JPH0649174B2 - Method for drying undried coating film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for drying an undried coating film applied to an object to be coated.

Conventional technology and its problems Conventionally, when drying or baking an undried coating film applied to an object to be coated, it is generally a method of drying it in the same appearance as when it was painted, or by horizontally or vertically drying. It was target.

However, when drying an undried coating film applied to a three-dimensional object by these methods, there are usually a horizontal plane, a vertical plane and a plane in between, and therefore, for example, a horizontal plane and a vertical plane. There is a 2-3 rank difference in the finished skin between them. This difference is considered to be due to the subtle sag of the undried coating until the flow (leveling) of the coating surface stops (micro sagging). Although being investigated, the difference in finished skin between the horizontal and vertical planes has not been improved.

On the other hand, in order to eliminate the difference in the finished skin between the horizontal surface and the vertical surface, there are also known methods of drying and baking while rotating the coated object, but these methods have complicated rotation mechanisms. However, there is a problem in that it is easy to generate dust and lumps. Further, there is a problem that the finished skin is deteriorated by the rotation.

The present invention provides a drying method capable of reducing the difference in finished skin between a horizontal surface and a vertical surface of an object to be coated and finishing both the horizontal surface and the vertical surface to be equal to or more than the horizontal surface according to the conventional method. To aim.

Means for Solving the Problems According to the present invention, the above-mentioned problems are solved in a method for drying an undried coating film applied to a non-cylindrical object to be coated, in which the horizontal central axis of the object is to be rotated. The object to be coated is dried while reversing the rotation direction at an inversion angle of 180 ° or less with respect to the rotation axis and with a constant rest time interval, and the rest time interval is the reverse of the object to be coated. The solution is to provide a method for drying a wet coating, which is characterized in that it has a longer time than a corner reversal.

Specific Example Next, a preferred specific example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an apparatus for carrying out the method according to a preferred embodiment of the present invention, and FIGS. 2a and 2b show the stopping of the coated object when the set reversal angles are 90 ° and 180 °, respectively. The position is shown in FIG. 3, and the rotation position of the article to be coated is shown in a time chart.

First, the apparatus shown in FIG. 1 has a robot cylinder 10 and a horizontal rotary shaft 1 installed on an appropriate installation member (not shown).
2 and.

The robot cylinder 10 is supplied with pulsed air from a combination of a solenoid valve and a twin timer (not shown), and can rotate the rotary shaft 12 at an arbitrary angle.

The rotating shaft 12 fixes, for example, a box-shaped article to be coated 14 as illustrated. For ease of explanation, as shown, the two horizontal surfaces of the box-shaped article 14 at the start of operation are referred to as A and D, and the two vertical surfaces thereof are referred to as B and C. .

According to this specific example, first, the box-shaped article to be coated 14 is coated under a predetermined apparatus condition, and immediately this is attached to a jig (not shown) provided on the rotary shaft 12, and at the same time, the operation of the robot cylinder 10 is performed. Then, the reversing operation of the rotary shaft 12 is started.

This inversion operation is performed according to the time chart shown in FIG. That is, after holding T at the rotational position (I) for a certain period of time,
Rotate within an angle of 180 ° (eg 90 ° or 180 °), hold at the rotation position (II) for a certain period of time T, then rotate in the opposite direction and place at the rotation position (I) for a certain period of time T. Hold. Such an inversion operation is repeated until the coating film has almost no flow.

The fixed time T is determined according to the flow characteristics of the coating film,
The time T is set to be shorter for the paint that is more likely to sag and flows.

Further, the rotation time ΔT when reversing from the rotation position (I) to the rotation position (II) shown in FIG. 3 does not cause troubles such as twisting of the coating film and tampering due to centrifugal force generated during rotation. The shorter the range, the better.

In this specific example, the constant time T for holding the object to be coated is
Is set by the twin timer dial setting, and the rotation time ΔT
Can be changed to a desired value by adjusting the above-mentioned pulse air supply speed with a speed controller.

Examples and Comparative Examples Acrylic resin-based clear paint (AC-661 clear manufactured by Kansai Paint Co., Ltd.) was applied to an object to be coated, which is a metal rectangular parallelepiped having a length of 30 cm and a square cross section of 20 cm × 20 cm. It was applied so that the thickness was 30 μ and 60 μ, and the length direction was made horizontal, and fixed on the rotating shaft as shown in FIG.

As a comparative example, the object to be coated was allowed to stand and the coating film was dried as in the conventional method.

As Example 1, the holding time T is 4 seconds and the rotation time ΔT is 2
Seconds and rotated 90 °.

As Example 2, the holding time T is 4 seconds and the rotation time ΔT is 2
Seconds and rotated 180 °.

The result of the finish by these drying methods is the Suga test machine.
It was measured by an image clarity measuring device (ICM) manufactured by Co., Ltd. The results are shown in Table-1. The larger the numerical value, the better the measured value.

As is clear from Table-1, it can be seen that Examples 1 and 2 have a better finish than the Comparative Examples. Also,
In the comparative example, sagging occurs on a vertical surface having a thickness of 60 μ,
The result was unsuitable for painting.

Further, as can be seen from Table-1, according to these examples, the difference in the finished skin between the horizontal surface and the vertical surface could be almost eliminated as compared with the conventional method.

Effects As described above, according to the present invention, it is possible to almost eliminate the difference between the finished skins on the horizontal surface and the vertical surface, and it is possible to significantly improve the overall skin rank.

[Brief description of drawings]

FIG. 1 is a simplified diagram of an apparatus that can be used to implement the preferred embodiment of the present invention. Figures 2a and 2b show reversal angles of 90 ° and 1 respectively.
Explanatory operation explanatory drawing of the to-be-coated article in case of 80 degrees. Figure 3 shows the time chart of the reversing operation. 10 ... Robot cylinder 12 ... Rotating shaft 14 ... Coating object

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Kitada 4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Kansai Paint Co., Ltd. (56) Reference JP-A-54-61933 (JP, A) JP 57-30581 (JP, A) JP 58-128171 (JP, A) JP 60-99364 (JP, A) JP 61-118757 (JP, A)

Claims (3)

[Claims] 1. A method for drying an undried coating film applied to a non-cylindrical object to be coated, the method comprising: a horizontal central axis of the object to be treated as a rotation axis; It is characterized in that the drying is performed while reversing the rotation direction at a reversal angle within 180 ° and at a constant rest time interval, and the above rest time interval is longer than the time for reversing the object at the above reversal angle. A method for drying an undried coating film. 2. The method for drying an undried coating film according to claim 1, wherein the reversal angle is 90 °. 3. The method for drying an undried coating film according to claim 1, wherein the reversal angle is 180 °.