JPS6055193B2 - How to paint the inner surface of long pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for applying a liquid paint containing a large amount of sedimentable particles to the inner surface of a long tube in a thin layer without causing the sedimentable particles to settle.

Various methods are used to paint the inner surface of pipes, such as spraying, dipping, and brush painting.However, spraying is the most effective method for applying liquid paint containing a large amount of sedimentary particles to the inner surface of long pipes. However, there are drawbacks such as the difficulty of spraying due to a small spray angle, and the fact that the settling particles are not uniformly dispersed in the dipping method.

In addition, with the brush coating method, small-diameter long pipes must be painted with a rotating brush, but when painting with a rotating brush, the paint is applied while being pulled in the direction of movement of the rotating brush, so it is difficult to supply the material. The coating thickness changes depending on the amount of paint applied, and if the amount of paint is too large, there are drawbacks such as sedimentation particles settling before the paint is applied. The present applicant has previously proposed in Japanese Patent Application No. 52-49303 a method for applying the liquid paint to the inner surface of a small-diameter long tube, in which the liquid paint is applied to the inner surface of a long tube in front of a rotating brush with bristles flocked in a spiral shape. A method is proposed in which liquid paint is supplied at a constant speed to a position where it does not come into contact with anything other than the paint, and the rotating brush is rotated at a constant speed so as to send the paint forward. There is.

However, in this method, when the inner diameter of the long tube becomes 5 mm or more, the amount of paint supplied increases, and since the paint contains a large amount of sedimentary particles, the rotating brush alone cannot remove the sedimentary particles. This made it difficult to lift it up, making it difficult to apply it uniformly in the circumferential direction of the inner surface of the tube.

The present invention has been made with the aim of eliminating the drawbacks of the conventional methods as described above. In particular, a liquid paint containing a large amount of sedimentary particles with a maximum particle size of 50 microns or less is coated on the inner surface of a long tube, particularly with an inner diameter of 5 mm or more. The object of the present invention is to provide a method for uniformly coating the inner surface of a long pipe with a large diameter in a thin layer.

That is, the gist of the present invention is to produce a liquid paint containing a large amount of sedimentary particles by relatively moving a rotating brush with bristles flocked in a spiral shape from one end to the other end of the inner surface of a long tube with an inner diameter of 50 wL or more. When coating the inner surface of the long tube, the liquid paint is supplied to the inner surface of a rotary vane provided on the same axis in close proximity to the rotary brush on the moving side of the rotary brush, and A long tube characterized in that the liquid paint is dispersed and deposited on the inner surface of the long tube by rotation, and the rotating brush is moved to the uncoated side while rotating the rotary brush in a direction to send out the liquid paint to the painted side. It consists in the method of painting the inner surface of the pipe. The liquid paint used in the present invention is a paint that contains a large amount of sedimentary particles and is generally used for coating the inner surface of steel pipes, and generally has a maximum particle size of 5.
It is preferable that 40 to 8 weight percent of settleable particles of 0 micron or less are contained, and zinc powder, aluminum powder, etc. are preferably used as the settleable particles.

The rotary brush used in the present invention has bristles flocked on its shaft in a spiral shape, and the diameter of the brush is preferably slightly larger than the inner diameter of the tube to be painted.

The rotating blade used in the present invention is provided on the moving side of the rotating brush, at a position close to the rotating brush, and coaxially with the rotating brush.

The shape is not particularly limited as long as the liquid paint supplied to the inner surface of the rotary vane can be dispersed and adhered to the inner surface of the long tube by centrifugal force by rotating the rotary vane, for example, a propeller shape, a wheel shape, etc. Examples include shapes such as shape. In the present invention, a rotating brush having the above-mentioned rotating blades disposed coaxially is inserted into a long pipe to be coated, the above-mentioned liquid paint is supplied to the inner surface of the rotating blade, and the liquid paint is transferred into the long pipe by the rotating blades. At the same time as it is dispersed and deposited on the surface, this liquid paint is sent out to the painted side of the rotating brush according to the helical bristles of the rotating brush, and while the rotating brush is rotating, it is moved to the unpainted side. be.

Instead of moving the rotating brush, a long tube may be moved. Note that any method may be used to supply the paint, but since the liquid paint containing a large amount of sedimentary particles is supplied to the rotating blades, it is preferable to supply the paint at a constant speed through the tube. Preferably, the tip of the tubular body is fixed at a position close to the rotating blade, and is preferably installed so as to move with the movement of the rotating brush.

Next, one embodiment of the coating method of the present invention will be explained with reference to the drawings.

FIG. 1 is a partially cutaway perspective view of an apparatus suitable for carrying out the coating method of the present invention. In Figure 1, 1 is diameter 0.2
It is a rotating brush with an outer diameter of 1,657 m, in which Tfn nylon bristles 11 are flocked in a spiral pattern at intervals of 14 Tn1n.

12 is a support for the nylon bristles 11.

3 is a rotating blade provided on the shaft 2 of the rotating brush 1 in front of the rotating brush 1, and the rotating blade 3 has a radius of 35T on the rotating plate 31! r! Four blades 32 with a size of 20×20TK1n tilted and rotated on a concentric circle of Ft
It is more than that.

Reference numeral 4 denotes a liquid paint supply pump, and the liquid paint is sent by the supply pump 4 through a supply pipe 5 and is supplied to the supply port 51 and the rotary vane 3 .

6 is a driving tool connected to the shaft 2, and the rotary brush 1
and the rotating blade 3 are simultaneously rotated by the driving tool 6.

Reference numeral 7 denotes an outer sleeve, which holds the shaft 2 through a bearing 8 so that it does not bend.

The supply pump 4, the driving tool 6, and the mantle tube 7 are installed on a pedestal 9 having wheels 91 installed on rails 10, and by moving the pedestal 9 on the rails 10, the rotating brush 1 and the rotating brush 1 are rotated. The rotating brush 1 can be moved inside the long tube 100 without changing the relative positions of the blades 3 and the liquid paint supply port 51. When painting the inner surface of a long tube with the above device, the rotating brush 1 and rotating blades 3 are inserted into one end of the long tube, installed near the other end, and the driving tool 6 is used to control the rotating brush 1 and rotating blades. 3 in the direction of the arrow, and then supplies liquid paint at a constant speed to the liquid paint supply pump 4, and at the same time moves the mount 9 at a constant speed to pull out the rotating brush 1 and the rotating blade 3 at a constant speed. This allows the inner surface of the long tube to be coated uniformly.

The structure of the method for painting the inner surface of a long pipe according to the present invention is as described above, in which the liquid paint is supplied to the inner surface of the rotating blade just before the rotating brush, and is dispersed and deposited on the inner surface of the long pipe by the rotation of the rotating blade. Since the paint is immediately applied by a rotating brush, the liquid paint supplied to the inner surface of the rotating blade is evenly distributed and adhered to the inner surface of the long tube due to the centrifugal force of the rotating blade, without causing sedimentation particles to settle and separate. Since it is painted, the inner diameter is 50
The coating is uniformly applied to long pipes of m or more in length.

In addition, since the settling particles in the liquid paint are applied without being deformed under pressure or settling and separating, the settling particles are uniformly dispersed in the coating film, and there are no pinholes in the coating film. It will be painted. Also, the rotating brush has bristles flocked in a spiral pattern, and since this rotating brush is rotated so as to send the paint to the painted side, there is no chance of excess paint remaining in front of the brush. Even a thin layer of 5 to 50 microns can be coated uniformly over the entire surface of a long tube from one end to the other. Next, the present invention will be explained using examples. Example Carbon steel pipe for 150A piping with blasted inner surface (
Outer diameter 165.277!5, inner diameter 155.2, length 5.
The rotating brush 1 of the coating device shown in FIG. 1 was inserted from the left end of the tube (5 m), and the rotating blade 3 was placed in contact with the right end entrance.

Ethyl silicate 24 parts Zinc powder (
maximum particle size 25μ or less) 6 parts isopropyl alcohol 14 parts polyvinyl butyral
Part 2 Next, a liquid paint having the above composition and a viscosity of 30 ■Ps is sent by the pump 4 at a speed of 31a1/min, and the rotating brush is sent in the direction of sending the paint to the painted side, that is, to the right (i.e., in the direction of the arrow). ) was rotated at 700r''.P.m. and drawn at a speed of 2.57n/min to coat the inner surface of the tube, and dried while rotating the steel tube.
It was possible to apply it uniformly to a thickness of 0μ.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an apparatus suitable for carrying out the coating method of the present invention. 1...Rotating brush, 2...Rotating brush shaft, 3...Rotating vane, 4...Liquid paint supply pump, 5... ... Supply pipe, 6...
- Drive tool, 7... Mantle tube, 10... Rule, 100... Long tube.

Claims (1)

[Scope of Claims] 1. A liquid paint containing a large amount of sedimentable particles is transferred by relatively moving a rotating brush with bristles flocked in a spiral shape from one end to the other end of the inner surface of a long tube having an inner diameter of 50 mm or more. When painting the inner surface of the long tube, the liquid paint is supplied to the inner surface of a rotary vane provided on the same axis in close proximity to the rotary brush on the moving side of the rotary brush, and the rotation of the rotary vane is The inner surface of the long tube is characterized in that the liquid paint is dispersed and deposited on the inner surface of the long tube, and the rotating brush is moved to the unpainted side while rotating the rotating brush in the direction of sending the liquid paint to the painted side. Painting method. 2. Claim 1 in which the liquid paint contains 40 to 80% by weight of settleable particles with a maximum particle size of 50 microns or less
Painting method described in section. 3. The coating method according to claim 1, wherein the liquid paint is supplied through a supply pipe.