KR20140092171A - Apparatus of plastic powder simultaneous coating onto interior and exterior surfaces of metal pipes and therof exterior and interior plastic coated metal pipes - Google Patents

Abstract

The present invention relates to an apparatus for simultaneously coating both sides of a metal pipe with metal powder which includes a frame; a pipe roller which has multiple turning rollers provided in an upper part of the frame; a powder coater which is inserted into a metal pipe rotated by the turning rollers and has a powder spray gun, which moves forward and backward; a plastic powder flame coater which is closely arranged to the outer surface of the metal pipe; at least one plastic powder supplier which is connected to the powder coater and plastic powder flame coater for supplying plastic powder; an air compressor which is connected to at least one plastic powder supplier and powder coater; and a combustion gas supplier which is connected to the plastic powder flame coater. A metal pipe having one open side or both open sides of inlet and outlet, or a metal tank, which forms a flange with a radius greater than or equal to 5 cm in one side or both sides, can be simultaneously plastic powder-coated using the present invention.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for simultaneously coating a plastic powder on both sides of a metal pipe and a metal pipe coated with a plastic powder on both sides using the same,

The present invention relates to a method and a device for storing a corrosive liquid or gas such as oil or gas or water, seawater, acid or alkali, or the like by installing it in an ocean floor or underground, An apparatus for simultaneously coating a plastic powder such as epoxy, polyethylene, polypropylene, or polyvinylidene fluoride (PVDF) with good corrosion resistance in a place as a device on both sides of a metal pipe or metal container used for transferring And a metal pipe or a metal container in which a plastic powder is coated on both sides using the same.

Generally, a metal pipe that is buried in the sea bed or underground and transports corrosive liquid such as water, seawater, acid, alkali or the like or corrosive gas is installed buried under the sea floor or underground, and water or seawater , Or a pipe coated with plastic on both sides of a metal pipe to be used for transporting a caustic liquid such as an acid or an alkali (alkaline) or a corrosive gas.

Among the metal pipes coated with plastic on both sides thereof, the metal pipe used as the water pipe is formed by coating the outer surface of the metal pipe with the powder epoxy and the primer adhesive layer resin by the electrostatic method, Is extruded or coated with an extruder to a thickness of about 2 to 3 mm, or a storage tank containing powder epoxy and a polyethylene having an adhesive property in a powder state, or a storage tank containing polypropylene having an adhesive property in a powder state, A metal pipe having a heat of 230 DEG C or higher is successively immersed in a storage tank containing a general powdered polyethylene having no adhesive property or a general powdered state polypropylene having no adhesive property and sequentially coated on the outer surface with the heat of the metal pipe, The inner circumferential surface is liquid epoxy, liquid polyurea Is a coating of liquid polyurethane with a thickness of 0.3 to 1.0 mm using a liquid coater, and polyolefin double-layer pipe or polyolefin triple-layer pipe is widely used as plastic coating pipe for tap water.

However, the technique of surface-coating the plastic on both sides of the metal pipe is complicated in the process of surface coating of the plastic, and the liquid epoxy or liquid polyurethane which is coated on the inner surface of the metal pipe, It is difficult to raise the thickness of 1 mm or more, the water absorption rate, which is inherent property of the thermosetting resin, is low, and the adhesiveness to the inner surface of the metal pipe is low, so that it is easily peeled off partly from the inner surface of the metal pipe and is corroded or rusted. There are problems in that the service life is not long.

As a technique for solving the problems of the prior art, Korean Patent No. 0030176 (hereinafter referred to as the "prior art") discloses a method of coating polyethylene on the inner surface or both surfaces of a metal pipe with a triple layer.

The method of coating with polyethylene triple layer described in the prior art is a method of triple coating polyethylene powder on both inner and outer surfaces of a metal pipe as a method of precoating inner and outer surfaces of a steel pipe to a necessary temperature through a surface pretreatment step and a preheating step, Fix the fixing bracket on both sides of the side. Since polyethylene does not have polarity, it does not have adhesive force even if it is coated directly on the surface of steel pipe. Therefore, it is immersed in a cylinder containing adhesive solvent for bonding polyethylene to the surface of metal pipe, And then moved again to immerse the preheated steel pipe in the polyethylene powder in which the polyethylene powder is stored. While the inner and outer surfaces of the metal pipe are coated with polyethylene powder, the inner and outer surfaces of the metal pipe are reheated again. It is described as a method of forming a film of polyethylene.

However, since polyethylene and polypropylene are thermoplastic resins in a polymer state, they are coated in a storage container containing a liquid adhesive solvent which can be adhered to the surface of polyethylene or polypropylene at room temperature without polarity and low surface energy, . However, a plastic material coated on the surface of a metal pipe is a thermoplastic plastic resin having no polarity and low surface energy and having no adhesion to the surface of a metal pipe.

Accordingly, as described in Korean Patent No. 0030176, even when the metal pipe is in a state of being at room temperature, and has a heating surface on the surface of the metal pipe through the preheating process, the adhesive solvent stored in the storage container There is a great deal of doubt as to whether the method of coating the powder of thermoplastics resin by burial can actually be done.

In general, if an adhesive solvent having adhesive property to polyethylene is an adhesive solvent in which a plastic resin composed of a thermosetting plastic resin is constituted by an adhesive component, a time for curing is necessarily required, And then coated on both sides of the metal pipe at the same time in a container containing polyethylene in a powder state, coating is carried out on the inner surface of the metal pipe to form a coated coating made of a polyethylene material in powder state It is difficult to control the thickness of the coating film uniformly or to control the thickness of the coating film. Also, in practice, a polyethylene pipe coated on both sides of a metal pipe without flanges at both ends does not cover polyethylene with a thickness of about 10 to 15 cm at both ends of the polyethylene-coated pipe. This is because both ends of the polyethylene-coated metal pipe are welded to both ends with a metal welding rod at the site where the metal pipe is installed, and when polyethylene is coated with the metal pipe or the connecting pipe, .

As a result, the polyethylene triple-layer coated steel pipe forming method disclosed in the prior art is disadvantageous in that it is not easy to remove the powdered epoxy or the polyethylene coated on both ends of the metal pipe after the coating.

In addition, one of the other prior arts is a liquid which is highly corrosive, such as acid, alkali, or crude oil, and is highly permeable to thermosetting plastic resins such as epoxy and thermoplastic plastics such as polypropylene and polyvinylidene fluoride The thickness of the coating of the plastic coating on the plastic coated metal pipe or metal tank for storing or transporting the corrosive liquid is usually 2 to 3 mm or more thick and the plastic resin Coating is required to have durability.

One of such use examples and one of the prior arts is a metal pipe for transporting corrosive crude oil as described above, which has good corrosion resistance, high heat resistance, and adhesion to the surface of a metal pipe through an electrostatic powder coating machine on both sides of the metal pipe It is conceivable to coat a good powdered epoxy with a single layer on both sides by the powder coating method using static electricity using an apparatus constituting the extrusion coated polyolefin triple layer coating pipe described above.

However, a method of covering the powdered epoxy with a single layer on both sides of the metal pipe by the electrostatic method includes a step of pretreating the metal pipe; And the metal pipe with the surface temperature of 230 ° C or more through the preheating step is placed on a turning roller which is a rotating device and rotated to one side. Powder coated by electrostatic method Powder organs and powders Long spray gun The metal pipe coated with the powder epoxy on the inner surface of the metal pipe is passed through a sintering furnace or a high-frequency furnace having a temperature of 250 ° C or higher again, The surface temperature of the outer surface of the metal pipe covered with the powder epoxy coating was passed through the heating device and then moved again to move the metal pipe in the horizontal direction on one side, A plurality of electrostatic powder particles are transferred through the organs to the metal pie The outer circumferential surface of the surrounding coating has a coating method of the coating method of coating a powder epoxy on both sides of the metal pipe.

However, in the method of coating the above-described powder epoxy on both surfaces of a metal pipe by using an electrostatic powder organs, the epoxy coated on the inner surface of the metal pipe has a very narrow and short temperature of 190 to 230 DEG C If the surface temperature of the metal pipe is lowered to 190 ° C or lower, powdery epoxy having a small powder particle size can not be melted. If the surface temperature of the metal pipe is less than 240 ° C, powdered epoxy is coated Since the surface of the metal pipe is carbonized and its physical properties are impaired, it is usually applied to coat the inner surface of the metal pipe with a thickness of 1 mm or more, or twice or more times to maintain the surface temperature of the metal pipe constantly between 190 and 230 ° C The surface of the metal pipe is heated by moving the metal pipe, There is a problem that an apparatus and a method for coating and coating the powder epoxy by covering the inner and outer surfaces of the metal pipe while maintaining the temperature of 230 DEG C are troublesome, require a lot of energy and time, and require separate heating devices.

It is an object of the present invention to overcome the above-mentioned problems of the prior art, and it is an object of the present invention to provide a metal pipe having a metal pipe or a metal tank having an opening with a diameter of 50 mm or more on one side or opposite sides thereof for the purpose of preventing corrosion or wear The metal pipe is moved to a metal pipe without flanges at both ends through a device for forming a plastic coating film on the plastic powder to prevent the metal pipe from reheating, The present invention provides a double-sided synthetic resin simultaneous coating apparatus for a metal pipe capable of coating a plastic having the same or different plastics types as a single layer or a multilayer of two or more layers and a metal pipe or a metal tank coated with plastic on both sides thereof have.

Another object of the present invention is to provide a device for forming a plastic coating film of a plastic powder for preventing corrosion or abrasion on both sides of a metal pipe or a metal tank having an opening with an opening of 50 mm or more on one side or opposite sides It is possible to form plastic coatings on both sides of the metal pipe and at the same time by varying the thickness of the plastic coating at a certain place or location, without reheating, by moving the metal pipe through the metal pipe without flanges at both ends In which the apparatus is provided.

It is still another object of the present invention to provide a metal pipe or a metal pipe in which a flange is bonded to one end or both ends of a metal pipe and a flange is bonded to one end or both ends of the metal pipe at a predetermined place or position without re- The thickness of the inner surface of the metal pipe or the metal tank or the metal container and the thickness for coating the plastic on the flange surface, the thickness of the metal pipe or metal tank excluding the inner surface and the flange surface of the metal pipe or metal tank, The present invention provides an apparatus capable of forming a plastic coating film with different thicknesses for the same, different, or coating coatings of plastics on the outer surface.

It is still another object of the present invention to provide an apparatus for simultaneously coating plastic on both sides of a metal pipe or a metal tank as well as a plastic powder spraying apparatus having a spray gun for spraying a plastic powder on the inner surface of a metal pipe, By rotating the pipe, the rotating device is rotated by the turning roller, and the plastic powder is sprayed on the outer surface of the metal pipe by the same spray gun. The flame is generated by burning the combustion gas, and the flame is sprayed into the generated flame. And a plastic powder flame coating machine for melting plastic powder instantaneously and melting and coating plastic on the outer surface of the metal pipe so that various plastics are coated on the inner surface of the metal pipe or metal tank with a thickness of 2 mm or more At the same time, It is possible to coat the surface by separating the action of heating on the surface and the plastic powder or ignite the combustion gas such as propane gas, acetylene gas or hydrogen gas through the plastic powder flame coater. By performing the function of separating and applying the heating action to the surface of the metal pipe through the spray gun of the plastic powder flame coater, or simultaneously coating the plastic powder together while heating the surface of the metal pipe, A metal pipe or a metal tank is coated with various plastics by freely selecting or adjusting the type and thickness of a plastic coating layer which is coated on both sides of a metal pipe or a metal tank by freely adjusting the surface temperature.

An object of the present invention is to provide a pipe turning roller having a frame of a steel material capable of rotating a circular metal pipe or a circular metal tank and a plurality of turning rollers provided on the upper portion of the frame; A compressed air storage container for storing compressed air through an air compressor or an air compressor, and a plastic powder which is charged into the metal pipe that is rotated by the turning roller and is forward and backward, And a hose for transferring the plastic powder supplied from the powder plastic storage container into the powder spray gun of the powder organs; A compressed air storage tank disposed adjacent to an outer circumferential surface of the metal pipe for storing air compressed through an air compressor and an air compressor, and compressed air supplied from an air compressor or a compressed air storage tank into a spray gun of a plastic powder flame coater Plastic hose, plastic hose, plastic hose, plastic hose, metal hose, plastic hose, plastic hose, plastic hose, plastic hose, plastic hose, A hose for transferring powder into a spray gun of a plastic powder flame coater is prepared and compressed air supplied from an air compressor or a compressed air storage tank is supplied through a hose to a plastic powder flame A plastic powder transfer hose connected to a compressed air transfer hose and a propane gas or a propane gas or acetylene gas connected to a compressed air transfer hose so that they can be sprayed together and sprayed out of the spray gun by compressed air pressure, Or hydrogen gas, and a hose for transferring the combustion gas from the container storing the combustion gas into the spray gun of the plastic powder flame coater, the aforementioned propane gas, or an acetylene gas or a hydrogen gas. At least one combustion One or more of the combustion gases described above are mixed on the outer surface of the metal pipe through the hose for transferring the gas into the plastic powder spray gun which is one of the plastic powder flame coaters and ignited and burned out of the thermal spray gun Fire due to combustion gas And is heated to the outer surface of the metal pipe by a function of a gas torch or through the spray gun of a plastic powder flame coater during the combustion of the combustion gas to generate a flame, The plastic powder is transported from the plastic powder storage container through the hose for transporting the plastic powder by the pressure of spraying compressed air from the spray gun of the plastic powder flame coater through the spray gun of the plastic powder flame coater, The powder gas is sprayed out of the spray gun of the plastic powder flame coater through the spray gun of the coater so that the combustion gas is burned through the spray gun of the plastic powder flame coater described above and passes through the flame of the generated combustion gas, A plastic powder flame coater for instantly melting by the thermal energy of the flame and heating the plastic powder on the surface of the metal pipe while spraying it together to instantly melt and coat it with a required thickness; A powder feeder for supplying a plastic powder and containing at least one or more powdered organs and at least one or more plastic powder storage containers connected to the plastic powder flame coater; An air compressor communicating with at least one of said plastic powder feeder and said powder coating machine; And a combustion gas supplier communicating with the plastic powder flame coater, wherein an inner circumferential surface and an outer circumferential surface of the metal pipe are simultaneously coated with a plastic powder by the powder coating machine and the plastic powder flame coater, At the same time.

In particular, the spray nozzles provided at the ends of the powder spray gun of the present invention may be provided in one or more than one according to the diameter of the metal pipe or the metal tank or the area and thickness of the plastic coating and the type of plastic, The number of guns can be set to one or more spray guns, and the spray guns can be sprayed with plastic powders of different kinds of plastic powders, and spray guns can be sprayed with a plurality of spray guns , Two or more kinds of plastic powders may be sprayed at the same time by varying the lengths of two or more spray nozzles or by arranging two or more kinds of plastic powders at different distances Or with some time difference It may act to apply by spraying the section.

Specifically, the plastic powder provided by the plastic powder feeder of the present invention may be selected from the group consisting of powder epoxy, maleated polyethylene, maleated polypropylene, acrylic acid treated polyethylene, acrylic acid treated polypropylene, chlorinated polypropylene treated polyethylene, chlorinated poly Propylene-treated polypropylene, polyamide, polyvinylidene fluoride, and ethylene tetrafluoroethylene.

Another object of the present invention is also achieved by a metal pipe or a metal tank coated with a plastic coating on both sides, characterized in that the inner circumferential surface and the outer circumferential surface of the metal pipe are simultaneously coated with a plastic powder, have.

Another object of the present invention is to provide a method of coating plastic on both sides of a metal pipe or a metal tank, wherein a thickness of the plastic coating layer to be coated is at least 3 mm or more.

The structure of the present invention as described above can be applied to a metal having one end opened or both end opened or one end opened and a flange attached or a flange attached to both ends for the purpose of reinforcing corrosion resistance and abrasion resistance A metal tank having a diameter of 50 mm or more in diameter or a metal tank having a flange having a diameter of 5 cm or more on one end or both ends at the same time, It is possible to freely coat the plastic powder with a thickness of 1 or more layers without being restricted by the type and thickness of the plastic.

1 to 3 are schematic views showing an apparatus for simultaneously coating a plastic powder on both sides of a metal pipe according to the present invention.
4 is a perspective view showing the plastic powder feeder of the present invention.
5 is a structural view showing the plastic powder flame coater of the present invention.
6 to 8 are cross-sectional views showing a double-side coated metal pipe as an embodiment by the apparatus of the present invention.

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

1 to 8, an apparatus for simultaneously coating plastic powder on both sides of a metal pipe according to the present invention includes a base frame B, a pipe rolling machine 70, a plastic powder spraying organs 10, The spray nozzle 12, the plastic powder flame coater 20, the air compressor 30, the compressed air storage container 40, the plastic powder feeders 51a, 51b, 53 and 55 and the combustion gas storage container 60 ).

The pipe rolling device 70 includes a frame (no number) capable of supporting the metal pipe 200 which is heavy in weight and a plurality of turning rollers (not shown) capable of rotating the metal pipe 200 at a desired speed, . Here, the turning rollers are preferably interlocked by one driving motor (not shown).

The plastic powder spraying organs 10 have at least one or more plastic powder spray guns which are charged into the interior of the metal pipe 200 so as to spread and spray the plastic powder, (12a), (12b) and (12c) are mainly made of plastic powder. Down direction. Here, the plastic powder spraying organs 10 are in communication with the air compressor 30, the first, second and third plastic powder feeders 51a, 51b and 53, respectively.

The plastic powder spraying organs 10 mix the plastic powder supplied from the plastic powder feeders 51a, 51b and 53 with the compressed air supplied by the air compressor 30 in the powder feeder, And sprayed to the lower side of the inner circumferential surface of the metal pipe (200) through the communicated plastic powder spraying nozzle (12).

Here, the plastic powder spraying degree diagram 10 of the present invention receives and discharges the plastic powder fed from the plastic powder feeders 51a, 51b and 53 in the following manner.

 Only the plastic powder supplied from the first and second plastic powder feeders 51a and 51b is sprayed. Here, the first and second plastic powder feeders 51a and 51b are filled with the same or different types of plastic powder.

 Only the plastic powder supplied from the third plastic powder feeder 53 is injected

 The respective plastic powders fed from the first, second and third plastic powder feeders 51a, 51b and 53 are mixed and injected, or different types of plastic powders are injected.

Here, in the embodiment and drawings of the present invention, description is made only in the case where there are three plastic powder feeders 51a, 51b and 53 for supplying powder to the powder coating machine 10, but the present invention is not limited thereto, It is possible to provide four or more pieces in accordance with the above.

The plastic powder feeders 51a, 51b, 53, and 55 of the present invention are chambers having a closed structure, which are formed with innumerable pores having a size of generally 5 to 100 μm, and are made of a porous material of a plastic material mainly composed of a foamed polyethylene material (P40i) communicating with a compressed air storage container (40) storing compressed air supplied from an air compressor (30) or an air compressor (30) on the basis of an air bearing plate And a hopper portion for storing the plastic powder of the powder. The plastic powder feeders 51a, 51b, 53, and 55 feed the plastic powder through the pipe P40d communicated with the hopper while the upper plastic powder is suspended by the compressed air supplied through the fine pores of the perforated plate. The plastic powder spraying is also supplied to the organ 10 and the plastic powder spraying nozzle 12. Here, the hopper is provided with a door (D) for opening or closing the plastic powder into the hopper or for taking out the used plastic powder, and a plastic powder flow controller, which is one of the long- It can be adjusted by communicating with compressed air pressure regulator.

In addition, the plastic powder feeders 51a, 51b, 53 and 55 are provided with shut-off valves which can supply or block the plastic powder to the pipes connected to the respective hoppers, A regulator may be provided.

 The plastic powder flame coater 20 is a plastic powder flame coater for coating the outer circumferential surface of a metal pipe 200 with a plastic powder or for coating a flange portion of a flanged metal pipe 300, The plastic powder supplied from the feeder 55 and the propane gas supplied from the combustion gas storage vessel 60 or one or more of acetylene gas or hydrogen gas may be mixed to form a heat source and the outer circumferential surface of the metal pipe 200, A specific portion or an entire surface of the flange surface of the metal plate 300 is selected to coat the plastic powder.

In addition, the plastic powder flame coater 20 can move horizontally to the left and right as a wheel with wheels mounted on the rails Ra of the steel, or to raise and lower the metal powder in a metal pipe 200 or a metal tank 300 mounted on a bracket (Br) mounted on a stand support (S) capable of freely adjusting an outer surface and a distance.

3, the plastic powder flame coater 20 is attached to a bracket (Br) mounted on a hanger (H) fixed to an upper frame or a ceiling wall, And moves in the horizontal direction to cover and coat the outer surface of the metal pipe 200 with the plastic powder.

Here, the plastic powder flame coater 20 has a plastic powder jetting port N55 for spraying the plastic powder as a single small hole mainly located at the center in the spray gun for spraying the plastic powder, and the above-described combustion gas storage container 60 And a plurality of small holes (h) for spraying the combustion gas supplied from the plastic powder flame coater (20) to the outside of the spray gun of the plastic powder flame coater (20).

The heat discharging port N60 is formed as a plurality of small holes in the structure of the spray gun and is disposed adjacent to the plastic powder discharging opening N55 for discharging the plastic powder outwardly with a plurality of small holes, The plastic powder Pp supplied through the powder feeder 55 and the pipe P55 for feeding the plastic powder fed from the powder feeder passes through the flame generated by generating the flame by burning the plastic powder Pp through the heat discharge port N60, The plastic powder Pp sprayed to the outside of the spray gun by the generated heat of the flame is momentarily melted and coated on the outer surface of the metal pipe 200. Here, the unexplained reference numeral P1 is a plate on which the small holes h described above are formed, and the reference numerals Pp, Fl, and N60 are plastic powder, flame, and combustion gas discharge ports, respectively.

The plastic powder flame coater 20 according to the present invention can ignite only the plastic powder or ignite it through the heat discharging port N55 of the spray gun which is one of the plastic powder flame coater apparatuses using the combustion gas without using a separate heating device . Is generated through the heat outlet (N55) located in the spray gun of the same plastic powder flame coater while heating the outer surface of the metal pipe using the flame heat generated by combustion or spraying the plastic powder through the plastic powder spray outlet (N60) The metal pipe 200 is melted instantaneously and passes through the heat of the flame and the flame, and is coated on the outer surface of the metal pipe 200 with the required kind of plastic powder and the required thickness of the coating film. can do.

The pipe connecting the plastic powder flame coater 20 and the hopper of the fourth plastic powder feeder 55 is provided with a shutoff valve capable of supplying or shutting off the plastic powder as described above, A powder flow regulator is provided. Here, the reference numerals P30, P55, and P60 are pipes communicating with the air compressor 30, the plastic powder feeder 55, and the combustion gas storage container 60, respectively.

The working relationship of the apparatus for simultaneously coating the plastic powder on both sides of the metal pipe according to the present invention will be described below as an example.

In order to construct the present invention, the metal pipe 200, which has been preheated to a surface temperature of 230 to 350 ° C. through a surface pretreatment and preheating step, is mounted on the upper surface of the turning roller of the pipe rolling machine 70. Here, the surface temperature of the metal pipe 200 should be constantly maintained at a specific maximum melting temperature of the required kind of plastic between 230 and 350 ° C mentioned above.

Herein, the preheating temperature is specified to be 350 DEG C, the fluorine resin such as polyfluoroalkoxy has a melting temperature range of 300 to 380 DEG C, and in the scope of the present invention, the melting temperature range of almost all plastic materials is 160 to < 350 < 0 > C.

At this time, the air compressor 30, the compressed air storage container 40, the plastic powder feeders 51a, 51b, 53 and 55, and the combustion gas feeder 60 are connected to the plastic powder spraying organ 10 It must be prepared in advance so that the plastic powder flame coater 20 can be used.

Thereafter, the plastic powder spraying is carried out in such a manner that the plastic powder spray gun 12 having a length for covering the organ 10 with the length of one end of the required metal pipe is prepared to be loaded into the inner circumferential surface of the metal pipe 200, The ends of the spray gun of the coater 20 and the plastic powder flame coater are positioned adjacent to each other considering the length of the spark that can be coated on the outer circumferential surface of the metal pipe 200. [

The distance between the end of the spray gun of the plastic powder flame coater and the outer surface of the metal pipe is usually about 15 to 50 cm when propane gas is used in the combustion gas. However, when the metal pipe is heated or only the plastic powder is sprayed The distance between the outer surface of the metal pipe and the tip of the spray gun depends on the kind of the plastic powder to be coated on the outer surface of the metal pipe and the thickness of the coating film In accordance with the size and length of the flame generated from the spray gun, it is used.

Subsequently, the plastic powder sprayer 10 and the plastic powder flame coater 20 are operated to simultaneously start coating the inner and outer circumferential surfaces of the metal pipe 200 using the plastic powder.

Here, the plastic powder flame coater 20 is one of the constituent processes for spraying only plastic powder, providing only flame heat, or spraying plastic powder, and passing the flame-heat through the flame to instantly melt and coat the plastic powder flame coater 20 And can be selectively provided.

The method of melting the plastic powder by using the combustion gas by the plastic powder flame coater 20 of the present invention and coating the outer surface of the metal pipe at the same time is a method in which the powder epoxy is coated and coated inside the metal pipe The surface temperature of the outer surface of the metal pipe is adjusted to the melting temperature inherent to the powder epoxy resin in order to coat the powder epoxy on the outer surface of the metal pipe because the powder epoxy does not reach the inherent melting temperature of the powder epoxy on the inner surface of the metal pipe. In order to increase the temperature to 190 to 230 ° C, the surface of the metal pipe having the surface temperature lowered to 190 ° C or lower is moved to heat the surface of the metal pipe through the sintering furnace or the high frequency heating device, A plurality of electrostatic powder particles are coated with a necessary thickness through an organ It does not constitute a cumbersome and complex coating process as in the case of coating.

In addition, in the method of coating both surfaces of plastic according to the present invention at the same time, heating can be continuously maintained by selectively providing flame heat in a state where the plastic powder is coated on the outer circumferential surface of the metal pipe 200, , The surface temperature of the metal pipe is adjusted to the required temperature and maintained constantly. Therefore, the thermal shock rate is low due to the small thermal temperature deviation as compared with the conventional technology, and the loss of heat energy due to reheating and the saving of manpower and time can be saved In addition, there is an advantage in that the coated coating of the plastic pipe covering the inner surface of the metal pipe can be more stable and the coating of the high quality plastic can proceed.

The metal pipe 200a manufactured by the simultaneous coating method on both sides of the metal pipe of the present invention has a coating film IL-1 on the inner peripheral surface and a coating film OL-1 on the outer peripheral surface at the same time.

In addition, the plastic powder spraying wire 10 for spraying and coating the plastic powder onto the inner surface of the metal pipe of the present invention and the spray nozzles 12 of the powder organs are two or three pieces 12a, 12b, 12c ) And a plastic spray with a short length of spray nozzle is also used. The spray of plastic powder, which is composed of a primer adhesive layer in the spray nozzle of long term and spray long term, For example, a plastic powder such as a powdery epoxy resin or a maleicide polyethylene, a maleic polypropylene, an acrylic acid-treated polyethylene, an acrylic acid-treated polypropylene, or a chlorinated polypropylene may be injected and sprayed. The powders that supply the powder also have powder epoxy or polarity in the organs, general low surface energy Polyethylene powder, or a non-polar, low-surface-energy, low-surface-energy polypropylene powder, is used as a primer layer through a short spray gun to provide a powdery epoxy or a polyvinylidene chloride, Polyethylene, acrylic acid-treated polypropylene, chlorinated polypropylene or the like is sprayed and applied onto the surface layer coated with the adhesive layer, followed by coating with a double layer of a plastic material. Can be coated almost simultaneously with the primer layer and the double layer.

In addition, the metal pipe 200b manufactured by coating the plastic powder at the same time with a double layer has a double coating layer (IL-1) (IL-2) formed on the inner peripheral surface thereof, Layer coating film (OL-1) is formed on the substrate.

In addition, the present invention has been described above with reference to a configuration in which a metal pipe is coated with a double layer of the same plastic type or a different type of plastic on the inner surface of the metal pipe.

In addition, another constitutional method of the present invention is to constitute a process of coating the inner surface of the metal pipe with a double layer of the same plastic type or a different type of plastic on the inner surface of the metal pipe, The two or more plastic powder feeders 55 are prepared in such a manner that they are coated with a double layer, and the combustion gas storage container 60 and the two or more plastic powder flame coaters are constituted, First, on the outer surface of the pipe, a plastic powder composed of a primer adhesive layer in one time, for example, a powdery epoxy resin having good adhesive strength, maleated polyethylene, maleated polypropylene, acrylic acid treated polyethylene, acrylic acid treated polypropylene or chlorinated Polypropylene or the like, and then spraying Another powder epoxy or other non-polar, non-polar, general-purpose polyethylene powder with low surface energy, or a polypropylene powder with low constituent and low surface energy, was prepared through a different prepared plastic powder feeder (55) and a plastic powder flame coater and spray gun First, as a primer layer, the plastic powder is covered with a plastic powder flame coater and a spray gun, and coated with a double layer on both sides of the metal pipe at the same time. A coating process can be accomplished.

Therefore, the metal pipe 200c manufactured by such a coating method of the present invention has a two-layer coating layer (IL-1) (IL-2) (OL-1) Respectively.

Here, it has been described that a coating film can be formed on both sides of a metal pipe manufactured by the apparatus according to the present invention with one or more layers of plastic powder at the same time.

Here, with the apparatus according to the present invention, the other one of the metal pipes may be a metal pipe having a hole having a diameter of 5 cm or more on one side or both ends thereof, or a flange having a diameter of 5 cm or more on one end or both ends, Or a closed filter housing having a flange having a diameter of 5 cm or more at both ends or a flange having a diameter of 5 cm or more on one end or both ends thereof, or a metal container such as a metal tank, And the specific portion or the entire surface portion of the flange surface can be coated on the outer surface of the metal pipe by the plastic powder flame coater of the present invention, The plastic can be coated and coated simultaneously with the inner surface of the metal container in the same manner.

FIG. 2 also shows a method of coating a plastic powder on both sides and flange surfaces of a metal pipe or a metal container such as a metal tank or a metal filter housing in which a flange is attached to one end or both ends thereof.

Hereinafter, in the present invention, a metal tank or a metal filter housing having a flange at one end, a flange at both ends, and the like are collectively referred to as a metal container.

2, the inner surface of a metal pipe or a metal container having a flange at one end or at both ends thereof is coated with a plastic powder by a plastic powder spraying organs 10 and a plastic powder spraying nozzle 12, The outer surface and the flange surface can be covered and coated with a plastic powder flame coater 20 by selecting the type and thickness of the plastic powder as required.

Therefore, the other one of the above-mentioned metal pipes may be a metal pipe having a hole having a diameter of 5 cm or more on one side or both ends thereof, a metal pipe having a diameter of 5 cm or more on one end or both ends, or a hole having a diameter of 5 cm or more on one side or both ends Or a metal filter such as a sealed filter housing or a metal tank in which a flange having a diameter of 5 cm or more is attached to one end or both sides of the flange is mounted on the same side of the plastic double- It is within the scope of the present invention to disclose that it is possible to coat a plastic powder coating.

Hereinafter, in the embodiments, the description is limited to the metal pipe. However, the present invention is not limited to the metal pipe.

The plastic powder to which the present invention is applied is as follows.

1) It is in the form of a solid powder, usually in the form of a powder having a particle size of from 5 to 500 um, or an average particle size of from 50 to 250 um, and the range of suitable melting temperatures inherent in plastics is usually as follows.

Polar Plastic

Epoxy (bisphenol A and amine curing agent binder composition or bisphenol F and amine curing agent binder composition) - 180 to 230 ° C

Maleic acid-treated polyethylene (maleic acid content 0.25% to 45%) - 80 to 230 ° C

Maleic acid-treated polypropylene (maleic acid content 0.25% to 45%) - 90 to 240 ° C

Acrylic acid-treated ethylene (Ethyl Acrylic Acid content: 6% to 25%) - 60 to 220 ° C

Acrylic acid-treated propylene (Ethyl Acrylic Acid content 5% to 26%) - 80 to 230 ° C

Chlorinated polypropylene (chlorine content 10 to 40%) - 90 to 230 ° C

Chlorinated Polypropylene and Propylene Composite Composite Polypropylene - 90 to 230 ° C

Polyamide-11 Polyamide-12 (including any kind) - 140 to 250 ° C

Poly Vinylidene Fluoride - 135 to 210 占 폚

Non Polar and Surface Energy Very low plastic type

Polyethylene (including HD-PE, MD-PE, LD-PE and L-LDPE) - 130 to 230 ° C

Polypropylene (Homopolymer or Copolymer) - 140 to 240 ° C

Ethylene Tetra Fluoro Ethylene - 200 to 290 DEG C

Here, the kind of the plastic coated with the plastic on one or both surfaces of the metal pipe used in the present invention is not limited to the above-mentioned plastic powder.

This is because the technology used in the present invention is a plastic material which is melted and coated on a metal surface having a preheating or heating by heating or heating of a sintering furnace or a high frequency heater or a plastic powder flame coater for preheating or heating in powder state, The types of plastics which can be sprayed by a spray gun of a tile plastic powder coating machine or sprayed by a plastic powder plastic flame coating machine or can be melted to be melted and coated on the surface of a metal pipe or a metal tank by obtaining a flame heat to be heated, Because.

One of the embodiments as described above is a plastic in powder form which is resistant to corrosion and abrasion and is in the form of a powder or of a polyester or fluoroethylene propylene or polyfluoroalkoxy, Ether ketone (Poly Ethyl Ether Ketone) and the like.

Also, as described in the above description, polyethylene and polypropylene have no polarity and have low surface energy, so that even when a coating film of polyethylene or polypropylene powder is formed on the inner surface of a metal pipe by the apparatus of the present invention, Which does not maintain the adhesion with the inner surface of the metal pipe but is peeled off. Therefore, in order to impart polarity to the polyethylene, it is preferable to add 0.25% to 25% of maleic acid to polyethylene and perform polymerization or compounding, (Maleic polyethylene) powder 51a, 51b (53b) made of polyethylene terephthalate or polyethylene terephthalate, or 0.25 to 45% of maleic acid in polypropylene, ) 55 to be used.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

10: Plastic powder injection long term
12; Plastic powder spray nozzle
20: Plastic powder flame coater
30: air compressor
40: Compressed air storage tank
51, 53, 55; Plastic powder feeder
60: Combustion gas storage container
70: Turning roller
200: Metal pipe without flanges at both ends
300: Metal pipe or metal container with a flange attached to one end or both ends
N55: Plastic Powder Flame Coater Spray Gun in Plastic Powder Spray
N60: Plastic Powder Flame Coater Spray Gun Combustion Gas Combustion Heat Exit

Claims (4)

A pipe rolling mill having a frame and a plurality of turning rollers provided on top of the frame;
And a powder spray gun which is charged into the metal pipe rotated by the turning roller and moves back and forth;
A plastic powder flame coater disposed adjacent to an outer circumferential surface of the metal pipe;
At least one plastic powder feeder supplying the plastic powder and connected to the plastic powder sprayer and the plastic powder flame coater, respectively;
An air compressor communicating with at least one or more of the plastic powder feeder and the plastic powder jetting road organ and the plastic powder flame coater;
And a combustion gas storage container communicating with the one or more plurality of plastic powder flame coaters and supplying a combustion gas,
Wherein the plastic powder spraying coating is performed by coating the plastic powder onto both sides of the metal pipe and simultaneously with each layer by the plastic powder flame coater.
The method according to claim 1,
And a plastic powder spraying nozzle for spraying a plastic powder onto the inner surface of the metal pipe and having two or more organs and a plurality of plastic powder spraying nozzles each having a length shorter than the length of one plastic powder spraying nozzle, Injection of powdered plastic powder organs and plastic powders Spray nozzles with short lengths of the organics are made of a primer adhesive layer in a single cycle. Powdered epoxy resin or acrylic polyurethane with good adhesion, maleic polypropylene, acrylic acid Or by spraying a plastic powder of one of polyethylenes, acrylic acid-treated polypropylene or chlorinated polypropylene, or polyamide, or polyvinylidene fluoride or ethylene tetrafluoroethylene plastic powder, On a surface layer covered with a primer layer, a powdered epoxy or non-polarized polyethylene, or a non-polarized polypropylene or polyvinylidene fluoride, etc., through a long plastic powder spray gun, Or two or more layers of plastic resin are coated on the inner surface of the metal pipe at the same time and at the same time the plastic powder is coated on the outer surface of the metal pipe so that two or more plastics The powder flame coater is constituted so that one plastic powder flame coater is made of a plastic material which constitutes the primer adhesive layer one time in the first place, and is made of powder epoxy or malleable polyethylene, maleated polypropylene, acrylic acid treated polyethylene, A polypropylene or chlorinated polypropylene, or a polyamide or polyvinylidene fluoride to form a surface layer in which the plastic powder is melted and coated with a single layer, or a powdery epoxy or polyvinylidene fluoride , Acrylic acid polypropylene, acrylic acid-treated polyethylene, acrylic acid-treated polypropylene or chlorinated polypropylene, or polyamide or polyvinylidene fluoride to melt the plastic powder and coat it with one layer On the surface of the primer coating layer constituting the surface layer constituting the surface layer, a powdery epoxy or non-polar polyethylene powder or a non-polar polypropylene powder or polyamide or a polyvinyl And one or more different types of plastic powders, one or more of which are coated with the plastic on the outer surface of the metal pipe at the same time.
3. The method according to claim 1 or 2,
The plastic powder provided by the plastic powder feeder,
Polyvinylidene fluoride, polyvinylidene fluoride, polyvinylidene fluoride, polyvinylidene fluoride, polyvinylidene fluoride, polyvinylidene fluoride, polyvinylidene fluoride, polyvinylidene fluoride, polyvinylidene fluoride and polyvinylidene fluoride. Ethylene tetrafluoroethylene, or a mixture of two or more kinds of plastic powders.
A metal pipe, wherein at least one layer of the plastic powder is coated on both the inner and outer surfaces at the same time by one device selected from any one of claims 1 to 3.

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