JPH0519894B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lining method using powdered resin.

[Conventional technology]

Methods for resin lining an object such as a metal strip generally include a method of using powdered resin and a method of pasting a preformed lining sheet.

A lining method using powdered resin is a method in which an object to be lined is heated, the powdered resin is brought into contact with the object, and the resin is heated and melted to form a coating layer. The principle of this powder resin lining is
The powder adhering to the object melts due to heat transfer from the object, and the viscous flow causes mass transfer between the particles, and the air between the particles is expelled by contraction pressure based on the reduction in surface energy. However, it is thought that a film is formed without air entrainment, and that the powder adhering thereon is melted by heat transfer and bonded to the previously formed film. Methods for applying or supplying powdered resin to an object include a fluidized dipping method, a sprinkle method, an electrostatic coating method, and the like.

[Problem to be solved by the invention]

However, since this method applies powdered resin to the object, coating may be uneven or impossible due to the shape and direction of the object, and there are many cases where thicker coating is required. It was very difficult. In order to eliminate uneven coating and coating failure, devices such as rotating, reversing, and moving the target object or coating device have been devised, but there are limits to this, and the object to be coated may be coated due to its shape or shape. Alternatively, there were restrictions regarding the amount of coating (or coating thickness).

On the other hand, lining sheets used in the method of pasting preformed lining sheets include:
Generally, thin films (about 0.01 to 0.1 mm) are used as cover materials for cosmetics, and thick films (about 0.3 to 5.0 mm) are used for long-term corrosion resistance, impact resistance, etc.
There are resin melt-molded thick film sheets for coating lining, but all of these are completely melt-molded. In order to attach a completely melt-molded lining sheet to an object such as a metal strip, simply heat welding the sheet will result in weak bonding strength, so it is necessary to heat weld it with an adhesive layer interposed. However, the lining work is troublesome. Furthermore, the method of attaching lining sheets is often used and adapted to flat or simply curved flat plates, the outer surface of metal pipes, etc.; It is unsuitable for shapes such as extremely large, small, or intermittent coatings. In addition, the lining sheet is formed by heating and melting the resin raw material in pellet form in an extruder and then extruding it, so the final physical properties of the resin are such that it cannot be reheated. However, when heat welding a lining sheet to a metal strip to be coated, there is a large difference in coefficient of thermal expansion between metal and plastic; However, during the subsequent cooling, solidification, and formation of a film, there are problems in that the film becomes sagging, wrinkled, and ends are turned up.

In order to solve this phenomenon such as sagging and wrinkles,
Tension is applied to the lining sheet during manufacturing, so that the sheet itself has shrinkage stress. The stress of this shrinkage appears as a shrinkage phenomenon during heat welding, and this shrinkage is used to absorb the difference in thermal expansion and prevent the occurrence of sagging, wrinkles, etc., but this method is not a mechanical method. Because the shrinkage effect is directional, there may be differences in the time and amount of heat transfer from the metal strip, or
In the case of a double layer consisting of an adhesive layer and a skin cover layer, the balance of expansion and contraction between the two layers may be lost, and it is extremely difficult to completely prevent sagging, wrinkles, etc. Moreover, problems such as overlapping of ends, steps, recesses, etc., remain, such as exhaustion of residual air.

There is also a method of applying tension when welding the lining sheet, but this method is difficult to use, for example, by coating the outer surface of a straight steel pipe with a simple fixed shape or direction, such as a coating method commonly known as a circular die or T-die method. limited to those of Moreover, in the welded coating lining construction using this method, the lining sheet is pressed down with a roller or the like or tension is applied to the lining sheet with a tension device, but the load, position, direction, shape, material, etc. of the roller or tension device are
In addition, since the surface of the lining sheet is the final finished surface, equipment, rollers, etc. must be used to prevent scratches, unevenness, etc. on the surface during the manufacturing or pasting of the lining sheet. Care must be taken when handling the
If regular maintenance was not performed sufficiently, defective products would occur.

Due to the above-mentioned drawbacks, the method of using a lining sheet is currently restricted due to its shape and its intended use is limited.

The present invention was made in view of such conventional problems; it is difficult to laminate thick films at once;
The disadvantages of the powder-resin lining method are that it is difficult or impossible to form a uniform lining coating layer on objects that cannot be moved, and that the coating is distorted due to heating, resulting in sagging, wrinkles, and unevenness. It is an object of the present invention to provide a resin lining method that is easy to apply and can solve both the disadvantages of the lining coating method using a lining sheet, such as the occurrence of the above problems and the need to use an adhesive.

[Means to solve the problem]

The present invention, which has been made to achieve the above object, is a powder resin lining that has a porous structure in which a powder resin that becomes fluid when heated and melted has a porous structure in an unmelted or partially melted state, and which is used for lining. Forming a powder resin molded body for lining by molding it into a shape that can be adapted to the object and a thickness that can form a lining coating layer of a desired thickness when heated and melted,
The powder resin molding is applied to the object to be runned, and the object is heated before and after that, and the powder resin molding is heated and melted from the side in contact with the object by heat transfer from the object. This is a powder resin lining method characterized by forming a resin lining coating layer.

The powder resin used in the present invention may be one that can be used for powder resin lining, that is, one that softens and melts when heated to become fluid, and solidifies when cooled to form a film. , thermosetting resin, or thermoplastic resin. The suitable size of the powder resin is 50 to 150μ.

[Effect]

As described above, in the present invention, before supplying the powder resin for powder resin lining to the object to be coated (mainly metal strips), it is made into a powder resin molded body with a porous structure. Since it is supplied to the target object in the same state, it is extremely easy to handle. In other words, it is sufficient to simply apply the powder resin molding to the object, and unlike conventional powder resin linings, a special feeding method of powder resin is required to form a film of uniform thickness. There is no need to adopt or rotate the object.

For lining, this powder resin molding is applied to the object to be coated, and the object is heated, or the molded object is applied after heating the object. As a result, first, the part of the powder resin molding that is in contact with the target object is heated and melted by heat transfer from the target object, and mass transfer between the powders occurs due to viscous flow, and also due to a decrease in surface energy. The air space between the powder particles is crushed by the contraction pressure, and a thin molten film is formed on the surface of the object while expelling air from the system. Next, the portion that contacts this molten film is heated and melted by heat transfer, and is integrated with the previous molten film, increasing the thickness of the molten film. Thereafter, similar operations are repeated. Here, since the above-mentioned molded body has a porous structure in which the powder resin is unmelted or partially melted, the melting operation in the molded body will eventually cause the lining powder to melt against the heated object. This is similar to supplying or applying powder (hereinafter simply referred to as powder) at regular intervals and heating and melting the powder. Thus,
After the entire powder-to-resin molding pair is heated and melted, it is cooled,
By solidifying, a resin lining coating layer of uniform thickness is formed. Here, the thickness of the powder resin molding is set so that the lining coating layer formed by melting it has the desired thickness, so one powder resin molding is pressed onto the object. By applying and heating and melting, a resin lining coating layer of a desired final thickness is formed.

Usually, in the method of forming a thick film lining coating layer using powder, heat transfer from a heated object melts the supplied or applied powder, and the powder is then supplied or applied to the molten state. Powder adheres, and it also melts due to heat transfer. By repeating this process, a predetermined film thickness is formed. melting, adhesion,
It takes time to repeat heat transfer and melting, and even if you supply or apply more powder than necessary, the amount of powder that will adhere to the molten area is fixed, and in order to obtain the required film thickness, it is necessary to It takes time. A lining coating layer with a uniform thickness is formed by sequentially and uniformly supplying or applying the powder using some kind of device or movement within that period of time, so it is impossible to apply such a movement to objects whose shape makes it impossible. In the case of powder, a non-uniform coating layer is formed, which naturally limits the application of powder.

However, with the powder resin molded product of the present invention, as described above, the molded product itself sequentially supplies uniform powder, so there is no need for a special feeding device or coating device, and , it is not necessary to rotate or invert the object to be coated.
Since the molded product has a porous structure composed of unmolten or only partially melted powder resin, it is easy to degas, soften and melt when heated, and then solidify and form a film by cooling. While passing through the process, expansion and contraction, changes in density, and changes in volume occur.
There is no stress-induced distortion in the solidified film after cooling.
Since the heat transfer efficiency during melting is good and there is little heat radiation, the coating layer formation time can also be shortened.

On the other hand, the lining sheet is softened and melted by heating, then solidified by cooling, and passes through or is in the process of being coated, and the final density and volume of the resin have changed. ,
When heat welding to objects such as metal strips, there is a serious problem of sagging, wrinkles, etc. due to distortion due to the difference in coefficient of thermal expansion with the object and distortion generated in the lining sheet itself due to heating. Although it has drawbacks, the powder resin molded body for lining according to the present invention does not undergo much expansion, contraction, density, or volume change during molding, even if it is the same molded product, and it does not change much in terms of heat melting and melting during lining construction. Cooling and solidification causes expansion and contraction, changes in density, and changes in volume, so there is no sag in the lining coating layer, unevenness due to wrinkles, or residual air that occurs in steps, recesses, and overlapped areas.

In the present invention, the powder resin molded body for lining is heated and melted at the part in contact with the object to be coated, the powder at the part in contact with the melted part is heated and melted, and by repeating this operation one after another, the powder resin molded body is heated and melted. Any film may be used as long as it increases the thickness of the film and includes a porous structure so that air bubbles can be discharged to the outside during that time. The structure of the molded body does not need to be uniform in the thickness direction;
For example, it may have a shape in which film portions are provided on both sides and the powder resin is wrapped in the film. It is sufficient that the molded body has enough strength to not break or crack during handling, ie, when being transported, stored, pressed against an object, etc. The shape of the powder resin molding may be any shape that can be adapted to the surface of the object to be lined, and does not necessarily have to match the surface of the object. In other words, if the powder resin molding is deformable, it can be pressed against the surface of the object and deformed to fit the object. It may be different from the shape of the object. For example, when the object is a pipe, a flat plate-shaped powder resin molding may be made and this flat plate may be pressed against the outer surface of the pipe. Furthermore, it is also effective to make appropriate cuts in order to make the powder resin molding easier to deform.

In the present invention, the method for producing the powder resin molded body may be any method such as heating and fusing the powder resin, pressurizing the resin, using a combination of heating and pressure, or integrating the powder resin with an adhesive. Further, the heating and pressurizing means may be any method such as a method using a mold or a method using a pair of rolls.

Thus, the powder resin for lining undergoes the processes of softening, melting, and decomposition when heated, so it is possible to perform molding by utilizing a temperature range below the decomposition temperature. The production of powder resin molded bodies obtained by molding can be roughly divided into two types depending on the temperature conditions during molding. That is, one is molded from powdered resin in an unmolten state, and the other is molded by partially melting it. It is preferable to use different types of these depending on the shape, location, etc. of the object to be lined.

A molded article in a completely unmolten state can be obtained by molding at a temperature at which the powder does not melt, that is, below the melting temperature of the powder. Molding the powder at room temperature without heating it at all is cheaper in terms of construction conditions and processing costs. However, the disadvantage is that the molded product obtained is brittle. To compensate for this, the material is heated below the melting temperature to around the softening temperature, which is close to the melting temperature. By heating near the softening temperature, the powder becomes soft and the mechanical bond between the powders improves, making it easier to process into the desired shape (cylindrical, chevron, etc.) and less likely to be damaged during handling or transportation. , the brittleness of room-temperature processed products is eliminated. It is also effective to use a suitable adhesive instead of or in parallel with this. For example, if EVA resin (ethylene vinyl acetate copolymer) is mixed into polyethylene powder resin, molding becomes easier and the adhesion to the object can be increased during lining construction.

The molded body is brought into a partially molten state at a temperature within a temperature range from just above the temperature at which melting starts to decomposition. To achieve this partially molten state, the best temperature is just above melting. To heat-form powder, the temperature of a mold or roll is usually raised to the desired molding temperature. The powder in contact with the rolls is first heated. Therefore, if the mold or roll is heated above the melting temperature, the screen (front, back, inside, outside) or one side of the molded product that comes into contact with the mold or roll will mainly melt and become a film, and the molding temperature will rise. The higher it is, the more it melts. As the amount of melting increases, the characteristics of the powder resin molded product disappear. In order to increase the melting temperature and reduce the amount of melting, a short construction process is sufficient, but since the lining coating layer has a thickness of about 5 mm at most,
At this level, heat transfer is rapid, and although it is not impossible to obtain a uniformly fused surface of a certain amount, it is difficult to construct. Therefore, if the molding is carried out at a temperature just above melting, the melted portion on the surface of the molded product can be made as thin as possible, making molding easier.

It is a well-known fact that when molding powder, it is easier to mold it by applying pressure in addition to the above-mentioned temperature. The powder resin molding only needs to have enough strength to not break during handling or transportation.
The pressing force during molding does not need to be very high, and the shape of the mold or roll used for molding and the pressing means may be simple.

Further, as a method for manufacturing a powder resin molded body in the present invention, first, a powder resin molded body of an appropriate shape, for example, a billet shape, is made using a press molding machine or the like, and this molded body is arranged in stages. There is also a method of rolling the material into a plate shape of a predetermined thickness using multiple pairs of rotating rollers with different intervals between them in stages. With this method, it is possible to easily produce a sheet-like elongated molded body.

Note that the powder resin molded body for lining used in the present invention is not limited to being used alone to form a lining coating layer, but can also be used in combination with a lining sheet. In other words, when wrapping spirally in a coating method using a lining sheet, the powder resin molding is rolled into the layer section as an adhesive layer, or as a base layer for the entire surface, instead of the conventional adhesive layer. This makes it possible to create a seat lining method that does not require any intervention.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to embodiments of the drawings.

FIG. 1 is a perspective view showing a powder resin molded body 1 for lining in one embodiment of the present invention. This powder resin molded body 1 is for flat surface construction and is in the form of a sheet, and at least the powder resin for lining inside the body has a porous structure in an unmolten state or a partially molten state.

FIG. 2 is a perspective view showing a molding apparatus for the powder resin molded body 1 of FIG. 1. In FIG. 2, 2 is a mold that determines the shape of the molded product 1, 3 is a press die, 4 is a receiving die, and 5 is a cylinder that moves the press die 3 up and down. A heater and a thermometer are installed inside the push mold 3 and the receiving mold 4, providing a mechanism that allows temperature control. For molding, first, powdered resin 6 for lining is supplied into the mold 2. The amount of powder at this time is an amount that takes into account bulk density and shrinkage allowance with respect to the amount that will be the final thickness of the lining coating layer. The powder pair 6 may be scattered approximately evenly within the formwork 2. If the spray is completely uneven and non-uniform, it can be spread evenly by adding a step of lightly pressing it 2 to 3 times. Thereafter, the press die 3 is lowered by the cylinder 5, and the powder pair is pressurized and molded. When thermoforming is performed, the press mold 3 and the receiving mold 4 are heated to a predetermined temperature. This heating may be performed before or after the powder is supplied, but heating to a predetermined temperature before the powder is supplied makes it easier for the temperature of the powder to rise quickly and uniformly. The pressure applied to the powder pair 6 during molding varies depending on the heating temperature, and when molding is performed at a temperature below melting, the pressure applied to the powder pair 6 is increased to ensure that the particles of the powder are bonded quickly and uniformly. It's nothing compared to body sintering. In order to make various powders into unmolten compacts, it is necessary to use 2 to 10 kg/kg, although it varies depending on the powder.
At a pressure of cm ² , the thickness (this thickness is regulated by the thickness of the formwork) is suitably 2 to 3 times the thickness of the final lining coating. The pressing time is determined by the melting point, heat conductivity, etc., and shape (size) of the powder.

FIG. 3 shows the sheet-like powder resin molded body 1 of FIG. 1.
FIG. 2 is a perspective view showing a state in which a flat metal plate 8 is lined using the lining. In this case, since the shape (area) of the metal flat plate 8 to be lined and the forming body 1 are the same, the sheet-like forming body 1 is simply brought into contact with the metal flat plate 8 and the metal flat plate is heated. Note that the metal flat plate may be heated before the molded body 1 is brought into contact with it. Due to this heating, the molded body 1 is melted one after another from the part that contacts the metal flat plate, and a molten resin is formed on the upper surface of the metal flat plate 8. After the molded body 1 is completely melted,
By cooling and solidifying, a resin lining coating layer with a predetermined thickness is formed.

FIG. 4 is a perspective view showing a state in which a flat metal plate 9 having a larger area than the sheet-like molded body 1 is lined. In this case, the sheet-like molded body 1 is placed on the top surface of the metal flat plate 9 so that it partially overlaps, and the surface is held down by a pressing device (preferably one made of a material that is smooth, elastic, and non-adhesive). ), heating the flat metal plate 9 while pressing it with a roller 10, for example. Note that the metal flat plate 9 may be heated before the molded body 1 is placed on it. As a result, the sheet-like molded body 1 is melted and the metal flat plate 9 is melted.
A lining coating layer is formed on top. At this time, by pressing the overlapping portions of the molded body 1 with the roller 10, the resin flows around the molded body when melted, and a smooth surface with no steps can be obtained in appearance. Note that even if the connecting parts of the molded bodies are simply butted together instead of overlapping, or if the construction is performed with a slight gap (approximately 2 mm), the molten resin will flow when the resin melts, so a smooth connection can be achieved.

FIG. 5 is a perspective view showing a cylindrical powder resin molded body 11. As shown in FIG. This powder resin molded body 11 is for lining the inner or outer surface of a pipe.
By attaching it to the inner or outer surface of a heated tube, or by heating the tube after attachment, it can melt and adhere to the inner or outer surface of the tube to form a resin lining coating layer. At this time, since the molded body 11 has a constant thickness, it is possible to form a resin lining coating layer of a constant thickness on the tube, and there is no need to rotate the tube as in the case of lining with powder and resin.

FIG. 6 shows a molding apparatus for manufacturing the cylindrical powder resin molded body 11 shown in FIG. 12 is an outer mold, 13 is an inner mold, 14 is a pedestal, and 15 is a cylinder. The powder resin 16 for lining is supplied into the space between the outer mold 12 and the inner mold 13, the outer mold 12 and the inner mold 13 are heated as necessary, and the cylinder 15 is lowered to form the lining powder. resin 16
The molded body 11 shown in FIG. 5 can be obtained by applying pressure to integrate the powder resin.

FIG. 7 is a sectional view showing a method of lining a steel pipe 19 having a resin lining 18 on its inner surface with a flanged short pipe 20 by melt splicing. A flanged cylindrical molded body 21 made of powder resin for lining is placed inside the flanged short pipe 20 and the steel pipe 19.
The ring-shaped powder resin molded body 22 is inserted into the inner surface of the contact area between the resin lining 18 and the molded body 21, and also inserted into the inner surface of the joint between the existing resin lining 18 and the molded body 21 so as to overlap. The steel pipe 19 and the flanged short pipe 20 are heated while the overlapping part and the flange part are lightly pressed with rollers (not shown), the powder resin molded bodies 21 and 22 are melted, and after melting, they are cooled and solidified. This forms a lining coating layer. In this case as well, the heating of the steel pipe and short pipe is performed by
There is no problem even if it is done before the installation.

FIG. 8 shows a sheet-like powder resin molded body 24 formed by molding powder resin for lining. This molded body has cuts 25 made at appropriate pitches, and a reinforcing sheet material 26 is pasted on its surface. After or while peeling off the sheet material 26 on the surface, the molded body 24 is pressed onto the outer periphery of a heated steel pipe 27 while bending the cut portion and sequentially wound in the circumferential direction, as shown in FIG. 9, and is melted. Make it adhere. After that, the overlapping portions at both ends are smoothed by pressing with a roller. Thereafter, a lining coating layer is formed by cooling and solidifying.

FIG. 10 shows a method of using a powder resin molded body 28 in still another embodiment of the present invention.
This molded body 28 is a long belt-like object, and is wound spirally around the outer periphery of a steel pipe 29 heated to a predetermined temperature, while being pressed down with a roller (not shown) to smooth the overlapping part. Melt while finishing. Thereafter, by cooling and solidifying, a resin lining coating layer is formed on the outer surface of the tube. Note that the long molded body 28 may be prepared in advance into a coil shape and supplied from the coil, or alternatively, the long molded body 28 may be supplied from a coil that is wound into a coil shape, or a sheet-like molded body may be continuously formed. A device may be provided and the molding device may be continuously supplied.

Specific examples of the present invention are shown below.

Example: The press mold 3 and receiving mold 4 of the press machine shown in Fig. 2 are 110
Heat to ℃. Softening temperature 97℃, melting temperature 125
℃, and a bulk density of 0.3 g/cm ³ , approximately 120 g of polyethylene powder resin for lining for lining is supplied into a mold 2 measuring 500 mm x 500 mm x 2.5 mm, and the amount is approximately evened out. Pressurize with a press cage pressure of 300 g/cm ³ with a cylinder diameter of 50 mm. After about 5 minutes, the press pressure was released and the mold was taken out of the mold to obtain a sheet-like molded product measuring 500 mm x 500 mm x 2.5 mm. This sheet-like molded product had a porous structure in which the powder resin was hardly melted and the powder was bonded together.

During molding, placing heat-resistant, non-adhesive thin film sheets on the top and bottom of the mold makes it easier to release the mold from the mold, and without peeling off the thin film sheet.
It has been found that when left adhered to the molded body, it acts as a reinforcing material for the molded body and has the effect of preventing damage to the molded body during handling and transportation.

An iron plate (width 500 mm x 500 mm x thickness 6 mm) (the surface has been subjected to pre-treatment such as grit blasting in advance. The same applies to each of the following examples),
Heat to 290℃ using a gas burner. The 500 mm x 500 mm x 2.5 mm sheet-shaped molded body was placed on the surface of the iron plate. After melting and welding for about 1 minute, cool with water from the iron side. Through this operation, a solidified polyethylene lining coating layer of about 1.2 mm was formed on the entire surface of one side of the iron plate. Further, a similar powder resin molded body was placed on a similar iron plate, and then the iron plate was heated with a gas burner to melt and weld the molded body, and then allowed to cool. This also made it possible to form a solidified polyethylene lining coating layer of about 1.2 mm.

Example: An iron plate measuring 500 mm wide x 500 mm x 6 mm thick is heated to approximately 280°C using a gas burner. On the plane, three sheet-shaped molded bodies of 500 mm width x 170 mm length x 2.5 mm thickness formed from polyethylene powder resin for lining are placed side by side so that the overlapping portion is 5 to 10 mm. After about 10 seconds, a smooth, elastic, heat-resistant, non-adhesive roller with a width of 500 mm and a weight of about 1.5 kg is moved over the entire surface while rotating for about 10 seconds. Thereafter, by melting for about 1 minute and cooling with water, a smooth solidified polyethylene lining coating layer with a thickness of about 1.2 mm was formed on one entire surface.

Example The entire circumference of the outer end of the A600 steel pipe with a width of 650 mm is heated to 280° C. using a gas burner. Prepare two curved sheets made of polyethylene powder resin for lining with a width of 500 mm, a length of 970 mm, and a thickness of 2.5 mm and a radius of curvature of 400 mm. In any direction at any time on the circumference,
Press the parts in sequence starting from the parts that are easier to press. Next, the second molded body is sequentially pressed starting from the part that is easier to construct so as to provide an overlapping part of about 5 to 10 mm.
After welding and sticking to the entire circumference, finish the entire surface with a roller etc. so that the uneven parts due to overlap are smoothed.After smoothing, let it cool and solidify to a width of 500mm and a thickness of approximately 1.2mm. A polyethylene lining coating layer was formed. It was also possible to line the inner surface of the steel pipe by performing a similar operation on the inner surface of the steel pipe.

Example A press machine shown in FIG. 6 is used. Split outer mold (inner diameter 153 mm x height 500 mm), inner mold (inner diameter 148
mm x height 500mm) to 110℃. Polyethylene powder and resin for lining with a softening temperature of 97℃, a melting temperature of 125℃, and a bulk density of 0.3g/cm ³ are placed between the outer and inner molds.
Approximately 160g is supplied between the cylinders and pressurized at a press gauge pressure of 250Kg/cm ² with a cylinder diameter of 50mm. After about 6 minutes, the press pressure is released and the mold is removed.
A cylindrical molded body with an outer diameter of 153 mm, an inner diameter of 148 mm, and a height of 400 mm was obtained. This molded body had a porous structure in which the powder resin was bonded with almost no melting.

A150, small diameter steel pipe with a wall thickness of 5 mm and a length of 400 mm (inner diameter
155mm) is heated to 280℃ using a gas burner. The above-mentioned cylindrical molded body is inserted into the inner surface of this steel pipe, and the inner surface of the inserted molded body is rotated and pressed for about 10 seconds with a roller having a length of 400 mm, and then allowed to cool. As a result, a uniform polyethylene lining coating layer with a thickness of approximately 1.2 mm was formed on the inner surface of the tube.

〔Effect of the invention〕

As is clear from the above description, the present invention produces a powder resin molded body by molding the powder resin used for powder resin lining into a porous structure in an unmelted or partially melted state, and then molding the powder resin. Since lining is performed using a powder, it is extremely easy to handle compared to powder, and can be extremely easily supplied to the object to be lined. Furthermore, in the present invention, this powder-resin molded body is applied to an object such as a metal strip, and is heated and melted by heat transfer from the object.
It exhibits the same behavior as the heating and melting of powder resin in powder resin lining, and it is possible to form a lining coating layer with no sagging, wrinkles, unevenness, or air entrainment. Unlike the conventional lining method, which supplies the object as it is, the resin is uniformly supplied to the lining surface, resulting in a plastic lining coating layer with an extremely uniform thickness and smooth surface, with excellent anti-corrosion performance. It has the effect of being able to form.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a powder resin molded body according to an embodiment of the present invention, FIG. 2 is a perspective view showing an apparatus for manufacturing the molded body, and FIGS. 3 and 4 are the same as those shown in FIG. 1. FIG. 5 is a perspective view showing a lining method using a molded body, FIG. 5 is a perspective view showing a powder resin molded body in another embodiment of the present invention, and FIG. 6 is a sectional view showing an apparatus for manufacturing the molded body. FIG. 7 is a sectional view showing a powder resin molded body in still another embodiment of the present invention and its usage state, FIG. 8 is a perspective view showing a powder resin molded body in yet another embodiment of the present invention, FIG. 9 is a perspective view showing a method of using the same, and FIG. 10 is a perspective view showing a powder resin molded product according to another embodiment of the present invention and a method of using the same. 1, 11... Powder resin molded body, 2... Formwork, 3
...Push mold, 4...Receive mold, 5...Cylinder,
8, 9...Metal flat plate, 6,16...Powder resin, 1
2...Outer mold, 13...Inner mold, 15...Cylinder,
18...Existing lining, 19...Steel pipe, 20...
...Flanged short pipe, 21, 22, 24, 28...
Powder resin molded body, 25... cut, 26... sheet.

Claims (1)

[Claims] 1 Powder resin used for powder resin lining, which becomes fluid when heated and melted, into a porous structure in an unmelted or partially melted state, and into a shape that can be adapted to the object to be lined, and which is heated and melted. When this is done, the molded powder resin for lining is molded to a thickness that can form a lining coating layer of the desired thickness, and the molded powder resin is applied to the object to be lined, and before and after that. heating the object;
The powder resin molded body is heated by heat transfer from the object,
A powder resin lining method characterized by forming a resin lining coating layer by heating and melting the resin from the side that contacts the object.