JPS63268746A - Corona discharge treatment device - Google Patents

Abstract

PURPOSE:To obtain a corona discharge treatment device always maintaining space in the vicinity of a material to be treated at a constant low humidity, preventing reduction in discharge efficiency resulting from moisture, by setting both a humidity sensor and dehumidifier. CONSTITUTION:A corona discharge treatment device which is equipped with a humidity sensor and a dehumidifier blowing dehumidifying air upon a material to be treated and dehumidifying the vicinity of the material to be treated. For example, the material 2 to be treated is arranged in a main body 1 of the corona discharge treatment device consisting of a treating chamber 3 provided with a discharge electrode 12, an electrode transferring means 13 and an opposing electrode 14, a middle chamber 5 provided with a corona discharge generating device 4 and a transformer storing chamber 7 provided with a high-voltage transformer 6 at the lower part and the humidity sensor 10 (electric resistance type using a thin film of semiconductor) is set in the vicinity of the material to be treated. When humidity rises, dehumidifying air is blown from the dehumidifier 8 through a piping 9 upon the material 2 to be treated and discharged through an exhaust dust 11 to always keep air in the vicinity of the material 2 to be treated at a constant low humidity (e.g. <=45% relative humidity).

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a corona discharge treatment apparatus for modifying the surface of resin products used for automobile parts and the like.

(Prior art) Polyolefin resins such as polyethylene and polypropylene used for automobile instrument panels, center pillars, wheel caps, etc. have few polar groups, making it difficult for paints, adhesives, etc. to adhere to their surfaces. There is.

Therefore, one method for modifying the surface of polyolefin resin is a corona discharge treatment method, and a corona discharge treatment apparatus is used to perform the treatment method. The corona discharge treatment apparatus includes a high-frequency applying means consisting of a high-frequency oscillator and a high-voltage transformer, an electrode moving means for moving an electrode in accordance with the object to be treated such as a polyolefin resin, and a counter electrode means facing the same. and a control unit for controlling the electrode moving means.

(Problems to be Solved by the Invention) The conventional corona discharge treatment device described above has a problem in that the discharge efficiency decreases when the humidity inside the corona discharge treatment device increases because it is not equipped with a dehumidifier. Structure (Means for Solving the Problems) In order to solve the above problems, the present invention provides a humidity sensor near the object to be treated, which is removably arranged in the main body, and also connects dehumidified air to the object to be treated. A configuration is adopted in which a dehumidifier is provided that dehumidifies at least the space near the object to be treated by spraying air onto the object.

(Function) By adopting the above configuration, the humidity sensor installed near the object to be processed detects the humidity and blows a predetermined amount of dehumidified air onto the object to be processed. Always maintain a constant low humidity, for example, relative humidity of 45% or less.

(Example) An example embodying the present invention will be described below with reference to the drawings.

As shown in the figure, the main body 1 of the corona discharge treatment apparatus includes a treatment chamber 3 in which the workpiece 2 is subjected to corona discharge treatment, an intermediate chamber 5 equipped with a corona discharge generator 4, and a lower transformer housing equipped with a high voltage transformer 6. It consists of room 7.

The object to be processed 2 is an automobile instrument panel pad (hereinafter referred to as an instrument panel pad) made of polypropylene, and has a length of about 1 m.

At both ends of the object 2 in the longitudinal direction, humidity sensors 10 for detecting humidity are provided at positions approximately 10 cm from both ends of the object 2, respectively. The humidity sensor 10 is an electrical resistance humidity sensor using a semiconductor thin film (product name: Neostall-H manufactured by Yamatake Honeywell Co., Ltd.).
615A).

The Neostat H615A has a built-in humidity sensor and a controller to control it.

Further, a dehumidifier 8 is attached to the outside of the processing chamber 3, and a pipe 9 for supplying dehumidified air from the dehumidifier 8 extends horizontally to the processing chamber 3.
It is provided up to the center part of , is bent downward from there, and is opened toward the object to be processed 2 . The dehumidification capacity of the dehumidifier 8 is 21.7 kgH2O/day. Then, dehumidified air from the dehumidifier 8 passes through the pipe 9 and is blown onto the object 2 to be treated. Further, the dehumidified air is supplied from the pipe 9a branched from the pipe 9 to the intermediate chamber 5 and the transformer storage chamber 7.
Air is blown to.

An exhaust duct 11 (exhaust capacity 16 r in this embodiment) has an exhaust capacity corresponding to the volumes of the processing chamber 3, the intermediate chamber 5, and the lower transformer storage chamber 7, in the central rear part of the main body 1.
rr/llll1n) is provided, and the exhaust duct 11 opens into each of the three chambers and exhausts the air from each chamber. In addition, a corona discharge electrode 1 is provided on the top surface of the main body 1.
An electrode moving means 13 for moving the electrode 2 is provided. On the other hand, a counter electrode 14 corresponding to the corona discharge electrode 12
is provided on the side of the object to be processed 2.

The functions and effects of the corona discharge treatment apparatus configured as described above will be explained.

First, an in-spring pad as the object to be processed 2 whose surface has been cleaned is placed approximately in the center of the processing chamber 3, and the counter electrode 14
Fit it on top. Further, the corona discharge electrode 12 is moved to a predetermined location on the object to be treated 2 by the electrode moving means 13.

Next, the dehumidifier 8 is operated to send dehumidified air into the processing chamber 3, while the air inside the processing chamber 3 is exhausted from the exhaust duct 11 to maintain the relative humidity within the processing chamber 3 at 45% or less. .

When the corona discharge generating device 4 is operated in this state, a corona discharge is generated from the corona discharge electrode 12, and the instrument panel pad is irradiated with the discharge, thereby starting a corona discharge process. Subsequently, the corona discharge electrode 12 is moved along the surface of the instrument panel pad by the electrode moving means 13.

During this time, the humidity sensors 10 provided at both ends of the object 2 detect the humidity near the object 2, and when the humidity increases, the flow rate of dehumidified air from the dehumidifier 8 is increased. By spraying it onto the object 2,
The relative humidity of the space near the object to be processed 2 is always maintained within a range of 45% or less.

The space near the object 2 to be processed is at least twice the volume of the object 2 to be processed.

Then, the air in the processing chamber 3 is exhausted from the exhaust duct 11 along with ml of ozone generated by the corona discharge treatment. Note that the humidity in the intermediate chamber 5 and the lower transformer storage chamber 7 is also maintained at a predetermined value by the descent of dehumidified air from the processing chamber 3.

In this way, while the corona discharge treatment is being performed, at least the space in the vicinity of the object to be treated 2 is maintained at a constant humidity level, even in a factory during the summer in Japan, when the outside air humidity is quite high. . Moreover, it can correspond to a wide temperature range of about 0 to 40 degrees Celsius outside air temperature.

The instrument panel pad that has undergone the corona discharge treatment as described above is taken out from the processing chamber 3, an adhesive such as urethane adhesive is applied to the surface, and a skin made of vinyl chloride resin is adhered on top of it. However, the corona discharge treatment significantly improves the adhesion between the instrument panel pad and the skin.

As described above, in the corona discharge treatment apparatus of this embodiment, the discharge output does not decrease due to an increase in the humidity of the outside air, and there is no risk that the dust attached to the high-voltage transformer will contain water due to humidity and cause an electric leakage. .

The present invention is not limited to the above embodiments, but can be configured as follows.

(1) The humidity sensor 10 may be placed in any position as long as it is installed near the object 2 to be processed, such as before or after the object 2 to be processed,
It can also be installed diagonally upward.

(2) The blowing of dehumidified air is not limited to only from above the object to be processed 2, but it is sufficient if the space near the object to be processed 2 can be maintained at a predetermined humidity level, and can be blown from either side of the object to be processed, front and rear, diagonally above the object to be processed, etc. It can also be the location. In particular, it is preferable that the dehumidified air flows around the outer periphery of the object 2 to be treated.

(3) The installation position of the exhaust duct 11 is not limited to the rear part of the processing chamber 3, but it may be designed so that the dehumidified air flows through the space near the object 2 to be processed. You can also make a hole and vent the air from there.

(4) In addition to an electrical resistance humidity sensor using a semiconductor thin film, the humidity sensor 10 is also an electrical resistance humidity sensor using an electrolyte, an electrical resistance humidity sensor based on the surface resistance of an electrically insulating material, and a swellable material such as a carbon film. Any humidity sensor, such as an electrical resistance humidity sensor based on the resistance of a substance, may be used.

(5) In addition to polypropylene, polyolefin resin such as polyethylene is used for the object 2 to be treated, and its uses include automobile parts such as center pillars and wheel camps in addition to instrument panel pads.

Effects of the Invention The corona discharge treatment apparatus of the present invention has an excellent effect in that the discharge efficiency does not decrease due to moisture.

[Brief explanation of the drawing]

The figure is a schematic perspective view showing a corona discharge treatment apparatus of the present invention. 1...Main body, 2...Workpiece, 8...Dehumidifier, 1
0...Humidity sensor

Claims (1)

[Claims] 1. A humidity sensor (10) is provided near the object to be processed (2) which is removably arranged in the main body (1), and dehumidified air is blown onto the object to be processed (2). A corona discharge treatment apparatus characterized in that a dehumidifier (8) is provided for dehumidifying at least a space near the object (2) to be treated. 2. The corona discharge treatment apparatus according to claim 1, wherein the humidity sensor (10) is an electrical resistance humidity sensor using a semiconductor thin film. 3. The corona discharge treatment apparatus according to claim 1, wherein the dehumidified air has a relative humidity of 45% or less.