and a liquid in a container are stirred by a stirrer.
A method for kneading a powder and a liquid, wherein a part of the mixture is withdrawn by a pump while being mixed and circulated through a container through a static mixer. 2. A container, a stirrer provided in the container,
A kneading apparatus comprising: a pump connected to a container and provided at a lower portion of the container; a static mixer connected to the pump; and a means for circulating the static mixer to the container.