JPS60208220A - Preparation of corrosion-proof coated steel sheet pile - Google Patents

Abstract

PURPOSE:To prepare a corrosion-proof coated steel sheet pile, by allowing a tubular body under a molten state to deform toward the outer peripheral surface of a two-ply steel sheet pile to bring the same into contact with the outer surface of said sheet pile. CONSTITUTION:A two-ply steel sheet pile 11 is supplied to a coating apparatus, to which steel sheet pile support and supply apparatuses are provided in subsidiary relationship, while the supply direction of the steel sheet pile is adjusted by said support and supply apparatuses and allowed to move through the internal space of the extrusion molding die 3 of said coating apparatus from the rear of said die 3 toward the ring shaped emitting orifice 1 thereof. A tubular plastic resin body 6 is continuously extruded to the periphery of the moving and advancing two-ply steel sheet pile 11 piercing through the die 3 and issueing from the inside of the emitting orifice 1 thereof in a molten or softened state and, at the same time, the inside 9 of the tubular body 6 and the internal space 2 of the die 3 are sufficiently reduced in pressure and the tubular plastic resin body 6 under a molten or softened state is deformed toward the outer peripheral surface of the two-ply steel sheet pile 11 and brought into close contact therewith to continuously apply the corrosion-proof coating of the plastic resin coating layer to the outer surface of the two-ply steel sheet pile.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Applications!r) This invention uses a specific extrusion coating device, and the coating device is fed into the coating device and passed through the interior space of the die. A tubular body of molten plastic resin is continuously extruded around the two-ply steel sheet pile coming out from the inside of the annular discharge opening of the extrusion molding die, and the inside of the tubular body and the above-mentioned internal space are By sufficiently reducing the pressure, the molten tubular body is deformed toward the outer surface around the two-ply steel sheet pile, and then brought into close contact with the outer surface around the steel sheet pile, and one side of each steel sheet pile is made of plastic. The two sheets of steel sheet piles are coated with a continuous anti-corrosion coating layer made of steel sheet piles, and the coating layer that integrally covers the two-ply steel sheet pile is cut in the longitudinal direction or a part is removed in the form of a band, and each anti-corrosion coating layer (zz
This relates to a method of manufacturing anti-corrosion coated steel sheet piles by dividing and separating them into steel sheet piles.

(Prior Art) Conventionally, steel sheet piles have been used for civil engineering and construction purposes, but sufficient measures have not always been taken to prevent corrosion.

In general, various types of steel sheet piles for civil engineering and construction are used for the purpose of protecting rivers, coasts, ports, etc. by lining up a large number of steel sheet piles in succession and driving them into the ground to form protective fences, or for construction, dredging, etc. It has been used to secure the ground at work sites and prevent mud from flowing into the work site and from collapsing.

These steel sheet piles are exposed to water such as river water, wastewater, rainwater, seawater, the atmosphere, and sunlight in the outdoor natural environment.
In addition, since it comes into direct and strong contact with earth, sand, mud, and debris during pouring or after sinking, corrosion is extremely likely to occur, especially in environments where running water, waves, etc., popularity, and sunlight interact repeatedly. For example, the above-mentioned corrosion occurs violently near the water surface of ports, estuaries, lakes, etc., but until now, no effective corrosion prevention measures have been taken.

A port? In areas such as rivers and lakes, the steel sheet piles mentioned above are placed in a continuous row to form a shelf to create a seawall, but one side of the shelf is covered with waves, quicksand, and drifting objects (driftwood, drift ice, etc.). etc.), wind and snow are often hitting the area particularly violently.
Corrosion was particularly severe near the water surface of the steel sheet piles. Therefore, even if conventional steel sheet piles are made of 6121+A, which has high corrosion resistance, they are susceptible to corrosion in the natural environment described above, and their durability is limited by the corrosion described above. In many cases, it became impossible to use it for a long period of time (for example, about 20 years or more).

Conventionally, in order to prevent corrosion of steel sheet piles, 5I+<113.
Painting with non-stick paints or tar/epoxy resin paints, and FRP-ruptured layers with epoxy resins or unsaturated polyester resins have been used, but these methods lack mechanical strength, long-term durability, and economic efficiency (particularly their effectiveness). It was not an effective corrosion prevention method in terms of workability during coating.

(Purpose of the Invention) The inventors have studied a method for manufacturing anti-corrosion coated steel sheet piles that can economically and industrially continuously produce steel sheet piles coated with a highly durable anti-corrosion coating. , is fed through a particular extrusion coating device and emerges from the inside of the extrusion die of that coating device from the inside of the double sheet pile J. By continuously extruding a resin tubular body and sufficiently reducing the pressure in both the inside of the tubular body and the inner space of the die of the coating device, the molten tubular body is applied to the outer surface around the two-ply steel sheet pile. It was discovered that an anti-corrosion coated steel sheet pile could be manufactured by making the curved ζ deformation -U closely adhered to the outer surface thereof, and the method for manufacturing the anti-corrosion coated steel sheet pile of the present invention was completed.

(Structure of the Invention) It has an annular discharge port that can extrude plastic resin into a tubular shape, and can freely move in the longitudinal direction when two long steel sheet piles to be coated are overlapped and opened. An extrusion molding die having a space penetrating the inside of the discharge port from the rear is provided, and the extrusion coating is provided with a sufficient inner space through which the inner space can be sufficiently evacuated. Using the extrusion coating device, the extrusion coating device supplies two long steel sheet piles in a stacked state using a supporting device and a feeding device for the diagonal steel sheet piles attached to the extrusion coating device, and extrudes the extrusion coating device. A moving two-ply steel arrow (k) is moved from the rear of the forming die toward the outlet of the die in the orientation space 11:j, and passes through the die and emerges from the inside of the annular outlet. A tubular body of plastics 1b1 (fat) is continuously extruded from the discharge port of the die, and at the same time, the pressure inside the tubular body and the internal space is sufficiently reduced to melt the plastics 11 (fat) in a molten state. The tubular body is deformed toward the outer surface of the entire circumference of the two-ply steel sheet piles, and brought into close contact with each other, and one side of each steel sheet pile is continuously coated with a plastic resin coating layer to prevent corrosion.Finally, the two-ply steel sheet piles are separated. The method is characterized in that two places on both sides of the coating layer that integrally covers the steel sheet pile are cut along the longitudinal direction of the steel sheet pile or a part thereof is removed in a band shape, and the anticorrosion coating is separated into one steel sheet pile. This article relates to a method for manufacturing anti-corrosion coated steel sheet piles.

The manufacturing method of the present invention uses an extrusion coating method to form an anti-corrosion coating layer made of plastic resin with excellent performance on the entire surface (including concave and convex surfaces) of one side of each of various two-ply steel sheet piles. This is a completely new method for producing anti-corrosion coated steel sheet piles, which has extremely high productivity and can continuously and stably produce two such excellent anti-corrosion coated steel sheet piles at a time.

The anti-corrosion coated steel sheet pile manufactured by the manufacturing method of this invention has stable and excellent mechanical strength, durability, anti-corrosion properties, etc., and has a plastic layer with a uniform thickness and smooth surface condition. Excellent anti-corrosion coating formed from 4
11, and is an excellent anti-corrosion coated steel sheet pile that exhibits corrosion protection that is effective for an extremely long period of time.

(Embodiments and Effects of the Invention) Hereinafter, the method for producing an anti-corrosion coated steel sheet pile of the present invention will be described in more detail based on embodiment examples shown in the drawings.

Figure 1 shows 1 of this invention! ! ! FIG. 2 is a cross-sectional view schematically showing a vertical cross section of the area around the extrusion molding die of an example of the coating apparatus used in the manufacturing method of the present invention; FIG. FIG. 2 is a schematic front view.

FIG. 3 is a sectional view showing the two-ply steel sheet pile coated with resin from the extrusion coating device in the manufacturing method of the present invention, and FIG. It is a sectional view showing a state in which two parts of the steel sheet pile are cut and removed and separated into respective corrosion-resistant coated steel sheet piles.

FIG. 5 is a perspective view showing an example of a general state in which a large number of steel sheet piles are lined up and driven into the ground to form a protective shelf.
The figure is a perspective view showing an example of a steel sheet pile used in the present invention.

As shown in FIGS. 1 and 2, the extrusion coating device used in the manufacturing method of the present invention includes a crosshead die 3 having an annular discharge port 1 capable of extruding tal plastics resin into a tubular shape. (b) There is an internal space 2 of sufficient width through which the two-ply steel sheet pile 11 to be coated can freely pass through from the rear of the die 3 to the inside of the discharge port l. An extrusion molding die 3 is provided (C1) and a suction path for suctioning gas in the internal space with a vacuum pump (not shown) so that the internal space 2 of the die 3 can be sufficiently reduced in pressure. Preferably, it is an extrusion coating device provided with a 4°4'.

In the extrusion coating apparatus, for example, an auxiliary equipment for supplying the two-ply steel sheet pile 1 which is inserted toward the internal space of the extrusion molding die 3 of the extrusion coating apparatus and maintaining its traveling direction and position is provided. As shown in FIG. 1, a support shaft 5 for supporting the steel sheet piles and determining the direction of movement of the steel sheet piles is integrally installed at the rear of the die, and further covers two piles of steel sheet piles. Numerous supply ports to feed the equipment (not shown in the drawings, but
at least one of which is connected to the drive)
It is preferable that it be provided as an accessory.

The support member 5 is fitted into the rear part of the die 3, and is attached to the rear part of the hollow opening 2 of the die 3 to an extent that does not hinder the movement (penetration) of the two-ply steel sheet pile. The inner space 2 of the die 3 is closed so as to appropriately seal the inner space.
This is suitable for sufficiently reducing the pressure.

The annular discharge port 1 opens an internal space L1 having an inner circumference larger than the outer circumference of the two-ply steel sheet pile so that the two-ply steel sheet pile can pass through with a margin.
If possible, the shape of the annular discharge port is not particularly limited, and in addition to the annular shape shown in Fig. A rectangular annular, pentagonal, hexagonal, or hexagonal annular outlet, or a similar shape corresponding to the outer circumferential shape of the two-ply steel sheet pile to be covered, and the outer circumferential shape of the two-ply steel sheet pile to be coated. It may be an annular discharge that can open an internal space with a large inner circumference L1.

The die of the extrusion coating apparatus described above may be of the type, provided it has the above-mentioned requirements, for example:
As shown in Fig. 1, two stacked ( )-shaped steel sheet piles 11
An internal space 2, which is larger than the outer circumferential shape of the cross-section of the die, is opened inside the die and allows the steel sheet piles to pass through the sheet pile fairly freely in the longitudinal direction, and an elliptical Mayubold lO is located at the rear of the die. An annular discharge port 1 that can extrude plastic and plastic resin into a tubular shape and a manifold IO are connected by a resin path 13, and an extruder (shown -Q) is connected to the Mayu hole (stream 0). It is sufficient that the resin supply path 8 from the resin is connected thereto.

It is preferable that a plurality of supply passages for the above-mentioned plastics) 4 are provided corresponding to the outer peripheral shape of the two-ply steel sheet piles, and in particular, if necessary, the supply passages are provided at the joints at both ends of the steel sheet piles. The part G corresponding to the part with a rough shape like
A separate resin supply path may be connected.

In the manufacturing method of the present invention, the extruder attached to the extrusion device may be any conventionally known extruder, and a plurality of extruders may be provided for each supply 1188.8 of the above-mentioned plastics resin. Alternatively, a plurality of supply paths for the plastics resin may be branched from the extruder on the stand and connected to the Mayupole.

In the manufacturing method of the present invention, the extrusion coating device described in Section 1.1. However, two-ply steel sheet piles 11
into the coating apparatus and the extrusion die 3
from the rear of the die 3 toward the annular discharge port 1 of the die 3. Around the steel sheet pile 11,
A tubular body 6 of plastic resin in a molten or softened state is continuously extruded, and at the same time, the pressure inside the tubular body 6 and the inner space 2 of the tie 3 in I is sufficiently reduced to extrude the plastic resin in a molten or softened state. The plastic resin tubular body 6 is deformed toward the outer circumferential surface of the two-ply steel sheet pile 11 and brought into close contact, so that the outer surface around the two-ply steel sheet pile is continuously protected against corrosion with a plastic resin coating layer. It is covered.

In the manufacturing method of the present invention, a tubular body 6 of plastic resin is inserted into the inside of the die 3 and out of its discharge port 1 (around the moving and progressing two-ply steel sheet pile 11 coming out from the separate opening). At the same time, the inside 9 of the tubular body 6 and the internal space 2 of the die 3 are sufficiently depressurized to extrude the molten plastic resin tubular body 6 around the two-ply steel sheet pile 11. Deformed towards the outer surface,
It is important that the pressure is reduced to a density of 21, and the degree of pressure reduction depends on the type of plastic resin used, its basic physical properties, the outer circumferential shape of the two-ply steel sheet pile to be coated,
For example, the polyolefin type mentioned below (when using H fat, about 0.9 months or more), especially 0.5 to 0.85
Appropriately, the pressure is about atmospheric pressure, more preferably about 0.6 to 0.8 atmospheric pressure. If the pressure at the time of decompression becomes too close to atmospheric pressure (rich pressure x 1 atm), the molten tubular body of plastic or M resin will deform toward the outer surface around the two-ply steel sheet pile. This is undesirable because it may not adhere tightly, and if the pressure at the time of decompression becomes too low, the molten plastic (-11) tubular body may not adhere tightly to the outer surface of the double-layered steel sheet pile. This is not preferable because it may cause significant thickness deviation or tearing during deformation.

In the manufacturing method of this invention, the annular discharge port l of the die 3
The ratio of the thickness (B) of the resin coating layer when it is in close contact with the outer surface around the two-ply steel sheet pile to the thickness (A) of the plastic resin tubular body immediately after extrusion from the plastics resin (B/A) value (also referred to as withdrawal ratio) is approximately 0.1 to 0.
8, particularly about 0.2 to 0.7.

If the draw-down ratio is too close to 1, the molten plastic resin tubular body will form convex wrinkles along the long direction of the steel sheet pile, and the wrinkles will appear on the surface of the steel sheet pile. Fragmented 1iHN with a flat surface that is adhered as it is
If the draw-down ratio is too small, the thickness of the tubular body may be significantly uneven or it may be torn, which is not preferable. In addition, in the manufacturing method of the present invention, it is most preferable to adjust the drawdown ratio by appropriately adjusting the discharge speed of the resin and the moving speed of the two-ply steel arrow.

In the present invention, it is preferable that the distance between the glue knobs at the portions corresponding to the recesses on the outer circumferential surface of the steel bar of the extrusion molding machine of the coating device is made considerably larger than the distances between the glue knobs at the points corresponding to the other convex portions.

The steel arrows used in the manufacturing method of this invention are generally used for civil engineering and construction purposes, such as arranging a large number of them and driving them into the ground to form a protective shelf, as shown in Figure 5. It can be of any length and shape, for example:
Any type of steel sheet pile may have a variety of cross-sectional shapes, such as IJ type, L type, U type, Z type, and air. A joint that has a main body with a mouth-shaped cross-sectional structure, and the rising parts (sometimes called flanges) on both sides are bent outward to form a groove with a small inner diameter. For example, the long phase silver structure Ifi+4 that each has.

In the manufacturing method of the present invention, steel sheet piles can be used regardless of their size and shape without replacing the die of the extrusion coating device. That is, in the manufacturing method of the present invention, in particular, if the extrusion molding die of the coating apparatus described above has a circular annular outlet or an elliptical annular outlet, a considerable amount of heat can be produced using one type of die. It has the feature that it can be used in accordance with the shape and size of steel arrows.

In the manufacturing method of this invention, the two-ply steel sheet piles may be stacked in any way, but in order to easily supply them stably to the extrusion coating equipment and to provide corrosion-resistant coating with good reproducibility, it is necessary to As shown in Fig. 3, it is most suitable that the convex portions of one sheet pile are overlapped with the convex portions of the other sheet piles, fitting into the concave portions of one sheet pile.

In this invention, when the steel sheet pile is used for coating, it is preferable that a suitable adhesive layer be provided on the outer surface of the steel sheet pile to be coated.

The adhesive layer provided on the surface of the steel sheet pile has, for example, an adhesion temperature within the range of about 50 to 200'C, and the plastic resin layer is applied to the surface of the steel sheet pile with an appropriate adhesive force. The adhesive that can be heat-bonded may be made of any kind of adhesive, for example, it may be made of an olefin-based (co)polymer as a main component, or it may be made of an adhesive with the above-mentioned (co)polymer. A heat-fusible adhesive (Ho7) whose main component is
+ Nord type adhesive, etc.) or heat-curing IJ
It is an adhesive such as F, which maintains appropriate elasticity or flexibility after adhesion, but becomes too hard.

It is an adhesive that does not stick to the silver surface after coating the surface of the steel sheet with a plastic resin layer.
0 degree peeling, tensile speed 10 m1/min, 20°C) is approximately 2k
It is preferable that the adhesive is made of an adhesive having an adhesive strength of 4 to 20 kg/cm or more, particularly about 4 to 20 kg/cm.

Examples of adhesives used in such adhesives include polycoolene, polyglopylene,
Polyvinyl chloride, Ni-Y-Ren I'i1 acidic acid copolymer, Ni-Y-Ren propylene copolymer, 21-tyrene/lower alkyl (meth)acrylate-IJ (small polymer, ethylene (meth)acrylic acid copolymers, etc., as well as modified polymers thereof (e.g., maleated polyethylene,
maleated polypropylene, etc.)
They may be used alone or as a mixture of two or more.

The tackifier (2) can be arbitrarily selected from the tackifiers (=J agents) commonly used in known adhesive compositions; Examples include rosin and rosin derivatives, pinene resins, coumaron resins, coumaron-indene resins, other aliphatic or alicyclic hydrocarbon resins, and aromatic hydrocarbon resins.

In addition to the above-mentioned components, the adhesive layer also contains inorganic fillers such as talc, charcoal, silica, alumina, mica, carhonfra, and lina, or antioxidants, colorants,
Additives such as softeners; furthermore, as corrosion inhibitors, inorganic corrosion inhibitors such as metal chromates, metal phosphates, metal 4■i phosphates, and gold salts of rIi'I acid; Organic corrosion inhibitors such as metal salts of aromatic carboxylic acids, aliphatic or aromatic compounds having a plurality of hydroxyl groups, and tannic acid may be added.

Plastic resins used in this invention include, for example, polyethylene, polypropylene, copolymers of ethylene and propylene, olefin polymers such as ethylene/vinyl acetate copolymers, polyvinyl chloride, polyester, polyimide, etc. of plastics resins, especially melt viscosity (high viscosity).

Using an arbiscometer, at a measurement temperature of 230°C and a shear rate of 1 sec, the constant value of 4'l) was 10~108
1511 constant temperature 230' using melt tension (melt run noyon meter; inlet angle 60 degrees)
Preferred are the plastic resins described in r'+:i, in which the C1 extrusion rate (measured at an extrusion rate of 10/min) is from 0.5 to 30 g, particularly from 1.0 to 25 g.

The plastic resin used to form the aforementioned 'ItIFd lit may contain other polymers, known additives, antioxidants, flt retardants, various colorants, fillers (charcoal, glue, carbon black, etc.). ), etc. may be blended.

The plastic coating layer has a tensile strength of 50 to 30Q kg/ after being coated on the surface of the steel sheet pile.
cot, and has a vertical resistance i measured with A37MG14.
'J property (per thickness lea) 10-200kg-CI
Since it is preferable to constitute the outermost Fif (protective layer) of the anti-corrosion coating layer, it is preferable to use a plastic made of the above-mentioned plastic resin and various other compounding agents to form the coating layer with such performance. It is desirable that the coating be formed by an extrusion coating method using a resin composition, particularly a polyolefin resin composition, under appropriately selected molding conditions.

In this invention, the temperature of the annularly extruded plastic resin from the outlet of the die of the extrusion coating device ranges from the melting point of those plastic resins to C plus 150°C. The temperature within the range is sufficient.

In this invention, if the plastic resin has a too low melt viscosity or melt tension, the plastic resin tubular body extruded from the extrusion coating device will be abnormally deformed due to the reduced pressure in the internal space of the die. This is undesirable because it becomes difficult to form a uniform coating on the outer surface of the two-ply steel sheet pile, and if the melt viscosity or melt tension is too high, the The tubular body of plastic resin may become like a cell, or it may not deform sufficiently due to the reduced pressure in the internal space and may not adhere tightly to the surface of the recess of the steel sheet pile.
Or, in that case, if the above-mentioned reduction is performed forcibly, the tubular body may be torn and cracked, which is not appropriate.

In the manufacturing method of the present invention, the steel sheet pile to be coated with plastic resin may have an adhesive layer on the surface to be coated, but the contact layer 71' is known to the steel sheet pile in advance. If it is formed by the method and set ζ, it is 1.

In the manufacturing method of this invention, the anticorrosion coating 11tfi of the two-ply steel sheet pile with anticorrosion coating obtained by this invention is as follows:
The overall thickness and the thickness of each layer are not particularly limited, but the thickness of the plastic or plastic resin layer is approximately 0.2 -
5.01, and the thickness of the adhesive layer is about 0.05 to
2.0 as (The ratio of the thickness of the plastic resin layer to the adhesive layer is preferably 1:2 to 100:1, and furthermore, the thickness of the entire coating layer is about 0. .4-6
．． It is preferably about 9 am, particularly about 1°0 to 3.5 am.

Note that the steel sheet pile having the adhesive layer that is continuously supplied for coating in the manufacturing method of the present invention has its surface subjected to some kind of treatment before the adhesive layer is formed on the surface. It may also have improved corrosion resistance. In addition, the plastic resin layer should be removed from the steel sheet pile by shot blasting, sandblasting, pickling, etc. to remove mill scale, red rust, scratches, etc. before coating with adhesive. This is preferable because it increases the bonding force to the steel sheet pile through the agent layer. In addition, prior to coating the surface of the steel sheet pile with the adhesive layer, the surface of the steel sheet pile is treated with chromic acid, phosphoric acid, etc.
If and/or an epoxy resin primer is applied, the adhesion and corrosion resistance will be even better.

In the manufacturing method of the present invention, as described above, the two-ply steel sheet pile coated by the extrusion coating device has a continuous resin coating layer on the outer surface of the two-ply steel sheet pile as shown in Fig. 3. If necessary, the coated two-ply steel sheet piles are appropriately cooled to around room temperature using a known cooling method, and then finally the two-ply steel sheet piles are Two suitable places on both sides of the coating layer around the steel sheet piles (in the case of Fig. 3, the overlapping parts of the joints on both sides of each steel sheet pile are suitable) are attached to the long flat surface of each steel sheet pile. The coating layer is cut along the direction with various cutting tools, such as a cutter, knife, rotary blade cutting device, hot wire cutting device, laser beam cutting device, etc., and if necessary, parts of the layer to be riboned that are not particularly required are cut. (For example, the outer surface of the joint of steel sheet piles, etc.)
The steel sheet piles are peeled off and removed in a band shape, and divided and separated into one sheet of corrosion-resistant coated steel sheet piles, each having a corrosion-resistant coating layer 12 or 12' as shown in +a+ and fbl in Fig. 4 on the surface of the concave or convex portions of the steel sheet pile. That's what I do.

In addition, when peeling off unnecessary portions of the above-mentioned coating layer, it is preferable to apply a release agent in advance to the peeling portions of the two-ply steel sheet pile to be coated.

The manufacturing method of this invention involves continuously supplying two piles of various steel sheet piles and continuously forming an anti-corrosion coating layer on the outer surface around the steel sheet piles (on one side of each sheet pile). C. A method for producing corrosion-resistant coated steel sheet piles that can continuously produce two types of steel sheet piles having excellent corrosion-resistant coating layers two at a time with high productivity.

The anti-corrosion coated steel sheet pile produced by the manufacturing method of this invention has a plastic resin layer (if necessary, via a heat-adhesive adhesive layer) on the concave and convex surfaces of the steel sheet pile for civil engineering and construction. Since they are joined together to form an anti-corrosion coating layer, they have extremely high impact resistance, weather resistance and durability against natural environments, making steel sheet piles suitable for use in civil engineering and construction. When used on-site, for example, when steel sheet piles are driven into the ground, there is a strong impact when they come into contact with underground stones, gravel, gravel, etc., or river water or sea water,
Furthermore, it can sufficiently resist impact and erosive forces such as those caused by drifting objects, and the plastic resin layer (optimally with an adhesive layer) The surface of the steel sheet pile is in close contact with and protects it, and the surface of the steel sheet pile should not be brought into direct contact with or exposed to water, air, or sunlight for a long period of time (for example, about 20 years). It exhibits a high level of anti-corrosion performance over a period of 30 years.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view schematically showing the longitudinal plane near the extrusion molding tie of an example of the coating device used in the manufacturing method of the present invention, and FIG. FIG. 3 is a front view schematically showing an extrusion molding die (-1 ton) of an example of a coating device. FIG. Fig. 5 is a sectional view showing a state in which the steel sheet piles have been removed and separated into respective corrosion-resistant coated steel sheet piles. Fig. 5 is a perspective view showing an example of a state in which a large number of steel sheet piles are lined up and driven into the ground to form a protective shelf. 6 is a perspective view showing an example of the steel sheet pile used in the present invention. 1: Discharge port of extrusion molding die, 2: Internal space of extrusion molding die, 3: Extrusion molding die, 4: Gas suction path, 5:
Supporting parts of two-ply steel sheet piles 4a, 6: Plastics 1
84 fat tubular body, 7: supply roll of two-ply steel sheet piles,
8: Resin supply path, 9: Inside of resin tubular body, IO = manifold, II: Steel sheet pile, 12: Covering layer, 11 resin path. Patent applicant Shin Nippon Seiseki Co., Ltd. Ube Industries Co., Ltd. Figure 4 (a) Figure 5

Claims (1)

[Claims] It has an annular discharge port that can extrude plastic resin into a tubular shape, and can also freely pass through two long steel sheet piles to be coated in the longitudinal direction in a stacked state. Using an extrusion coating device that is provided with an extrusion molding die in which a sufficient internal space passes through the inside of the discharge port from the rear, and that can sufficiently reduce the pressure in the internal space, the extrusion coating device The steel sheet piles are supplied in a stacked state by a steel sheet pile supporting device and a feeding device attached to the steel sheet pile, and the inside of the sheet pile is supplied from the rear of the extrusion molding die of the extrusion coating device toward the discharge port of the die. around a moving two-ply steel sheet pile that is moved in space and passes through the die and emerges from the inside of its annular discharge port;
A tubular body of plastic resin is continuously extruded from the discharge port of the die, and at the same time, the pressure inside the tubular body and the internal space is sufficiently reduced, and the tubular body of plastic resin in a molten state is extruded into two layers of steel. The steel sheet piles are deformed toward the outer surface around the entire circumference, brought into close contact, and one side of each steel sheet pile is continuously coated with a plastic resin solution for anticorrosion.Finally, the two piles of steel sheet piles are coated together. A method for producing an anti-corrosion coated steel sheet pile, which comprises cutting or removing a portion of the steel sheet pile in a band shape along the longitudinal direction of the steel sheet pile, and separating the steel sheet piles into respective steel sheet piles with anti-corrosion coating layers. .