JPH09329583A - Measuring apparatus for friction charge amount of powder - Google Patents
Measuring apparatus for friction charge amount of powderInfo
- Publication number
- JPH09329583A JPH09329583A JP14548496A JP14548496A JPH09329583A JP H09329583 A JPH09329583 A JP H09329583A JP 14548496 A JP14548496 A JP 14548496A JP 14548496 A JP14548496 A JP 14548496A JP H09329583 A JPH09329583 A JP H09329583A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- gas
- charge amount
- blown
- wire mesh
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
- Developing Agents For Electrophotography (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、試料粉体と接触相
手粉体との間の摩擦帯電量を精度よく、かつ迅速・簡便
に測定することのできる接触帯電量測定装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact charge amount measuring device capable of accurately, quickly, and easily measuring the amount of triboelectric charge between a sample powder and a contact partner powder.
【０００２】[0002]
【従来の技術】一般に、試料粉体の摩擦帯電特性を測定
する手段は、試料粉体に帯電を付与する接触相手粉体と
混合し、風力，遠心力，機械力，衝撃力，静電気力，振
動などを加えて摩擦帯電された両者を分離して、一方の
粉体に残留している（残った）電荷量の測定で行ってい
る。すなわち、試料粉体および接触相手粉体に粒径の差
がある場合、たとえば金網を用いて分離すると、金網の
目開きを通して小粒径粉体のみを選択的に除去できるた
め、残存・残留した比較的粒径の大きい粉体に残った帯
電量を測定することができる。また、試料粉体および接
触相手粉末のいずれか一方が強磁性体である場合には、
両者の分離に磁石を用いて強磁性体粉体のみを選択的に
固定することにより、強磁性体粉体の帯電量を容易に測
定できる。摩擦帯電された試料粉体および接触相手粉体
の分離に風力を用い、金網を用いて大粒径粉体を捕集し
てその帯電量を測定する方法は、ブローオフ法と呼ば
れ、最も一般的に使用されている。このブローオフ法で
は、少なくとも一端に金網を張設した金属円筒（以下フ
ァラデーケージ本体と称する）内に、予め混合して十分
な摩擦帯電をもった試料粉体および接触相手粉体の混合
物を収容し、一端から他端の金網面に向けて圧縮空気を
吹き付けて両者を分離することを骨子としている。2. Description of the Related Art Generally, a means for measuring triboelectric charging characteristics of a sample powder is to mix a powder with a contact partner powder that imparts an electric charge to the sample powder, and to measure wind force, centrifugal force, mechanical force, impact force, electrostatic force, The frictionally charged particles are separated by applying vibration or the like, and the amount of electric charge remaining (remaining) on one powder is measured. That is, when there is a difference in particle size between the sample powder and the contacting partner powder, for example, if they are separated using a wire net, only the small particle size powder can be selectively removed through the openings of the wire net, so that they remain or remain. The amount of charge remaining on the powder having a relatively large particle size can be measured. Further, when either one of the sample powder and the contact partner powder is a ferromagnetic material,
The electrification amount of the ferromagnetic powder can be easily measured by selectively fixing only the ferromagnetic powder by using a magnet to separate the two. The method of using wind force to separate triboelectrically charged sample powder and contact partner powder and collecting large particle size powder with a wire net to measure the charge amount is called blow-off method and is the most common method. Is being used for. In this blow-off method, a mixture of sample powder and contact partner powder that have been premixed and have sufficient triboelectrification is contained in a metal cylinder (hereinafter referred to as the Faraday cage body) having a wire mesh stretched at least at one end. The main point is to blow compressed air from one end toward the wire mesh surface at the other end to separate the two.
【０００３】すなわち、試料粉体もしくは接触相手粉体
のいずれか一方は、金網の目開きより大きい粒径とし、
また他方は金網の目開きより小さい粒径となるようにす
る。その結果、分離した一方の粉体は金網の目開きを通
してファラデーケージ本体外に吹き飛ばされる。ファラ
デーケージ本体内に残った大粒径粉体の表面には、ファ
ラデーケージ本体外に吹き飛ばされた小粒径粉体がもち
去ったと等量で、かつ逆の電荷が残っているため、この
電荷量を測定することによって両者の摩擦帯電量を知る
ことができる。なお、圧縮空気を吹き付ける代わりに、
ファラデーケージ本体内および金網面を通して気体を吸
引する方式を採っても同様に、両者の摩擦帯電量を測定
できる。That is, one of the sample powder and the contact partner powder has a particle size larger than the mesh opening of the wire mesh,
On the other hand, the grain size is smaller than that of the mesh. As a result, one of the separated powders is blown out of the Faraday cage body through the openings of the wire mesh. On the surface of the large particle size powder remaining inside the Faraday cage main body, the same amount as that of the small particle size powder blown out of the Faraday cage main body is removed, and the opposite electric charge remains. By measuring the amount, the triboelectric charge amount of both can be known. In addition, instead of blowing compressed air,
Even if a method of sucking gas through the Faraday cage main body and through the wire mesh surface is adopted, the triboelectric charge amount of both can be similarly measured.
【０００４】[0004]
【発明が解決しようとする課題】上記、ブローオフ手段
は、構造，操作が簡便で、試料粉体および接触相手粉体
の摩擦帯電特性を迅速、かつ高精度に知ることができる
ので、一般的な手法として広く実用されている。しかし
ながら、従来のブローオフ帯電量測定では、次のような
問題があり、その解決・解消が望まれている。The above blow-off means has a simple structure and operation, and can quickly and accurately know the triboelectric charging characteristics of the sample powder and the contact partner powder. It is widely used as a method. However, the conventional blow-off charge amount measurement has the following problems, and its solution and elimination are desired.
【０００５】(1)ファラデーケージ本体内で分離した試
料粉体と接触相手粉体とが、静電的に引き合って再び合
体し、接触と分離を繰り返す傾向がある。つまり、ファ
ラデーケージ本体が１種の摩擦帯電器として作用し、帯
電測定値の一定化までに時間がかかり、迅速な帯電量の
測定が困難である。(1) The sample powder separated in the Faraday cage body and the contact partner powder tend to electrostatically attract each other and coalesce again, and contact and separation tend to be repeated. In other words, the Faraday cage body acts as one kind of frictional charger, and it takes time to stabilize the charge measurement value, and it is difficult to measure the charge amount quickly.
【０００６】(2)ブローオフ操作で、試料粉体とファラ
デーケージ本体内壁面との摩擦帯電、試料粉体と金網と
の摩擦帯電も生じるので、精度の高い帯電量測定が困難
である。 (3)ファラデーケージ本体内壁面や金網の一
部に分離粉体が付着し易いため、測定帯電量に誤差が生
じ易い。(2) The blow-off operation causes frictional electrification between the sample powder and the inner wall surface of the Faraday cage body, and frictional electrification between the sample powder and the wire net, which makes it difficult to measure the amount of charge with high accuracy. (3) Since the separated powder easily adheres to the inner wall surface of the Faraday cage body or a part of the wire net, an error is likely to occur in the measured charge amount.
【０００７】(4)金網面で大粒径粉体もしくは金網の磨
耗が発生し、この磨耗によって帯電起きるため、測定帯
電量に誤差を生ずる恐れがある。(4) The large particle size powder or the wire mesh is worn on the surface of the wire mesh, and this wear causes charging, which may cause an error in the measured charge amount.
【０００８】(5)試料粉体と接触相手粉体との間の摩擦
帯電量が大きくなるに伴って、分離に時間がかかるだけ
でなく、ときには分離できない場合もあり、迅速な測定
や適切な測定が困難である。(5) As the amount of triboelectric charge between the sample powder and the contact partner powder increases, not only separation takes time, but sometimes separation may not be possible. It is difficult to measure.
【０００９】本発明は、上記事情に対処して成されたも
ので、試料粉体の摩擦帯電量を精度よく、かつ迅速に測
定できる粉体の摩擦帯電量測定装置の提供を目的とす
る。The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a powder triboelectric charge amount measuring device capable of accurately and quickly measuring the triboelectric charge amount of a sample powder.
【００１０】[0010]
【課題を解決するための手段】請求項１の発明は、一端
に圧縮気体の吹き込み口を備えた導電金属製のファラデ
ーゲージ本体と、前記ファラデーゲージ本体の他端に架
張され、かつこのファラデーゲージ本体内に収容された
試料粉体および接触相手粉体のうち試料粉体を前記圧縮
気体の吹き込みで選択通過させる金網と、前記金網の外
側面に沿って水平方向に気体を流入し、かつ金網面に沿
って渦流を発生させる気体供給手段と、前記ファラデー
ゲージ本体内に残存する接触相手粉体の帯電量を測定す
る帯電量測定手段とを具備していることを特徴とする粉
体の摩擦帯電量測定装置である。 請求項２の発明は、
請求項１記載の粉体の摩擦帯電量測定装置において、金
網の外周縁に沿った渦流を発生させる気体供給手段が、
ほぼ一定の間隔，方向で設定された複数のノズルである
ことを特徴とする。According to a first aspect of the present invention, there is provided a Faraday gauge main body made of a conductive metal having a compressed gas blowing port at one end, and the other end of the Faraday gauge main body. A wire net for selectively passing the sample powder out of the sample powder and the contact partner powder contained in the gauge body by blowing the compressed gas; and a gas flowing in a horizontal direction along the outer surface of the wire net, and A powder supply means for generating a vortex flow along the wire mesh surface; and a charge amount measuring means for measuring the charge amount of the contact partner powder remaining in the Faraday gauge body. This is a triboelectric charge amount measuring device. The invention of claim 2 is
The powder triboelectric charge amount measuring device according to claim 1, wherein the gas supply means for generating a vortex flow along the outer peripheral edge of the wire mesh comprises:
It is characterized by a plurality of nozzles set at substantially constant intervals and directions.
【００１１】請求項３の発明は、請求項１もしくは請求
項２記載の粉体の摩擦帯電量測定装置において、金網の
外周縁に沿った渦流を発生させる気体供給手段が、金網
の外周に対して接線方向複数個設定されていることを特
徴とする。According to a third aspect of the present invention, in the powder triboelectric charge amount measuring device according to the first or second aspect, the gas supply means for generating a vortex flow along the outer peripheral edge of the wire mesh is attached to the outer periphery of the wire mesh. It is characterized in that a plurality of tangential directions are set.
【００１２】請求項４の発明は、請求項１ないし請求項
３いずれか一記載の粉体の接触帯電量測定装置におい
て、気体を流入する気体供給手段の設置面に、試料粉体
を含む気体を吸引する気体吸引機構を連設したことを特
徴とする。According to a fourth aspect of the present invention, in the powder contact electrification amount measuring apparatus according to any one of the first to third aspects, a gas containing sample powder is provided on the installation surface of the gas supply means for introducing the gas. It is characterized in that a gas suction mechanism for sucking in is connected in series.
【００１３】本発明は、少なくとも一端に金網が架帳
（架設）されたファラデーゲージ本体内に、摩擦帯電さ
せた試料粉体および接触相手粉体を収容し、これに圧縮
気体を吹き込んで金網を通して一方の粉体を選択的に吹
き飛ばとともに、ファラデーゲージ本体内に残った粉体
の帯電量を測定する装置の改良である。すなわち、ブロ
ーフロー方式の摩擦帯電量測定装置において、目開きを
通して粉体を吹き飛ばす金網面に沿わせて水平の方向に
渦流気体を発生させる気体供給手段を付設した点で特徴
付けられる。According to the present invention, a Faraday gauge main body having a wire mesh at least at one end is installed, and the frictionally charged sample powder and contact partner powder are accommodated therein, and compressed gas is blown into the Faraday gauge main body to pass through the wire mesh. This is an improvement of the device that selectively blows off one of the powders and measures the charge amount of the powder remaining in the Faraday gauge body. That is, it is characterized in that the blow flow type triboelectric charge measuring device is additionally provided with a gas supply means for generating a vortex gas in a horizontal direction along a wire mesh surface for blowing the powder through the openings.
【００１４】そして、この発明は、次のような知見に基
づいてなされたものである。すなわち、本発明者らは、
上記問題点の解決・解消に対応して鋭意研究・検討を重
ねた結果、ファラデーケージ本体内およびその外側を含
めた気体の流れを適正に制御した場合、 (a)試料粉体お
よび接触相手粉体の分離効率が向上すること、また、
(b)分離した試料粉体が効率よく吹き飛ばし除去される
こと、 (c)前記の (a)および (b)に伴って従来見られな
かったレベルの高い精度の測定が可能になることを見出
して、本発明に係る粉体の摩擦帯電量測定装置を提供す
るに至ったものである。The present invention was made based on the following knowledge. That is, the present inventors,
As a result of repeated studies and studies to solve and solve the above problems, when the gas flow inside and outside the Faraday cage body is properly controlled, (a) sample powder and contact partner powder To improve the efficiency of body separation,
It was found that (b) the separated sample powder can be efficiently blown off and removed, and (c) it becomes possible to measure with a high level of accuracy that was not seen in the past with (a) and (b) above. As a result, a powder triboelectric charge amount measuring device according to the present invention has been provided.
【００１５】本発明において、ファラデーゲージ本体
は、一般的に、圧縮気体の吹き込み口を備えた一端側か
ら金網を装着した他端側にその内径が広大化る構成を採
った筒状体を成している。そして、この筒状体は、たと
えば軸方向に分割された複数個の筒状体片を係合・組み
合わせた構成としてもよい。また、金網の装着は、前記
筒状体の他端側に配置し、この他端側に係合可能な取り
付け具を装着することによって行ってもよいし、あるい
は前記筒状体の他端側を縮径した形とて、その内側面に
配置する着脱可能な構成としてもよい。In the present invention, the Faraday gauge body is generally formed as a cylindrical body having a structure in which the inner diameter is enlarged from one end side having a compressed gas blowing port to the other end side to which a wire net is attached. are doing. The tubular body may have a configuration in which a plurality of axially divided tubular pieces are engaged and combined with each other. Further, the wire mesh may be mounted by arranging the wire mesh on the other end side of the tubular body and mounting a fitting tool engageable with the other end side, or alternatively, the other end side of the tubular body. The diameter may be reduced, and it may be detachably arranged on the inner side surface.
【００１６】さらに、金網面に沿わせて水平の方向に渦
流気体を発生させる気体供給手段は、たとえば取り付け
具，筒状体の縮径部，専用スペーサーもしくは気体吸引
筒の端面部に、孔や溝ないし段差を接線方向に設置する
ことにより容易に付設できる。勿論、独立的に気体供給
用のノズルを設置しても差支えない。そして、この渦流
気体を発生させる気体供給手段は、ファラデーゲージ本
体からのブローフロー量などによっても異なるが、ブロ
ーフローの口径が20〜60mm程度の場合、たとえば取り付
け具面，筒状体の縮径部端面，専用スペーサー面もしく
は気体吸引筒の端面に 0.3〜 2.0mm程度のギャップがで
きるような段差をほぼ等間隔に設定すればよい。Further, the gas supply means for generating the vortex gas in the horizontal direction along the wire mesh surface is, for example, a fixture, a reduced diameter portion of a cylindrical body, a dedicated spacer or an end surface portion of a gas suction cylinder, and has a hole or a hole. It can be easily attached by installing the groove or step in the tangential direction. Of course, it does not matter even if the nozzle for gas supply is installed independently. The gas supply means for generating the vortex gas varies depending on the amount of blow flow from the Faraday gauge main body, but when the diameter of the blow flow is about 20 to 60 mm, for example, the diameter of the mounting surface or the cylindrical body is reduced. The steps may be set at approximately equal intervals so that a gap of about 0.3 to 2.0 mm is formed on the end surface of the part, the dedicated spacer surface, or the end surface of the gas suction cylinder.
【００１７】[0017]
【発明の実施の形態】以下図１〜図６を参照して実施例
を説明する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments will be described below with reference to FIGS.
【００１８】図１は本発明に係る粉体の摩擦帯電量測定
装置の構成例を示す断面図である。図１において、１は
導電性材料で作製された一端から他端側に向かって、内
径が広大化した筒状のファラデーケージ本体、２は前記
ファラデーケージ本体１の一端（内径の小さい側）に装
着された圧縮気体を吹き込む圧縮気体ノズル、３は前記
ファラデーケージ本体１の他端（内径の大きい側）に取
り付け具４によって着脱可能に架張・装着された金網で
ある。ここで、金網３は、一次的にファラデーケージ本
体１とで容器を形成し、この金網３面上に試料粉体５お
よび接触相手粉体６が収納・配置され、前記圧縮気体ノ
ズル２からの圧縮気体（たとえば空気）が吹き付けられ
るようになっている。そして、金網３の目開きは、圧縮
気体の吹き付けによって、試料粉体５および接触相手粉
体６が分離し、試料粉体５のみが（選択的に）金網３の
目開きを通して吹き飛ばされるように選択されている。FIG. 1 is a sectional view showing a structural example of a powder triboelectric charge amount measuring device according to the present invention. In FIG. 1, reference numeral 1 denotes a tubular Faraday cage body having an enlarged inner diameter from one end to the other end made of a conductive material, and 2 denotes one end (smaller inner diameter side) of the Faraday cage body 1. The compressed gas nozzle 3 for blowing the compressed gas is a wire mesh detachably stretched and attached to the other end (the side having a large inner diameter) of the Faraday cage body 1 by a mounting tool 4. Here, the wire net 3 primarily forms a container with the Faraday cage main body 1, and the sample powder 5 and the contact partner powder 6 are housed and arranged on the surface of the wire net 3 and the powder from the compressed gas nozzle 2 is discharged. A compressed gas (for example, air) is blown. The mesh of the wire mesh 3 is separated by spraying the compressed gas into the sample powder 5 and the contact partner powder 6, and only the sample powder 5 is (selectively) blown through the mesh of the wire mesh 3. It is selected.
【００１９】また、７は金網３を着脱可能に架張・装着
する取り付け具４に近接して配置され、金網３を含むフ
ァラデーケージ本体１の端縁面に対し平行（水平方
向）、かつ接線方向に圧縮気体（たとえば空気）を吹き
込む複数のノズルである。すなわち、前記圧縮気体ノズ
ル２からの圧縮気体吹き付けで、金網３の目開きを通し
てファラデーケージ本体１外に吹き飛ばされた試料粉体
５が、この吹き飛ばされる方向に対してほぼ水平、かつ
接線方向からの圧縮気体の吹き付け・渦流・加速によつ
て、即座にファラデーケージ本体１外に運ばれるように
なっている。Further, 7 is arranged in the vicinity of a fixture 4 for detachably stretching and mounting the wire netting 3, and is parallel (horizontal direction) to the end face of the Faraday cage main body 1 including the wire netting 3 and tangential line. A plurality of nozzles that blow compressed gas (for example, air) in one direction. That is, the sample powder 5 blown out of the Faraday cage main body 1 through the openings of the wire net 3 by blowing the compressed gas from the compressed gas nozzle 2 is substantially horizontal to the blowing direction and is tangential to the direction. The compressed gas is blown, swirled, and accelerated so that it can be immediately transported to the outside of the Faraday cage body 1.
【００２０】図２は、圧縮気体を吹き込む複数のノズル
７の配設状態例を平面的に示したもので、この場合、ほ
ぼ水平な方向から吹き付け流入する気体は、金網３の目
開きを通してファラデーケージ本体１外に吹き飛ばされ
た試料粉体５を渦巻き状の流れとして即座に排除する。
すなわち、この実施例の場合は、水平方向に流入させた
気体流が金網３の周縁に沿った渦流を発生して、金網３
の目開きを通してブローオフされる試料粉体５を速やか
に、かつ効率よく吹き飛ばすことになる。FIG. 2 is a plan view showing an example of the arrangement of a plurality of nozzles 7 for injecting compressed gas. In this case, the gas blown in from a substantially horizontal direction flows through the mesh of the wire mesh 3 into the Faraday. The sample powder 5 blown out of the cage body 1 is immediately eliminated as a spiral flow.
That is, in the case of this embodiment, the gas flow introduced in the horizontal direction generates a vortex flow along the peripheral edge of the wire net 3 and
Thus, the sample powder 5 blown off through the openings will be quickly and efficiently blown off.
【００２１】さらに、８はコンデンサー（容量Ｃ）、９
はエレクトロメーターであり、前記ファラデーケージ本
体１外に吹き飛ばされた後、ファラデーケージ本体１側
に残っている電荷による充電電圧から試料粉体５の帯電
量を測定するものである。すなわち、試料粉体５がファ
ラデーケージ本体１外に持ち去ったと当量で、かつ逆の
電荷が接触相手粉体６に残っている。したがって、この
電荷がファラデーケージ本体１に接続したコンデンサー
８を充電するので、コンデンサー８両端の電圧（Ｖ）を
エレクトロメーター９で測定し、試料粉体５の帯電量｜
Ｑ｜を、｜Ｑ｜＝ＣＶとして求める構成となっている。Further, 8 is a condenser (capacity C), 9
Is an electrometer for measuring the charge amount of the sample powder 5 from the charging voltage due to the charges remaining on the Faraday cage body 1 side after being blown out of the Faraday cage body 1. That is, when the sample powder 5 is taken out of the Faraday cage main body 1, an equivalent amount and the opposite electric charge remain in the contact partner powder 6. Therefore, since this charge charges the capacitor 8 connected to the Faraday cage body 1, the voltage (V) across the capacitor 8 is measured by the electrometer 9, and the charge amount of the sample powder 5 |
The configuration is such that Q | is obtained as | Q | = CV.
【００２２】なお、この構成例においては、ブローフロ
ー側に、たとえば円筒状の遮蔽体を配置し、ブローフロ
ー流を収束させるようにすれば、ブローフロー粉体の飛
散などを確実に回避することもできる。In this configuration example, if a cylindrical shield is arranged on the blow flow side to converge the blow flow flow, it is possible to reliably avoid the blow flow powder from scattering. You can also
【００２３】図３は、他の実施例に係る粉体の摩擦帯電
量測定装置の要部構成を示す断面図である。この実施例
では、試料粉体５のブローオフ側に吸引部10を密着的に
取り付けた構成を採っている。すなわち、導電性材料製
の、一端から他端側に向かって内径が広大化した筒状の
ファラデーケージ本体１の一端（内径の小さい側）に圧
縮気体ノズル２が装着され、また、金網３が、前記ファ
ラデーケージ本体１の他端（内径の大きい側）に取り付
け具４によって着脱可能に架張・装着された構成を採っ
ている。そして、前記取り付け具４に対して、気体吹き
込み溝（ギャップ）７′を備えたスペーサー11を介して
吸引部10の一端を密着的に配置・装着したものである。
ここで、スペーサー11の気体吹き込み溝（ギャップ）
７′は、取り付け具４下端面との間に、 0.2〜 2.0mm程
度の段差でほぼ等間隔に接線方向のギャップを形成する
形で設けられている。FIG. 3 is a cross-sectional view showing the essential structure of a powder frictional charge amount measuring device according to another embodiment. In this embodiment, the suction unit 10 is closely attached to the blow-off side of the sample powder 5. That is, the compressed gas nozzle 2 is attached to one end (the side having a small inner diameter) of the tubular Faraday cage body 1 made of a conductive material, the inner diameter of which is increased from one end to the other end, and the wire mesh 3 is attached. The Faraday cage body 1 is detachably stretched and attached to the other end (the side having a large inner diameter) by a mounting tool 4. Then, one end of the suction part 10 is closely arranged and attached to the fitting 4 through a spacer 11 having a gas blowing groove (gap) 7 '.
Here, the gas blowing groove (gap) of the spacer 11
7'is provided in such a manner that a tangential gap is formed between the lower end surface of the fixture 4 and the lower surface of the fixture 4 at steps of about 0.2 to 2.0 mm at substantially equal intervals.
【００２４】すなわち、専用スペーサー11は、図４に平
面的に示すごとく、試料粉体５の吸引路12の外周方向に
吸引・ブローオフ流の渦流13を生ずるような、深さ 0.2
〜 2.0mm程度の気体流入（気体吹き込みもしくは気体吸
い込み）溝７′が形設されている。そして、試料粉体５
の摩擦帯電量測定時においては、ファラデーケージ本体
１に装着した取り付け具４と吸引部10の一端とをスペー
サー11を介して密着させた状態とし、圧縮気体のブロー
および吸引を同時に行うと、金網３の目開きを通して吹
き飛ばされた試料粉体（たとえばトナー粒子）５は、ス
ペーサー11から吸い込まれる（吹き込む）気流によって
発生した渦流13によって即座に除去される。That is, as shown in plan view in FIG. 4, the dedicated spacer 11 has a depth of 0.2 so as to generate a vortex 13 of suction / blow-off flow in the outer peripheral direction of the suction passage 12 for the sample powder 5.
A gas inflow (gas blowing or gas sucking) groove 7'of about 2.0 mm is formed. And the sample powder 5
At the time of measuring the triboelectric charge amount, the fitting 4 mounted on the Faraday cage body 1 and one end of the suction unit 10 are brought into close contact with each other via the spacer 11 and the compressed gas is blown and sucked at the same time. The sample powder (for example, toner particles) 5 blown off through the openings 3 is immediately removed by the vortex 13 generated by the air flow sucked (blown) from the spacer 11.
【００２５】なお、この実施例では、スペーサー11に気
体吸い込み溝７′を形設した構成を示したが、取り付け
具４もしくは吸引部10の一端面にほぼ等間隔、かつ接線
方向に段差をつけ、スペーサ11面との間にギャップを設
けて気体吸い込み溝７′とする構成を採ってもよいし、
また、気体吸い込み溝７′の代りに、細孔を設けこの細
孔から吸引気体が吸い込まれる（流入する）ようにして
もよい。いずれにしても、吸引気体の吹き出し路12の外
周方向に、吸引気体による渦流13を生ずるように設置す
ると、試料粉体５の除去効率が最も高いことが確認され
た。また、この実施例の場合は、気体吸い込み溝７′か
ら吸引（流入）される気体の圧力がポイントとなり、試
料粉体５をより効率よく除去するためには 300〜3000mm
Aq程度の範囲が望ましい。In this embodiment, the gas suction groove 7'is formed in the spacer 11; however, one end face of the attachment 4 or the suction portion 10 is provided with a step in the tangential direction at substantially equal intervals. It is also possible to adopt a structure in which a gap is provided between the spacer 11 surface and the gas suction groove 7 ',
Further, instead of the gas suction groove 7 ′, a fine hole may be provided so that the sucked gas is sucked (flows in) from this fine hole. In any case, it was confirmed that the removal efficiency of the sample powder 5 was highest when the suction gas was installed in the outer peripheral direction of the blowing path 12 so as to generate the vortex 13 by the suction gas. Further, in the case of this embodiment, the point is the pressure of the gas sucked (flowed) from the gas suction groove 7 ′, and in order to remove the sample powder 5 more efficiently, it is 300 to 3000 mm.
A range around Aq is desirable.
【００２６】次に、この実施例に係る摩擦帯電量測定装
置による電子写真用トナーの摩擦帯電量測定例を説明す
る。Next, an example of measuring the triboelectric charge amount of the electrophotographic toner by the triboelectric charge amount measuring apparatus according to this embodiment will be described.
【００２７】図３に図示した摩擦帯電量測定装置の構成
において、金網３として目開き40μm のステンレス鋼製
の金網を張設したファラデーケージ本体１中に、電子写
真用のトナー・キャリア混合体を収容した。その後、口
径 3mmの圧縮気体吹き込み口２から 0.4Kg／cm2 の圧縮
空気を吹き付けると同時に、吸引部11を2000mmAqの圧力
で吸引し、金網３の目開きを通してトナー粉体（トナー
粒子）を吸引部10側にブローフローさせた。In the structure of the triboelectrification amount measuring device shown in FIG. 3, a toner / carrier mixture for electrophotography is placed in a Faraday cage body 1 in which a wire net 3 made of stainless steel having an opening of 40 μm is stretched. Accommodated. Then, 0.4 kg / cm 2 of compressed air is blown from the compressed gas blowing port 2 having a diameter of 3 mm, and at the same time, the suction portion 11 is sucked at a pressure of 2000 mmAq, and the toner powder (toner particles) is sucked through the openings of the wire mesh 3. Blow-flow was made to the part 10 side.
【００２８】この過程において、ファラデーケージ本体
１に接続されたエレクトロメーター９で測定された帯電
量は、圧縮気体吹き込み口２からの圧縮気体吹き付けと
ともに増加し、 3秒後にはファラデーケージ本体１内の
トナー粉体５の全てが吹き飛ばされて測定帯電量が飽和
した。試料（トナー・キャリア混合体）を充填した状態
でのファラデーケージの重量を、前記摩擦帯電量を測定
する前後で測定したところ、ブロー時間 3秒後の重量差
は試料粉体５の重量に相当する値を示し、試料中のトナ
ー粉体５がほぼ完全に吹き飛ばされていることが確認さ
れた。また、前記摩擦帯電量測定後のファラデーケージ
本体１下端部および金網３の下面には全くトナーが付着
しておらず試料粉体５の除去効果が非常にすぐれている
ことが分かった。In this process, the amount of charge measured by the electrometer 9 connected to the Faraday cage main body 1 increases with the compressed gas blowing from the compressed gas blowing port 2, and after 3 seconds, the inside of the Faraday cage main body 1 is discharged. All of the toner powder 5 was blown off and the measured charge amount was saturated. The weight of the Faraday cage filled with the sample (toner / carrier mixture) was measured before and after the measurement of the triboelectric charge amount. The weight difference after 3 seconds of blowing time was equivalent to the weight of the sample powder 5. It was confirmed that the toner powder 5 in the sample was almost completely blown off. Further, it was found that no toner adhered to the lower end of the Faraday cage body 1 and the lower surface of the wire net 3 after the triboelectric charge measurement, and the effect of removing the sample powder 5 was very excellent.
【００２９】一方、比較のため、従来の摩擦帯電量測定
装置（金網の下面に沿って渦流れを発生させる機構を備
えていない）によって、前記と同じ条件で摩擦帯電量の
測定を行った。この場合は、帯電量が飽和に達するまで
に、20秒以上を必要としただけでなく、飽和帯電量も実
施例の場合に比べて約 1.5倍の値になった。この帯電量
の差は、ファラデーケージ本体内の全トナーが、金網の
目開きを通してファラデーケージ本体外に吹き飛ばされ
るまでに、キャリアとの分離接触を複数回繰り返したこ
とによる摩擦帯電分に起因するものであるといえる。On the other hand, for comparison, the triboelectric charge amount was measured under the same conditions as above using a conventional triboelectric charge amount measuring device (which does not have a mechanism for generating a vortex flow along the lower surface of the wire mesh). In this case, not only 20 seconds or more were required until the charge amount reached saturation, but the saturation charge amount was about 1.5 times the value of the embodiment. This difference in the amount of charge is due to the amount of frictional charge due to repeated separation and contact with the carrier multiple times before all the toner in the Faraday cage body was blown out of the Faraday cage body through the mesh openings. You can say that.
【００３０】図５および図６は、上記図３に図示した摩
擦帯電量測定装置および従来の摩擦帯電量測定装置によ
る測定例を比較して示したものである。図５は、正帯電
系トナー（スチレンアクリル系高硬度トナー）を試料粉
末として摩擦帯電量を測定したときの測定時間と測定値
の関係で、曲線Ａは実施例の測定装置による場合を、曲
線ａは従来の測定装置による場合をそれぞれ示す。ま
た、図６は負帯電系トナー（シリカ系外添剤を含むポリ
エステル系トナー）を試料粉末として摩擦帯電量を測定
したときの測定時間と測定値の関係で、曲線Ｂは実施例
の測定装置による場合を、曲線ｂは従来の測定装置によ
る場合をそれぞれ示す。FIGS. 5 and 6 show comparative examples of measurement by the triboelectric charge amount measuring device shown in FIG. 3 and the conventional triboelectric charge amount measuring device. FIG. 5 shows the relationship between the measurement time and the measured value when the triboelectric charge amount was measured using positively charged toner (styrene acrylic high hardness toner) as the sample powder. Curve A is the curve obtained by the measuring device of the example. a shows the case of the conventional measuring device, respectively. Further, FIG. 6 shows the relationship between the measurement time and the measured value when the triboelectric charge amount was measured using a negatively charged toner (polyester toner containing a silica-based external additive) as a sample powder, and the curve B is the measuring device of the example. And the curve b shows the case by the conventional measuring device.
【００３１】図５および図６の特性比較から分かるよう
に、本発明の摩擦帯電量測定装置の場合は、速やかに、
かつ精度よく摩擦帯電量を測定できる。As can be seen from the characteristic comparison of FIG. 5 and FIG. 6, in the case of the triboelectric charge measuring device of the present invention, the
In addition, the triboelectric charge amount can be accurately measured.
【００３２】また、この摩擦帯電量測定においては、測
定前後の試料の重量減少が試料粉体の量より大きく、ブ
ロー操作によって、金網面でキャリア表面が磨耗を生じ
ていることを示す。さらに、測定後ファラデーケージ本
体下端部に僅かのトナーが再付着しており、試料粉体を
完全に除去することが困難であることも確認された。な
お、本発明は、上記実施例に限定されるものでなく、発
明の趣旨を逸脱しない範囲でいろいろの変形を採ること
ができる。たとえば、金網面に沿って渦流を発生させる
ため流入もしくは供給する気体流入路は溝型（隙間）の
他、孔もしくはノズル型などとしてもよい。Further, in this triboelectric charge amount measurement, the weight loss of the sample before and after the measurement is larger than the amount of the sample powder, and it is shown that the carrier surface is abraded on the wire mesh surface by the blowing operation. Further, it was also confirmed that it was difficult to completely remove the sample powder, because a small amount of toner was reattached to the lower end of the Faraday cage body after the measurement. The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. For example, the gas inflow path for inflowing or supplying in order to generate a vortex flow along the wire mesh surface may be a groove type (gap), a hole type or a nozzle type.
【００３３】[0033]
【発明の効果】本発明の粉体帯電量測定装置によれば、
次のような作用・効果が容易に得られ、たとえば高品質
な電子写真画像を再現性よく現像・形成するためのトナ
ーの品質管理を始め、各種の材料の帯電特性の評価など
が容易になる。According to the powder charge measuring device of the present invention,
The following functions and effects can be easily obtained. For example, quality control of toner for developing and forming a high-quality electrophotographic image with good reproducibility and evaluation of charging characteristics of various materials can be easily performed. .
【００３４】(1)ファラデーケージ本体内で分離した試
料粉体と接触相手粉体とが静電的に引き合って再び合体
して接触と分離を繰り返す、いわゆるファラデーケージ
本体が１種の摩擦帯電器して働くという作用がなくなる
ので、迅速に、また、正確な摩擦帯電量を測定すること
ができる。(1) A friction charger of which the so-called Faraday cage body is a kind of friction charger, in which the sample powder separated in the Faraday cage body and the contact partner powder electrostatically attract and coalesce again to repeat contact and separation. Since it does not work, the amount of triboelectrification can be measured quickly and accurately.
【００３５】(2)試料粉体の選択的な除去効率が高く、
また、ブローオフ操作でも試料粉体とファラデーケージ
本体内壁との摩擦帯電や試料粉体と金網との摩擦帯電を
極少量に抑制できるため、正確な摩擦帯電量を測定する
ことができる。(2) High efficiency of selective removal of sample powder,
In addition, since the triboelectric charging between the sample powder and the inner wall of the Faraday cage body and the triboelectric charging between the sample powder and the wire net can be suppressed to a very small amount even by the blow-off operation, the triboelectric charge amount can be accurately measured.
【００３６】(3)ファラデーケージ本体内壁や金網の一
部に、分離した試料粉体の付着が回避されるため、測定
帯電量に誤差を生じるおそれもない。(3) Since the separated sample powder is prevented from adhering to the inner wall of the Faraday cage main body or a part of the wire mesh, there is no possibility of causing an error in the measured charge amount.
【００３７】(4)金網面において、接触相手方粉体もし
くは金網の磨耗発生や、磨耗による帯電量の発生で、測
定帯電量に誤差が生ずることもないので、正確な摩擦帯
電量を測定することができる。(4) Accurate measurement of the triboelectric charge amount, because there is no error in the measured charge amount due to wear of the contact partner powder or wire mesh on the wire mesh surface, and generation of charge amount due to wear. You can
【図１】一実施例の摩擦帯電量測定装置の要部構成を示
す断面図。FIG. 1 is a cross-sectional view showing a main part configuration of a triboelectric charge amount measuring device according to an embodiment.
【図２】図１の摩擦帯電量測定装置における気体流入手
段の配設状態を示す平面図。FIG. 2 is a plan view showing an arrangement state of gas inflow means in the triboelectric charge amount measuring device of FIG.
【図３】他の実施例の摩擦帯電量測定装置の要部構成を
示す断面図。FIG. 3 is a cross-sectional view showing a main part configuration of a triboelectric charge amount measuring device according to another embodiment.
【図４】図３の摩擦帯電量測定装置における気体流入手
段の配設状態を示す平面図。FIG. 4 is a plan view showing a disposition state of gas inflow means in the triboelectric charge amount measuring device of FIG. 3;
【図５】他の実施例の摩擦帯電量測定装置による正帯電
系トナーの摩擦帯電量の測定特性を従来の摩擦帯電量測
定装置による場合と比較して示す特性図。FIG. 5 is a characteristic diagram showing the measurement characteristics of the triboelectric charge amount of positively charged toner by the triboelectric charge amount measuring apparatus of another embodiment in comparison with the case of a conventional triboelectric charge amount measuring apparatus.
【図６】他の実施例の摩擦帯電量測定装置による負帯電
系トナーの摩擦帯電量の測定特性を従来の摩擦帯電量測
定装置による場合と比較して示す特性図。FIG. 6 is a characteristic diagram showing the measurement characteristics of the triboelectric charge amount of the negatively charged toner by the triboelectric charge amount measuring apparatus of another embodiment in comparison with the case of the conventional triboelectric charge amount measuring apparatus.
１……ファラデーケージ本体 ２……圧縮気体吹き込み口（ノズル） ３……金網 ４……取り付け具 ５……試料粉体（粒径小） ６……接触相手方粉体（粒径大） ７，７′……気体流入手段 ８……コンデンサー ９……エレクトロメーター 10……吸引部 11……スペーサー 12……吸引路 13……渦流 1 …… Faraday cage body 2 …… Compressed gas injection port (nozzle) 3 …… Metal mesh 4 …… Mounting tool 5 …… Sample powder (small particle size) 6 …… Contact partner powder (large particle size) 7, 7 '... Gas inflow means 8 ... Condenser 9 ... Electrometer 10 ... Suction part 11 ... Spacer 12 ... Suction path 13 ... Eddy current
Claims (4)
電金属製のファラデーゲージ本体と、 前記ファラデーゲージ本体の他端に架張され、かつこの
ファラデーゲージ本体内に収容された試料粉体および接
触相手粉体のうち試料粉体を前記圧縮気体の吹き込みで
選択通過させる金網と、 前記金網の外側面に沿って水平方向に気体を流入し、か
つ金網面に沿って渦流を発生させる気体供給手段と、 前記ファラデーゲージ本体内に残存する接触相手粉体の
帯電量を測定する帯電量測定手段とを具備していること
を特徴とする粉体の摩擦帯電量測定装置。1. A Faraday gauge main body made of a conductive metal having a compressed gas blowing port at one end, and a sample powder which is stretched over the other end of the Faraday gauge main body and accommodated in the Faraday gauge main body. Wire mesh for selectively passing the sample powder among the contact partner powder by blowing the compressed gas, and gas supply for injecting gas horizontally along the outer surface of the wire mesh and generating vortex along the wire mesh surface A frictional charge amount measuring device for powder, comprising: a means and a charge amount measuring means for measuring a charge amount of the contact partner powder remaining in the Faraday gauge body.
気体供給手段が、ほぼ一定の間隔，方向で設定された複
数のノズルであることを特徴とする請求項１記載の粉体
の摩擦帯電量測定装置。2. The friction of powder according to claim 1, wherein the gas supply means for generating a vortex flow along the outer peripheral edge of the wire mesh is a plurality of nozzles set at substantially constant intervals and directions. Charge amount measuring device.
気体供給手段が、金網の外周に対して接線方向に複数個
設定されていることを特徴とする請求項１もしくは請求
項２記載の粉体の摩擦帯電量測定装置。3. A plurality of gas supply means for generating a vortex flow along the outer peripheral edge of the wire mesh are set in a tangential direction with respect to the outer circumference of the wire mesh. Powder triboelectric charge measuring device.
に、試料粉体を含む気体を吸引する気体吸引機構を連設
したことを特徴とする請求項１ないし請求項３いずれか
一記載の粉体の接触帯電量測定装置。4. The gas suction mechanism for sucking the gas containing the sample powder is continuously provided on the installation surface of the gas supply means for inflowing the gas. Powder contact charge amount measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14548496A JP3347940B2 (en) | 1996-06-07 | 1996-06-07 | Powder triboelectric charge measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14548496A JP3347940B2 (en) | 1996-06-07 | 1996-06-07 | Powder triboelectric charge measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09329583A true JPH09329583A (en) | 1997-12-22 |
| JP3347940B2 JP3347940B2 (en) | 2002-11-20 |
Family
ID=15386335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14548496A Expired - Fee Related JP3347940B2 (en) | 1996-06-07 | 1996-06-07 | Powder triboelectric charge measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3347940B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5836004A (en) * | 1997-01-07 | 1998-11-10 | Industrial Technology Research Institute | Differential mode time to digital converter |
| US6686743B2 (en) * | 2000-10-24 | 2004-02-03 | Univation Technologies, Llc | Apparatus for measuring the static charge of flowable solids |
| CZ303324B6 (en) * | 2009-03-05 | 2012-08-01 | Vysoká škola bánská - Technická univerzita Ostrava | Shear cell for measuring dependence of particulate matter internal friction angle on boundary conditions |
| CZ303325B6 (en) * | 2009-03-05 | 2012-08-01 | Vysoká škola bánská - Technická univerzita Ostrava | Measuring cell for measuring friction parameters of particulate matter on boundary conditions |
-
1996
- 1996-06-07 JP JP14548496A patent/JP3347940B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5836004A (en) * | 1997-01-07 | 1998-11-10 | Industrial Technology Research Institute | Differential mode time to digital converter |
| US6686743B2 (en) * | 2000-10-24 | 2004-02-03 | Univation Technologies, Llc | Apparatus for measuring the static charge of flowable solids |
| CZ303324B6 (en) * | 2009-03-05 | 2012-08-01 | Vysoká škola bánská - Technická univerzita Ostrava | Shear cell for measuring dependence of particulate matter internal friction angle on boundary conditions |
| CZ303325B6 (en) * | 2009-03-05 | 2012-08-01 | Vysoká škola bánská - Technická univerzita Ostrava | Measuring cell for measuring friction parameters of particulate matter on boundary conditions |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3347940B2 (en) | 2002-11-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH09329583A (en) | Measuring apparatus for friction charge amount of powder | |
| JP2006214975A (en) | Device for measuring charged state, and development device equipped therewith | |
| JP2011008231A (en) | Device for measuring adhesive strength of toner and method for measuring adhesive strength of toner | |
| JP3112904B2 (en) | Apparatus and method for measuring triboelectric charge of powder | |
| JP3487464B2 (en) | Blow-off device | |
| JPH04152274A (en) | Distribution measurement device for electrified unary system toner amount | |
| JPH0422880A (en) | Method for measuring distribution of extent of electrification of developer | |
| JP5152623B2 (en) | Magnetic separator for electrophotographic carrier | |
| JPH02242276A (en) | Toner separation device for two-component developer | |
| Oguchi | A New Blow-off Apparatus for Measuring Intrinsic Toner-Carrier Charges | |
| JPH0651008A (en) | Measuring method for electric charge amount on toner | |
| JPS61290369A (en) | Toner electric charge distribution measuring instrument | |
| JPH04115170A (en) | Apparatus for measuring charge quantity distribution of one-component type toner | |
| JPH0415574A (en) | Measuring instrument for toner electrification quantity distribution | |
| JPH0415572A (en) | Electrification quantity distribution measuring method | |
| JPH0415567A (en) | Electrification quantity distribution measuring method for one-component compound toner | |
| JPH0943198A (en) | Measuring device of amount of electrification powder | |
| JPH04118565A (en) | Measuring device for charge quantity distribution | |
| JPH0412281A (en) | Method for measuring distribution of electrostatically charged quantity of toner | |
| JPS63187163A (en) | Method for measuring charge quantity of toner | |
| JPH0415571A (en) | Electrification quantity distribution measuring instrument | |
| JPH0453311B2 (en) | ||
| JPS5922941B2 (en) | Electrostatic image developing device | |
| JPH0415573A (en) | Electrification quantity distribution measuring instrument for one-component compound toner | |
| JPH0416775A (en) | Apparatus for measuring charge quantity distribution of toner |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20020820 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080906 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090906 Year of fee payment: 7 |
|
| LAPS | Cancellation because of no payment of annual fees |