JP2681625B2 - Discharge processing method and discharge processing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge treatment method and an electric discharge treatment apparatus for performing electric discharge treatment with a high frequency and high voltage in order to modify the surface of a plastic film, paper or resin plate.

[0002]

2. Description of the Related Art Conventionally, in order to improve the "wettability" of an insulating base material such as a plastic film or paper, a plastic film is guided by a roll (earth electrode), and a high frequency is applied to a discharge electrode facing the roll. An apparatus for applying a high voltage to perform corona discharge treatment on a plastic film is known, for example, from Japanese Patent Publication No. 64-11055.

[0003]

In the case of such an electric discharge treatment apparatus, an insulating base material such as a plastic film or paper is charged when it passes between the discharge electrode and the roll, but the charge is removed. If necessary, a separate static eliminator is installed on the transport line for insulating base materials such as plastic film and paper to eliminate static electricity as a post-treatment. Was charged separately. Therefore, the cost is increased by the amount of the static eliminator or the DC charging device, and the size of the device is increased. Further, since the static elimination treatment or the electrification treatment is performed independently of the corona discharge treatment, it is not possible to appropriately perform the static elimination or the charge amount adjustment according to the degree of the corona discharge treatment.

An object of the present invention is to make it possible to automatically adjust or eliminate the charge amount of a treated object using a discharge electrode for discharge treatment without requiring a DC charging device or a static eliminator.

[0005]

In order to achieve such an object, the discharge treatment method of the present invention is characterized by applying a high frequency high voltage to a discharge electrode and subjecting a treated object such as a film or paper to a discharge treatment. By superimposing a DC voltage on the high frequency high voltage and applying it to the discharge electrode, the charge amount of the object to be treated is controlled. By measuring the charge potential of the object to be treated after passing through the treatment section by the discharge electrode and superimposing the DC voltage according to the measured potential on the high frequency high voltage, the charge amount can be automatically controlled in a feedback manner. it can. At that time, if the charge amount is controlled to be 0, the charge can be removed.

In order to achieve the same object, the discharge treatment apparatus of the present invention has a DC power source for superimposing a DC voltage on a high frequency high voltage which is an output of the high frequency power source, and a discharge electrode after passing through a treatment section. An electric potential sensor for measuring the charged electric potential of the object to be treated and a control circuit for outputting a DC voltage according to the measured electric potential from a DC power supply are provided. In the DC power supply,
It is advisable to provide a capacitor that bypasses the high frequency high voltage from the high frequency power supply to the ground.

[0007]

When the DC voltage is superimposed on the high frequency high voltage applied to the discharge electrode, the waveform of the high frequency high voltage shifts from the solid line to the minus side or the plus side by the voltage of the DC voltage as shown by the broken line, as shown in FIG. Since the voltage is shifted, it is possible to adjust the charge amount of the object to be treated such as film or paper by the shifted voltage. When the charged potential of the object to be processed after passing through the processing part by the discharge electrode is measured with a potential sensor and the DC voltage to be superimposed is adjusted according to this measured potential, it is possible to automatically adjust to a constant amount of charge and also when static elimination is intended. Can eliminate static electricity accurately.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of an electric discharge treatment apparatus of the present invention for performing corona discharge treatment on an insulating base material 1 such as a plastic film or paper. The insulating base material 1 is provided on the outer peripheral surface of a grounded dielectric roll 2. It is guided by the guide roll 3 and travels in the direction of the arrow.

The outer peripheral surface of the dielectric roll 2 is lined with silicon. A discharge electrode 4 is arranged above the dielectric roll 2 so as to face it. As shown in FIG. 4, the discharge electrode 4 is provided with a plurality of (6 in the example shown in the figure) knife-type electrode portions 6 that are long in the front-back direction and have rounded front edges in parallel. In the discharge electrode 4, the insulator 6 is arranged so that these knife-shaped electrode portions 6 are parallel to the axis of the dielectric roll 2 and form a discharge gap 5 with the outer peripheral surface of the dielectric roll 2. It is hung from the support frame 7 via. The discharge gap 5 can be varied by adjusting the height of the discharge electrode 4 with a gap adjuster 8 mounted on the support frame 7.

The discharge electrode 4 and the insulator 6 are provided with a support frame 7
It is covered with a resin hood 9 provided on the. Inside the chamber 10 surrounded by the hood 9 and the support frame 7,
In order to collect and remove ozone generated by corona discharge from the discharge electrode 5, the ozone is sucked through the exhaust duct 11.

In this discharge treatment apparatus, in addition to a high frequency power source 12 for applying a high frequency high voltage to the discharge electrode 4, a DC power source 1
3 is also provided. One of the two output terminals 14a and 14b of the high frequency power supply 12 is connected to the discharge electrode 4, while the other output terminal 14b is connected to the DC power supply 13
In order to superimpose the DC voltage from, the DC power supply 13 is connected to one of the two output terminals 15a and 15b of the DC power supply 13. The other output terminal 15b of the DC power supply 13 is grounded, and two output terminals 15a
A capacitor 16 is connected between b to bypass the high frequency current from the high frequency power supply 12 to the ground.

A potential sensor 17 is arranged on the way from the dielectric roll 2 to the guide roll 3, and the charging potential of the insulating base material 1 subjected to corona discharge treatment between the discharge electrode 4 and the dielectric roll 2. Is detected by the potential sensor 17 without contact. The detected charging potential is taken out as a voltage signal according to the potential by the potential measuring circuit 18 and input to the control circuit 19. The control circuit 19 includes an isolation amplifier that converts the voltage signal from the potential measuring circuit 18 into a current signal, so that the DC voltage output from the DC power supply 13 changes according to the voltage signal from the potential measuring circuit 18. , DC power supply 13 is automatically controlled.

According to this structure, the DC voltage output from the DC power supply 13 is adjusted according to the charging potential of the insulating base material 1 immediately after the corona discharge treatment, and the adjusted DC voltage is supplied from the high frequency power supply 12. The high frequency high voltage superposed on the output high frequency high voltage and applied to the discharge electrode 4 shifts to the negative side or the positive side by the superposed DC voltage. In this case, if the charging potential of the insulating base material 1 detected by the potential sensor 17 is positive, the high frequency high voltage is shifted to the negative side, and if the charging potential is negative, the high frequency high voltage is shifted to the positive side. To be done. Potential sensor 17
The feedback system from the DC power supply 13 to the DC power supply 13 controls the DC power supply 13 so that the charge amount of the insulating base material 1 becomes constant in the range of 0 to 2 KV, for example. The waveform diagram of FIG.
A solid line shows the case where the DC superimposed voltage is 0 KV with respect to the high frequency high voltage of 5 KV, and a broken line shows the case where the DC superimposed voltage is -3 KV.

<Experimental example> The present inventor uses a biaxially oriented polypropylene film (wetness of untreated is 31 dyn / cm) as the insulating base material 1 to be subjected to corona discharge treatment. A comparative experiment was carried out between the case where a DC voltage was superimposed on and applied to the discharge electrode 4 and the case where only a high frequency high voltage was applied as in the conventional case. The specifications of the equipment used are as follows.

Discharge electrode 4: number of knife type electrode parts 6
Book, length 1100 mm, width 4 mm, spacing 3 mm, height 5
mm High frequency power supply 12: Kasuga Denki KK AGI-080 type (8KW type), constant power control method DC power supply 13: Kasuga Denki KK HD-1505PN
Type (15 KV, 5 mA type), constant voltage control method Dielectric roll 2: Silicon lining thickness 4 mm Discharge gap 5: 2 mm Insulating substrate 1 processing speed: 100 m / min

The experimental results are shown in Table 1 below. In Table 1, 1-a to 9-a indicate that when only high frequency high voltage is applied to the discharge electrode 4 and the discharge power is changed stepwise,
1-b to 9-b show a case where a direct current voltage is superimposed on a high frequency high voltage and applied to the discharge electrode 4, and the discharge power is changed stepwise. FIG. 3 shows “No” in Table 1.
The waveform in the case of "6-a" is indicated by the solid line, and the waveform in the case of "6-b" is indicated by the broken line.

[0017]

[Table 1]

Explaining Table 1, "Discharge amount"
Is the amount of work on the insulating base material 1 by corona discharge, and the corona discharge power is determined based on this amount of work. The amount of discharge can be calculated by the following calculation. (Discharge amount) = (Discharge power) / {(Insulating substrate processing speed)
X (electrode length)} "Discharge degree" represents the discharge density, and the electrode area is 1
Discharge power output per cm ² . The degree of discharge can be calculated by the following calculation. (Discharge degree) = (Discharge power) / (Electrode area) As can be seen from the item of "charge amount" in Table 1, in the case of 1-a to 9-a in which only high frequency high voltage is applied, The charge amount is 27.0 to 36.0 KV, but in the case of 1-b to 9-b where the DC voltage is superposed, the charge amount is 0.0 KV, and the charge is properly removed. It shows that. This result also shows that the charge amount is 0 KV
It can be said that it proves that it is possible to accurately control other constant values.

FIG. 4 shows another example of the discharge treatment apparatus according to the present invention. In this example, a dielectric-coated electrode 4a held in a hood 9a via an insulating plate 6a while guiding a treated object 1a having an insulating film formed on the surface of a conductive base material such as aluminum foil with an earth roll 2a. A high-frequency high voltage on which a DC voltage is superimposed is applied to the object 1a to perform corona discharge treatment on the object to be treated 1a and at the same time, to remove the charge.

[0020]

As described above, according to the present invention, the following effects can be obtained. The DC voltage is superimposed on the high frequency high voltage applied to the discharge electrode, and the high frequency high voltage is shifted to the minus side or the plus side by the superimposed voltage. Therefore, the charged voltage of the processed object such as film or paper is adjusted by the shifted voltage. can do. Therefore, since a direct current charging device or a static eliminator is not required, it is economical and the size of the device can be reduced, and a discharge electrode for discharge treatment is used to meet the degree of discharge treatment. Appropriate charge amount adjustment or static elimination can be efficiently performed. When the charged potential of the object to be processed after passing through the processing part by the discharge electrode is measured with a potential sensor and the DC voltage to be superimposed is adjusted according to this measured potential, it is possible to automatically adjust to a constant amount of charge and also when static elimination is intended. Can eliminate static electricity accurately. By bypassing the high frequency high voltage from the high frequency power source to the ground by the capacitor provided in the DC power source, the DC power source can be protected and stable voltage control can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a discharge processing apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of a discharge electrode in the discharge processing apparatus.

FIG. 3 is a waveform diagram showing that a high frequency high voltage waveform is shifted by superimposing a DC voltage on the high frequency high voltage.

FIG. 4 is a schematic configuration diagram of another example of the discharge processing apparatus of the present invention.

[Explanation of symbols]

 1 Insulating Base Material 2 Dielectric Roll 3 Guide Roll 4 Discharge Electrode 5 Discharge Gap 6 Insulator 7 Support Frame 8 Gap Adjuster 9 Hood 10 Chamber 11 Exhaust Duct 12 High Frequency Power Supply 13 DC Power Supply 14a / 14b Output Terminal of High Frequency Power Supply 15a ・15b Output terminal of DC power supply 16 Capacitor 17 Potential sensor 18 Potential measuring circuit 19 Control circuit

Claims (5)

(57) [Claims] 1. A discharge treatment method for applying a high-frequency high voltage to a discharge electrode to discharge a treated object such as a film or paper by applying a DC voltage to the high-frequency high voltage and applying the DC voltage to the discharge electrode. A discharge treatment method characterized by controlling the charge amount of a treated object. 2. A discharge treatment method of applying a high-frequency high voltage to a discharge electrode to discharge a treated object such as a film or paper by measuring a charged potential of the treated object after passing through a treatment section by the discharge electrode. A discharge treatment method characterized in that a direct current voltage according to the measured potential is superimposed on the high frequency high voltage and applied to the discharge electrode to control the charge amount of the treated object. 3. A discharge treatment method, wherein a high frequency high voltage is applied to a discharge electrode to discharge a treated object such as a film or a paper, and a charged potential of the treated object after passing through a treatment section by the discharge electrode is measured. A discharge treatment method, wherein a DC voltage corresponding to the measured potential is superimposed on the high-frequency high voltage and applied to the discharge electrode to discharge the object to be treated. 4. A discharge processing apparatus for applying a high frequency high voltage from a high frequency power supply to a discharge electrode to discharge a processed object such as film or paper, wherein a DC voltage is superimposed on the high frequency high voltage output from the high frequency power supply. A direct current power supply for controlling, a potential sensor for measuring a charging potential of the object to be processed after passing through the processing section by the discharge electrode, and a control circuit for outputting a direct current voltage according to the measured potential from the direct current power supply. Discharge treatment device characterized by. 5. The discharge treatment apparatus according to claim 4, wherein a capacitor for bypassing a high frequency high voltage from the high frequency power source to the ground is provided in the DC power source.