JPS62287148A - Measuring method for frictional electrostatic charging - Google Patents

Abstract

PURPOSE:To accurately measure the initial electrostatic discharging state of a sample which is high in discharging speed by rubbing a friction body against the surface of the sample while the sample is held by a support from behind, and then moving the sample to face a static electricity detector and the separat ing the support from the sample. CONSTITUTION:The sample 1 is held by a holder 2, which is fixed to an upper- side rotary arm 3. The columnar support 5, on the other hand, is fitted to a lower-side rotary arm 6 and when the arm 6 is moved up, the upper arm 3 and lower arm 6 are united to support the sample 1 by the support 5 in contact from below. Those united bodies are rubbed against the sample surface at a position A by the frictional body and then moved to a position B integrally, thereby putting the sample 1 opposite the detector 4. Then, the lower arm 6 is moved down to separate the support 5 from the sample. Various voltages of the sample begin to be measured once the sample 1 faces the detector 4, and the time required for the separation is preferably <=1sec after the end of the friction.

Description

Detailed Description of the Invention 8. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a fabric-like object, that is, a woven fabric, a non-woven fabric,
This invention relates to a method for measuring triboelectric charging properties and charging voltages of paper, leather, sheets, films, and similar materials.

(Key points while conventional techniques and inventions are trying to settle down) Many methods have been proposed for measuring frictional electrification of fabrics, etc., and JIS L 1094 (1980) also states N%B%.
Three methods of C and reference method 2F1 are described. Measurement of electrostatic voltage is also important for practical purposes, and is described as method B in the above-mentioned JIS. However, the Kyoto University Kaken 2 rotary static tester used in the JIS B method is an old device that was developed more than 20 years ago, and has (1) low reproducibility of direct measurements and large variations; (2) The measured electrostatic voltage is low compared to the actual electrostatic charge, (3) It is difficult to measure the attenuation state of the electrostatic charge, and (4) It is cumbersome and inconvenient to operate. be pointed out.

In order to compensate for this drawback, the present inventors devised a much improved measurement method and disclosed it in Japanese Patent Application Laid-Open No. 56-48550. In this method, the sample is supported from behind and moved in front of the rubbed barley and detector, and most of the drawbacks of the JIS B method, including reproducibility, have been improved.

However, in the method of JP-A-56-48550, in order to move the sample after friction, the sample is released 1a during movement.
occurs, and for "sample with high discharge rate", the "
The problem was found that it was difficult to accurately grasp the initial discharge status. An object of the present invention is to solve this problem, and to provide a new method that can more accurately measure the initial discharge state of a sample with a high discharge rate.

(Means and effects for solving the problems) The method of the present invention involves inspecting the surface of a fabric sample with a friction body in the palm of the hand while supporting it from behind with a support, and simultaneously or after the completion of the friction. Detect static electricity facing the sample by moving the sample and the support while keeping them in close contact with each other to make the sample face the electrostatic detector, and then separating the support from the sample at the same time or after the movement is completed. It is characterized by measuring 71 strips of sample using a device.

Hereinafter, the present invention will be explained with reference to the drawings. FIG. 1 is a perspective view of a friction measuring device 11'W fi showing a specific example of carrying out the method of the present invention. In the figure, a sample (1) is held in a holder (2), and the holder (2) is fixed to an upper rotating arm (3). On the other hand, a cylindrical support (5) is attached to the lower rotary arm (6), and when the lower arm (6) is moved upward, it merges with the upper arm (3) and becomes one body. ) is in close contact with the support (5) and supported from below. The figure shows a situation in which the lower arm is forced downward and separated from the sample, and static electricity is measured by the detector (4) facing the sample.

The measurement procedure is as follows.

First, ■ combine the upper arm (3) and the lower arm (6) and place the sample (1) at the position (A) in the figure shown by the dotted line.
is supported from behind (from below) by a support (5).

(2) Using a suitable friction body, for example, the blackboard-shaped 1-shape ruber described by the present inventors in JP-A No. 56-48550, manually rub the surface of the sample 5 to 20 times 9 degrees. χ(Do.

■ Top: After combining the regular arm (3) and the lower arm (6), rotate it horizontally to position B)? the sample (1) to face the detector (4).

■ Push the handle (3) downward to move the lower arm (6) downward and pull the support (5) away from the sample.

■ Measurement of the charged voltage of the sample starts as soon as sample f-1 (1) faces the detector (4), but while the sample (1) and support (5) are in close contact, the voltage is low or zero, and as soon as the support (5) is pulled away, the potential increases and the original (high) voltage is measured.

・: Ri is one stone and is attached to the upper arm (3) and lower arm (6) respectively, so that the sample (1) and the support (5) maintain the correct contact state when the two are combined. work.

(7) and (8) are arms (3) & (5) with handles.
Used when moving in the horizontal and vertical directions. (9) is a guide, OI is the horizontal rotation axis, and 01) is the vertical rotation axis.

In Figure 1, the upper arm (3) and the lower arm (
All of the movements in step 6) are performed manually, but they can easily be performed mechanically or automatically.

At the same time or after the completion of 91, the sample (1) is transferred to the support (5
), the sample is transferred to the electrostatic detector, and the support (5) is further separated from the sample (5). The time from the completion of one cycle to the completion of separation of the support is generally preferably as short as possible; for example, within 5 seconds, particularly preferably within 2 seconds, and most preferably within 1 second.

The support must be transferred as quickly and smoothly as possible and must be pulled away from the sample sufficiently far. The support is separated from the sample at the same time as the horizontal movement is completed (it does not have to be completely simultaneous, but just about the same time is sufficient) or soon thereafter. If it is left for a long time after weeding is prohibited until the separation is completed, discharge will occur during that time and the voltage will attenuate. For the purpose of measuring electrical discharge when the sample and the support are in close contact with each other, the support may be separated after an arbitrary (targeted) time from the end of the friction. However, in order to observe the highest charged voltage and the earliest initial discharge phenomenon immediately after friction, it is desirable to complete the horizontal movement and separation of the support (5) as soon as possible after the end of friction. The time required for separation is preferably 1 second or less, particularly 0.3 seconds or less, and most preferably 0.1 seconds or less.

The distance by which the support (5) is separated from the sample (1) is preferably large to some extent, for example, 1 cm or more, particularly 2 cm.
Above, it is most preferably 3 cm or more, and in many cases, 5 to 10 cm is sufficient. For manual operation, it is convenient to use an arm with a handle as shown in the figure, and for automatic operation, it is convenient to use an electromagnetic device (for example, an electromagnetic clutch), an air cylinder, a hydraulic cylinder, a spring, or any other device that allows quick and smooth movement. is particularly useful. In addition, in order to maintain close contact between the sample and the support, a magnet (permanent or 'r4tTi1
stones) are conveniently used. The number of magnets may be one or more. It is also possible to use one side as a magnet and the other side as an iron plate or the like.

By using a support with a high separation speed, it is possible to observe an extremely rapid discharge phenomenon after 1 U of wear. Of course, for this purpose, it is necessary to sufficiently increase the tracking speed of the detector (4), an amplifier, a recording device, etc.

For example, if the apparent time constant of those devices is 0.2 seconds or less,
In particular, it is preferably 0.1 seconds or less, most preferably 0.05 seconds or less. The detector can be a rotating sector type, a vibrating lead type, a radiation type, or any other type, but in the case of an AC conversion type, the conveyance Ii! 5 A high wave number, for example, 50H2 or more, especially 100 llI2 or more is preferable in terms of tracking speed, and 2QOF (z or more is most preferable. gCj recording devices include a pen recorder, a dot recorder, All kinds of recording devices can be used, such as magnetic recorders such as data recorders, semiconductor memory circuits such as integrated circuits, magnetic disks, and optical disks.Furthermore, they can be digitized and used with an arithmetic device (computer) to determine the maximum charge voltage [α, attenuation, etc.]. speed (half-life, etc.), charging voltage after a predetermined time (e.g. 1 second, 5 seconds, 10 seconds, 30 seconds, 60 seconds), their average when measured multiple times (
It is possible to calculate and output the 1d1 variation range, deviation, etc.

The material of the support body (5) is arbitrary, but wood (such as oak wood), metal, synthetic resin, and others can be used.

In addition, it is preferable to use the metal A type by covering it with cloth, film, gold m, ia, etc., and grounding it. (There is no need to eliminate static electricity before measurement) This is preferable. The upper surface of the support may be a flat surface or a curved surface with a slightly raised central portion.

In addition to the above-mentioned curved shape, the body is preferably hemispherical, circular, jaw-shaped, etc., and has a cutout material inside. Any other material may be used. Brush 9? The three bodies have already been disclosed by the present inventors in Japanese Unexamined Patent Publication No. 114754/1983. The movement by the moving body may be performed manually or mechanically (automatically), for example, using mechanical movement, rotational movement, etc. The test may be performed once or multiple times, but in most cases 5 to 20 times is preferred. There may be one or more Takarin bodies. For example, each radial arm:
A constriction body can be attached and rotated to create friction.

A donut-shaped rotating body can also be used.

FIG. 1 is an example of a "vertical type" in which the sample is placed horizontally and the central axis connecting the centers of the detector, sample, and support is vertical. The central axis may be arranged horizontally or diagonally. There is a concern that manual (manual) dosuri has large individual differences and variations and lacks reproducibility, but if a Kyorin body with an appropriate cushion is used, it is possible to achieve fukuichimo with extremely high reproducibility and almost no individual differences. 1, it is possible to perform measurements with high reliability and accuracy by operating the hour wheel device u1.

Calibration of the instrument is easily carried out by placing a metal plate of substantially the same size as the sample in place of the sample and applying a known DC voltage (for example, IKV, 10 [V, etc.) to the metal plate. obtain.

(Example) Using the apparatus shown in Figure 1, a sample was held between a holder (2) made of a 3 mm thick stainless steel plate with a circular hole of 73 mm in diameter and a presser plate made of stainless steel and also 1 mm thick. The detector (7) was a four-blade rotating sector type with a rotation speed of 3200 rl) rL carrier frequency of 213 Hz fixed at a distance of 100 mm from the sample, and the recorder (9) was a pen. A tracking speed full scale (200 mm) Q of 2 seconds was used. +5 [The body was a blackboard erasable mold with a wooden body stuffed with absorbent cotton and sealed with cotton cloth, and covered with well-washed wool (muslin). Senshi Tokukyu is made of Hou wood and has a diameter of 53
mm.

Using one with a 3 mm raised center part, manually adjust the height to 0.
Move it 39mm downward in less than 1 second.

The sample was a blended fabric of polyethylene terephthalate and cotton, with 20d/6f polyester conductive union m fibers (
An antistatic fabric was used, which was mixed and woven with 20 mm spacing (Beltron) and finished with dyeing. The sample was thoroughly washed and rinsed, dried at 80°C, and then dried at 20'C, 55% RH.
The measurement was carried out after being left in the measurement chamber for 24 hours. The time from the end of the rubbing to the completion of the movement is 0.2 seconds or less, the time from the completion of the movement to the start of separation of the support is approximately 0.2 seconds, and the time required for separation is 0.1 seconds.
It took less than a second. That is, the total time from the end of the first inspection to the completion of separation is less than 0.5 seconds.

The frictional charging voltage obtained by the method of the present invention for the above sample and its attenuation curve are shown by curve 04 in FIG. On the other hand, for comparison, the results of measuring the same sample using the method described in JP-A-56-48550, in which the sample is separated from the support after friction and moved to face the detector, are shown in Figure 2. Dotted line (1
Indicated by 3. As can be seen from the comparison of the curve (to) and α fathom,
The method of the present invention clearly captures the rapid discharge phenomenon immediately after friction, which could not be detected using conventional methods.

Note that the holder (a grounded metal plate was used as an illusion, but wood, Bakelite, or other materials may also be used. In the case of an insulator, the holder itself will be charged and cause errors, but in that case, Errors can be eliminated by metal plating the holder surface (detector side) or by covering it with a gold plate.

Similarly, the holder is made of 10,000 gold plates, and the side in contact with the sample (
By pasting a GJ film made of polyethylene or the like on the inside (inside), charging and discharging can be measured in an insulated state.

(Effects of the Invention) As shown in Fig. 1, the method of the present invention can be carried out with a relatively simple device, and can measure the high-speed discharge phenomenon immediately after friction, which was conventionally impossible or extremely difficult to measure (for example, As shown in Figure 2), it has the advantage of being easily measurable, and is extremely useful for elucidating the i-electric phenomenon and developing antistatic products.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view of a l':Ji triboelectric tonnage measuring device showing a specific embodiment of the method of the present invention, and FIG. This shows an example of a comparison of the same curves obtained using the method. Fig. 1 12° Stone Scabbard

Claims (5)

[Claims] (1) With a fabric-like sample supported from behind by a support, rub the surface of the sample with a friction body, and at the same time or after the friction ends, move the sample and the support in close contact to electrostatically charge the sample. Frictional charging voltage characterized in that the charged voltage of the sample is measured by an electrostatic detector facing the sample by causing the support to face the detector and separating the support from the sample at the same time as or after the completion of movement. How to measure. (2) The method according to claim 1, wherein the sample is rubbed manually or mechanically. (3) The method according to claim 1, wherein the movement of the sample and the support is started within 1 second after the end of the friction. (4) The method according to claim 1, wherein the movement of the sample and the support and the separation of the support from the sample are performed manually or mechanically. (5) The method according to claim 1, wherein the sample and support are moved by electromagnetic force or a fluid cylinder.