JP3346308B2 - Manufacturing method of heavy-duty coated steel sheet pile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a heavy-duty corrosion-resistant steel sheet pile having a heavy-duty corrosion-resistant coating formed on the surface of a steel sheet pile by sticking a polyolefin sheet, and more particularly, to a long-term adhesion between the sheet and the steel material. The present invention relates to a method for producing a heavy-duty anticorrosion coated steel sheet pile having excellent resistance.

[0002]

2. Description of the Related Art Steel sheet piles forming quays of oceans, harbors, rivers, etc. are exposed to a severe corrosive environment. Therefore, a sheet made of polyolefin resin such as polyethylene or polypropylene is adhered to the surface of the sheet piles via an adhesive layer. By doing so, so-called heavy-corrosion-coated steel sheet piles that have been subjected to corrosion protection have been increasingly used.

[0003] This heavy duty steel sheet pile is disclosed in
As disclosed in Japanese Patent No. 24717 or Japanese Patent Application Laid-Open No. 60-8058, a base treatment layer consisting of a chemical conversion treatment layer, a primer layer and the like is formed on a steel sheet pile whose base has been adjusted, and then a modified polyolefin or the like is bonded. Through the agent layer,
As a manufacturing method, a method is known in which an anticorrosion polyolefin layer is formed, and a sheet-shaped anticorrosion polyolefin layer is attached to a preheated steel sheet pile to produce the anticorrosion polyolefin layer. In some cases, a sheet in which the modified polyolefin layer and the anticorrosion polyolefin layer are integrated is coated.

[0004]

However, a polyolefin-coated steel sheet pile manufactured by sticking a sheet, when exposed to the marine environment for a long time after casting, particularly in the middle of the sea, has a strong adhesive force between the sheet and the steel material. In the worst case, the coating may be lifted or turned over.

[0005] In recent years, the design life of harbor facilities and the like has also been prolonged, and in view of the current situation in which it is desired to reduce the maintenance costs during that time, the long-term adhesion of the coating of the heavy corrosion-resistant coated steel sheet pile is further improved. This is a very significant issue that can produce enormous economic effects.

[0006] The cause of the decrease in the adhesion strength of the heavy-corrosion-coated steel sheet pile in seawater is caused by the fact that a polyolefin sheet having a larger linear expansion coefficient than a steel material is attached to a high-temperature steel sheet pile.
There is considerable shrinkage stress in polyolefin sheets,
It is conceivable that these shrinkage stresses are relaxed with the passage of time, but are partially present as residual stresses, and act in a direction in which the sheet is peeled off at the curved surface portion or the end portion. In addition, due to long-term exposure to seawater, it is thought that the adhesion layer and the base treatment layer deteriorate due to moisture and oxygen permeating the anticorrosion polyolefin layer of the coating, and that the adhesion between the coating layer and the steel material decreases. Can be

The inventors of the present invention have found that it is effective to make the cooling rate of the surface of the anticorrosive polyolefin layer higher than the cooling rate of the surface on the opposite side of the steel sheet pile, and that water cooling is particularly effective as the cooling means. It was found to be effective, and these contents were applied for a patent (Japanese Patent Application No. 9-866).
13, Japanese Patent Application No. 9-351491).

Meanwhile, it is preferable to manufacture heavy-corrosion-coated steel sheet piles by running them while running them in order to increase production efficiency.

However, in this case, the water used for water cooling of the steel sheet pile flows down from the longitudinal end of the steel sheet pile and flows into the pressing portion for pressing the anticorrosion polyolefin layer, so that the water flows between the anticorrosion polyolefin layer and the steel sheet pile. There is a possibility that moisture may be mixed in or the compression temperature may be lowered, and sufficient adhesion may not be obtained.

The present invention has been made in order to solve the above-mentioned problems, and relates to a heavy-duty corrosion-resistant coated steel sheet pile having a polyolefin sheet adhered to the surface of the steel sheet pile, and to provide a long-term adhesion of the coating layer in seawater. It is an object of the present invention to provide a method for producing a heavy duty anticorrosion coated steel sheet pile having excellent resistance.

[0011]

As a result of various studies of the measures, the present inventors have found that the water flow in the longitudinal direction of the steel sheet pile during water cooling is stopped to prevent the steel sheet pile from flowing into the pressing portion. And succeeded in completing the present invention.

That is, the present invention provides a method for cooling a steel sheet pile, which is running while being heated and pressed with an anticorrosive polyolefin layer via a modified polyolefin layer, wherein the cooling is carried out by water cooling from the upper surface of the steel sheet pile. The present invention relates to a method for manufacturing a heavy-duty anticorrosion-coated steel sheet pile, comprising a water stopping means for blocking a water flow flowing in the sheet pile longitudinal direction.

In the above method, the upper surface of the steel sheet pile is concave, and the water collected by the water stop at both ends is sucked, and the upper surface of the steel sheet pile is convex, and the water stop is applied to the web portion and both sides. The method characterized in that it is performed at the edge grip portion, the method characterized by performing water cooling from the surface where the anticorrosive polyolefin layer is pressed, and also cooling from the opposite surface after the modified polyolefin layer is solidified, The present invention relates to a method of performing air cooling, a method of performing water cooling by a water flow flowing down from a slit or a weir, and a method of guiding a water flow flowing down from a slit or a weir by transmitting a guide.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Steel sheet piles used in the present invention are used for revetment of harbors, rivers, landfills, etc.
U-type, Z-type, and I-type prescribed in JIS A 5528, and those having a shape conforming thereto can be used.
There are no particular restrictions on its dimensions. In the present invention,
The heavy duty anticorrosion coating is applied to the parts where anticorrosion needs to be applied. For example, when used for seawall protection in a port, the coating is often applied mainly to the side facing the sea. It goes without saying that the heavy corrosion protection coating can be applied to both sides of the steel sheet pile, in which case the side with the higher cooling rate is the newly provided and heated corrosion protection polyolefin layer side.

The steel sheet pile used in the present invention is previously subjected to a known base adjustment such as degreasing, pickling, shot blasting, grit blasting, and sand blasting to remove oil, scale, and the like on the surface of the steel material. It is desirable. The level of the substrate adjustment is preferably, for example, about Sa2 1/2 or more in the Swedish standard (SIS). If the substrate adjustment is insufficient, the long-term anticorrosion of the heavy duty anticorrosion coating is significantly impaired. Furthermore, long-term adhesion can be achieved by performing a chemical conversion treatment such as a known chromate treatment.
It is preferable from the viewpoint of anticorrosion properties.

Preferably, a primer layer is provided on the surface of the steel sheet pile on which the anticorrosion polyolefin layer is to be applied.
The primer layer is an epoxy resin-based or urethane resin-based organic resin-based primer having excellent adhesion between the surface of the steel sheet pile subjected to substrate adjustment and the modified polyolefin layer. The primer layer is formed by a known coating method such as air spraying, airless spraying, brush coating, or the like, and if necessary, heated after coating to form a complete cured film. The thickness of the primer layer is 10 to 200 μ
m, particularly preferably about 20 to 100 μm. 10μ
If the thickness is less than m, the adhesion of the polyolefin sheet to the steel material is reduced, so there is a problem that the polyolefin sheet is peeled off, and if the thickness exceeds 200 μm, the residual stress of the primer layer itself increases, Adversely affect the long-term adhesion of

The modified polyolefin used in the present invention is obtained by modifying a polyolefin resin such as polyethylene or polypropylene with an unsaturated carboxylic acid such as maleic acid, acrylic acid or methacrylic acid or an anhydride thereof by a graft reaction or the like. It refers to a resin that has significantly improved adhesion to other substances as compared to a simple substance. Modified polyolefins are known to have various thermal properties depending on the type and amount of the functional group to be grafted, but the Vicat softening point of the modified polyolefin used in the present invention is 50 ° C.
The temperature is preferably 120 ° C. or lower and 120 ° C. or lower. If the softening point is less than 50 ° C., it is not preferable because the temperature rise due to sunshine or the like causes a decrease in the adhesiveness of the sheet in the aerial part of the heavy-duty steel sheet pile. Energy cost increases due to
It is not preferable because long-term adhesion decreases due to an increase in thermal stress accompanying an increase in the application temperature. Further, when the temperature exceeds 90 ° C., an increase in the residual stress of the sheet tends to be a problem. Therefore, a more preferable Vicat softening point is 50 to 90 ° C, further preferably 55 to 80 ° C, particularly preferably 55 to 70 ° C.
It is.

Other physical properties of the modified polyolefin include:
The melt index is about 0.2 to 10 g / 10 minutes, preferably about 0.5 to 5 g / 10 minutes, and the density is 0.85 to 0.8.
Those having a melting point of about 98 g / cm ³ and a melting point of about 60 to 135 ° C., preferably about 60 to 100 ° C. are suitable. This modified polyolefin layer functions as an adhesive layer for the anticorrosion polyolefin layer, and the layer thickness is about 0.1 to 1.5 mm, preferably about 0.2 to 1 mm.

The polyolefin resin of the anticorrosion polyolefin layer used in the present invention is a low-density polyethylene,
Known polyolefins such as medium density polyethylene, high density polyethylene, linear low density polyethylene and polypropylene, and known polyolefin copolymers such as ethylene-propylene random or block copolymers.

Particularly preferred are those having a density of 0.940 g.
/ Cm ³ or more, so-called high-density polyethylene. For the purpose of improving environmental stress crack resistance, impact resistance, and toughness, an ethylene copolymer containing a polyolefin-based component such as propylene, butene-1, hexene-1, or the like as a copolymer component can also be used. The upper limit of the density does not matter, but a commercial product is usually 0.1.
About 970 g / cm ³ is the upper limit. Particularly preferred density is about 0.940 to 0.960 g / cm ³ . The melt index is preferably not more than 0.3 g / 10 minutes, and is preferably about 0.1 to 0.3 g / 10 minutes. 0.3g
If the time exceeds / 10 minutes, environmental stress and cracking property are undesirably reduced. The Vicat softening point is 100-130 ° C.
Degree, especially about 110-125 ° C. Preferred softening point difference with the modified polyethylene layer is 10 to 70 ° C.
It is about.

It is preferable to add various additives such as carbon black, coloring pigments and antioxidants to the anticorrosion polyolefin layer in order to improve long-term properties such as weather resistance. The thickness of the anticorrosion polyolefin layer is about 1 to 6 mm, particularly 1 to 4 mm.
The range of about mm is preferable from the viewpoint of long-term adhesion, long-term corrosion resistance, and maintenance of the mechanical strength of the coating layer. By the way, the standard of anti-corrosion polyolefin of heavy corrosion-resistant steel sheet pile is 2.
0 mm or more, and generally the thickness of the anticorrosion polyolefin layer is often 2.0 mm or more.

Next, a method of manufacturing a heavy-corrosion-coated steel sheet pile according to the present invention will be described. The scale is completely removed by blasting, and a chemical conversion treatment such as a chromate treatment is performed. Further, the primer coating is applied by a spray coating method or another method, and cured by standing or heating to form a primer layer.

The steel sheet pile that has been subjected to blasting, chemical conversion treatment, and primer treatment such as primer coating is heated by a heating device such as a heating furnace. The heating temperature needs to be a temperature necessary for fusing the polyolefin sheet, and therefore, is higher than the melting point of the modified polyolefin layer, preferably 10 to 100 from the melting point.
This is a temperature that is as high as about ℃, and is usually in the range of about 80 to 200 ℃.

The heated steel sheet pile is coated with an anticorrosion polyolefin layer via a modified polyolefin layer. As the coating method, a modified polyolefin layer and an anticorrosion polyolefin layer are previously integrated to form a molded polyolefin sheet, and the integrated sheet is supplied onto a steel sheet pile so that the modified polyolefin layer side contacts the steel sheet pile. preferable. However, it is not always necessary to integrate them, and only the modified polyolefin layer may be formed in advance on a steel sheet pile that has been subjected to base treatment, and a sheet made of only the anticorrosive polyolefin layer may be adhered thereon. In this case, the modified polyolefin layer may be formed by melt extrusion coating, powder coating, sheet sticking, or the like. Further, in order to thermally bond the polyolefin sheet, the modified polyolefin layer needs to be at least in a molten state.

Further, the sheet supplied onto the steel sheet pile is adhered by pressing the sheet against the steel sheet pile with a pressing device such as a roll. At that time, the steel sheet pile is running. It is preferable to sequentially press the steel sheet pile from the central portion to the curved surface portion and then to the peripheral portion in order to prevent air bubbles and the like from being mixed into the sheet and to efficiently attach the sheet.

The method of the present invention is characterized by the cooling of the steel sheet pile which is running with the heated and anticorrosive polyolefin layer pressed.

That is, the cooling is performed by water cooling from the upper surface of the steel sheet pile, and the water is stopped so that the water flow flowing in the longitudinal direction of the steel sheet pile does not flow down from the end. Examples of the water stopping means include a waste cloth and a sponge placed at both ends, and blowing of gas, particularly air, from a jet air nozzle. Air blowing is the most effective in that water can be completely stopped.

The water stopping performance of various water stopping devices was examined as shown in FIG. The figure shows various water-stopping tools, one of which was used. III for steel sheet pile 1
A type was used. The jet air nozzle has a distance of 25 mm between the web surface and the
Seven pieces were arranged in one horizontal row at an inclination angle of 0 to 60 °. As a result, the water stopping brush leaked at an early stage and the water stopping effect was insufficient. The sponge was initially watertight enough, but gradually leaked from around the steel sheet pile. on the other hand,
Water stoppage by the jet air nozzle was complete. When the water level is 10 mm or less, an air pressure of about 0.5 kg / cm ² is sufficient.
Water could be completely stopped by adjusting the pressure to 0 to 1.5 kg / cm ² .

The nozzle may be a circular nozzle, a slit nozzle, or the like. However, usually, a plurality of nozzles are used and arranged so that water can be stopped effectively.

When the upper surface of the steel sheet pile is concave, that is, when the web portion is at the bottom, water stopping means is provided on the web portion. When both ends are stopped, water accumulates in the meantime, which should be removed by suction.

On the other hand, when the upper surface of the steel sheet pile is convex, that is, when the web portion is on the upper surface, water collects in the grooves of the grip portions on both side edges of the steel sheet pile, so that the water stopping means is provided not only on the web portion but also on the grip portion. Is provided. In this case, the water accumulated in the groove of the grip portion may overflow over both side edges, but this is usually acceptable.

The amount of water used for water cooling is preferably 0.1 m ³
/ H or more, preferably 0.1 to 7.2 m ³ / h, particularly preferably 1.0 to 7.2 m ³ / h. 7.2m
It is uneconomical to use ³ / h or more.

It is preferable to use a small amount of water for water cooling as much as possible. For this reason, it is preferable to spray the water or to make the water flow down from a slit or a weir in a curtain shape. FIG. 6 shows a state where the water flows down from the weir 3 in a curtain shape. that time,
In order to reduce the scattering of falling water, as shown in FIG. 7, it is preferable that the guide 14 that guides the flowing water flow to the surface of the steel sheet pile is suspended. The material of this guide may be either hard or soft. Particularly preferred is a method of spraying water as shown in FIG. If the water flow of this spray is strengthened, the cooling water will be scattered. Therefore, it is preferable that the cooling water is caused to flow down in a spray form using a watering can. The water flow can be divided into two parts as shown in FIG. FIG.
Although a weir is used, it goes without saying that sprays can be provided in two places instead of the weir.

Water cooling is carried out at least until the modified polyolefin layer reaches the Vicat softening point. However, even if the cooling means is stopped, the cooling does not stop immediately. Therefore, even if the cooling is stopped at a temperature higher than the Vicat softening point by about 0 to 10 ° C., a certain effect can be obtained. On the other hand, it is more preferable to continue cooling until the temperature becomes lower than the Vicat softening point by about 0 to 20 ° C. After reaching the Vicat softening point and solidifying the modified polyolefin layer, it is preferable to also cool from the steel sheet pile surface opposite to the anticorrosive polyolefin layer to which the compression is applied, and to cool quickly from the steel sheet pile surface. Can be The measurement of the surface temperature may be performed by using a commercially available non-contact type or contact type surface temperature measuring device.

The cooling is performed so as to be substantially uniform over substantially the entire surface of the polyolefin sheet (the entire width when the sheet is conveyed), but from the center of the steel sheet pile to the side edges, that is,
It is preferable to sequentially cool the web, the corner, the flange, and the grip in this order. Thereby, the contraction of the sheet can be shifted to the center side, and the residual stress can be further reduced. This can be achieved to some extent by adjusting the water flow rate when the steel sheet pile is arranged on a convex surface, since the water flows to both sides if the water flow is supplied to the center. By changing the position of the water flow, several places, that is, web part, corner part,
By supplying the flange portion and the grip portion in this order, the effect can be more reliably exerted.

The running speed of the steel sheet pile is 0.2 to 5.0 m / m.
in, particularly preferably about 0.5 to 1.5 m / min.

FIG. 1 shows an embodiment of the water stopping state of the present invention.
As shown in FIG. 1, a spray 2 having a weir 3 is disposed substantially at the upper center, and jet air nozzles 4 and 5 are disposed on both sides of the spray 2 as water stopping means. A suction port 6 is provided between the spray 2 and the jet air nozzle 5 on the outlet side so as to be vertically movable, and a residual water suction / drain pump 7 is connected to the suction port 6. A water reservoir 8 is provided below the space between the jet air nozzles 4 and 5. The steel sheet pile 1 having a concave upper surface is advanced from the left to the right in the drawing to reach the jet air nozzle 4 on the entry side (state (1)). Therefore, jet air nozzles 4, 5
Air from the tank and the flow of water from the tank 2 are started,
The steel sheet pile 1 is further advanced rightward in the drawing, and the tip reaches the water flow flowing down from the water tank 2 to start water cooling. The water collected on the web 9 at the bottom of the steel sheet pile 1 is prevented from entering the drawing leftward by the air blown from the jet air nozzle 4, and the water flows down from the leading end and enters the water reservoir 8 (state (2)). ). When the steel sheet pile 1 further moves to the right in the drawing and reaches the jet air nozzle 5 on the exit side at the tip, the water-cooled water is prevented from flowing out by the air blown from the jet air nozzles 4 and 5, and the water-cooled water accumulates at the center. Therefore, the suction port 6
Is lowered to the vicinity of the web portion, and the residual water suction / drain pump 7 is operated to suck the water accumulated therein (state (3)). When the steel sheet pile 1 further advances and its rear end passes through the jet air nozzle 4 on the entry side, the cooling water flow and the residual water suction / drain pump are stopped. The flow of water on the web portion 9 to the right in the drawing is stopped by the jet air nozzle 5 on the exit side, flows down from the rear end of the steel sheet pile 1 and enters the water reservoir 8 (state (4)). The steel sheet pile 1 further advances rightward in the drawing, and the water cooling ends. In this way, it is prevented from entering the left side of the drawing beyond the jet nozzle 4 on the inlet side of the water-cooled water, thereby preventing the failure of the pressing portion.
The cooled steel sheet pile 1 can be taken out in a state where water-cooled water has been removed by blowing air from a jet air nozzle on the exit side.

[0038]

EXAMPLE A test apparatus shown in FIG. 3 was prepared. Spray 2 is arranged on the upper left side of the drawing of steel sheet pile 1 with concave upper surface,
Water stopping means is provided at both ends of the steel sheet pile 1. In the figure, a jet air nozzle 4 is arranged on the left side, and a sponge 10 is arranged on the right side.
Seven jet air nozzles 4 were arranged in one horizontal row. A suction port 6 is provided at the center of the steel sheet pile slightly to the right so as to be vertically movable, and a suction / drainage pump 7 is connected to the suction port 6 so that water sucked by the suction / drainage pump is received in a water tank 11. I made it. The water collected in the water tank 11 was returned to the spray 2 by the water pump 12, and the flow rate was confirmed by the flow meter 13. For the water stoppage on the right side, jet air may be used.

FIG. 4 shows a water-cooled state when the steel sheet pile 1 has the convex surface facing upward. The water-cooled water falls from the web portion 9 of the steel sheet pile 1 to the flange portion 15 and collects on the grip portion 16.
Therefore, the jet air nozzles 4 and 5 are used for stopping water collected at the grip portion. However, since some water flows in the web portion 9 in the longitudinal direction, the water stopping means 17 is also provided in the web portion.
It is preferable to take the following.

Next, a heavy corrosion-resistant coated steel material was prepared by the above-described test apparatus according to the following procedure.

That is, a U-shaped steel sheet pile (effective width 500 m)
m, height 225 mm, thickness 24.3, length 6 m) by sandblasting the concave or convex surface until it becomes SIS Sa2 1/2, and applying a chromate treatment agent to the surface in contact with the sea during use. It was baked to form a chromate film having a total chromium adhesion of 500 mg / m ² . After curing the unpainted part, an epoxy-based primer was spray-coated on the surface so as to have a thickness of 40 μm, and was cured by heating.

Thereafter, the steel sheet pile was heated to 140 ° C. in a heating furnace, and the steel sheet pile in a high temperature state was formed as a maleic anhydride-modified polyethylene layer having a thickness of 0.5 mm and a corrosion prevention layer having a thickness of 2.0 m.
m, a sheet formed integrally with the non-crosslinked polyethylene layer was placed thereon, and pressed and fused. The polyethylene of the anticorrosion polyethylene layer has a density of 0.945 g / cm ³ and an MI of 0.20.
g / 10 min.

After attaching the sheet, the steel sheet pile was cooled by the following various cooling methods. (1) Spread water almost uniformly in the width direction from the polyethylene side to form a cooling concave. (2) Cool the (1) until the surface temperature on the opposite side of the steel sheet pile becomes lower than the Vicat softening point of the modified polyethylene layer used. Water is then sprayed from the polyethylene side and cooled. (3) When cooling by spraying water from the polyethylene side, the center part (web part) of the steel sheet pile is cooled first, and then the corner part and the side part (flange part) , Cooling joints in order to the joint (grip) (weirs and sprays are arranged in plurals so that they can be sprayed at each position.) (4) Cooling convex as in (3) (5) Polyethylene side and steel Simultaneously cooling the sheet pile side (6) Cooling concave form by spraying water only from the steel sheet pile side (7) Cooling convex form by spraying water only from the steel sheet pile side (8) Spraying water from the polyethylene side to cool At the time, first, the central part of the steel sheet pile ( After cooling to the corners, side surfaces (flanges), and joints (grips), water is sprayed from the steel material to form cooling concaves (9) (8). Molds (10) to (15) Cooling concaves as in (8) (16) (3) Cooling concaves as in (3) (17) to (22) Cooling convex as in (8) (16) (3) Cooling concave type (23) Cooling convex type similarly to (3)

Thereafter, the entire side end portion of the sheet was sealed with a band-shaped sealing material to produce a heavy duty anticorrosion coated steel sheet pile of the present invention.

The following evaluation was performed on this steel sheet pile. Investigation of the residual stress of the coating After cooling, a part of the coating was peeled from the steel sheet pile while keeping the coating from deformation, and the residual stress of the coating was calculated from the dimensional difference before and after peeling and the Young's modulus of the polyethylene used for the coating did. Warm salt water immersion test The obtained steel sheet pile is cut into an appropriate size, and the temperature is 50 ° C and 3%.
Was immersed in a salt water for 3000 hours, and the peel distance from the end of the coating after immersion was examined. Salt spray test

The obtained steel sheet pile is cut into a suitable size,
The salt spray test specified in JIS K 5400 was performed to determine the peel distance from the edge of the coating after 3000 hours.

The results obtained are shown in Table 1 and FIG.

[0048]

[Table 1]

In all the cases where the water was stopped by the jet air nozzle, there was no water leakage in the longitudinal direction of the steel sheet pile. What went on with the sponge was a little leaky. If water was not stopped, water could reach the pressing portion and the polyethylene could not be covered.

[0050]

According to the present invention, it is possible to prevent a water flow from flowing from the longitudinal end of the steel sheet pile and to produce a heavy corrosion-resistant coated steel sheet pile smoothly.

[Brief description of the drawings]

FIG. 1 is a process chart illustrating an example of the method of the present invention.

FIG. 2 is a diagram illustrating a state in which the water stopping performance of various water stopping means has been examined.

FIG. 3 is a diagram illustrating a configuration of a test apparatus used in an example.

FIG. 4 is a perspective view showing a state in which a steel sheet pile having a convex upper surface is water-cooled.

FIG. 5 is a graph showing the relationship between the amount of cooling water and the salt spray peel strength obtained in the above test.

FIG. 6 is a perspective view showing a state of flowing water from a weir.

FIG. 7 is a cross-sectional view showing a flowing water state when a guide is provided below the weir.

FIG. 8 is a perspective view showing a state in which a weir is used to split a water flow into two locations.

[Explanation of symbols]

 1 ... steel sheet pile 2 ... spray 3 ... weir 4, 5 ... jet air nozzle 6 ... suction port 7 ... residual water suction and drain pump 8 ... water pool 9 ... web section 10 ... … Sponge 11… water tank 12… water supply pump 13… flow meter 14… guide 15… flange 16… grip 17… water stopping means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-11-179845 (JP, A) JP-A-10-278174 (JP, A) JP-A-5-305695 (JP, A) JP-A-60-1985 27520 (JP, A) JP-A-3-142225 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 15/08 B05D 3/00 B05D 7/14

Claims (10)

(57) [Claims] 1. A method for cooling a steel sheet pile, which is running while being heated and pressed against an anticorrosion polyolefin layer via a modified polyolefin layer, wherein the cooling is carried out by water cooling from the upper surface of the steel sheet pile and in the longitudinal direction of the steel sheet pile. A method for producing a heavy-duty coated steel sheet pile, comprising a water stopping means for blocking a water flow flowing through the steel sheet pile 2. The method according to claim 1, wherein an upper surface of the steel sheet pile is concave, and water collected by stopping water at both ends is sucked. 3. The method according to claim 1, wherein the upper surface of the steel sheet pile is convex, and water is stopped by the web part and the grip parts on both side edges. 4. The method for producing a heavy-corrosion-coated steel sheet pile according to claim 1, wherein the water-cooling is performed from the surface on which the anticorrosion polyolefin layer is pressed. 5. The method according to claim 1, wherein after the modified polyolefin layer is solidified, cooling is performed from the opposite surface.
3. The method for producing a heavy-duty corrosion-coated steel sheet pile according to 3 or 4 6. The method according to claim 1, wherein the water is stopped by blowing air. 7. The method according to claim 1, wherein water cooling is performed by a water flow flowing down from a slit or a weir.
The method for producing a heavy-corrosion-coated steel sheet pile according to 4, 5, or 6 8. The method according to claim 7, wherein the water flowing down from the slit or the weir is guided by a guide. 9. Water cooling from the upper surface of the steel sheet pile until the modified polyolefin layer reaches the Vicat softening point is carried out at a cooling water volume of 0.1%.
The method according to claim 1, 2, 3, 4, 5, 6, 7, or 8, wherein the method is performed with a water amount of 1 m ³ / h or more. 10. The method according to claim 1, wherein water cooling is performed by spraying.