JP5773457B2 - Charged body static elimination container and charged body static elimination method using the same - Google Patents

Description

  The present invention relates to a charged body discharging container and a charged body discharging method using the same.

  It is known that when a resin pellet is transported to a metal container as a hopper using a suction device, the resin pellet is charged by contact with a transport hose forming a transport path or contact between resin pellets. In many cases, the resin pellets are already charged before being transported in the transport path.

When resin molding is performed using a plurality of types of resin pellets, if the resin pellets are charged, the plurality of types of resin pellets may not be uniformly dispersed. In other words, it becomes impossible to supply resin pellets to the resin molded part in an appropriate blended state, which may adversely affect the quality of resin molded products, such as the occurrence of color unevenness and reduced mechanical strength. There is.
In addition, the charged resin pellets cause electrostatic induction and dielectric polarization in the surroundings, and after being put into a metal container or the like as a transport destination, the resin pellets adhere to the metal container or the like due to the action of static electricity. There is also a problem in that the material detection sensor disposed in 1 erroneously detects the presence or absence of the material, and the subsequent process is stopped due to the material running out.

  In order to solve such a problem, a configuration in which a neutralizing device for resin pellets in which a self-discharge electrode is arranged in a metal container is provided (for example, Patent Document 1), or any location in the resin pellet conveyance path The structure of the static elimination apparatus (for example, the nonpatent literature 1 and the nonpatent literature 2) which arrange | positioned the ionizer for neutralizing the resin pellet to is proposed.

JP 2010-113837 A

“Esthetechno Co., Ltd.”, “Static electricity accumulates electric potential due to contact between the transported objects (air, ducts, hoses, pipes) and the inner wall surface. As a countermeasure, use a static eliminator AT type! ”, [Online], [Search June 7, 2013], Internet <URL: http://estecno.jp/seidenki/AT_gata.html> Matsui Manufacturing Co., Ltd., “Ionizer (Static Countermeasure Equipment) / Improvement Proposal Product / Proposed Product / Matsui Manufacturing Co., Ltd.”, [online], [Search June 7, 2013], Internet <URL: http: // matsui -mfg.co.jp/suggest/isp/ionizer.html>

In the static eliminator disclosed in Patent Document 1, the self-discharge electrode is disposed in the internal space of the container in which the resin pellets are accommodated. If the self-discharge electrode is damaged, There is a problem that foreign matter may be mixed in. In general, resin pellets are managed at a low humidity. However, this static eliminator introduces air from the outside in order to diffuse ions, and there is a problem that the resin pellets absorb moisture.
Further, according to the configuration of the ion neutralization type static eliminator disclosed in Non-Patent Document 1 and Non-Patent Document 2, the resin pellet is electrically neutralized by attaching ions to the charged resin pellet. ing. For this reason, if it cannot be operated so that positive or negative ions necessary for electrically neutralizing the resin pellets can be appropriately supplied to the surface of the resin pellets, the expected static elimination effect cannot be obtained. There is also a problem that there are things.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a charged body discharging container capable of indirectly discharging a charged body from the outside and a charged body discharging method using the same.

In order to solve the above problems, the present inventor has intensively studied, and as a result, has come up with the following configuration.
That is, a metal container in which a charged body can be accommodated and electrically floated, and a corona discharge electrode standing on the outer surface of the metal container in an electrically connected state with the metal container. The electrostatic energy of the charged body accommodated in the metal container moves to the outer surface of the metal container via electrostatic induction generated in the metal container, and from the corona discharge electrode to the corona. the electrostatic energy is consumed by being discharged, the charging member is a charging member neutralization container, characterized in Rukoto the charge elimination. As a result, the charged body can be neutralized by indirect corona discharge without any modification inside the container.

Further, the charged body is a resin pellet, one end is connected to the metal container, and the other end is connected to the metal container and a conveyance path formed in a pipeline connected to the material tank of the resin pellet. An air suction device, wherein the resin pellets are provided so as to be transportable in the transport path by air suction by the air suction device, and the metal container is connected to the air suction device of the pipe line. It is preferable that the resin pellet is disposed as a hopper for supplying the resin pellet to the resin molding portion at a midway position with respect to the material tank. According to this configuration, it becomes possible to supply the resin pellets in a static-removed state to the resin molding part, and no uneven color occurs in the resin molded product, and the mechanical strength as designed can be obtained. .

According to another aspect of the present invention, there is provided a charged body static elimination method for removing static electricity generated when a charged body is transported in a transport path from the charged body, wherein the above-described method is provided at a midway position in the transport path. The charged body discharging container according to any one of the above, wherein the charged body is housed in a metal container, and electrostatic energy is generated in the metal container due to static electricity of the charged body housed in the metal container. together via electrostatic induction is moved to the outer surface of the metal container which, by corona discharge from the corona discharge electrode, a step that consumes the electrostatic energy, and characterized by having There is also an invention of a charged body static elimination method. According to this configuration, it becomes possible to supply the resin pellets in a static-removed state to the resin molding part, and no uneven color occurs in the resin molded product, and the mechanical strength as designed can be obtained. .

  According to the configuration of the charged body neutralizing container and the charged body neutralizing method using the same according to the present invention, the charged body can be neutralized by indirect corona discharge without any modification inside the container. Become.

It is a see-through | perspective front view which shows the structure of the charged body static elimination container in 1st Embodiment. It is a see-through | perspective front view which shows the structure of the charged body static elimination container in 2nd Embodiment. It is a schematic block diagram of the resin molding apparatus provided with the charged body static elimination container shown in FIG.

(First embodiment)
Hereinafter, the charged body neutralizing container according to the present embodiment will be specifically described with reference to the drawings. In the present embodiment, a description will be given by exemplifying a resin pellet in a charged state as the charged body P, but the charged body P is not limited to a resin pellet in a charged state.
As shown in FIG. 1, the charged body neutralizing container 10 includes a metal container 20 in an electrically floating state, and a corona discharge electrode 30 disposed on the outer surface of the metal container 20. The metal container 20 according to the present embodiment includes a main body portion 21 formed in a so-called hopper shape formed by combining a cylinder and a hollow inverted frustoconical body, and an upper lid 22 that covers the upper surface opening surface of the main body portion 21. Yes.

  An insulating member 21A as an insulating part is attached to the bottom surface of the main body part 21 in order to electrically float the main body part 21 (metal container 20) from the installation part. The bottom surface of the main body portion 21 shown in FIG. 2 is formed in an opening portion, and an insulating member 21A having an annular shape in plan view is attached in accordance with the shape of the opening portion on the bottom surface of the main body portion 21. As another form, the bottom surface of the main body portion 21 may be formed as a closed bottom surface, and the insulating member 21 </ b> A may be attached to the outer bottom surface of the main body portion 21.

  The upper lid 22 is made of the same material as the main body 21. The upper lid 22 is detachably formed by means such as screwing with the main body 21. A corona discharge electrode 30 is erected on the upper surface side of the upper lid 22. The corona discharge electrode 30 is electrically connected to the metal container 20 (the main body 21 and the upper lid 22).

As the corona discharge electrode 30 in the present embodiment, a so-called static elimination brush is employed. In addition to the static elimination brush, a corona discharge electrode 30 has a configuration in which one or more metal wires are erected on the upper lid 22 or a configuration in which one or more metal protrusions are erected on the upper lid 22. May be adopted. When a metal projecting body is erected on the upper lid 22 to form the corona discharge electrode 30, a projecting body (corona discharge) is formed by adopting a projecting body having a sharp free end. This is advantageous because corona discharge from the working electrode 30) can be promoted.
The corona discharge electrode 30 is preferably orthogonal to the mounting surface of the upper lid 22.

Next, a method for neutralizing a charged body using the charged body neutralizing container 10 shown in FIG. 1 will be described.
After removing the upper cover 22 of the main body portion 21 of the charged body neutralizing container 10 shown in FIG. 1 and storing the charged body P in a negatively charged state in the internal space of the main body portion 21 by an appropriate method, 22 is installed.

  The main body 21 in which the negatively charged charged body P is accommodated attracts positive charges to the inner surface of the main body 21 by the action of electrostatic induction. At this time, since the charge moves so as to cancel the potential difference in the conductor, a negative charge appears on the outer surface of the main body portion 21 on the opposite side of the positive charge. Furthermore, since the metal surface is equipotential, the upper lid 22 electrically connected to the main body 21, that is, the outer surface of the metal container 20 is in a state where negative charges are diffused at equal intervals and have the same potential. Here, if the metal container 20 is connected to the ground, the charge on the outer surface immediately flows to the ground and the potential on the outer surface becomes zero, but the metal container 20 is electrically floated. The outer surface potential is not lost.

  As described above, the metal container 20 is placed on the installation surface via the insulating member 21 </ b> A so as to be in an electrically floated state, and the upper lid 22 that constitutes a part of the metal container 20 includes Since the corona discharge electrode 30 is disposed, corona discharge is generated from the corona discharge electrode 30 into the atmosphere by electrostatic energy due to negative charges on the outer surface of the main body 21. When corona discharge is performed from the corona discharge electrode 30, electrostatic energy on the outer surface of the metal container 20 is consumed. That is, the electrostatic energy of the charged body P moves to the outer surface of the metal container 20 via electrostatic induction and is consumed by corona discharge. Therefore, the electrostatic energy of the charged body P gradually decreases, resulting in charging. The body P can be neutralized.

  As described above, after the charged body P is accommodated in the metal container 20 and the corona discharge electrode 30 erected on the outer surface of the metal container 20 by the electrostatic energy of the accommodated charged body P is subjected to corona discharge in the atmosphere. If the upper lid 22 of the metal container 20 is removed and taken out from the main body portion 21, the resin pellets in a state of being neutralized can be obtained. The resin pellets neutralized by the charged body neutralizing container 10 according to the present embodiment are sent directly from the charged body neutralizing container 10 (metal container 20) to the next step, and the resin pellets once subjected to the neutralizing treatment are not charged again. It has a configuration like this.

  In this way, by using the charged body neutralizing container 10 according to the present embodiment, the charged body P can be neutralized by indirect corona discharge without any modification inside the container. It is advantageous in that various problems (mixing of foreign matters due to electrode breakage and moisture absorption of resin pellets due to introduction of external air) caused by incorporating a static eliminator can be avoided. Moreover, since corona discharge automatically consumes electrostatic energy appropriately according to the amount of charge of the charged body P, it is advantageous that no operation or adjustment is required.

(Second Embodiment)
Next, a second embodiment will be described based on FIGS. FIG. 2 is a partially transparent front view showing the configuration of the charged body neutralizing container in the second embodiment. FIG. 3 is a schematic configuration diagram of a resin molding apparatus including the charged body neutralizing container shown in FIG. In the charged body neutralizing container 10 of the present embodiment, the same components as those of the charged body neutralizing container 10 described in the first embodiment are denoted by the same reference numerals as in the first embodiment, and detailed description thereof is omitted here.
As shown in FIG. 2, the charged body neutralizing container 10 according to the present embodiment is such that the lower portion of the main body portion 21 is formed in the opening and the main body portion 21 is provided with a communication portion with the outside. Is characteristic.

The insulating member 21A attached to the bottom of the main body portion 21 (or the remaining amount confirmation portion 40) is formed in an annular shape in plan view. The insulating member 21A thus formed can be used as a packing. Specifically, as shown in FIG. 3, it is convenient when the charged body neutralizing container 10 is attached to the resin molding portion 90 in a state of being electrically floated.
In the present embodiment, a remaining amount confirmation unit 40 is disposed immediately below the charged body discharge container 10, and a resin molding unit 90 is disposed immediately below the remaining amount confirmation unit 40. Thus, the charged body static elimination container 10 in this embodiment comprises the material supply hopper in the resin molding apparatus 100 with the residual amount confirmation part 40. FIG. For this reason, the insulating member 21 </ b> A may be attached to the bottom of the remaining amount confirmation unit 40 instead of the bottom of the main body 21.

In addition, as shown in FIG. 2, the metal container 20 in the present embodiment is provided with a first communication part and a second communication part that communicate the internal space of the metal container 20 with the outside.
Specifically, on the side surface of the main body portion 21 of the metal container 20, a material input portion 23 as a first communication portion is disposed. The material input part 23 is connected to the material tank 60 via the conveyance path 50 formed with the synthetic resin tube which is a pipe line. In addition, an air suction portion 25 as a second communication portion is disposed outside the upper surface of the upper lid 22. Furthermore, a filter member 27 that allows passage of air and does not allow passage of the charged body P by a metal wire net or the like is disposed inside the upper surface of the upper lid 22. The air suction unit 25 is connected to an air suction device 80 via an air suction tube 70 made of synthetic resin.

  According to such a configuration of the metal container 20 (charged body neutralization container 10), when air suction is performed by the air suction device 80 connected to the air suction portion 25 via the air suction tube 70, the metal container 20 The internal space of is in a reduced pressure state. As a result, the charged body P (resin pellets that are already charged or uncharged) stored in the material tank 60 is taken into the metal container 20 via the transport path 50 and the material charging unit 23. At this time, the charged body P sucked in air from the material tank 60 is taken into the metal container 20 in a charged state due to friction with the transport path 50 when air is transported through the transport path 50. Since the filter member 27 is disposed between the air suction part 25 and the main body part 21, the charged body P taken in the metal container 20 is sucked from the air suction part 25 to the outside of the metal container 20. There is nothing.

In the resin molding apparatus 100 according to the present embodiment, operation control is performed by an operation control program incorporated in a computer (not shown).
Specifically, a material detection sensor is disposed inside or outside the remaining amount confirmation unit 40, and the air suction operation of the air suction device 80 is controlled based on the detection result of the material detection sensor.

  In the present embodiment, since the resin pellets that have been subjected to the charge removal process by the charged body discharge container 10 are supplied to the remaining amount confirmation unit 40, the resin pellets do not adhere to the inner surface of the remaining amount confirmation unit 40. . Thereby, there is no false detection of a material detection sensor, and the resin pellet of the state which is always appropriate qualitatively and quantitatively can be supplied to the resin molding part 90. FIG. Therefore, the resin molded product obtained by the resin molded part 90 does not have a problem that the occurrence of color unevenness or the mechanical strength becomes lower than the design strength, and the yield of the resin molded product can be increased.

Since the neutralization mechanism of the charged body P in the charged body neutralizing container 10 in the present embodiment is the same as that in the first embodiment, a detailed description thereof is omitted here.
Also in this embodiment, the charge removal process of the charged body P is a batch process. However, since the consumption of electrostatic energy by the corona discharge from the corona discharge electrode 30 is used, the inside of the charged body discharge container 10 (metal container 20) is merely a space. Therefore, there is no structure that can cause damage in the space in which the resin pellets are transported, and this is advantageous in terms of maintenance and management of the resin molding apparatus 100 in that there is no possibility of foreign matter entering the resin molded product.

  As mentioned above, although the charged body static elimination container 10 and the charged body static elimination method using the same were demonstrated in detail based on embodiment, the technical scope of this invention is not limited to embodiment described above. Absent. For example, in the above embodiment, the negatively charged resin pellet is described as the charged body P. However, the charged body P to be subjected to the charge removal process may be positively charged.

  Further, the corona discharge electrode 30 in the above embodiment has a configuration in which the electrode is simply erected on the upper surface of the upper lid 22, but is not limited to this configuration. For example, the attachment portion of the corona discharge electrode 30 is not limited to the upper lid 22 but may be the outer surface of the main body 21. Since the metal surface is equipotential, the effect does not change if the corona discharge electrode 30 is erected on the outer surface of the metal container 20.

  Further, it is preferable that another electrode connected to the ground or the voltage source is disposed in a state where the discharge gap is separated from the tip of the corona discharge electrode 30 and is opposed to the corona discharge electrode. According to this configuration, corona discharge (consumption of electrostatic energy of the charged body) from the corona discharge electrode 30 is promoted, which is advantageous in that the charge removal efficiency of the charged body can be improved. .

  Further, the metal container 20 need not always be electrically floated by the insulating member 21A. When the inside of the metal container 20 is empty, it is convenient to connect the metal container 20 to the ground and reset it to electrical neutral, because stable electrostatic induction always occurs when the charged body P is put into the metal container 20. is there.

DESCRIPTION OF SYMBOLS 10 Charged body static elimination container 20 Metal container 21A Insulation member 21 Main body part 22 Upper cover 23 Material input part 25 Air suction part 27 Filter member 30 Corona discharge electrode 40 Remaining quantity confirmation part 50 Conveyance path 60 Material tank 70 Air suction tube 80 Air Suction device 90 Resin molding unit 100 Resin molding device P Charged body (resin pellet in a charged state)

Claims (3)

A metal container that can accommodate a charged body and is electrically floated;
A corona discharge electrode erected on the outer surface of the metal container in an electrically connected state with the metal container ,
The electrostatic energy possessed by the charged body accommodated in the metal container moves to the outer surface of the metal container via electrostatic induction generated in the metal container, and is corona discharged from the corona discharge electrode. the electrostatic energy is consumed by Rukoto, charged body neutralization vessel the charging member is characterized Rukoto the charge elimination. The charged body is a resin pellet,
One end is connected to the metal container, and the other end is connected to the resin pellet material tank .
An air suction device connected to the metal container,
The resin pellets are provided so as to be transportable in the transport path by air suction by the air suction device ,
The metal container according to claim 1, in intermediate position between said air suction device and the material tank of the conduit, characterized in that it is arranged the resin pellets as a hopper for feeding the resin molding part serial mounting of the charging member neutralization container. A charged body neutralizing method for removing static electricity generated when a charged body is transported in a transport path from the charged body,
The step of accommodating the charged body inside the metal container in the charged body neutralizing container according to claim 1 or 2 disposed at a midway position in the transport path;
Electrostatic energy due to static electricity of the charged body housed in the metal container is moved to the outer surface of the metal container via electrostatic induction generated in the metal container, and corona discharge from the corona discharge electrode. by charging member neutralization method is characterized in that a, a step that consumes the electrostatic energy.

Images