JPS62234573A - Method and device for producing steel sheet pile coated with fused resin powder - Google Patents

Abstract

PURPOSE:To coat one surface of a steel sheet pile with an org. resin efficiently and uniformly by supplying resin powder from a supply means, sprinkling the powder over the steel sheet pile, and recovering the surplus resin powder by a recovery means traveling in the same direction. CONSTITUTION:Resin powder is supplied from the traveling powder supply means 11 which are provided at regular intervals in the lengthwise direction of the steel sheet pile 1, and sprinkled over the derusted and preheated steel sheet pile 1 in the method for applying anticorrosive coating of an org. resin to the surface of the steel sheet pile. The powder is circulated by a powder circulating means 16, and then the surplus powder is recovered by the powder recovery means 13 traveling in the same direction as the supply means 11. consequently, the fused resin powder can be coated on the surfaces of both recess and protrusion of the steel sheet pile in uniform thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for manufacturing a resin powder fusion-coated steel sheet pile, which applies an anticorrosion coating of an organic resin to the surface of the steel sheet pile.

<Prior art and its problems> Generally, steel pipe piles, steel pipe sheet piles, and steel sheet piles are used for the purpose of constructing structures and retaining earth and sand in ports, rivers, coasts, etc. These steel materials, especially on the water surface, are exposed to water such as river water, wastewater, rainwater, seawater, the atmosphere, sunlight, etc., and are also subject to impact from running water, waves, or sources, and are susceptible to corrosion. situation.

However, until now there has been no effective corrosion prevention method, and corrosion prevention has been achieved by using inorganic zinc paints, tar epoxy resin paints, epoxy resin 11FF, FRI!'4''i1 made of Japanese polyester resin, etc. However, they are inferior in terms of mechanical strength, long-term durability, etc.
It was not an effective corrosion prevention method.

Furthermore, to prevent corrosion in underwater areas, cathodic protection methods have often been applied, or they are not effective in tidal zones or splash zones, so painting is relied upon, but as mentioned above, the effectiveness of these methods is not 70% effective.

However, later on, with regard to steel pipe piles, we took advantage of anti-corrosion coating technology for line pipes and applied a plastic layer made by extruding polyolefin resin, which is a coating material with high anti-corrosion effects and excellent durability, to the steel pipe surface using an adhesive in a molten state. Products with excellent anti-corrosion coatings have been put into practical use by methods such as extrusion coating methods in which the surfaces of steel pipes are coated with tar-urethane resins and urethane elastomer resins by airless spray coating, and they have improved in terms of performance and economy. A significant number of pieces were made.

On the other hand, steel pipe sheet piles and steel sheet piles have complex shapes such as claws on both sides, so plastic coating cannot be done using the extrusion coating method described above, and tar/urethane resin and urethane elastomer resin cannot be coated using airless coating. Spray coating methods have been applied with significant defeat.

However, tar urethane resin paint and urethane elastomer resin paint coating using the airless spray method have a high water supply rate in the coating film itself, and are slightly inferior in corrosion resistance compared to polyolefin coatings. Efficiency is low and there are environmental problems such as paint scattering, and there has been a strong desire for a method to improve these drawbacks.

In order to eliminate these drawbacks, JP-A-59-224717 and JP-A-59-224718 disclose a method of pressure-bonding a cross-linked polyethylene sheet onto a steel sheet pile using rolls, but these methods do not contain air bubbles during coating. There is a problem that the polyethylene sheet is easily deformed when the polyethylene sheet is crimped.

Furthermore, as a resin powder coating method, a method of coating the entire surface of a steel pipe by a fluidized dipping method is disclosed in, for example, Japanese Patent Application Laid-open No. 59-42069, and a method of coating only the outer surface of a steel pipe is described in, for example, Japanese Patent Application Laid-Open No. 58-202073. For example, a method of coating one side of steel sheet piles on the other side is disclosed in JP-A-60-23.
Although it is disclosed in Japanese Patent No. 0848, there is a problem that the polyolefin is deformed when the polyolefin is pressed.

<Object of the Invention> The present invention has been made in view of the above circumstances, and provides a resin powder fusion-coated steel for solving the above-mentioned problems and efficiently and uniformly coating one side of a steel sheet pile with an organic resin. The object of the present invention is to provide a method and device for manufacturing sheet piles.

<Structure of the Invention> According to the present invention, when a steel sheet pile is derusted and preheated, and then resin powder fusion is performed to produce a resin powder liquid)'it steel sheet pile, The resin powder is supplied at a rate of 4 iL/distance from a supply means that moves at a distance, followed by 1 iL/distance in the longitudinal direction.
1. Provided is a method for producing a resin powder-coated steel sheet pile, characterized in that resin powder fusion is performed by spinning all the resin powder from a collection means that moves relatively in the same direction as the supply means. be done.

Further, according to the present invention, there is provided an apparatus for manufacturing resin powder-coated steel sheet piles by derusting and preheating steel sheet piles, and then performing resin powder fusion bonding, the apparatus having an opening along a concave or convex surface of the steel sheet piles. a powder supply means and a powder recovery means arranged at a predetermined interval in the longitudinal direction of the steel sheet pile; and a powder supply means and a powder recovery means disposed between the powder supply means and the powder recovery means to circulate the powder. A resin powder characterized by having a powder circulation means for moving the powder supply means, a powder recovery means, and a powder circulation means for moving the powder supply means, the powder recovery means, and the powder circulation means relative to the steel sheet pile. An apparatus for manufacturing a fusion-coated steel sheet pile is provided.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the steel sheet pile 1 has rising parts on both sides, and the ends of the rising parts each have claw parts 1a.
, lb.

First, either the concave surface (Fig. 1) or the convex surface, which is the surface to be fused to the powder of the steel sheet pile 1, is subjected to pretreatment such as shot blasting, sandblasting, or pickling to remove mill scale, rust, etc. preferably chromic acid compound 2 and/or
Alternatively, a brimer 3 made of acrylic resin, urethane resin, epoxy resin, etc. is applied.

This steel sheet pile 1 is connected to an induction heater (not shown),
This heated steel sheet pile is heated (preheated) to 200℃ or higher in an electric furnace, gas furnace, etc. On top of the steel sheet pile 1, resin powder 17 (FIG. 2) is fused while moving the resin powder spraying device 10 relative to the steel sheet pile 1 at a constant speed, as will be described later. The reason why the preheating temperature is set to 200° C. or higher is preferably at this level from the viewpoint of line productivity, and the heating temperature may be selected depending on the type of resin powder 17 used.

The resin powder dispersing device 1O has a powder supply device 11 and a powder supply port 12 as powder supply means, and a powder recovery device 13 and a powder recovery port 14 as powder recovery means, which are powder circulation means. The powder supply device 11 and the powder recovery device 13 are preferably connected by a powder transport pipe 16, and a powder sieve device 15 is disposed in the transport pipe 16 between the powder supply device 11 and the powder recovery device 13.

The powder supply port 12 and the powder recovery port 14 are arranged at the front end and the rear end of the powder transport pipe 16, respectively, and are separated by an interval z.
(m).

Here, the resin powder spraying device 10 and the resin powder fusion coating will be described separately for cases in which the surface of the steel sheet pile 1 to be fused is a convex surface and a concave surface.

When the surface of the steel sheet pile l to be fused is a convex surface, as shown in FIG. 12a-1
2e are branched, and the tips of each of these vibrators 12a to 12e are opened in a horizontal direction on the convex surface of the steel sheet pile 1 to form a powder supply port 12. Each powder supply port 12 is
It is slightly spaced upward from the convex surface of the steel sheet pile.

This powder supply port! A powder recovery port 14 having the same shape as the powder transport pipe 16 is connected to the powder transport pipe 16 at a predetermined distance z (m) from the convex surface and slightly spaced apart from the convex surface.

A formwork 7.8 having an angular cross-section is attached to the outer wall of the rising portion of the steel sheet pile 1 in contact with the claw portions 1a and 1b using adhesive tape or the like, for example. This formwork 7.8 is for preventing the resin powder 17 from spilling downward when the resin powder 17 is supplied by the resin powder spraying device 10.

In order to fuse the organic resin powder 17 onto the convex surface of the steel sheet pile 1 using the resin powder spraying device 10 having the powder supply port 12 and the powder recovery port 14 having such a shape, the steps shown in FIGS. 2 and 3a are as follows. As shown in the figure, the resin powder spreading device 10 is positioned above one end in the length direction of the heated steel sheet pile 1, and the resin powder spreading device IO is moved toward the other end of the steel sheet pile 1 using an appropriate driving means (not shown). 2) at a moving speed of x m1 minute. The resin powder spreading device 10 may be stationary without being moved, and the steel sheet pile 1 may be placed on a rail (not shown), for example, and moved at X (m/min).The essence is the resin powder spreading device! 0 and steel sheet pile 1
What is necessary is just to configure it so that it can be moved relatively at a moving speed of X (m/min).

While relatively moving the steel sheet pile 1 and the powder spreading device lO in this way, the unused resin powder 17 supplied to the powder supply device 11 from the supply path (not shown) is transferred via the powder transport pipe 16. The powder is supplied by compressed air [112] and sprayed onto the steel sheet pile 1.

z / A resin powder fused coating 18 is continuously formed on the sheet pile l.

The resin powder 17 sucked and collected from the powder collection port 14 is
The powder is sent from the powder recovery device 13 to the powder sieving device 15 via the powder transport pipe 16, sieved, and further sent to the powder supply device 11.

Here, depending on the case, only the unused resin powder 17 supplied from the above-mentioned supply path is mixed, or only the recovered resin powder 17 is passed through the powder transport pipe 16 to the powder supply port 1.
2 onto the steel sheet pile 1. The supply of unused resin powder 17 may be carried out in response to generation of particles exceeding a preset particle size, thermal deterioration, etc.

Thereby, the resin powder 17 can be circulated to efficiently form the resin powder fused coating 18 on the steel sheet pile 1.
(See Figure 3b).

Thereafter, it is cooled to about 40° C. by air cooling, water cooling, or the like.

As shown in FIG. 3a, the powder supply port 12 is widened parallel to the convex surface of the steel sheet pile 1 to prevent uneven coating, and the formworks 7 and 8 prevent the resin powder 17 from scattering. can be prevented.

When the surface of the steel sheet pile l to be powdered is concave, as shown in FIG. 12h N
12n is branched, and each tip of each of these vibrators 12h to 12n is expanded in parallel to the concave surface of the steel sheet pile 1 to form a powder supply port 12. A powder recovery port 14 having the same shape as the powder supply port 12 is connected to a powder transport pipe 16 at a predetermined distance z (m).

Then, the claw parts 1a and 1b at the tip of the rising part of the steel sheet pile 1
It is possible to attach a formwork 7.8 with a cross-sectional shape to the outer wall of the steel sheet pile l, and form a resin powder fusion coating 18 on the four sides of the steel sheet pile l in exactly the same manner as in the case of the convex surface described above (see Fig. 4b). ).

In addition, whether the convex surface or the concave surface of the steel sheet pile l is used as the surface to which the resin powder is fused, the resin powder 17 sprayed and applied from the powder supply [112] is applied to the film thickness of the fusion coating 18 that is finally formed. No. 3
It is preferable to form the fusion coating 18 with good thermal efficiency by making the thickness 5 times or more.

In addition, in preliminary experiments etc., the resin powder fusion coating 18
If the contact time of the resin powder 17 with the steel sheet pile l, for which the steel material surface temperature, cooling temperature, etc. are set respectively, is y minutes in order to obtain a predetermined film thickness, then from the relationship z=xy, the relative movement speed x The distances Z and y between the powder supply port 12 and the powder recovery loe 4 may be changed as appropriate depending on the m7 minutes.

Next, the resin powder used in the present invention will be described.

Examples of resin powder include polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-acrylonitrile copolymer, polypropylene, polyvinyl chloride, polybutyne, polyester, polyamide, polyether ether ketone, polyether. Salkhon, P.
Examples include fluorine-containing resin powder such as TFE.

In the case of polyolefin-based organic resin powders, these organic resin powders are coated with a single layer of polyolefin modified with maleic anhydride, acrylic acid, etc., or coated with unmodified polyolefin powder on top of these layers. It may also be layered.

It is preferable to use an ultraviolet deterioration prevention agent, a heat deterioration prevention agent, carbon black, or a color pigment in the organic resin powder mentioned above, and the thickness of the anticorrosion coating including the adhesive to be 0.5 am or more. . This is because if the thickness is less than 0.5 mm, there is a risk that pinholes will occur in the coating.

Further, the particle size of the organic resin powder is preferably in the range of 50 to 800 μl, preferably 100 to 450 μm. If the particle size is too small, there will be a lot of scattering when compressed air is supplied to the steel sheet pile surface, reducing coating efficiency and increasing costs.
If the particle size is too large, the coating efficiency will be improved, but the melting of the powder will tend to be insufficient, and as a result, the surface of the coating will tend to be difficult to obtain.

<Example> Next, the present invention will be explained in more detail based on examples.

In addition, as shown in FIG. 5, on the uneven surface of the steel sheet pile used in the first to fourth embodiments described below, the concave surface has a
On the convex surface, measurement points of 0 to m were provided, and the relationship between the IIQ thickness of the resin powder fusion coating, the type of resin powder, and the portions outside the uneven surface was investigated.

[Example 1] M-type steel sheet pile with a length of 5 m (dimensions 400”Xl 30hX
l:1. After grid blasting the concave surface of the steel sheet pile and applying a chromate treatment agent (chromic acid compound), the steel sheet pile was heated to 100°C, and an epoxy primer was applied by airless spray painting to a thickness of approximately 30 μm. was heated to 260°C.

After that, formwork to prevent powder from spilling is attached to the steel sheet pile, and the steel sheet pile is moved at a conveyance speed of 1 m/min using conveyor rollers, and the interval between the powder supply port and the powder collection [1] is set in advance to 2 m. Adhesive polyethylene powder (M! = 3.0, density = 0.925, melting point 121°C, softening point 98°C, particle size 100-350 μm) was
Spray it on and then collect it by suction. The contact time of the spray-applied resin powder on the steel sheet pile is 2 minutes.

After that, the powder of the steel sheet pile is completely fused to the surface using the heat retained in the steel sheet pile, and the powder is air-cooled and then water-cooled to an average of 11QJ''.
A concave polyethylene-coated steel sheet pile with a diameter of 5 mm was obtained.

When the film thickness of this concave polyethylene coating was measured using an electromagnetic film thickness meter at each site a to 0 shown in FIG. 5, the results shown in FIG. 6 were obtained.

[Example 21] Under exactly the same conditions as in Example 1, a polyethylene coating was applied to the convex surface of a steel sheet pile.

When the thickness of this convex polyethylene coating was measured for each region c''-m shown in FIG. 5 in the same manner as in the first embodiment, the results shown in FIG. 6 were obtained.

[Example 3] ■-shaped steel sheet pile with a length of 5 m (dimensions 400' x 130 x
13. After grid blasting the concave surface of the OLmm) and applying acrylic brusher to a thickness of about 30 μm, the steel sheet pile was
Preheated to 80°C.

After that, formwork to prevent powder spillage was attached to the steel sheet pile, and the steel sheet pile was moved at a conveyance speed of 11 n/min using conveyor rollers, and the interval between the powder supply port and the powder recovery port was set to 1.5 nm.
Polyvinyl chloride resin powder (particle size: 50 to 150 μm) is sprayed and applied using a resin powder spraying device set in advance at m, and then collected by suction.

The contact time of the jet-applied resin powder on the steel sheet pile is 1.5 minutes.

After that, the powder on the steel sheet pile was completely fused to the surface using the heat retained by the steel sheet pile, and then air-cooled and then water-cooled to an average film thickness of 2.5 mm.
A thick concave PVC coated steel sheet pile was obtained.

When the film thickness of this concave polyvinyl chloride coating was measured using an electromagnetic film thickness meter at each site a to 0 shown in FIG. 5, the results shown in FIG. 7 were obtained.

[Example 4] Under exactly the same conditions as in Example 3, a polyvinyl chloride coating was applied to the concave surface of a steel sheet pile.

The film thickness of this concave polyvinyl chloride coating was measured at each site c''-m shown in FIG. 5 using the same method as in Example 3, and the results shown in FIG. 7 were obtained.

<Effects of the Invention> As described in detail above, according to the present invention, the resin powder fusion coating is applied almost uniformly to both the concave and convex surfaces of the steel sheet pile. Further, since resin powder fusion coating can be performed efficiently and with high precision even on an actual production line, there are advantages in terms of production, such as simplification of the manufacturing process and cost reduction.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a diagram showing the coating configuration of a resin powder fusion-coated steel sheet pile. Figure 2 is an explanatory diagram showing a method of applying resin powder fusion coating to steel sheet piles using a resin powder spraying device. Figure 3a is an end view showing the relationship between the powder supply port and the steel sheet pile when applying resin powder fusion coating to the convex surface of the steel sheet pile, and Figure 3b is the resulting resin powder fused steel sheet pile. FIG. Fig. 4a is an end view showing the relationship between the powder supply port and the steel sheet pile when coating the concave surface of the steel sheet pile with resin powder, and Fig. 4b shows the resulting resin powder-fused steel sheet pile. FIG. FIG. 5 is an explanatory view showing the resin powder fusion coating J-so measurement portion of the steel sheet pile according to the present invention. FIG. 6 shows the concave surface of the polyethylene-coated steel sheet pile according to the present invention;
IN of each part on the convex surface! It is a figure showing Q thickness distribution. FIG. 7 is a diagram showing the film thickness distribution at each location on the concave and convex surfaces of the polyvinyl chloride-coated steel sheet pile according to the present invention. Explanation of symbols 1...Steel sheet pile, 2...Chromic acid compound, 3
...Brymer, 7.8-...Formwork, 10...
Resin powder spreading device, 11... powder supply device (powder supply means), 12...
Powder supply 1'' (powder supply means), 13-... powder recovery device (powder recovery means), 14-... powder recovery port (powder recovery means), 15... powder sieving device , 16--Powder transport pipe (powder circulation means), 17--Resin powder, 18--Resin powder fusion coating patent applicant
Kawasaki Steel Co., Ltd. 11. ;. ,'C! jj', pierced FIG, 1 FIG, 2 FIG, 3a FIG, 3bb FIG, 4a FIo, 4bFIG
, 5

Claims (2)

[Claims] (1) When manufacturing resin powder-coated steel sheet piles by derusting and preheating steel sheet piles, resin powder is fused from a supply means that moves relative to the steel sheet piles in the longitudinal direction. The resin powder is supplied and scattered, and the remaining resin powder is subsequently collected from a collection means that moves longitudinally in the same direction as the supply means, thereby performing resin powder fusion. A method for producing body-clad steel sheet piles. (2) A device for manufacturing resin powder-coated steel sheet piles by derusting and preheating steel sheet piles and then performing resin powder fusion, which has an opening along the concave or convex surface of the steel sheet piles, and A powder supply means and a powder collection means arranged at a predetermined interval in the longitudinal direction of the sheet pile, and a powder supply means arranged between the powder supply means and the powder collection means for circulating the powder. A resin powder fusion-coated steel comprising: a body circulation means; and a drive means that makes these powder supply means, powder recovery means, and powder circulation means movable relative to the steel sheet pile. Sheet pile manufacturing equipment.