JP7330094B2 - Charge control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for suppressing electrification of powder or granules when conveying the powder or granules using a resin hose. The present invention also relates to resin hoses used in such antistatic methods.

Resin hoses have advantages such as being lightweight and resistant to crushing, and are used in a wide variety of applications. Granules such as resin pellets and powders such as wood powder, paper powder, and metal powder are sometimes conveyed through resin hoses. When powder or granules are conveyed by a resin hose, static electricity may be generated due to friction between the wall of the hose and the powder or granules. If the hose is charged with static electricity, there is a risk of electric shock or sparking, so it is desired to suppress the generation of static electricity.

In order to suppress charging of the hose due to static electricity, a technique of introducing a conductive material or member into the hose is known.
For example, Patent Document 1 discloses a resin hose in which a hard portion is spirally integrated with a cylindrical soft portion, in which the hard portion is exposed to the inside and outside of the hose, and the hard portion is electrically conductive. A hose technology is disclosed in which a hard part is made conductive by mixing a flexible material, and according to the hose, it is possible to reduce the occurrence of sparks due to frictional static electricity such as powder transported inside. Are listed.

JP-A-2006-57654

In the hose of Patent Literature 1, electrification of the hose is suppressed by grounding using a conductive material. However, there is still a risk that the conveyed powders and granules will be charged. If the powder or granules are electrically charged, it is not preferable because the hopper or the like is easily clogged with the hopper.

An object of the present invention is to provide a method for suppressing electrification of powder or granules when conveying the powder or granules using a resin hose. Another object of the present invention is to provide a flexible resin hose for use in such an antistatic method.

As a result of intensive studies, the inventors discovered that the soft vinyl chloride resin composition and the soft polymethyl methacrylate resin composition are exposed on the inner peripheral surface of the hose, and that the material of the powders and granules to be conveyed has a triboelectric series. The present invention has been completed based on the finding that when the resin composition is positioned between the two types of resin compositions in order, the charging of powders and granules is suppressed.

The present invention is a method for suppressing electrification of powder or granules when conveying powder or granules using a resin hose, wherein the resin hose comprises an inner peripheral surface of the hose. The first resin and the second resin are exposed to, the first resin is a polymethyl methacrylate resin composition having a durometer type A hardness of 50 degrees to 90 degrees, and the second resin is a plasticizer A resin hose made of a vinyl chloride resin composition having a durometer type A hardness of 50 degrees to 90 degrees, wherein the poly A method for suppressing electrification using a polyamide resin positioned between the methyl methacrylate resin composition and the vinyl chloride resin composition (first invention).

In the first invention, the polymethyl methacrylate resin composition preferably contains an ethylene-vinyl acetate copolymer resin (second invention) .

Further, the present invention is a method for suppressing electrification of powder or granules when conveying powder or granules using a resin hose, wherein the resin hose is an inner part of the hose. The first resin and the second resin are exposed on the peripheral surface, the first resin is a polymethyl methacrylate resin composition having a durometer type A hardness of 50 degrees to 90 degrees, and the second resin is A resin hose made of a vinyl chloride resin composition having a durometer type A hardness of 50 to 90 degrees containing a plasticizer. A method for suppressing electrification, wherein a vinyl chloride resin composition containing no plasticizer is positioned between the polymethyl methacrylate resin composition and the vinyl chloride resin composition (a third aspect of the invention) . In the third invention, preferably, the plasticizer contained in the second resin contains trioctyl trimellitate or diisononyl phthalate ( fourth invention).

According to the electrification suppressing method of the present invention (first and third inventions) , the two types of resins exposed on the inner peripheral surface of the hose tend to electrify the powder or granular material in opposite directions. , charging of powders and granules is suppressed. Moreover, according to the electrification suppressing method of the first invention, it is possible to suppress electrification of the polyamide resin powder or granules . Moreover, according to the electrification suppressing method of the third invention, it is possible to suppress electrification of powders and granules of a vinyl chloride resin composition that does not contain a plasticizer.

Also, in the second invention, the strength of the flexible hose used in the electrification suppressing method is increased. Moreover, in the fourth invention, the flexibility of the resin hose used in the electrification suppressing method is further improved.

1 is a partial cross-sectional view showing the structure of a resin hose according to a first embodiment; FIG. FIG. 4 is a cross-sectional view showing a modification of the hose wall configuration; It is a figure which shows the modification of arrangement|positioning of 1st resin and 2nd resin in a hose internal peripheral surface. It is a schematic diagram which shows the manufacturing method of the resin-made hose of 1st Embodiment. The electrification series exemplified in MIL-HDBK-263B.

An embodiment of the invention will be described below with reference to the drawings, taking a resin hose used for conveying resin pellets as an example. The invention is not limited to the individual embodiments shown below, and can be implemented by changing the form. The powders and granules conveyed by the resin hose are not limited to resin pellets. The material that constitutes the powder or granules to be conveyed may be paper, wood, fiber, ceramic, metal, medicine, food material, or the like.

FIG. 1 is a partial cross-sectional view showing the configuration of the resin hose 1 of the first embodiment. The upper left side of the figure is a cross-sectional view. The resin hose 1 has a cylindrical hose wall 11 and a reinforcing body 12 integrated with the hose wall 11 . The hose wall 11 is flexible and contributes to the flexibility of the resin hose 1 . The resin hose 1 can be used for conveying powder or granules.

In the resin hose 1, the reinforcing body 12 is not essential. When the reinforcing body 12 is provided, the resin hose 1 is less likely to collapse. In this embodiment, the reinforcing body 12 is spirally integrated with the outer peripheral surface of the hose wall 11 . Moreover, in this embodiment, the reinforcing body 12 is made of a resin that is harder than the resin that makes up the hose wall 11 .

The resin hose 1 does not necessarily have to be made of only resin. It is sufficient that the main body of the resin hose, especially the main body of the hose wall portion, is made of resin. The constituent members of the resin hose 1 may include metal wire, metal foil, metal mesh, glass fiber, carbon fiber, and the like. For example, a hard steel wire may be integrated with the resin hose as part of the reinforcing body.

Although not essential, in this embodiment, the inner peripheral surface of the hose wall 11 is formed in a smooth cylindrical shape. The inner peripheral surface of the hose wall 11 may not be completely smooth, may be bellows-shaped, and may have some steps or gaps.

The cylindrical hose wall 11 is made of relatively flexible resin. The hose wall 11 is configured by combining a plurality of resin materials, and a first resin and a second resin, which will be described later, are exposed on the inner peripheral surface of the hose wall 11 . In FIG. 1, the first resin is exposed on the first portion 14a of the inner peripheral surface of the hose wall, and the second resin is exposed on the second portion 14b of the inner peripheral surface of the hose wall.

Although not essential, in the present embodiment, the first resin is formed in a tape shape and arranged in the inner peripheral portion of the hose in a spirally wound state. On the other hand, the second resin is formed in a cylindrical shape so as to cover the spiral first resin tape. When viewed from the inside of the hose, the second resin is exposed on the inner peripheral surface of the hose from the spiral gap where the first resin is exposed, and the second resin is the outer periphery of the first resin tape. is closely related to It is preferable that the first resin and the second resin are integrated with each other.

The first resin is a polymethyl methacrylate (PMMA) resin composition with a durometer type A hardness of 50 degrees to 90 degrees. This resin composition is hereinafter also referred to as "soft PMMA resin composition". Durometer type A hardness is hardness measured according to JIS-K-6253-1997. Examples of such a soft PMMA resin composition include a resin composition obtained by mixing PMMA resin with acrylic rubber, and a resin composition obtained by adding a rubber component to PMMA resin molecules. The soft PMMA resin composition may be mixed with other resins, additives, and the like. As the main resin material of the soft PMMA resin composition, for example, a soft acrylic resin sold by Kuraray Co., Ltd. under the product name of "Parapet (registered trademark) SA" can be used.

The soft PMMA resin composition, which is the first resin, preferably contains an ethylene-vinyl acetate copolymer resin (EVA resin). When the EVA resin is included, the flexibility and strength of the first resin are increased, while the charge suppression performance is less likely to change.

The second resin is a vinyl chloride (PVC) resin composition with a durometer type A hardness of 50 degrees to 90 degrees containing a plasticizer. This resin composition is hereinafter also referred to as "a PVC resin composition containing a plasticizer". Various additives may be mixed in the PVC resin composition containing the plasticizer.

As the plasticizer contained in the PVC resin composition containing the plasticizer as the second resin, various plasticizers for vinyl chloride resins can be used alone or in combination. Among others, the plasticizer preferably contains trioctyl trimellitate (TOTM) or diisononyl phthalate (DINP).

The first resin and the second resin have different orders of electrification series.
Here, the electrification series is an order in which substances and materials are arranged in the order of their electrification tendency, i.e., which is more likely to be positively charged and which is more likely to be negatively charged when two solids of different types are rubbed together. is. A rough order is shown in Appendix A of MIL-HDBK-263B or the like. The hierarchy for Appendix A of MIL-263B is shown in FIG. The charging order between the material used in the hose and the material to be transported is revealed by bringing the materials into contact and rubbing them together to see which polarity (+ or -) each material is charged. can do.

As shown in the electrification series of MIL-HDBK-263B, a general tendency of electrification series appears depending on the type of resin material. Taking solid resin materials as an example, the order is polyamide resin (nylon), hard rubber, acetate resin, polyester resin, polyurethane resin, polypropylene resin, vinyl chloride resin, silicone resin, and fluororesin, in descending order of positive charge. is likely to appear. That is, according to this order, when the resins are rubbed together, the polyamide resin is most likely to be positively charged, and the fluororesin is most likely to be negatively charged. When resins and other substances are rubbed together, the other substances or materials are placed somewhere in the electrification series of such resins. For example, as shown in the MIL-HDBK-263B triboelectric series of FIG. 5, wood and paper are positioned between polyamide and polyurethane resins.

As will be described later, in the case of suppressing electrification of powder or granules conveyed using the resin hose, the powder or granules are arranged in the order of the electrification row. The selection of these materials is made such that they are positioned between the first resin and the second resin. This suppresses electrification of conveyed powders and granules (paper pieces, wood powder, resin pellets, etc.).

The resin hose can be manufactured by applying a conventionally known hose manufacturing method. An example is given below. FIG. 4 shows a schematic diagram of a method for manufacturing the resin hose 1 of the first embodiment. A hose manufacturing apparatus 9 having a hose forming shaft SFT configured to be capable of rotationally feeding while winding a strip or wire is prepared. Note that this device may be a known device. A strip T1 having a predetermined cross-sectional shape is co-extruded from the first resin and the second resin and supplied in a semi-molten state to the hose molding shaft SFT so as to obtain a predetermined hose cross-section. The strip T1 is helically wound on the hose molding shaft, and both edges of the strip T1 are fused together to form a cylindrical hose wall 11 . Furthermore, the resin to be the reinforcing member 12 is extruded into a wire having a predetermined cross section to form a wire T2, which is supplied in a semi-molten state to the hose molding shaft SFT. The wire rod T2 is spirally wound on the outer peripheral surface of the hose wall 11 and is fused and integrated with the hose wall to form the reinforcing body 12 . After that, the hose wall 11 and the reinforcing member 12 are cooled to fix the shape of the hose. By continuously performing these series of steps on the hose molding shaft, the resin hose 1 of indeterminate length can be continuously molded.

The effect of suppressing electrification of the resin hose will be described.
In order to suppress electrification of powders and granules conveyed using the above-mentioned resin hose, when arranging them in the order of the triboelectric series, the materials constituting the powder or granules should These materials may be selected so that they are positioned between the first resin (soft PMMA resin composition) and the second resin (PVC resin composition containing a plasticizer). This suppresses electrification of the conveyed powder or granular material.

Table 1 shows the change in the resin material when another resin material is brought into contact with the soft PMMA resin composition as the first resin and the PVC resin composition containing the plasticizer as the second resin. The results of measuring the charged state are shown.

The charging state measurement test was conducted as follows.
A 1 mm thick, 12 cm square press sheet is made from each material.
A sample (e.g., PP) on the vertical axis and a sample (e.g., soft PMMA) on the horizontal axis in Table 1 were selected, and each was charged by an ionizer (static eliminator), and the potential became zero with an electrostatic potential measuring machine. to confirm.
Two samples that have been selected and neutralized are placed in close contact with each other and peeled apart. After peeling off, the potential of the sheet surface of the sample (for example, PP) on the vertical axis is measured by an electrostatic potential measuring machine.

In Table 1, "soft PMMA" is a soft PMMA resin composition, specifically "Parapet (registered trademark) SA-CW001" manufactured by Kuraray Co., Ltd., and its hardness is 60 degrees A.
In Table 1, "soft PMMA + EVA" is a soft PMMA resin composition. Specifically, EVA resin (Tosoh Corporation It is a resin composition containing 30 parts by weight of Ultrathene YX11), and its hardness is 70 degrees A.

In Table 1, "soft PVC (DINP)" is a PVC resin composition containing a plasticizer, and specifically, a resin composition in which 90 parts by weight of DINP is blended with 100 parts by weight of vinyl chloride resin having a degree of polymerization of 1300. and its hardness is 63 degrees A.

In Table 1, "PE" means polyethylene resin, specifically Petrothene 360 from Tosoh Corporation.
In Table 1, "PP" means polypropylene resin, specifically Sumitomo Noblen AD571 manufactured by Sumitomo Chemical Co., Ltd.
In Table 1, "rigid PVC" means a rigid vinyl chloride resin containing no plasticizer, specifically SE-4000 from Sun Arrow Kasei Co., Ltd.
In Table 1, "ABS" means acrylonitrile butadiene styrene resin, specifically GR-2000 from Denka Co., Ltd.
In Table 1, "PA" is a polyamide resin, specifically Leona 1300S manufactured by Asahi Kasei Corporation.
In Table 1, "PA (GF)" is glass fiber-filled polyamide resin, specifically Zytel 70G33 from DuPont.
In Table 1, "hard acrylic" means a hard polyacrylic resin, specifically Parapet HR-L manufactured by Kuraray Co., Ltd.
In Table 1, "POM" means polyoxymethylene resin, specifically Tenac 7050 manufactured by Asahi Kasei Corporation.
In Table 1, "PC" is a polycarbonate resin, specifically Iupilon S-2000 of Mitsubishi Engineering-Plastics Corporation.
In Table 1, "PBT" means polybutylene terephthalate resin, specifically DURANEX 2002 from Polyplastics Co., Ltd.
In Table 1, "PPS" means polyphenyl sulfide resin, specifically FZ-2100 from DIC Corporation.

As shown in Table 1, for example, polyethylene resin (PE) is negatively (-) charged by contact and rubbing with the soft PMMA resin composition, which is the first resin. In addition, the polyethylene resin (PE) is positively (+) charged by contacting and rubbing against the PVC resin composition containing the plasticizer, which is the second resin. A similar electrification tendency appeared also when the plasticizer contained in the plasticizer-containing PVC resin composition was TOTM.
The other resins (PP, rigid PVC, ABS, PA, PA (GF), rigid acrylic, POM, PC, PBT, PPS) shown on the vertical axis in Table 1 are all soft resins that are the first resin. By contacting and rubbing with the PMMA resin composition, it is charged negatively (-), and by contacting and rubbing with the PVC resin composition containing the plasticizer, which is the second resin, it is charged positively (+). . The unit of charging voltage in Table 1 is kV.

The granules to be conveyed may flow within the hose, contact the inner peripheral surface of the hose, rub against each other, and generate static electricity. According to the resin hose of the above-described embodiment, when the granules (for example, PE resin) to be conveyed rub against the first resin exposed on the inner peripheral surface of the hose, the granules to be conveyed are placed in the order of the electrification row. shows a tendency to be negatively charged. On the other hand, when the granules (for example, PE resin) to be conveyed rub against the second resin exposed on the inner peripheral surface of the hose, the granules to be conveyed tend to be positively charged due to the order of the electrification row.

Since both the first resin and the second resin are exposed on the inner peripheral surface of the hose, the conveyed granular material contacts and rubs against both resins. Since the tendency of the conveyed granules to be charged when it comes into contact with the first resin and when it comes into contact with the second resin is opposite in terms of plus and minus, the granules conveyed have one polarity. Accumulation of charges is suppressed, and charging is suppressed. In order to obtain such an effect, the material constituting the powder or granules should be positioned between the first resin and the second resin when they are arranged in the order of the electrification series.

Further, in the resin hose of the above embodiment, the first resin is a polymethyl methacrylate resin composition having a durometer type A hardness of 50 to 90 degrees, and the second resin is a durometer type A containing a plasticizer. Since the vinyl chloride resin composition has a hardness of 50 degrees to 90 degrees, it is possible to suppress charging of the conveyed resin pellets for various resin materials as shown in Table 1.
That is, the resin hose of the above-described embodiment is composed of at least polyethylene resin, polypropylene resin, rigid vinyl chloride resin containing no plasticizer, acrylonitrile-butadiene-styrene resin, polyamide resin, polyamide resin containing glass fiber, rigid polyacrylic resin, polyoxy For methylene resin, polycarbonate resin, polybutylene terephthalate resin, and polyphenyl sulfide resin, it is possible to suppress charging of resin pellets being transported.

Above all, in the resin hose of the above-described embodiment, even if the material constituting the powder or granules (resin pellets) is a polyamide resin, it is possible to suppress charging of the conveyed resin pellets. The inventors discovered that when the soft PMMA resin composition, which is the first resin, and the polyamide resin are in contact with each other and rubbed against each other, the polyamide resin tends to be negatively charged (column PA in Table 1). This finding is the opposite trend to the order of the electrification series of MIL in FIG. That is, the effect of suppressing electrification when the resin pellets of the polyamide resin are transported by the resin hose of the above embodiment is an effect that cannot be predicted.

In addition, in the resin hose of the above embodiment, even if the material constituting the powder or granular material (resin pellet) is a vinyl chloride resin composition that does not contain a plasticizer, a so-called hard vinyl chloride resin, the resin to be conveyed Electrification of pellets can be suppressed. The inventors have found that when a PVC resin composition containing a plasticizer, which is the second resin, and a vinyl chloride resin composition containing no plasticizer are brought into contact and rubbed against each other, the vinyl chloride resin composition containing no plasticizer is It was found to have a tendency to charge positively (Rigid PVC column in Table 1). This finding is a trend not seen in the ordering of the MIL electrification series in FIG. That is, the effect of suppressing electrification when the resin pellets of the vinyl chloride resin composition containing no plasticizer are conveyed by the resin hose of the above embodiment is an effect that cannot be predicted.

In addition, in the resin hose of the above embodiment, both the first resin and the second resin have a durometer type A hardness of 50 degrees to 90 degrees. The wall becomes highly flexible, the flexibility of the hose is less likely to be impaired, and the hose becomes flexible.

Further, when the PVC resin composition containing a plasticizer, which is the second resin, contains trioctyl trimellitate (TOTM) or diisononyl phthalate (DINP) as the plasticizer, the hardness of the second resin tends to be lowered, The hose can be made more flexible.

Further, if the soft PMMA resin composition, which is the first resin, contains an ethylene-vinyl acetate copolymer resin (EVA resin), the strength and elongation of the first resin can be improved. Further, as shown in Table 1, even if the soft PMMA resin composition, which is the first resin, contains EVA resin, the tendency of charging of the rubbing object resin (PE, PP, rigid PVC, etc.) , both remain negative (-) and do not change. That is, if the soft PMMA resin composition, which is the first resin, contains an ethylene-vinyl acetate copolymer resin (EVA resin), a flexible hose can be produced without reducing the types of resins having an antistatic effect. Increases strength.

Further, if the first resin and the second resin are each exposed in a spiral shape on the inner peripheral surface of the hose, when the powder or granules are conveyed inside the hose, these powders or granules can be The granules can evenly contact both the first resin and the second resin, and the electrification suppressing effect is enhanced.

The invention is not limited to the above embodiments, and can be implemented with various modifications. Other embodiments of the invention will be described below, but in the following description, differences from the above embodiment will be mainly described, and detailed descriptions of the same parts will be omitted. Moreover, these embodiments can be implemented by combining some of them with each other or replacing some of them.

The specific configuration of the hose wall is not limited to the illustrated embodiment, and other embodiments are possible. For example, the structure of the hose wall may be as follows. FIG. 2 shows a cross-sectional view of the hose wall portion of the resin hose taken along a plane including the central axis of the hose.

As for the structure of the hose wall, like the structure shown in FIG. 2(a), about half of the resin band 15a composed of the first resin is exposed on the inner peripheral surface of the hose, and the first resin is formed. The other half of the strip 15a may be sandwiched between the resin 15b made of the second resin. Such a configuration can be manufactured by applying the hose molding method described above. Even with such a configuration, charging of the conveyed granular material can be similarly suppressed.

As for the structure of the hose wall, as shown in FIG. 2(b), a resin band 16a made of the first resin and a resin band 16b made of the second resin A cylindrical outer layer 16c may be formed of a third resin so as to alternately spirally coil around the inner peripheral surface and cover the resin strips 16a and 16b. The first resin band 16a and the second resin band 16b are joined and integrated to the inner peripheral surface of the third resin outer layer 16c. A hose wall having such a configuration can be manufactured by applying the hose molding method described above. Even with such a configuration, charging of the conveyed granular material can be similarly suppressed.

As shown in FIG. 2(c), the structure of the hose wall is such that resin strips 17a made of the first resin and resin strips 17b made of the second resin are alternately arranged. Even if the first resin strip 17a and the second resin strip 17b are wound together in a spiral shape and are integrally joined together at their side edges, good. Such a configuration can be manufactured by applying the hose molding method described above. Even with such a configuration, charging of the conveyed granular material can be similarly suppressed.

In addition, in the description of the above embodiment, two types of resin are exposed on the inner peripheral surface of the hose, but three or more types of resin may be exposed on the inner peripheral surface of the hose. In this case, if the at least two resins are selected to be the first resin and the second resin, the effect of suppressing electrification of the conveyed powders and granules can be similarly obtained.

Further, the inner peripheral surface of the hose wall is preferably formed in a smooth cylindrical shape, but the inner peripheral surface shape may be such that some irregularities or gaps are present on the inner peripheral surface of the hose. In order to suppress electrification of the transported body, it is sufficient that the transported powder or granular material contacts both the first resin and the second resin. It is preferable that the first resin portion and the second resin portion have substantially the same height in the hose radial direction. If there is a step in the radial direction of the hose between the first resin portion and the second resin portion, the size of the step may vary between the first resin portion and the second resin portion. It is preferably 1/3 or less, more preferably 1/5 or less, of the width (the length of these portions in the hose axial direction).

The means for joining and integrating the materials constituting the hose is not particularly limited, and may be selected according to the structure of the hose and the characteristics of the material, such as welding, adhesion, mechanical engagement, and embedding. Further, the material constituting the hose may contain a thermosetting resin such as synthetic rubber as long as it can be integrally molded with the hose.

FIG. 3 schematically shows the pattern of the portion where the first resin material is exposed and the portion where the second resin material is exposed on the inner peripheral surface of the hose wall. In addition, in FIG. 3, only the hose inner peripheral surface is shown. In the embodiment shown in FIG. 1, the portion 14a where the first resin material is exposed and the portion 14b where the second resin material is exposed are spirally provided. As shown in FIG. 3(a), the portions 18a, 18a where the first resin material is exposed and the portions 18b, 18b where the second resin material is exposed are each formed in a ring shape, extending in the length direction of the hose. They may be arranged alternately. As with the helical form, when resin pellets are transported, the transported pellets easily come into contact with the two types of resin exposed on the inner surface of the hose alternately, resulting in an excellent antistatic effect. ing.

As shown in FIG. 3(b), the portion 19a where the first resin material is exposed and the portion 19b where the second resin material is exposed are each formed linearly along the length direction of the hose, You may provide so that it may line up alternately in a direction. This configuration is useful when directly extruding the inner peripheral portion of a cylindrical hose wall.

Although the resin hose 1 of the illustrated first embodiment includes a reinforcing member, the reinforcing member is not essential. That is, the resin hose may be tube-shaped without a reinforcing member. Also, the resin hose may be provided with other components. For example, the resin hose may have other layers, such as reinforcing layers containing reinforcing fibers. Moreover, the resin hose may have a conductor (such as a metal wire) in addition to the hose wall and the reinforcing member. Also, the resin hose may contain materials other than resin, such as reinforcing fibers, fiber mesh, metal foil, metal wire, and metal mesh.

Conductivity may be imparted to a part or the whole of the resin hose. Conductivity can be imparted, for example, by arranging a metal wire or metal mesh on or inside the hose wall or on or inside the reinforcing body. Alternatively, the resin material forming part of the hose may be kneaded with metal powder, conductive carbon, or the like to impart electrical conductivity.

Although the resin hose described above can be used for conveying powders and granules, it can also be used for other purposes, such as conveying gases and liquids.

The resin hose and the antistatic method using the resin hose can be used, for example, for transporting powders and granules (resin pellets, etc.), and have a high industrial utility value.

1 resin hose 11 hose wall 14a first resin exposed portion 14b second resin exposed portion 12 reinforcing body 9 hose manufacturing apparatus SFT hose manufacturing axis T1 belt-like body T2 serving as hose wall wire rod serving as reinforcing body

Claims (4)

A method for suppressing electrification of powder or granules when conveying the powder or granules using a resin hose, comprising:
The resin hose is
The first resin and the second resin are exposed on the inner peripheral surface of the hose,
The first resin is a polymethyl methacrylate resin composition having a durometer type A hardness of 50 degrees to 90 degrees,
The second resin is a vinyl chloride resin composition containing a plasticizer and having a durometer type A hardness of 50 degrees to 90 degrees.
It is a resin hose,
The material constituting the powder or granule is a polyamide resin positioned between the polymethyl methacrylate resin composition and the vinyl chloride resin composition when arranged in the order of the electrification series.
electrification suppression method. The polymethyl methacrylate resin composition contains an ethylene-vinyl acetate copolymer resin
The electrification suppression method according to claim 1 . A method for suppressing electrification of powder or granules when conveying the powder or granules using a resin hose, comprising:
The resin hose is
The first resin and the second resin are exposed on the inner peripheral surface of the hose,
The first resin is a polymethyl methacrylate resin composition having a durometer type A hardness of 50 degrees to 90 degrees,
The second resin is a vinyl chloride resin composition containing a plasticizer and having a durometer type A hardness of 50 degrees to 90 degrees.
It is a resin hose,
A vinyl chloride resin composition containing no plasticizer, wherein the materials constituting the powder or granules are located between the polymethyl methacrylate resin composition and the vinyl chloride resin composition when arranged in the order of the electrification series. is a thing
electrification control method. the plasticizer contained in the second resin comprises trioctyl trimellitate or diisononyl phthalate;
The electrification suppression method according to claim 3.

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