JPH0243548B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an airless painting method in which the coating width can be arbitrarily adjusted and excess paint is recovered.

Airless painting uses a mechanism that applies high pressure to the paint, expels the paint from a nozzle with fine holes, and uses a rapid pressure change to atomize the paint and adhere it to the object being coated. Therefore, compared to air spray painting, airless painting is
It can also be applied to high viscosity paints with little solvent.
It is possible to paint a thick film with one coat, and in addition, there is less paint (overspray paint) that is carried away by air currents without being applied to the object to be coated, and the paint application efficiency is high. It has the following characteristics.

However, in airless painting, paint particles fly in a straight line due to the painting mechanism, so the painting width is determined by the way the paint particles fly out and does not widen any further. Therefore, the coating width is determined by the nozzle size, and therefore, depending on the required coating width, it is necessary to interrupt the coating and replace the nozzle each time. In addition, areas that did not need to be painted were masked, but this not only made the work more complicated, but the paint applied to those areas became semi-gelled or solidified, making it difficult to collect and reuse, resulting in a loss of paint. There were other drawbacks.

The present invention eliminates the various drawbacks of airless painting as described above, and aims to provide a painting method that does not require replacing the nozzle each time depending on the painting width and allows efficient recovery of unnecessary paint. .

The purpose of this is to make it possible to adjust the painting width by installing a shielding material between the spray gun and the object to be coated in airless painting, and to paint while collecting the paint collected by the shielding material. This is accomplished by painting.

The present invention will be explained below with reference to the drawings.

FIG. 1 shows a schematic diagram of a typical airless coating according to the present invention. In other words, in Figure 1, a high-pressure generating pump a sucks up the paint in a paint tank b and applies high pressure, and when spraying paint onto an object d from an (airless) spray gun c, the system prevents unnecessary parts from being painted. This figure shows a state in which a shielding material e is installed between an airless painting gun c and an object to be coated d, and unnecessary paint collected by the shielding material e is collected in a paint recovery tank f.

According to the method of the present invention, the shielding material e can be applied to the first layer without replacing the nozzle that matches the width or shape of the coating, or without masking the object to be coated.
By installing it as shown in the figure, the coating width can be adjusted as desired.

In addition, the paint collected by the shielding material e is shorter than the paint that has fallen into the paint booth, the paint that has adhered to the wall surface, or the paint that has adhered to the masking material. It has the characteristics that the amount of evaporation, etc. is small, the composition change is minute, there is no contamination of foreign substances, and it can be easily recovered and reused.

Next, the shielding material e used for airless painting of the present invention
A specific example will be explained.

FIG. 2 shows an example in which a box-shaped shielding material e is used. Figure 2 shows the case where only the rim of an aluminum wheel is to be painted as the object d.
The two shielding materials e are placed between the spray gun c and the object to be coated d, so that only the rim part is coated. It was adjusted and installed. In addition, during painting, the object to be painted d is painted while being rotated, and the paint collected on the shielding material e is collected into the paint recovery tank f through the pipe g.

Figure 3 shows the shielding material e when the object to be coated d is directly above it.
This is an example using .

FIG. 4 shows an example of the shielding material e that is suitable when the object to be coated is located diagonally above or below the spray gun.

Figure 5 shows an example of the shielding material e, which has a narrowed tip and can easily change the width and shape of the coating by inserting this tip into the spray pattern. .

FIG. 6 shows an example in which a disk-shaped shielding material e is used and the shielding material e is rotated during painting. The paint collected by the shielding material e is recovered by a scraping device (rubber spatula) h.

FIG. 7 shows an example in which an endless sheet of shielding material e is used. Similar to Figure 6, the shielding material e
The collected paint is collected with a rubber spatula h, but a transfer roll can also be used instead of the rubber spatula.

As shown in Figures 2, 3, 4, 5, 6, and 7 above, the shape of the shielding material e is box-shaped, plate-shaped, disc-shaped, plate-shaped, etc. Any material can be used, and there is no particular restriction as long as it can shield the spray paint for adjusting the coating width.

However, the tip of the shielding material has a comb tooth shape (the fourth
It is particularly desirable to use a shielding material having a structure that allows a portion of the spray paint to pass through, such as a mesh-like structure (see FIG. 8) or a strip-like structure (see FIG. 9). In other words, in airless painting, compared to air spraying, bumps and steps were created in the paint film near the boundary between painted and non-painted areas or in overcoated areas, making it impossible to perform gradation painting with a gentle slope. This can be solved by making the tip of the shielding material have the structure described above.
Coating films as shown in FIGS. 10, 11 and 12 are obtained. For example, in Fig. 10, A-C of the object d to be coated
If you want to paint a part, if you install the shielding material e as shown in Figure 2, the paint will not be blocked by the shielding material e in the A-B area and a thick coating will be obtained, and the tip of the shielding material e will be in the B-C area. The structure allows part of the spray paint to pass through (the amount of paint passing through increases toward the tip), so a smooth coating film is obtained, and there is a step between the coating area and the non-coating area. do not have. Further, in FIG. 11, a striped coating film is obtained in the E-F and G-H regions. Furthermore, as shown in Figure 12, when painting over a wide area with multiple spray guns, in the conventional method the paint film was thicker in the overpainted areas than in other areas, but as shown in Figure 12, the coating film was thicker in the overpainted areas. When installed, the paint film on the overpainted area will be the same as other areas, and a smooth paint film will be obtained. In other words, when painting the I-J part of the object d with three spray guns C, C', C'', installing four shielding materials e, e', e'', e will prevent the overcoated area from being painted. A coating film with no difference in film thickness can be obtained.

The size of the structure at the tip of the shielding material through which a portion of the spray paint passes can be arbitrarily selected depending on the coating conditions of the object to be coated, etc. For example, in the case of the tooth-shaped comb shown in FIG. 4, the pitch n is usually 0.5 to 3 cm, and the tooth length m1 to 10 cm.

Next, the position of the shielding material is determined by the pressure of 10 to 150 kg/cm ² usually applied to the paint in the case of airless painting.
The distance between the spray gun and the object to be coated is usually about 10 to 60 cm, and any position within that range is acceptable, but a suitable position is a distance between the spray gun and the object of about 5 to 30 cm. In addition, in the case of airless painting, there is no fast air flow like in air spray painting, so even if the spray paint collides with the shielding material, the paint will not bounce back and there is no risk of disturbing the direction of the paint, so it is necessary to install a shielding material. No problems will arise due to this.

Next, during painting, it is preferable to fix the spray gun so that the distance from the object to be coated can be adjusted, and to paint while moving the object to be coated. In addition, the shielding material is installed so that it can be moved vertically and horizontally so that the coating width can be adjusted as desired. In addition, when using a shielding material whose tip part allows part of the spray paint to pass through, be careful not to create stripes on the paint film due to the shadow of the teeth of the comb.
It is desirable to paint while rotating or reciprocating left and right in a direction substantially perpendicular to the direction in which the spray paint travels.

Next, one embodiment of the present invention will be described with reference to FIG. FIG. 13 shows an example in which a disk e (10 cm in straight shape) with a comb tooth-shaped tip is used as a shielding material. The pitch of the teeth at the tip of the shielding material e is 5.
mm, the tooth length is 3 cm, and the rotation axis 1 is the rotation device 2.
is fixed. There is a shielding material e inside the pipe of the rotating shaft 1.
A pipe is installed that leads to the top surface of the pipe to suck up the collected paint, and the collected paint is collected from the pipe 3 into a collected paint tank (not shown). Rotating device 2
is fixed to the vertical moving device 5 by a moving shaft 4.
Further, the distance between the rotating device 2 and the vertical moving device 5 is adjusted by a device 7 that has a rotating female screw that rotates on the screw of the screw shaft 6 and turns the rotating female screw. Similarly, the shielding material e is moved up and down along the movement axis 8 by operating the screw shaft 9.

When painting, the position of the shielding material e is determined according to the coating width, and painting is started while rotating the shielding material e at a speed of about 10 to 40 rpm. In this case, the spray gun c is fixed and the object to be coated d is painted while being moved (rotated). For example, slurry paint (viscosity
18,000 centipoise) on a plate-shaped object, the distance between the fixed gun and the shielding material e is 20 cm, the distance between the object to be coated and the shielding material e is 20 cm, and the distance between the object to be coated is 2 m. Paint is sprayed from a nozzle (the shape of the nozzle opening is elliptical, with a major diameter of 320 μm and a short diameter of 128 μm) at a nozzle pressure of 100 kg/cm ² while moving at a speed of 100 kg/cm 2 . in this case,
The rotation speed of the shielding material e is 30 rpm.

With the method of the present invention, there is no need to change the nozzle of the appropriate size each time depending on the painting width, there is no need for masking treatment on the object to be coated, the work is simplified, and unnecessary excess paint can be easily collected and reused. It became possible.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the airless coating of the present invention, Figure 2
Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7,
8 and 9 are representative shielding materials used in the present invention, FIGS. 10, 11, and 12 are diagrams showing the state of coating film formation by the method of the present invention, and FIG.
The figure is a drawing showing one embodiment of the present invention. a... High pressure generation pump, b... Paint tank, c
...Airless spray gun, d...Object to be coated, e...
...shielding material, f...paint recovery tank, g...piping,
h... Paint scraping device, 1... Rotating shaft, 2, 7
...Rotating device, 3...Piping, 4,8...Moving axis,
5... Vertical movement device, 6, 9... Screw shaft.

Claims (1)

[Scope of Claims] 1. The coating width can be adjusted by installing a shielding material between the spray gun and the object to be coated at a position where the composition of the discharged paint changes minutely, and the coating width can be adjusted by the shielding material. An airless painting method characterized by collecting collected paint. 2. The airless painting method according to claim 1, wherein the tip of the shielding material has a structure that allows a portion of the spray paint to pass through. 3. The airless coating method according to claim 2, wherein the tip of the shielding material has a comb-like shape, a net shape, or a comb-like shape. 4. The airless painting method according to claim 3, wherein the coating is performed while the shielding material is rotated in a direction substantially perpendicular to the direction of travel of the spray paint or reciprocated from side to side.