JPH03101873A - Method for rubbing coating film - Google Patents

Abstract

PURPOSE:To prevent the occurrence of streaks and coarse grains on a coating film due to rubbing with a brush and to obtain a dense finished surface by specifying the count of abrasive grains contained in a suspension and regulating the concn. of the grains to a certain value or below. CONSTITUTION:A brush 1 for rubbing is turned and relatively moved on a coating film on the surface of an automobile body 4 to rub the film 4a. During this rubbing, a suspension contg. #800-2,000 count abrasive grains 5b in water 5a at <=5% concn. is sprayed under low pressure from a spray nozzle 6 on the contact part between the brush 1 and the film 4a. The abrasive grains 5b are held in the gap between rubbing wires 3 and compensate for rubbing with the wires 3. A dense coated surface is easily obtd. at a low cost.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides an abrasive suspension in which abrasive grains are dispersed in water using a rotary polishing blank in which fine abrasive threads are provided radially. This invention relates to a coating film polishing method for polishing a coating film on an automobile body, etc., while spraying a slurry.

(Prior Art) For example, as described in Japanese Patent Application Laid-open No. 58-64157, the painted surface (coating film) of the body of an automobile, etc., which has undergone an undercoating process or an intermediate coating process by electrodeposition coating, etc., is In the process, it is polished smooth using a polishing brush held by a playback type robot or the like. This polishing brush uses a foil-shaped material made by radially planting nylon fibers with abrasive grains attached to a drum, and the polishing brush is rotated by an actuator such as an air motor. At the same time, the paint film is polished by applying pressure to the painted surface with a predetermined pressing pressure, supplying water by a separately provided water supply device, and moving the polishing brush.

(Problem that the invention aims to solve) However, when polishing with such a polishing brush, the structure of the polishing brush has an uneven distribution density of the polishing threads, which causes polishing streaks on the coating film (polishing surface). This may occur;
In such cases, it is not possible to obtain a dense and high-quality polished surface.

Therefore, for example, as described in Japanese Patent Publication No. 6B-22948, in order to perform fine polishing, abrasive grains are incorporated into the polishing thread of a polishing brush, and coarse and fine grains are contained instead of water. There are some products that use sand suspension, but if you do this, the abrasive grains will be incorporated into the abrasive threads of the polishing brush, which will increase the cost.
Since different types of sand are used, there are also problems with quality control.

The present invention has been made in view of these points, and an object of the present invention is to provide a coating film polishing method that can inexpensively and easily obtain a dense painted surface (coating film).

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a rotary polishing brush in which fine polishing threads are provided radially.
In a polishing method of polishing the paint film of an automobile body, etc. while spraying an abrasive suspension in which abrasive grains are dispersed in water, the abrasive grains included in the abrasive suspension are 800# to 20.
00# is used, and the abrasive grain concentration of the abrasive grain suspension is 5% or less.

(Function) Using a rotating polishing brush with fine abrasive threads arranged radially, apply 5% abrasive grains of 800# to 2000#.
A coating film on an automobile body or the like is polished while spraying an abrasive suspension containing the following abrasive grain concentration.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1 showing an example in which the method of the present invention is applied to polishing the paint film of an automobile body, 1 is a wheel-shaped rotary polishing brush, and abrasive grains are mixed radially with respect to a drum 2. A large number of grinding threads 3 are planted.

This polishing brush 1 is used, for example, in a water polishing process in a painting line for automobile bodies, and the polishing at that time is performed as follows.

When polishing by rotating the polishing brush 1 and moving it relatively over the coating film 4a (painted surface) on the surface of the car body 4 that has completed the undercoating process or intermediate coating process by electrodeposition coating, etc., Abrasive grains 5b with a grain size ranging from 800# to 2000# (e.g. alumina AJII!03) are placed in water 5a.
Abrasive grain suspension 5 (polishing aid) containing at an abrasive grain concentration of 5% or less
The coating film 4a of the vehicle body 4 is polished while being sprayed at low pressure from the jet/J nozzle 6 onto the contact area between the polishing brush 1 and the coating film 4a. At this time, since the abrasive grains 5b contained in the abrasive grain suspension 5 are held in the gap between the polishing threads 3 of the polishing brush 1, the abrasive grains 5b hold the abrasive grains 5b. Polishing by the thread 3 is assisted. Further, the abrasive grains 5b contained in the abrasive grain suspension 5 are
It also functions as an anti-slip agent for the coating film 4a (polishing surface) of the polishing thread 3.

This makes it possible to obtain a high-quality polished surface (coating film 4a) that could not be obtained by conventional methods such as manual polishing, dry polishing with a nylon brush, or wet polishing. That is, there are no sharpening lines or rough edges caused by the polishing brush 1, and the finished surface is dense and uniform.

Next, FIG. 2 shows the results of an investigation into the influence of the grit of the abrasive wheel 5b included in the abrasive grain suspension 5 on the surface roughness of the coating film 4a of the automobile body 4.

Note that the polishing thread 3 is aromatic polyamide fiber (trade name;
A fine thread of 1000# made of Conex) is used as the abrasive grain 5b. , S i C, A (J2
Three types of 0+ were used, and the test conditions were that the rotation speed of the polishing brush 1 was 120 rpm, the pressing amount was 1 song, and the feed rate was 318/min.

From Fig. 2, the amount of polishing changes in the order of S i02 > S ic > Aρ, 03, but when polishing the coating film 4a of the car body 4 while spraying an abrasive suspension, SiO2 and SiC are When polishing the coating film 4a of the car body 4, A. It is most desirable to use Q20h (alumina). Also, 17203 (alumina) is SiO! , is cheaper than SiC, and is advantageous in terms of price.

Therefore, since the target surface roughness of the coating film 4a of the car body 4 is about 4 μm, the abrasive grains 5b have a diameter of 800 μm.
It is sufficient if it is in the range of # to 2000 #, but preferably 1
It can be seen that the range of 200# to 1500# is good.

Next, three types of abrasive grains (800#, 1200#, 1500# A, Q
FIG. 3 shows the results of a test conducted on the influence of the abrasive grain concentration of the abrasive grain suspension on the surface roughness of the coating film 4a of the car body 4.

As mentioned above, since the target surface roughness of the coating film 4a of the car body 4 is about 4 μm, it is sufficient that the abrasive grain concentration of the abrasive grain suspension is 5% or less, but preferably 0.5% or less. 5
It can be seen that a range of 3% to 3% is preferable.

From the above test results, the abrasive grain suspension 5 can achieve the desired effect if the abrasive grains 5b contained therein have a grain size of 800# to 2000# and the abrasive grain concentration is 5% or less. Preferably, the abrasive grains 5b have a grain size of 1200# to 1500# and an abrasive grain concentration of 0. It can be seen that it is desirable that the content be in the range of 5 to 3%.

In addition, compared to the technology described in Japanese Patent Publication No. 6B-22948, the present invention is less expensive because there is no need to incorporate abrasive grains into the polishing thread, and the number of abrasive grains contained in water is 1. Since any type can be used, management is easy and workability is good.

(Effects of the Invention) As described above, the present invention provides that the abrasive grains contained in the abrasive suspension sprinkled on the polished part by the polishing brush have a count of 80.
Since we use abrasive grains of 0# to 2000# with a concentration of 5% or less, the finished surface of the polished surface is maintained without any scratches or rough spots caused by the polishing brush on the coating film (polished surface). can be made precise.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a diagram showing a schematic structure of a polishing method for a coating film on an automobile body, and FIG. Figure 3 shows the test results on the relationship between the abrasive grain concentration of the abrasive grains contained in the abrasive suspension and the surface roughness of the car body paint film. FIG. l... Polishing brush 4... Vehicle body 4a... Coating film 5... Abrasive grain suspension 5b... Abrasive grain l. ... Polishing brush 4 ... Car body 4a ... Paint film 5 ... Abrasive grain suspension

Claims (1)

[Claims] (1) Using a rotating polishing brush with fine abrasive threads arranged in a radial pattern, it polishes the paint film on car bodies, etc. while spraying an abrasive suspension made of abrasive grains dispersed in water. In the polishing method, the abrasive grains contained in the abrasive suspension have a grain size of 800# to 2000#, and the abrasive grain concentration of the abrasive grain suspension is 5% or less. polishing method.