JPS6215233A - Plasma treatment and apparatus therefor - Google Patents

Abstract

PURPOSE:To diffuse a gas all over the housing chamber and activate uniformly an article to be treated, by housing the article to be treated in the housing chamber having a plasma fluidizing means and operating/stopping the above- mentioned fluidizing means while sucking the plasma gas through a gas dis charge port. CONSTITUTION:A synthetic resin article to be treated is housed in a housing chamber 1 having a plasma jetting pipe 10, gas discharge port 2 and plasma gas fluidizing means 3 for diffusing a plasma gas, and the housing chamber 1 is decompressed. The plasma fluidizing means 3 is subjected to the states of stop operation stop while sucking the plasma gas jetted from the plasma jetting pipe 10 to apply plasma uniformly to the whole surface of the article to be treated. A dead space (D) formed by the flow (alternate long and short dash line system) of the plasma gas in the case of only suction from the gas discharge port 2 is eliminated by the plasma gas flow (indicated by broken lines) by the operation of the fluidizing means 3.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) The present invention relates to a plasma treatment method and a treatment apparatus for irradiating plasma gas onto the surfaces to be painted of bumpers and other synthetic resin products. be.

(Prior Art) Resin products made of non-polar polymer materials such as polypropylene and polyethylene have poor paint adhesion, so a method has been considered to improve paintability by subjecting their surfaces to plasma treatment.

Conventionally, a plasma processing apparatus used for this type of method has a sealed storage chamber 6 as shown in FIGS. 11 to 13.
A plasma injection tube 61 is provided on the inner wall of the storage chamber 60, and an exhaust port 62 is provided on the inner wall facing the plasma injection tube 61 for reducing the pressure inside the storage chamber 60 and discharging plasma gas. It has been considered that a rotary storage device 63 is provided in the storage chamber 60 to store and rotate the items to be processed.

This plasma processing apparatus stores a plurality of automobile bumpers B made of synthetic resin such as polypropylene as objects to be processed, for example, on a storage stand 64 provided in the rotary storage device 63.
Plasma gas was injected from the plasma injection pipe 61 onto the bumper 8 surface while rotating the bumper 8, and the plasma gas was sucked from the exhaust port 62 to activate the bumper 8 surface.

(Problems to be Solved by the Invention) However, in the above plasma processing apparatus,
As shown in the figure, a dead space D in which the plasma gas does not spread is generated from the vicinity of the inlet of the exhaust port 62 of the storage chamber 60 to the inner wall on both ends in the longitudinal direction and on the inner wall on the inner peripheral side. Therefore, there is a problem in that the portion of the surface of the bumper 8 that passes through these dead spaces D is not activated as much as the portion that passes through the center of the storage chamber 60.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, in the first invention, in a storage chamber equipped with a plasma injection pipe, an exhaust port, and a plasma gas flow means for diffusing plasma gas. , storing a synthetic resin processed article between the plasma injection tube and the exhaust port, then reducing the pressure in the storage chamber, and sucking the plasma gas injected from the plasma injection tube at the exhaust port; However, a method is adopted in which the plasma gas flow means is changed from a stopped state to an activated state or from an activated state to a stopped state, and the entire surface of the object to be treated is uniformly irradiated with plasma.

The second invention also includes a plasma injection tube for injecting plasma gas and an exhaust port for sucking the plasma gas and reducing the pressure inside the apparatus to provide an apparatus that is directly used for carrying out the first invention. It consists of a containment chamber equipped with a fan that diffuses plasma gas within the containment chamber.

(Function) In the first invention, the plasma gas injected from the plasma injection tube is sucked by the exhaust port and flows inside the storage chamber,
During this time, the item to be processed is irradiated. During irradiation, by changing the plasma gas flow means for diffusing plasma gas from a stopped state to an activated state or from an activated state to a stopped state, plasma gas is caused to flow into a space where plasma gas does not reach due to suction from the exhaust port. The light flows and irradiates the objects to be processed within the same space. Therefore, the entire surface of the object to be treated is activated uniformly without excess or deficiency.

In the second aspect of the invention, plasma gas is injected from the plasma gas injection pipe and is sucked through the exhaust port to diffuse inside the storage chamber. At this time, the fan operates, and the plasma gas is force-fed to the opposing inner walls of the storage chamber, spreads, and spreads in the longitudinal direction of the storage chamber. It is sucked through the space. Therefore, the dead space caused by the suction of the exhaust port is eliminated, and the plasma gas is spread throughout the accommodation chamber.

(First Example) Hereinafter, a first example embodying the present invention and the second invention will be described with reference to FIGS. 1 to 10.

As shown in FIG. 3, the sealable storage chamber 1 of the plasma processing apparatus is formed into a hollow cylindrical shape, and a door 1a that can open and close the storage chamber 1 is provided on the right side thereof. Further, an exhaust port 2 for reducing the pressure in the storage chamber 1 is provided at the center of the lower wall, and a valve 4 is installed and connected to a pipe 6. The piping 6 is connected to a mechanical booster 8 of a pressure reducing device 7 for reducing and suctioning the inside of the storage chamber 1. A rotary pump 9 is connected.

As shown in Fig. 2.4, 180 mm relative to the exhaust port 2
A single stainless steel plasma injection tube 10 for injecting plasma gas is disposed on the upper inner wall of the storage chamber 1, which faces each other. Further, as shown in FIGS. 5 to 7, on the outer periphery of the plasma injection tube 10, there are a large number of injection ports 50 whose arrangement interval gradually decreases and whose inner diameter increases toward the end of the injection tube IO. It is formed. Each injection port 50 is oriented forward at a predetermined angle θ1 (30 in this embodiment) with respect to the vertical plane S.
The opening 50a is opened in the direction of inclination (degree), and the opening 50b is opened in the direction of inclination toward the rear at a predetermined angle θ2 (30 degrees in this embodiment).

Injection ports 50a that slope toward the front and injection ports 50b that slope toward the rear are alternately arranged.

Further, as shown in FIG. 3, an introduction pipe 11 is connected to a plasma introduction port (not shown) formed approximately in the middle of the plasma injection pipe 10, and a plasma generator fixed outside the storage chamber 1 is connected to the introduction pipe 11. It is connected to the pipe 12. The plasma generation tube 12 is enclosed in a cooling section and generation furnace (not shown), and a waveguide 13 and a high frequency oscillator 1 constitute the plasma generation device.
4. The plasma generation tube 1 is connected to a Tesla coil (not shown) and an oxygen bomb that is a raw material for plasma gas.
A plasma discharge is generated within the chamber 2 to generate plasma gas.

As shown in FIG. 4, a fan 3 consisting of four blades for diffusing plasma gas as a plasma gas flow means is provided on the inner wall side of the storage chamber 1. The core direction intersects the plane connecting the plasma injection tube 10 and the exhaust port 2 at 90 degrees.

Further, the fan 3 is connected to a drive shaft 5 of a motor M fixed to the outer wall of the storage chamber 1 via a sealing member (not shown) for maintaining airtightness within the storage chamber 1.

Now, to further describe the position of the fan 3, the fan 3 fills a dead space D where the plasma gas does not spread, which is created when the plasma gas injected from the plasma injection pipe 1o is sucked into the exhaust port 2. It is placed in a position where it can be removed.

Further, as shown in FIG. 3.4, a base 15 is provided at the bottom of the storage chamber l above the exhaust port 2, and a rotating storage device 16 is provided above the base 15. There is. As shown in FIG. 8, the rotary storage device 16 is supported by a square frame 17 on which a roller 17a is rotatably mounted, and a pair of support members 18 provided at the front and rear of the frame 17. The main components are a rotating shaft 19 rotatably supported on the upper ends of both support members 18, and the rotating shaft 1.
A pair of support disks 20a, 20 fixed near both ends of 9.
It is composed of b. And both support disks 20
Six storage stands 21 are arranged at predetermined angular intervals between the inner surfaces of a and 20b on which bumpers B made of polypropylene as objects to be processed are placed.

Further, as shown in FIG. 9, each storage stand 21 includes a pair of support pieces 22 formed by bending a metal plate, and both support pieces 22.
It is composed of an erection rod 23 installed between them, and a connecting rod 23a arranged on the lower surface of each support piece 22 so as to connect each end of each installation rod 23, and each support piece 22 has an upper end. The support disks 20a and 20b are relatively rotatably supported by metal fittings 24 and the like. Therefore, the rotating shaft 19
Each storage stand 21 is held in a horizontal state when the supporting parts 120a and 20b are rotating and when they are stationary.

Further, a net 25 is provided in the center notch of each support piece 22 to allow passage of plasma gas.

As shown in FIG. 4, a chain wheel 26 is fitted into the end of the rotating shaft 19, and a chain wheel 27 and a transmission gear 2 that rotate about one axis are mounted on the frame 17.
A chain 24 is provided between both chain gears 2G and 27.
is hung thereon, and a drive gear 30 that is rotationally driven by a drive motor (not shown) is meshed with the transmission gear 28. As the drive gear 30 rotates, the transmission gear 28. Chain gear26. Support disk 20a together with rotation shaft 14 via chain 24 and chain gear 27.

20b is adapted to be rotated.

Bumper B is subjected to plasma treatment using the apparatus configured as described above.

First, open the door 1a of the storage chamber 1, take out the rotary storage device 16 together with the frame 17 outside the storage chamber 1,
A bumper B to be subjected to plasma treatment is placed on each of the storage tables 21.

Next, the rotary storage device 16 is pushed into the storage chamber 1 again and the door 1a is closed. As a result, the plasma injection tube 10
Bumper B is stored between the exhaust port 2 and the exhaust port 2. Then, the rotating storage device 16 is rotated and the pressure reducing device 7 is rotated.
Open the valve 4 of the rotary pump 9. Activate the mechanical booster 8 and go to the containment chamber 1.
The inside pressure is reduced to a predetermined pressure (approximately 0.5 to 0.6 torr).

When the predetermined pressure is reached, the drive motor (not shown) of the rotation storage device 16 is activated, and the drive gear 30. Transmission gear 28.
Chain wheel 27. The rotation shaft 19 and the support disk 20 are rotated via the chain 29 and the chain wheel 26. Then, each storage table 21 together with the placed bumper B rotates relative to each support disk 20 around its upper end, and each bumper B is held in a horizontal state while each support disk 20 is rotating. .

The high frequency oscillator 1 is activated almost at the same time as the rotating storage device 16 is driven.
4 is oscillated, and the high frequency wave is introduced into the plasma generating tube 12 through the waveguide 13. The plasma generation tube 12 has already been supplied with oxygen gas, which is a raw material for plasma gas, and a voltage is applied to a Tesla coil (not shown) to cause plasma discharge and generate plasma gas.

The generated plasma gas is introduced into the plasma injection tube 10 via the waveguide 11, and is irradiated from each injection port 50 onto the bumper B placed on each revolving storage table 21, and is also irradiated from the exhaust port 2 begins to be attracted.

Here, the flow of the plasma gas during this period will be explained with reference to FIG. 1.2, in which the base 15 and the rotary storage device 16 are omitted from the storage chamber l. As shown by the dashed line in FIG. 1, the plasma gas injected from the plasma injection tube 10 is
As a result, a dead space D (space) where the plasma gas does not spread is created from the vicinity of the entrance of the exhaust port 2 to the lower part of the inner wall in the longitudinal direction. The plasma gas injected at this time mainly irradiates the upper center of each bumper B to activate the surface, but the plasma gas does not sufficiently spread to both ends of the bumper B that pass through the dead space D, so the plasma gas is not activated. is insufficient. after that,
As the fan 3 rotates, the plasma gas injected from the plasma gas injection tube 10 is forced toward the opposing inner wall as shown in FIGS. 1 and 2. The pumped plasma gas hits the opposing inner wall through the gap between the revolving bumper B and the storage table 21, and spreads and diffuses in both longitudinal ends of the inner wall and in the vertical direction. The diffused plasma gas spreads to both ends of the storage chamber 1 in the longitudinal direction so as to wrap around both ends of the bumper B, irradiates and activates both ends of the bumper B, flows along the inner wall, and fills the dead space D. The air is sucked into the exhaust port 2 through the air. As described above, by irradiating the center and both ends of the bumper B with the plasma gas, the entire surface of the bumper B is activated in just the right amount.

From the above, in the first invention, the plasma treatment is performed by suction through the exhaust port 2, and the dead air generated by the exhaust port 2 is further processed using a plasma gas flow means that diffuses the plasma gas. Since the plasma treatment is performed on both ends of the bumper B passing through the space D, the entire surface of the bumper B is uniformly activated without excess or deficiency.

In the second invention, the exhaust port 2 sucks the plasma gas injected from the plasma injection tube 10 and diffuses it in the storage chamber l, and then the fan 3 that diffuses the plasma gas rotates, and the plasma gas is transferred to the storage chamber l. The air is forced toward the inner wall of the chamber 1, spreads along the inner wall, flows along the inner wall, and is sucked into the exhaust port 2 via the dead space D.

Therefore, by providing the fan 3 that diffuses the plasma gas, the dead space D generated by the suction of the exhaust port 2
Since this eliminates the problem, the plasma gas can be spread throughout the storage chamber 1.

(Second Embodiment) In the first embodiment, the fan 3 was installed on the inner wall of the storage chamber 1, but in this embodiment, the fan for diffusing plasma gas is placed stationary approximately at the center of the rotating shaft 19 of the rotating storage device 16. This embodiment differs from the first embodiment only in that it is installed in the same state.

That is, as shown in FIG. 10, approximately at the center of the rotating shaft 19 is a set table that rotates relative to the rotating shaft 19 via a bearing 32 and remains stationary with respect to the accommodation chamber l. 30 is installed. A motor M equipped with a fan 33 for diffusing plasma gas is attached to the upper part of the set table 30 so as to be horizontally rotatable (oscillating) from 0 degrees to 180 degrees. Further, a weight 34 is attached to the lower part of the set table 30 to keep the set table 30 stationary, and the weight 34 has a weight large enough to cancel out the moment generated by the thrust of the fan 33. There is. Further, the motor M of the fan 33 is connected to a power outlet (not shown) in the accommodation chamber 1 through a cable (not shown).

Here, to explain the fan 33, the fan 3
3 has four blades and is rotated by the motor M, and also rotates (oscillates) horizontally in the range of 0 degrees to 180 degrees depending on the shape, size, etc. of the product B to be processed. Both ends of item B are irradiated with plasma gas. Furthermore, when the rotational direction (oscillation direction) of the fan 33 changes, the rotational direction (oscillation direction) of the fan 33 is increased for a certain period of time, and the plasma gas is made to spread over both ends of the storage chamber I in the longitudinal direction.

As described above, the same effects as in the first embodiment are exhibited.

Note that the present invention is not limited to the above-mentioned embodiments, and may be embodied as follows.

(1) In the first embodiment, after the inside of the storage chamber 1 is depressurized and suctioned through the exhaust port 2, the fan 3 is rotated along with the suction to spread plasma gas inside the storage chamber 1, and the bumper B is subjected to plasma treatment. However, conversely, after operating the fan 3 together with suction through the exhaust port 2 to irradiate the plasma gas mainly to both ends of the bumper B, the fan 3 is stopped and the plasma gas is only generated by suction through the exhaust port 2. You may switch to irradiation.

(2) The plasma processing time may be shortened by operating the fan 3 together with the exhaust port 2 from the beginning by changing the rotation speed of the fan 3 and adjusting the amount of plasma gas sent.

(3) The fan 3 may be operated continuously.

Effects of the invention As detailed above, in these first and second inventions,
Even for objects to be processed placed in spaces where plasma gas does not reach in the storage chamber, that is, dead spaces, the excellent effect of uniformly activating the entire surface of the objects is exhibited.

[Brief explanation of drawings]

Fig. 1 is a three-sectional explanatory diagram showing the flow of plasma gas in a state where the base of the storage chamber and the rotary storage table device of the plasma processing apparatus embodying the present invention are removed, and Fig. 2 is the same (Fig. 3 is an explanatory diagram showing the plasma processing apparatus, FIG. 4 is a sectional view taken along the line T-T in FIG. 3, FIG. 5 is a front view showing the plasma injection tube, and FIG. The figures are also a sectional view showing the C-C cross section of the plasma injection tube, FIG. 7 is the same sectional view showing the E-E cross section of the plasma injection tube, FIG. FIG. 10 is an explanatory view showing a fan and a set stand similarly showing the second embodiment. FIG. 11 is an explanatory view of a conventional plasma processing apparatus.
FIG. 2 is an explanatory diagram similarly showing the flow of plasma gas in the storage chamber, and FIG. 13 is an explanatory diagram similarly showing the flow of plasma gas on the side surface of the storage chamber. Storage chamber 1, exhaust port 2, plasma gas flow means 3, fan 3.33, plasma injection pipe 10, workpiece B1 dead space D0

Claims (1)

[Claims] 1. In a storage chamber (1) equipped with a plasma injection tube (10), an exhaust port (2), and a plasma gas flow means (3) for diffusing plasma gas, the plasma injection tube (1
0) and the exhaust port (2), and then the storage chamber (1) is depressurized and the product is injected from the plasma injection pipe (10). While suctioning the plasma gas through the exhaust port (2), the plasma gas flow means (3) is changed from a stopped state to an activated state or from an activated state to a stopped state to spread the plasma gas over the entire surface of the article to be treated (B). A plasma processing method characterized by uniform plasma irradiation. 2. Consisting of a storage chamber (1) equipped with a plasma injection tube (10) for injecting plasma gas and an exhaust port (2) for suctioning the plasma gas and reducing the pressure inside the device. (1) A fan (3,
33) A plasma processing apparatus characterized by comprising: 3. The plasma processing apparatus according to claim 2, wherein the exhaust port (2) is installed 180 degrees opposite to the plasma injection tube (10). 4. The axial direction of the fan (3, 33) intersects at approximately 90 degrees with respect to the straight line connecting the plasma injection tube (10) and the exhaust port (2). The plasma processing apparatus according to any one of the range 2 or 3. 5. The plasma processing apparatus according to claim 2 or 4, wherein the fan (33) rotates (oscillates) in a horizontal direction.