JP7158379B2 - Plasma processing equipment - Google Patents

Description

TECHNICAL FIELD The present application relates to a technique for plasma-treating the surface of powder.

Conventionally, various techniques for plasma-treating the surface of powder have been proposed.

For example, in the powder surface treatment apparatus using atmospheric pressure plasma described in Patent Document 1, the powder is suspended and transported by a rare gas or the like in the process of floating and transporting the powder, and glow discharge is generated under a pressure higher than the atmospheric pressure. The surface of the powder is plasma-treated.

JP-A-6-228739

However, in the above conventional apparatus, the powder to be treated, that is, the workpiece is directly thrown into the discharge space, so there is a risk of electrical and thermal damage to the workpiece.

In addition, in the above-described conventional apparatus, it is necessary to manufacture a plasma processing unit dedicated to powder, which increases the manufacturing cost.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present application to provide a plasma processing apparatus capable of performing plasma processing on the surface of a powder to be processed without causing electrical or thermal damage to the powder to be processed, while suppressing manufacturing costs. and

In order to achieve the above object, the plasma processing apparatus of the present application is a powder container into which powder is placed, which is a hollow powder container surrounded by walls, and a plasma jet from the outside of the powder container. and a flow path for flowing the powder to the outside of the powder container through the upper part of the inner part of the powder container. is plasma-treated, and the plasma-treated powder is discharged to the outside of the powder container.

According to the present disclosure, the powder to be treated is less likely to be electrically and thermally damaged, and the powder surface can be plasma-treated in a desired state.

1 is a perspective cross-sectional view showing how an atmospheric pressure plasma head is connected to a plasma processing apparatus according to an embodiment of the present application; FIG. 2 is a perspective partial cross-sectional view showing the internal structure of the plasma processing apparatus of FIG. 1; FIG. FIG. 2 is a perspective partial cross-sectional view showing an example of how the plasma processing apparatus of FIG. 1 plasma-processes the powder surface;

Hereinafter, embodiments of the present application will be described in detail with reference to the drawings.

A plasma processing apparatus 100 according to an embodiment of the present application is configured to be connectable with a plasma head 210 of a plasma generation apparatus 200, as shown in FIG. 1 to 3, when referring to directions, the directions of the arrows shown in each drawing are used.

The plasma processing apparatus 100 has a rectangular parallelepiped outer shape as shown in FIG. 2, and is composed of vertically stacked rectangular parallelepiped members 110 and 150 having the same shape in plan view. Hereinafter, the upper member 110 will be referred to as the upper member 110 and the lower member 150 will be referred to as the lower member 150 . The upper member 110 and the lower member 150 are detachably fixed, for example, by screws (not shown).

As shown in FIG. 1, the upper member 110 has a rectangular parallelepiped recess 112 with an open bottom surface. The recess 112 is formed by a ceiling wall 112a and a peripheral wall 112b.

On the other hand, the lower member 150 has a rectangular parallelepiped concave portion 152 with an open upper surface. The recess 152 is formed by a floor wall 152a and a peripheral wall 152b.

Since the opening 112c of the recess 112 and the opening 152c of the recess 152 face each other, a hollow room 170 surrounded by walls is formed. This chamber 170 is filled with the powder W to be processed by the plasma treatment (see FIG. 3), so this chamber 170 is hereinafter referred to as a powder container 170 .

The powder container 170 functions not only as a container for containing the powder W, but also as a floating space in which the powder is sucked up and floats, as will be described later. The concave portion 152 mainly functions as a container, and the concave portion 112 mainly functions as a floating space. Therefore, the opening 112c of the recess 112 functions as an inlet for the powder W. As shown in FIG. The area of the opening surface of the opening 112 c of the recess 112 is smaller than the area of the opening surface of the opening 152 c of the recess 152 .

A peripheral wall 112b of the recessed portion 112 is formed by four walls on the front, rear, left, and right. Holes 114 and 116 are formed in the left and right walls, respectively. The hole 114 penetrates the outer surface of the plasma processing apparatus 100 to which the plasma head 210 is connected and the inner surface of the powder container 170 . On the other hand, the hole 116 penetrates the inner surface of the powder container 170 and the opposite outer surface of the plasma processing apparatus 100 . The hole 114 and the hole 116 allow the plasma jet emitted from the plasma head 210 to flow into the powder container 170 and then be discharged to the outside of the powder container 170 , that is, the plasma processing apparatus 100 . A flow path 118 is formed. Since the holes 114 and 116 are formed in the upper portion of the powder container 170 , that is, near the ceiling wall 112 a, the flow path 118 is formed in the upper portion of the powder container 170 .

Since the hole 114 allows the plasma jet to flow into the powder container 170, the opening of the hole 114 on the powder container 170 side is referred to as an inlet 114a. On the other hand, since the hole 116 discharges the plasma jet flowing into the powder container 170 to the outside of the powder container 170, the opening of the hole 116 on the powder container 170 side is referred to as a discharge port 116a.

The inlet 114a and the opening 112c are formed so that the area of the inlet 114a is much smaller than the area of the opening 112c of the recess 112, which functions as an inlet for the powder W. . Conversely, the opening 112c is formed to have a sufficiently large area compared to the area of the inlet 114a.

An air hole 120 is formed through the left wall of the four walls forming the peripheral wall 112b from the upper surface 111a of the upper member 110 to the lower surface 111b of the upper member 110. As shown in FIG. The air hole 120 has the function of drawing outside air into the powder container 170 .

Next, the plasma processing of the surface of the powder W performed by the plasma processing apparatus 100 configured as described above will be described with reference to FIG.

The powder W before plasma treatment is loaded on the bottom surface of the powder container 170 , that is, on the floor wall 150 a of the concave portion 152 of the lower member 150 . In this state, when a plasma jet is ejected from the plasma head 210 of the plasma generator 200, the plasma jet flows through the flow path 118 in the direction of the arrow F1.

The area of the inlet 114a included in the flow path 118 is sufficiently smaller than the opening 112c of the recess 112 functioning as an inlet for the powder W, as described above. Therefore, the flow velocity of the plasma jet that flows into the powder container 170 from the inlet 114 a and is discharged from the outlet 116 a is significantly higher than the flow velocity of air in other spaces within the powder container 170 . fast.

Further, the flow path 118 is formed in the upper part of the powder container 170, that is, near the ceiling wall 112a of the concave portion 112 of the upper member 110, as described above.

Therefore, according to Bernoulli's law, the space below the flow path 118 in the powder container 170 has a negative pressure. After flowing into the vicinity of 152a, it flows inside the powder container 170 toward the discharge port 116a. A portion of the powder W is sucked up by this outside air and flows toward the discharge port 116a together with the outside air.

Part of the powder W flowing into the discharge port 116a comes into contact with the plasma jet inside the flow path 118, that is, inside the hole 116, so that the surface of the powder W is plasma-treated. Part of the plasma-treated powder W is discharged outside the plasma processing apparatus 100 together with the plasma jet.

Such operation processing is repeated until the powder W placed in the powder container 170 is exhausted or until the operation processing is stopped, and the surface of the powder W is plasma-processed.

The plasma-treated powder W discharged outside the plasma processing apparatus 100 can be collected in a large container (not shown) or directly sprayed onto a coating agent or the like.

The plasma processing time for the powder W can be adjusted by changing the flow rate of the plasma jet and the area of the inlet 114a and the opening 112c depending on the mass and particle size of the powder W. Also, by changing the gas mixture ratio of the plasma jet, it is possible to selectively control the plasma processing capability and effect.

As described above, the plasma processing apparatus 100 of the present embodiment is a powder container 170 in which the powder W is placed. and a flow path 118 that flows from the outside of the powder container 170 through the upper part of the powder container 170 to the outside of the powder container 170. By flowing, the powder W is sucked up and plasma-treated, and the plasma-treated powder W is discharged to the outside of the powder container 170 .

As described above, in the plasma processing apparatus 100 of the present embodiment, the surface of the powder W is plasma-processed by the plasma jet supplied from the outside without directly throwing the powder W to be processed into the discharge space. Therefore, the powder W to be treated is less likely to be electrically and thermally damaged, and the surface of the powder W can be plasma-treated in a desired state. Further, the plasma processing apparatus 100 of the present embodiment does not incorporate the plasma generator 200 for generating a plasma jet, and the plasma jet generated using the existing plasma generator 200 is used in the plasma processing apparatus of the present embodiment. Since the powder can be supplied from the outside of 100, there is no need to manufacture a plasma processing unit dedicated to powder. Thereby, it becomes possible to suppress the manufacturing cost of the plasma processing apparatus 100 .

Further, the plasma processing apparatus 100 of the present embodiment further includes an air hole 120 penetrating the inside and outside of the powder container 170 to draw air into the inside of the powder container 170 .

This makes it easier to suck up the powder W.

The walls surrounding the powder container 170 include peripheral walls 112b and 152b, a ceiling wall 112a and a floor wall 152a, and the powder W is placed on the floor wall 152a of the powder container 170.

The peripheral wall 112b has an inlet 114a through which the plasma jet flows into the powder container 170, and an outlet through which the plasma jet flowing into the powder container 170 from the inlet 114a is discharged to the outside of the powder container 170. 116 a , with inlet 114 a and outlet 116 a included in channel 118 .

Further, an opening 112c is further provided between the floor wall 152a and the ceiling wall 112a in the powder container 170 to introduce the sucked powder W and flow it into the flow path 118. The area of the opening 112c is , is sufficiently large compared to the area of the inlet 114a.

This makes it easier to suck up the powder W.

Incidentally, the opening 112c is an example of the "introduction port".

It should be noted that the plasma processing apparatus of the present application is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention.

In the above embodiment, the upper member 110 and the lower member 150 are detachably fixed with screws, but fixing members are not limited to screws, and other members such as bolts and nuts may be used. Also, the lower member 150 may be made to be pulled out.

100 plasma processing apparatus 110 upper member 112 recess 112a ceiling wall 112b, 152b peripheral wall 112c, 152c opening 114, 116 hole 114a inlet 116a outlet 118 channel 120 air hole 150 bottom Member 152 Recess 152a Floor wall 170 Powder container 200 Plasma generator 210 Plasma head

Claims (5)

a hollow powder container surrounded by walls;
a flow path through which the plasma jet flows from the outside of the powder container through the upper part of the powder container to the outside of the powder container;
with
With the powder placed in the powder container, plasma treatment is performed on the powder while the powder is sucked up by causing the plasma jet to flow through the flow path, and the plasma treatment is performed. discharging the powder to the outside of the powder container;
Plasma processing equipment. 2. The plasma processing apparatus according to claim 1, further comprising an air hole penetrating the inside and the outside of said powder container for drawing outside air into said powder container. The walls include a peripheral wall, a ceiling wall and a floor wall,
The powder is placed on the floor wall of the powder container.
The plasma processing apparatus according to claim 1 or 2. The peripheral wall includes an inlet through which the plasma jet flows into the powder container, and an outlet through which the plasma jet flowing into the powder container from the inlet is discharged to the outside of the powder container. with
wherein the inlet and the outlet are included in the channel;
The plasma processing apparatus according to claim 3. further comprising an inlet for introducing the sucked powder into the flow path between the floor wall and the ceiling wall in the powder container;
the area of the inlet is sufficiently large compared to the area of the inlet;
The plasma processing apparatus according to claim 4.

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