JP2679908B2 - In-pipe resin lining method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for lining resin in a pipe, and more particularly to an improved method and apparatus for lining a resin in a pipe for lining the inner surface of a cast iron pipe or the like.

[0002]

2. Description of the Related Art Conventionally, an inner surface of a metal pipe such as a cast iron pipe is lined with a resin having excellent chemical resistance for the purpose of preventing corrosion. As a means for this resin lining, a heated metal tube is rotated around an axis, a trough-shaped trough is inserted into the inside thereof, and a thermoplastic powder resin is supplied and melted to be uniformly attached. The thermoplastic powder resin has conventionally been blended with a filler such as sand for the purpose of improving coating film strength and adhesion to a metal substrate.

[0003]

[Problems of Prior Art By the way, some cases of sewer pipes through which fluid flows, is possible surface because a change in flow rate caused by the density state of the inner surface must be a smooth corrosion paint by gravity flow, granular sand When the lining was performed with the powdered resin paint containing the above-mentioned filler, there was a problem that the flow efficiency was deteriorated. Such a problem can be solved by reducing the amount of granular filler such as sand that causes the surface to be rough or adding no filler at all, but when such a powder resin coating is used, the service life and adhesion of the lining are considerably poor. There was a problem. In addition, it is also conceivable that after coating with a powder resin containing a granular filler such as sand, the surface coating is performed only with the powder resin containing no filler.
Due to the difference in melting time, there was a problem that the adhesion of the powder resin to be supplied later to the substrate was poor and delamination occurred. Therefore, there is a problem that it is very difficult to apply an inner surface anticorrosion coating having a long service life and good flow-down efficiency and a smooth surface.

[0004]

In view of the above problems, the present invention provides a resin lining for pipes which has a high coating strength, is rich in anticorrosion function, and can be subjected to a smooth surface lining which does not reduce the flow efficiency. It is made for the purpose of providing a method and an apparatus thereof.

[0005]

That is, a method for lining a resin in a pipe of the present invention is a lining made of a polyethylene resin powder containing sand as a filler when the resin powder is supplied to the inner surface of a heated metal pipe for lining. After uniformly distributing and supplying the material, at the same time as uniformly melting the resin, a polyethylene resin powder containing no filler is uniformly dispersed and melted, and then cooled. An apparatus for performing the above method, comprising: two trough-shaped troughs supported on a trolley, which are inserted into a heated metal tube rotatably supported on a rotating table, and an inversion of the two troughs. And a drive device for performing the operation.

[0006]

In the present invention, the metal pipe to be lined is a commonly used metal pipe such as a cast iron pipe and a ductile pipe, and there is no particular description on the material thereof. In the present invention, when the inner surface of the pipe is subjected to lining, first, the metal pipe subjected to the base treatment is heated, and the inner surface thereof is uniformly sprayed with a lining material made of a polyethylene resin powder containing sand as a filler, and then supplied. , polyethylene of the resin powder is immediately after started to melt by heat, it does not contain filler
Len resin powder is evenly dispersed and melted. By successively spraying with this very small time difference, the first sprayed resin powder layer and the second sprayed resin powder layer are mixed and melted, and the boundary between the two disappears, and the lining layer surface becomes very smooth. is there. The apparatus of the present invention achieves the above-mentioned object by inserting two trough-shaped troughs into the pipe in order to spray the resin powders of different formulations with a small time difference, spraying one trough, and then spraying from the other. is there.

[0007]

Next, an embodiment of the present invention will be described. FIG. 1 is a side sectional view of an apparatus for carrying out an embodiment of the present invention, and FIG.
FIG. 3 is an enlarged vertical sectional view of the apparatus of FIG. 3, and FIG. 3 is an enlarged sectional view of a main part of a lining pipe embodying the present invention.

Examples 1 to 6 The inner surface of a cast iron pipe 1 having an inner diameter of 50 cm was surface-treated by sandblasting, the cast iron pipe 1 was placed on a turntable 2, rotated at 60 RPM, and heated to 330 ° C. by blowing hot air. Next, a trolley 3 that supports two trough-shaped troughs 2A and 2B in parallel is prepared, and one trough 2A of each trough 2A has 5 parts by weight of a high-density polyethylene resin powder and a low-density polyethylene 5 1 part by weight of the ionomer resin, 5 parts by weight of silica sand powder was mixed with the resin powder A, and the other trough 2B was supplied with the resin powder B consisting only of the high-density polyethylene resin powder. And the trough 2A was turned upside down and the resin powder containing the filler was supplied to the trough 2A so that the resin powder was evenly spread over the inner surface of the tube. It takes 20 seconds to less than 1 minute to form this uniform coating film, depending on the type of resin described below.
Immediately after confirming the homogenization, the other trough 2B was inverted to supply the resin powder. Therefore, the two kinds of resin powders supplied were in a layered supply state with a slight time lag, and were dispersed on the inner surface of the metal tube. After confirming that the two kinds of resin powders were sprayed over the entire circumference of the pipe, the trough was retracted, and the coating was cured by slowly cooling while the metal pipe 1 was still rotated. When the cross section of the coating film is enlarged and observed with a microscope, as shown in FIG. 3, the resin A with the filler and the resin B without the filler are laminated and integrated on the surface of the metal tube 1 with the boundary being unclear. It had been. In Example 2, low-density polyethylene was used in place of the high-density polyethylene used in the powder B of Example 1, ionomeric resin was added to high-density polyethylene in Example 3, and low-density polyethylene was also used in Example 4. Polyethylene to which an ionomer resin was added, the same adhesive polyethylene as in Example 5 and the same powder epoxy paint as in Example 6 were used. Only the final powder epoxy paint was supplied by spraying, not by trough.

Comparative Example 1 The same cast iron pipe 1 as in Example 1 was used, the same surface treatment was carried out, and then rotary heating was carried out under the same conditions as in Example. A trolley supporting one conventionally used trough is prepared in this tube, and the powder resin having the same filler composition as that of A of Example 1 is supplied to the trough and inserted into the heated metal tube 1. At the same time, the trough was reversed to supply the resin powder containing the filler, and after confirming that the resin powder was uniformly distributed in the pipe, the trough was immediately withdrawn, and subsequently the same powder resin without filler as in Example 1B was used. Was supplied to the same trough, again inserted into the tube, inverted, and supplied to the inner surface of the tube. It should be noted that the time required from the application of the powder resin containing the above filler to the subsequent application of the powder resin is 2
It was strong. After confirming that the powdered resin which was sprayed later was uniformly supplied into the tube, the trough was pulled out and the coating film was cured in the same manner as in Example 1.

Comparative Example 2 By the same means as in Comparative Example 1, only the powder resin containing the filler was supplied, and the coating film was cured in the same manner.

The in-pipe resin lining device G used in the above embodiment is cantilevered troughs 2A and 2B, which are cantilevered troughs 2A and 2B, respectively, on drive devices 5A and 5B composed of motors supported on a carriage 3 as shown in FIGS. They are supported and connected, and each of them is independently driven to be inverted by a switch or the like.

The surface roughness of the lining pipes obtained in Examples and Comparative Examples 1 and 2 was measured according to JIS B 0601 and the adhesion of the lining layer was tested. The results are shown in Table 1.

[0013]

[Table 1] In Table 1, the evaluation of adhesiveness x indicates a state in which it is easily peeled off when raised with a nail or the like.

As is clear from Table 1, the adhesiveness between the underlayer (A) and the surface layer (B) is clear in Example 1 and Comparative Example 1 even though the same powder resin coating material is used. And the average surface roughness Ra of Examples 1 to 6 is 1.8.
It was found to show a very good value of ~ 6.6.

[0015]

As described above, according to the present invention, a resin having excellent smoothness is laminated on a lining layer containing a filler having high adhesion and durability, and both are integrated in a fused state. A lining layer having excellent smoothness and strength can be formed quickly and easily. Further, since the apparatus used for the method of the present invention has a simple structure, it has various effects such as easy implementation.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an apparatus for carrying out an embodiment of the present invention.

2 is a vertical cross-sectional view of the device of FIG.

FIG. 3 is an enlarged cross-sectional view of a main part of a lining pipe embodying the present invention.

[Explanation of symbols]

 1 ... Cast iron pipe, 2A, 2B ... Trough, 3 ... Truck.

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Claims (2)

(57) [Claims] 1. When lining is performed by supplying resin powder to the inner surface of a heated metal pipe, a lining material made of polyethylene resin powder mixed with sand as a filler is uniformly dispersed and supplied, and then the resin is uniformly melted. At the same time, the polyethylene resin powder containing no filler is evenly dispersed and melted,
A method for resin lining in a pipe, characterized by cooling thereafter. 2. From two gutter-shaped troughs supported on a trolley, which are inserted into a heated metal tube rotatably supported on a rotary table, and a drive device for inverting the two troughs. In-tube resin lining device characterized by the following.