KR100705711B1 - Methods for manufacturing steel pipe using SPC covering - Google Patents

Abstract

The present invention relates to a method for producing a steel pipe using a coating of modified sulfur cement (hereinafter referred to as 'SPC'), and more specifically, to a steel pipe body by coating a nonwoven fabric impregnated with SPC mixture on a steel pipe body. The present invention relates to a method for manufacturing tap water pipes, which can reduce the thickness and does not require a separate anti-rust treatment. To this end, the method for producing a steel pipe using the SPC coating of the present invention comprises the steps of: (a) heating the impregnating tank to maintain a constant temperature of the SPC mixture contained therein; (b) heating the steel pipe body and then installing it on a swivel table; (c) impregnating a reinforcement cloth drawn from the winding roller in an impregnation tank; And (d) covering the steel pipe body with the reinforcing cloth impregnated while rotating the steel pipe body.

SPC, Cloth, Steel Pipe

Description

Method for manufacturing steel pipe using SPC covering {Methods for manufacturing steel pipe using SPC covering}

1 is a flow chart showing a method for manufacturing a steel pipe using a sulfur polymer cement (SPC) coating according to a preferred embodiment of the present invention.

Figure 2 is a perspective view showing a SPC coated steel pipe manufactured according to a preferred embodiment of the present invention.

3 is a detail view of portion A of FIG. 2;

Figure 4 is a cross-sectional view showing the coating of the steel pipe body with a reinforcement cloth impregnated SPC according to a preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: steel pipe body 20: reinforcement cloth

30: epoxy resin layer 40: impregnation tank

50: sealed space 60: swivel

70: winding roller 80: guide roller

100: steel pipe

The present invention relates to a method for manufacturing a steel pipe using a SPC (sulfur polymer cement) coating, and more specifically, by coating the steel pipe body with a non-woven fabric impregnated with SPC can reduce the thickness of the steel pipe body and does not require a separate anti-rust treatment The present invention relates to a method of manufacturing water pipes.

In general, coated steel pipes (coated steel pipe) is produced by coating polyethylene or the like on the outer surface of the steel pipe body. That is, the coated steel pipe for water supply is manufactured by applying an adhesive to the outer surface of the steel pipe body and then coating polyethylene, or by spraying powder epoxy on the outer surface of the steel pipe body and then applying an adhesive and coating polyethylene. .

The polyethylene or the like is coated to improve chemical resistance, weather resistance and the like of the steel pipe. However, polyethylene coated on the outer surface of the steel pipe body or powder epoxy sprayed on the steel pipe body is not sufficient to supplement the strength of the steel pipe body. Therefore, there is a problem in that the production cost increases because a steel pipe body having a thick thickness must be used to manufacture a steel pipe for waterworks.

In addition, the steel pipe using a thick steel pipe body has a problem that the sedimentation is likely to occur after the construction because of its large weight.

In addition, there is a problem that the production process is complicated because a process of applying an adhesive before coating polyethylene or a process of spraying powder epoxy before coating polyethylene to perform antirust treatment is required.

Steel pipe manufacturing method using the SPC coating of the present invention was devised to solve the above problems, by reducing the thickness of the steel pipe body by covering the steel pipe body with a non-woven fabric impregnated with SPC mixture that can supplement the strength of the steel pipe body. The purpose is to provide a method for manufacturing a steel pipe.

Another object of the present invention is to provide a method for producing a steel pipe that can prevent the settlement by the self-weight by reducing the thickness of the steel pipe body to reduce its own weight.

Still another object of the present invention is to provide a method for manufacturing a steel pipe, which does not require a separate process for antirust treatment.

Another object of the present invention to provide a method for producing a steel pipe that can simplify the production process.

In order to achieve the above object, a method of manufacturing a steel pipe using SPC coating according to the present invention includes the steps of: (a) heating a impregnation tank to maintain a constant temperature of the SPC mixture contained therein; (b) heating the steel pipe body and then installing it on a swivel table; (c) impregnating the reinforcement cloth drawn from the winding roller in the impregnation tank; And (d) covering the steel pipe body with the reinforcing cloth impregnated while rotating the steel pipe body.

Preferably, step (d) moves the steel pipe body horizontally and simultaneously.

Preferably, the preparation method, before the step (a), (a1) adding a material for improving the SPC and physical properties of the liquid in the mixer, the step of preparing the SPC mixture by stirring the material and the SPC; And (a2) supplying the SPC mixture to the impregnation bath.

Preferably, the manufacturing method, before the step (a), (a1 ') the step of injecting a solid state SPC and a material for improving physical properties into the mixer; (a2 ') stirring the SPC and the material to prepare an SPC mixture; And (a3 ') supplying the SPC mixture to the impregnation bath.

In addition, the manufacturing method, in the step (d), the impregnated reinforcement is guided by the guide roller is moved to the steel pipe body, the guide roller is preferably heated to a predetermined temperature by a heating member installed therein. .

In addition, the impregnation tank is preferably installed in a predetermined closed space to maintain the temperature of the SPC mixture contained therein.

Here, the reinforcing fabric is a nonwoven fabric, and the step (a) is preferably heating the impregnation tank so that the temperature of the SPC contained in the impregnation tank is maintained at 130-140 ℃.

Preferably, the manufacturing method, after the step (d), (e) further comprises the step of forming an epoxy resin layer on the inner surface of the steel pipe body.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

1 is a flow chart showing a method of manufacturing a steel pipe using the SPC coating according to a preferred embodiment of the present invention, Figure 2 is a perspective view showing a SPC coated steel pipe manufactured according to the manufacturing method, Figure 3 is A of FIG. A detailed view of the part.

Referring to the drawings, the manufacturing method, step S10 (Sulfur polymer cement), filler, admixture, reinforcing material is added to the mixer (S10), and SPC, filler, admixture, reinforcing material is added to the mixer to prepare the SPC mixture Step (S20), supplying the SPC mixture to the impregnation tank (S30), heating the impregnation tank to maintain the SPC mixture contained therein at a predetermined temperature (S40), and then heating the steel pipe body. Step (S50) to install on the swivel, the step of impregnating the reinforcement cloth drawn from the take-up roller in the impregnation tank (S60), and the step of covering the impregnated reinforcement cloth while rotating and horizontally moving the steel pipe body (S70) ).

The SPC is a first selected from dicyclopentadiene, methyl cyclopentadiene, divinyl benzene, cyclooctadiene, cyclodecatriene, octadiene and myrcene, as disclosed in Patent Publication No. 1983-2618. 5-20% by weight of hydrocarbons (relative to sulfur) and 5-20% by weight of second hydrocarbons (relative to sulfur) selected from dipentene, styrene, vinyltoluene, pinene and octene are high enough for exothermic reactions with sulfur elements It is made by reacting at a temperature, that is, 120 to 200 ° C.

The SPC exists as a solid phase at 100-110 ° C. or lower, and in a liquid phase at a temperature higher than 150 ° C., and when the temperature reaches 150-160 ° C. or higher, a change in physical properties occurs, such as an increase in viscosity and discharge of sulfur components. Therefore, in order to use SPC, it is preferable to maintain the temperature of 130-140 degreeC.

The SPC has a transmittance of 5 to 100, a softening point of 10 to 70 ° C. and a ductility of at least 100, and the heat transfer rate is considerably low. In addition, SPC has high corrosion resistance, corrosion resistance, acid resistance, antimicrobial storage resistance, and freeze thaw resistance. In addition, SPC is a non-toxic material that is harmless to organisms.

The steel pipe 100 manufactured by the manufacturing method includes a steel pipe main body 10 and a reinforcement cloth 20 coated on an outer surface of the steel pipe main body 10 and impregnated with the SPC mixture.

Meanwhile, in the present specification, the term "steel pipe body" refers to a steel pipe before the SPC mixture is coated with the reinforcement cloth 20 impregnated, and the term "steel pipe" refers to the reinforcement cloth 20 impregnated with the SPC mixture. It means steel pipe. In addition, the "reinforcement fabric" refers to a nonwoven fabric, etc. that can be impregnated with the SPC mixture. That is, a nonwoven fabric such as hessian cross, glass mat, or the like may be used as the reinforcement cloth. In addition, the 'SPC mixture' refers to a mixture in which a substance for improving physical properties is added to the SPC. Materials for improving physical properties include fillers, admixtures, reinforcing materials and the like.

The SPC is added to a mixer (not shown) together with a material for improving physical properties (S10). The material improves physical properties such as strength when the nonwoven fabric 20 impregnated with the SPC mixture, that is, the reinforcement cloth 20 is coated on the steel pipe main body 10.

The filler includes fly ash and / or silica fume, and the admixture includes paraffin and the like. Further, the reinforcing material includes polyethylene fiber or polypropylene fiber and the like.

When the SPC is in a solid state, it is heated in a separate auxiliary tank (not shown) and converted into a liquid phase, and then introduced into a mixer. If the SPC is in a solid state in powder form, it can be added directly to the mixer without passing through the auxiliary tank.

On the other hand, the liquid SPC is supplied to the mixer from the SPC storage tank (not shown).

The SPC storage tank includes a tank accommodating the SPC, a heating unit for heating the SPC contained in the tank to a predetermined temperature, and a rotary vane that is rotated by a motor and stirs the SPC. The heating unit is such that the SPC contained in the tank is maintained at 130-140 ℃. Preferably, the heating unit heats the SPC by the indirect heating method by the fruit oil. Such storage tanks are disclosed in Korean Utility Model Registration No. 20-0371838.

Preferably, the mixer includes a stirring blade for stirring the contents, that is, the SPC mixture, and a heating member capable of heating the SPC mixture. By heating the inside of the mixer, the heating member keeps the temperature inside the mixer constant, and when the SPC is in a solid state, the SPC can be melted in the liquid phase. More preferably, the heating member heats the inside of the mixer by an indirect heating method by the fruit oil.

As such, the mixer prepares the SPC mixture by stirring the SPC, filler, admixture, and reinforcing material (S20). The prepared SPC mixture is supplied to the impregnation tank (40 in FIG. 4) (S30).

The impregnation tank 40 allows the SPC mixture contained therein to maintain a predetermined temperature (S40). The impregnation tank 40 includes a heating means (not shown) for heating the SPC mixture, and a guide roller 42 for guiding the movement of the reinforcement cloth 20. The guide roller 42 is bent while the impregnated reinforcement cloth 20 is in contact with the outer surface.

Preferably, the heating means heats the temperature of the SPC mixture to be maintained at 130-140 ° C. More preferably, the heating means heats the impregnation tank 40 by an indirect heating method using fruit oil.

The impregnation tank 40 is preferably installed in a predetermined sealed space 50 so that the temperature of the SPC mixture contained therein can be maintained constant. That is, the impregnation tank 40 may be installed in the sealed space 50 formed by the heat insulator 52. The heat insulator 52 is formed with an inlet port 54 through which the reinforcement cloth 20 flows in, and a discharge port 56 through which the reinforcement cloth 20 is discharged.

On the other hand, the steel pipe body 10 is manufactured by a conventional method. First, a steel plate of a predetermined thickness is cut into a predetermined size and then bent into a cylindrical shape. Then, the edge portions are welded to each other. The manufactured steel pipe body 10 is heated to a constant temperature. This is to increase the adhesive force with the nonwoven fabric 20, ie, the reinforcement cloth 20, to which the SPC mixture is impregnated by drying the steel pipe main body 10. After the steel pipe main body 10 is heated, compressed air is sprayed on the steel pipe main body 10 to remove dust and the like remaining in the steel pipe main body 10.

After removing dust and the like, the steel pipe main body 10 is heated to a predetermined temperature. This is to prevent the SPC from quenching when the steel pipe body 10 is coated with the reinforcing cloth 20 impregnated with the SPC mixture. The predetermined temperature is a temperature at which the reinforcing fabric 20 impregnated with the SPC mixture can be easily bonded.

Next, the steel pipe main body 10 is installed on the swivel table 60 (S50).

The swivel table 60 rotates while supporting the steel pipe main body 10 and simultaneously moves the steel pipe main body 10 horizontally.

Preferably, the swivel table 60 includes a rotating roller 62 for rotating while supporting the steel pipe main body 10 and a moving member 66 for horizontally moving the steel pipe main body 10.

The rotating roller 62 rotates the steel pipe body 10 while being selectively rotated by a rotating motor (not shown). The moving member 66 has a rail 67 and a wheel 68 moved along the rail 67. The moving member 66 horizontally moves the steel pipe main body 10 such that the reinforcing cloth 20 impregnated with the SPC mixture is spirally coated on the outer surface of the steel pipe main body 10.

As an alternative to the swivel table 60, the swivel table is a gripping unit (not shown) for gripping and selectively rotating the steel pipe body 10 by biasing the inner surface of the steel pipe body 10 to the outside. A mobile unit (not shown) for horizontally moving the unit may be provided.

After the steel pipe main body 10 is installed on the swivel 60, the reinforcing cloth 20 is taken out of the winding roller 70 and impregnated in the impregnation tank 40 (S60).

The winding roller 70 supplies the reinforcing cloth 20 wound on its outer circumferential surface to the impregnation tank 40. The reinforcement cloth 20 is moved to the impregnation tank 40 through the inlet port 54, and is moved to the steel pipe main body 10 through the outlet port 56.

Preferably, the reinforcement cloth 20 is moved to the steel pipe main body 10 while being guided by the guide roller 80 installed between the impregnation tank 40 and the swivel table 60.

More preferably, the guide roller 80 is heated to a predetermined temperature by a heating member 82 provided therein. By heating the guide roller 80 to a predetermined temperature, the reinforcement cloth 20 can be prevented from being cooled during the movement. The heating member 82 may heat the guide roller 80 by using an indirect heating method using fruit oil.

After impregnating the SPC in the reinforcement cloth 20, the reinforcing cloth 20 is coated on the outer surface of the steel pipe main body 10 while rotating the steel pipe main body 10 and moving horizontally (S70). When the steel pipe main body 10 is rotated by the rotating roller 62 and moved horizontally by the moving member 66, the reinforcing cloth 20 is spirally coated on the outer surface of the steel pipe main body 10.

Since the reinforcement cloth 20 impregnated with the SPC mixture has sufficient compressive strength and tensile strength, it is possible to supplement the strength of the steel pipe body 10. Therefore, since the thickness of the steel pipe main body 10 can be reduced by that much, the production cost of the steel pipe 100 can be reduced.

In addition, since the self-weight of the steel pipe 100 can be reduced, it is possible to prevent settlement by self-weight, and since the SPC has excellent anti-rusting property, a separate process for rust prevention is not required. In addition, the steel pipe 100 has excellent corrosion resistance, acid resistance, antimicrobial storage properties, and freeze thaw resistance.

Furthermore, the reinforcement cloth 20 impregnated with the SPC mixture may be adhered to the steel pipe body 10 without a separate adhesive. Since the process of applying the adhesive to the steel pipe main body 10 is not necessary, the production process can be simplified, and the production cost can be reduced by that much.

When the coating step (S50) is completed, the reinforcing cloth 20 is cut. At this time, the reinforcement cloth 20 is firmly adhered to the steel pipe main body 10 by pressing the cut end of the reinforcement cloth 20. To this end, it is preferable to install a pressing roller (not shown) capable of pressing the end portion at a position close to the steel pipe main body 10.

Preferably, after the coating step (S50), the epoxy resin layer 30 is formed by spraying or applying an epoxy resin on the inner surface of the steel pipe body (10). Meanwhile, a process of cooling the steel pipe 100 may be selectively added between the coating process S50 and the epoxy resin layer forming process.

On the other hand, the present specification has described that the rotating table 60 is moved in the horizontal direction and the impregnation tank 40 and the winding roller 70 is fixed, the impregnation tank 40 and the winding roller 70 in the horizontal direction It may be moved and the swivel table 60 may be fixed. That is, the impregnation tank 40 and the winding roller 70 may be installed on a predetermined frame, and the impregnating tank 40 and the winding roller 70 may be rotated while the frame is moved in the horizontal direction.

Method for producing a steel pipe using the SPC coating according to the present invention has the following effects.

First, the thickness of the steel pipe body can be reduced by covering the steel pipe body with a reinforcing cloth impregnated with SPC mixture that can supplement the strength of the steel pipe body.

Second, it is possible to prevent the settlement of the steel pipe due to its own weight.

Third, no separate process is required for the rust prevention treatment.

Fourth, it is possible to produce a steel pipe having excellent corrosion resistance, acid resistance, antimicrobial storage resistance, and freeze thaw resistance.

Fifth, the production process of steel pipe can be simplified.

Claims (8)

delete delete (a) heating the impregnation tank to maintain a constant temperature of the SPC mixture contained therein; (b) heating the steel pipe body and then installing it on a swivel table; (c) impregnating the reinforcement cloth drawn from the winding roller in the impregnation tank; And (d) covering the steel pipe body with the reinforcement cloth impregnated while rotating the steel pipe body; Before step (a) above, (a1) preparing a SPC mixture by adding a liquid SPC and a substance for improving physical properties into a mixer and then stirring the substance and the SPC; And, (a2) supplying the SPC mixture to the impregnation tank; method for producing a steel pipe using an SPC coating, characterized in that it comprises a. (a) heating the impregnation tank to maintain a constant temperature of the SPC mixture contained therein; (b) heating the steel pipe body and then installing it on a swivel table; (c) impregnating the reinforcement cloth drawn from the winding roller in the impregnation tank; And (d) covering the steel pipe body with the reinforcement cloth impregnated while rotating the steel pipe body; Before step (a) above, (a1 ') adding a solid SPC in a powder state and a substance for improving physical properties into the mixer; (a2 ') stirring the SPC and the material to prepare an SPC mixture; And (a3 ') supplying the SPC mixture to the impregnation tank; a method of manufacturing a steel pipe using an SPC coating, comprising: a. (a) heating the impregnation tank to maintain a constant temperature of the SPC mixture contained therein; (b) heating the steel pipe body and then installing it on a swivel table; (c) impregnating the reinforcement cloth drawn from the winding roller in the impregnation tank; And (d) covering the steel pipe body with the reinforcement cloth impregnated while rotating the steel pipe body; In step (d), The impregnated reinforcement cloth is moved to the steel pipe body while being guided by a guide roller, and the guide roller is heated to a predetermined temperature by a heating member installed therein. (a) heating the impregnation tank to maintain a constant temperature of the SPC mixture contained therein; (b) heating the steel pipe body and then installing it on a swivel table; (c) impregnating the reinforcement cloth drawn from the winding roller in the impregnation tank; And (d) covering the steel pipe body with the reinforcement cloth impregnated while rotating the steel pipe body; The impregnation tank is a steel pipe manufacturing method using the SPC coating, characterized in that installed in a predetermined closed space to maintain the temperature of the SPC mixture contained therein. The method according to any one of claims 3 to 6, The reinforcing fabric is a nonwoven fabric, The step (a) is a method for manufacturing a steel pipe using SPC coating, characterized in that for heating the impregnation tank so that the temperature of the SPC contained in the impregnation tank is maintained at 130-140 ℃. The method of claim 7, wherein After step (d), (e) a method of manufacturing a steel pipe using an SPC coating, further comprising forming an epoxy resin layer on an inner surface of the steel pipe body.

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