TWI727215B - Method for coating an inner surface of a pipe and the pipe having the coating - Google Patents

Abstract

There is provided a method for coating an inner surface of a pipe and the pipe having the coating. The method may comprise pressing a lining material spirally against an inner surface of a pipe over a length of the pipe and heating the pressed lining material to attach the lining material as a coating on the inner surface of the pipe. The lining material may be an elongate strip. The method may comprise overlapping a portion of edges of the elongate strip as the lining material is pressed spirally against the inner surface of the pipe over the length of the pipe.

Description

Method for coating inner surface of pipe fitting and pipe fitting with coating

The invention relates to a method for coating the inner surface of a pipe fitting and a pipe fitting with a coating on the inner surface of the pipe fitting.

The inner surfaces of various types of conventional pipe fittings used in industry (such as water pipes, gas pipe fittings, heat transfer pipes, etc.) need to be resistant to corrosion and chemical reactions between the pipe fittings and the fluid flowing therein. This can be achieved by coating the inner surface of the pipes with a resin layer such as a fluororesin layer.

Coating or lining fluororesin is often used especially in chemical, medical and semiconductor plants that may be exposed to highly corrosive chemicals.

The fluororesin material may be in the form of a powdery powder, whereby it contains the resin itself or as a compound mixed with additives such as coloring agents, acid scavengers, or fillers. The method of applying the fluororesin material to the inner surface of the pipe can be performed by applying an electrostatic powder coating to the inner surface of the pipe using an electrostatic powder spray gun, and then heating the pipe to melt the powder to form a coating. However, this method can only produce pipes with only one film at a time. If several layers of film are required, several separate coatings are required to achieve the target film thickness. This slows down the pipe fitting manufacturing time. In addition, back ionization is a problem in this method, because the excessive accumulation of electric charge prevents the electrostatic powder from further depositing on the surface of the pipe with the existing coating.

Another method is the Roto-lining method, which involves introducing granular fluororesin materials and heating pipes on the inner surface of the substrate, so that the granular fluororesin materials are melted and allowed to go through a well-controlled rotation and heating process Flow evenly. Since the flow depends not only on the rotation of the substrate, but also on factors such as heating uniformity and the interaction between the fluororesin material and the substrate, it is inherently difficult to control the exact flow of the molten particulate fluororesin material. Generally speaking, the rotary lining method is suitable for linings or coatings with a thickness of more than 1mm, and not suitable for thinner linings or coatings with a thickness of less than 1mm.

In the two aforementioned methods, it is difficult to obtain a uniform thickness of the inner coating without lining defects, because it is difficult to control the spray of the electrostatic powder spray gun and the flow of the molten particulate fluororesin material.

In response to the aforementioned problems/difficulties, various technological developments have been made. For example, fluororesin powder is coated on a metal flat plate before bending and welding to obtain a tubular pipe with an inner surface coating. However, there are negative effects caused by the use of welding technology. The parts subjected to welding will experience a temperature higher than the thermal decomposition temperature of the fluororesin lining material. It is necessary to modify the affected parts in which the fluororesin lining material has decomposed due to high temperature. In addition, the decomposition of fluororesin leads to the release of harmful gases that pose a risk to the human body.

Another method as described in Japanese Patent Application No. JP1992-352689 involves lining the inner surface of the tank with a single piece of fluororesin film, where the fluororesin film does not have any overlap. The end edges of the fluororesin film are adjacent to each other so that the edges form a butt joint. The sealing film is then placed over the butt joint to cover it. The butt joint is sealed using techniques that involve the application of heat and pressure to the sealing film (e.g., heat sealing or welding). However, this process requires additional heating and melting of the sealing film. These additional steps make it difficult to control the thickness uniformity of the coating and reduce the efficiency of the process of coating the inner surface of the tank.

On the other hand, Japanese Patent No. 3954120 describes a method involving drawing a tubular lining hydrocarbon-based material into a metal pipe and pressing the tubular lining onto the inner surface of the pipe by compressed air supplied to the lining material. This method can be applied to hydrocarbon resins such as polyethylene and polypropylene, but it is not applicable to other resins (such as fluororesins) with higher yield point strength. Unlike hydrocarbon resins, fluororesins require higher pressure before they are plastically deformed. Therefore, if this method is applied to coating fluororesin, significant pressure will be required in the manufacturing process, which will affect the efficiency of the manufacturing process or cause safety risks.

According to an aspect of an example of the present disclosure, a method for coating the inner surface of a pipe is provided. The method may include applying the lining material spirally to the inner surface of the pipe over the length of the pipe. Heat can be applied to the pressurized lining material to form a coating on the inner surface of the pipe.

According to another aspect of an example of the present disclosure, there is provided a pipe having a coating applied by the method on the inner surface of the pipe. The coating has a lining material spirally attached to the inner surface of the pipe over the length of the pipe.

100‧‧‧Pipe fitting

102‧‧‧Press roller

103‧‧‧Press roller

104‧‧‧Inner Lining Material

105‧‧‧Distributor

106‧‧‧Overlapping part

107‧‧‧Along the longitudinal axis of the length of the pipe 100

108‧‧‧The diameter of the pipe 100

109‧‧‧Circumference of pipe 100

110‧‧‧The shortest distance; the width of the non-overlapping part

111‧‧‧Width of lining material 104

112‧‧‧Non-overlapping part of lining material 104

121‧‧‧First distributor

122‧‧‧Second Distributor

123‧‧‧Fluorine resin film

124‧‧‧Fluorine resin film

125‧‧‧Guide roller

126‧‧‧Guide roller

127‧‧‧Multilayer film

128‧‧‧Guide roller

129‧‧‧Press roller

130‧‧‧Press roller

131‧‧‧Guide roller

202‧‧‧Rotating shaft of pressure roller 102

204‧‧‧The axis orthogonal to the rotation axis of the pressure roller 102

302‧‧‧Expanded part of lining material 104

500‧‧‧Cross section view of lining material 104

502‧‧‧Top floor

504‧‧‧Middle layer

506‧‧‧Bottom

509‧‧‧Perspective view of part of lining material 104

510‧‧‧Cross-section view of lining material 104

512‧‧‧Top floor

514‧‧‧Bottom

519‧‧‧Perspective view of part of lining material 104

520‧‧‧Cross-section view of lining material 104

522‧‧‧Top floor

524‧‧‧Bottom

529‧‧‧Perspective view of part of lining material 104

532‧‧‧Floor

534‧‧‧Floor

542‧‧‧Floor

544‧‧‧Floor

550‧‧‧Cross-section view of lining material 104

560‧‧‧Cross-section view of lining material 104

562‧‧‧Top floor

564‧‧‧Middle layer

566‧‧‧Middle floor

568‧‧‧Bottom

569‧‧‧Perspective view of part of lining material 104

802‧‧‧Taper roller

803‧‧‧Supporting structure

804‧‧‧Axis

805‧‧‧Mounting block

806‧‧‧Slim support

900‧‧‧Supporting equipment

902‧‧‧Support shaft

903‧‧‧Guide roller support

904‧‧‧Extendable shaft

905‧‧‧roller support

906‧‧‧roller support

907‧‧‧roller

α‧‧‧Inclination angle

Those skilled in the art will be able to better understand and easily understand the specific examples of the present invention by the following written explanations only through examples and combined drawings. Among them: Figure 1 has a spiral coating on its inner surface. A perspective view of the lining material pipe.

Fig. 2 is a top view of the pipe and the pressing roller positioned on the outer surface of the pipe of Fig. 1;

Fig. 3 is a perspective view of a pipe which is spirally coated with the lining material of Fig. 1;

Fig. 4 is a perspective view of a pipe which is spirally coated with the overlapped portion of the lining material of Fig. 1;

Fig. 5A is a first example of a cross-sectional view of the lining material of Fig. 4 along the line A-A in Fig. 4.

Fig. 5B is a second example of a cross-sectional view of the lining material of Fig. 4 along the line A-A in Fig. 4.

Fig. 5C is a third example of a cross-sectional view of the lining material of Fig. 4 along the line A-A in Fig. 4.

Fig. 5D is an example of a lining material including 5 layers and a part for overlapping.

Fig. 5E is another example of a lining material including 5 layers and a part for overlapping.

Fig. 5F is an example of a lining material including one layer and a part for overlapping.

Fig. 5G is an example of a lining material including 4 layers and a part for overlapping.

Figure 6 illustrates an example of how multiple layers of lining material are fed to the pressure roller to spirally coat the inner surface of the pipe.

Fig. 7 is a front view of the lining material distributor and guide roller used to feed the lining material to the inner surface of the pipe of Fig. 1.

FIG. 8A is a front view showing an example of a lining material distributor and a guide roller used to feed the lining material to the inner surface of the pipe of FIG. 1.

FIG. 8B is a top view showing an example of the lining material distributor and guide roller used to feed the lining material to the inner surface of the pipe of FIG. 1.

Fig. 9 is a perspective view of a pipe showing an example of how the position of the pressing roller can be fixed to the pipe.

These figures are not drawn to scale and are intended for illustrative purposes only.

The present disclosure relates to a method for coating the inner surface of pipe fittings. This method includes: a) applying lining material spirally on the inner surface of the pipe over the length of the pipe; and b) heating the pressed lining material so that the lining material is attached to the pipe as a coating On the inner surface.

The lining material may be an elongated strip, and the method may further include overlapping a part of the edge of the elongated strip when the lining material is helically pressed on the inner surface of the pipe over the length of the pipe.

The pipe fitting with the coating applied by the method on the inner surface of the pipe fitting has a coating, which is a lining material that is spirally attached to the inner surface of the pipe fitting over the length of the pipe fitting.

Figure 1 shows an example of how this method can be performed. In Fig. 1, a pipe 100 coated with a liner material 104 is shown. The lining material 104 is in the form of an elongated strip. The lining material is spirally coated on the inner surface of the pipe 100 so that part of the edges of the elongated strips overlap each other over the length of the pipe 100. The lining material 104 is distributed from a distributor 105 positioned inside the pipe 100 and fed between the pressure roller 103 positioned on the inner surface of the pipe 100 and the pipe 100. The pressing roller 103 presses the lining material 104 on the inner surface of the pipe and the pressing roller 102 presses the outer surface of the pipe opposite to the inner surface of the pipe 100.

In this example, the tube 100 is substantially tubular or cylindrical in shape, and has a hollow core suitable for conveying objects such as fluid in the tube. The cross section of the tube 100 is annular, which is substantially circular. However, it should be understood that other shapes of the tube 100 suitable for coating the inner surface with the lining material 104 are also possible. For example, the tube 100 may have a substantially quadrilateral or polygonal cross-section. For these non-tubular shapes, the corners of the inner surface of the tube 100 can be rounded to facilitate coating via the curved or rounded surface of the pressure roller 103. The pressing roller 103 can be mechanically configured to reach the corner of the non-tubular pipe 100, and is oriented obliquely to coat the inner surface of the pipe 100 spirally as needed. In this case, the other pressing roller 102 can be configured to cooperate with the pressing roller 103 to apply pressure.

In this example, the pipe 100 is made of metal (for example, aluminum or copper). However, it should be understood that the pipe can be made of different types of materials (including metal, plastic, or composite materials) depending on the fluid or object that is intended to be conveyed through the pipe.

The lining material 104 may include an adhesive surface adhered to the inner surface of the pipe 100, or the lining material 104 may be made of an adhesive material that can adhere to the inner surface of the pipe 100. In the case where the lining material 104 is made of a viscous material, the adhesive properties of the lining material 104 may be activated when the lining material 104 is heated to a certain temperature. An adhesive material containing a carboxyl functional group is an example of a material with adhesive properties suitable for use as the inner liner material 104 or the adhesive surface on the inner liner material 104.

In this example, the lining material 104 is a fluororesin film. Examples of fluoropolymers that can be used to form fluororesin films include ethylene tetrafluoroethylene (ETFE) and perfluoroalkoxy alkanes (PFA). The fluorocopolymer as described in the patent publication US7112640B2 is also an example of a suitable polymer that can be used to form a fluororesin film. In other configurations, the lining material 104 may be composed of more than one layer of fluororesin film. The fluororesin film layer directly in contact with the inner surface of the pipe 100 may be configured as an adhesive surface with adhesive properties for adhering to the inner surface of the pipe 100. A fluororesin film containing a carboxyl functional group is suitable as an example of a material having adhesive properties for the lining material 104 that is in direct contact with the inner surface of the pipe 100.

In this example, two pressing rollers 102 and 103 are provided and moved in series. There are two pressure rollers 102 and 103 to provide a counterbalance, which exerts a fastening or clamping pressure on an area or part of the inner surface of the tube 100 to be coated. However, in another configuration, only the pressing roller 103 may be provided, but in this case, the pipe 100 must be held to prevent the pipe 100 from moving due to the pressing roller 103 pressing the lining material 104 on the inner surface of the pipe 100.

The shapes of the pressing rollers 102 and 103 are each substantially cylindrical. The pressure rollers 102 and 103 are rotatable around a rotation axis. In another configuration, it is possible that only the pressure roller 103 is rotatable and the pressure roller 102 does not rotate.

There are several methods for spiral coating of the lining material on the inner surface of the pipe. In this example, initially, the starting end of the lining material 104 is sandwiched between the pressing roller 103 and the inner surface of the pipe 100. The other pressing roller 102 moves in series with the pressing roller 103 to provide a counter-force for applying fastening or clamping pressure on the area or part of the inner surface of the pipe 100 to be coated. During the coating process, the rotation of the pressing roller 103 pulls the lining material 104 fed from the distributor 105 and presses the lining material 104 on the inner surface of the pipe 100. The dispenser 105 includes a roll of lining material 104, and when it is used up, a new roll of lining material 104 needs to be reloaded.

It should be understood that the spiral coating of the lining material on the inner surface of the pipe as described in the text has advantages in terms of better control of the thickness of the coating layer and reduction of the occurrence of lining defects. Unlike the conventional rotary lining method, the thickness of the lining material 104 in this example is not limited to 1 mm or more.

An example of spirally coating the inner surface of the pipe 100 is to keep the pressure roller 103 fixed and the pipe 100 to continuously rotate. When the lining material 104 is pressed by the pressure roller 103, the pipe 100 is in the direction along the length of the pipe 100. Moving in. The pressing roller 103 will rotate and pull the lining material 104 fed from the distributor 105 when the pipe 100 rotates and moves. Or, in another example, while the lining material 104 is being pressed and the pipe 100 remains fixed, the pressing roller 103 can continuously rotate around the circumference of the inner surface of the pipe 100 and move in the direction along the length of the pipe 100 . The pressing roller 103 will rotate and pull the lining material 104 fed from the dispenser 105 when the pressing roller 103 moves. In yet another example, while the lining material 104 is being pressed and the pipe 100 is moved in the direction along the length of the pipe 100 without rotating the pipe 100, the pressure roller 103 can surround the inner surface of the pipe 100. The circumference continuously rotates without moving the pressure roller 103 in the direction along the length of the tube 100. In another example, while the lining material 104 is being pressed and the pipe 100 is rotated without moving the pipe 100 in the direction along the length of the pipe 100, the pressure roller 103 can be moved along the length of the pipe 100. Move in the middle without causing the pressing roller 103 to rotate around the circumference of the inner surface of the pipe 100. In all such instances, another pressure roller 102 will move in series with the pressure roller 103 if it exists.

The pressing roller 103 may rotate and roll over the inner surface of the pipe 100, or the pressing roller 103 may alternatively be rotated by moving the pipe 100 while the pressing roller 103 remains fixed. In order to spirally coat the inner surface of the pipe 100, the pressing rollers 102 and 103 are arranged at an oblique angle with respect to the longitudinal axis along the length of the pipe. Details of the inclination angle of the pressure rollers 102 and 103 with respect to the longitudinal axis along the length of the tube will be provided later.

In this example, when the lining material 104 is a type that adheres to the pipe 100 when heat is applied, the pressed lining material 104 is attached to the inner surface of the pipe 100 as a coating by heating. The heat applied to the pressed lining material 104 reduces the viscosity of the pressed lining material 104 and makes it sufficiently viscous to adhere to the inner surface of the pipe 100.

It should be noted that the heating of the lining material 104 should not completely melt the pressed lining material 104 or the pipe 100. Otherwise, there will be undesirable changes in the coating thickness of the lining material 104 on the entire inner surface of the pipe 100. Applying heat to the pressurized lining material 104 for a short period of time, for example, less than 1 minute (which is suitable for this example), helps prevent the pressurized lining material 104 from melting completely. In addition, in this example, the pressurized lining material 104 is heated to a temperature between 60° C. lower than the melting point of the lining material 104 and 10° C. higher than the melting point of the lining material 104. This is to soften the lining material 104 to the inner surface of the pipe 100 and/or to adhere to another lining that already exists on the inner surface of the pipe 100 when the lining material is overlapped. The desired temperature range of the degree of the material. In addition, since the melting point of the lining material 104 is much lower than the temperature used in the welding process (which involves molten metal), the aforementioned temperature range will not melt the pipe 100 or decompose the lining material 104. Therefore, unlike some conventional techniques involving metal welding for coating the inner surface of pipe fittings, the method described herein has the advantage that the lining material 104 will not be heated to the metal welding temperature that will decompose the lining material 104 .

The heating of the lining material 104 may be performed while the lining material 104 is pressed by heating the pressing roller 103 and/or the pressing roller 102. Alternatively, in the case where the pipe 100 is made of a thermally conductive material such as metal, the pipe 100 may alternatively be heated to make the lining material 104 adhere to the inner surface of the pipe 100. In another configuration, the pressure roller 103 and/or the pressure roller 102 and the tube 100 can be heated. In yet another configuration, the lining material 104 can be pressed and adhered to the inner surface of the pipe 100, and then heated on the lining material 104 to ensure that it adheres to the inner surface of the pipe 100.

The pressing roller 103 may be coated or manufactured with a non-adhesive material to prevent the heated and pressed lining material 104 from adhering to the pressing roller 103. Examples of such non-sticky materials include fluoropolymers such as polytetrafluoroethylene (PTFE) and the like. The application of heat to the lining material 104 can be accomplished by, for example, the induction heating of the pressure rollers 102 and/or 103, and/or the pipe 100.

In this example, when the lining material 104 is pressed spirally on the inner surface of the pipe 100 over the length of the pipe 100, a part of the edge of the lining material 104 overlaps to form an overlapping portion 106. The lining material 104 may be overlapped so that the thickness of the overlapping portion 106 of the lining material 104 is 20% to 100% greater than the thickness of the non-overlapping portion of the lining material 104. More information on how the overlap portion 106 can achieve this thickness will be discussed later. Depending on the degree of overlap to be implemented, the thickness of the lining material in the tube 100 can be between 100 μm and 500 μm. This thickness can be achieved by having more than one layer of lining material 104. This thickness range of the lining material 104 is suitable for metal pipe fittings used to transport metal corrosive fluids in the industry. It should be noted that this overlap of the lining material 104 is optional and can be provided as appropriate. For example, in the case where the pressurized lining material 104 coating on the inner surface of the pipe 100 is intended to prevent the contents of the pipe 100 from directly contacting the inner surface of the pipe 100, the coating of the lining material 104 should cover the pipe The entire inner surface of the tube 100 does not leave any gaps that expose the inner surface of the pipe 100. The overlap portion 106 helps to ensure that there is no exposed inner surface of the tube 100 that is not covered by the lining material 104. This advantageously reduces the occurrence of lining defects and provides a stronger adhesion of the lining material 104 to the inner surface of the pipe 100.

FIG. 2 shows a top view of the pressure roller 102 of FIG. 1 set at an inclination angle α with respect to the longitudinal axis 107 along the length of the tube 100. FIG. More specifically, the axis 204 orthogonal to the axis of rotation of the pressure roller 102 is inclined at an angle α with respect to the longitudinal axis 107 along the length of the tube 100. The pressing roller 103 of FIG. 1 is arranged in the pipe 100 in the same manner as the pressing roller 102 and at the same inclination angle α.

FIG. 3 further illustrates how the tilt angle α described with reference to FIG. 2 can be obtained. Fig. 3 shows the pipe 100 of Fig. 1 vertically displaced and coated with some lining material 104. As shown in Figs. FIG. 3 is deliberately drawn as a perspective to show the lining material 104 coated on the inner surface of the pipe 100. The diameter 108 of the pipe 100 is marked in FIG. 3. For illustrative purposes, the expanded portion 302 of the lining material 104 is shown in FIG. 3. The expanded portion 302 has a right-angled triangle shape, and the bottom is the circumference 109 of the tube 100. Therefore, the bottom has a size equivalent to the circumference 109. The bottom of the expanded portion 302 is longer than the height of the expanded portion 302. In the example of FIG. 1, there is an overlap 106 of the lining material 104. The shortest distance 110 from the point where the bottom and height of the expanded portion 302 intersect the hypotenuse of the expanded portion 302 is defined as the width of the non-overlapping portion of the lining material 104 in FIG. 1. In other words, the width of the non-overlapping portion of the lining material 104 on the inner surface of the pipe 100 is 110. The tilt angle α described with reference to FIG. 2 can be obtained from Equation 1 shown below.

In Equation 1, D refers to the diameter 108 of the pipe 100, πD refers to the circumference 109 of the pipe 100, and W refers to the width 110 of the non-overlapping portion of the lining material 104 in FIG. 1.

FIG. 4 further illustrates the features in the previous figures and is deliberately drawn in perspective to show the lining material 104 in FIG. 1 coated on the inner surface of the pipe 100 in FIG. 1. The pipe 100 is displaced horizontally in FIG. 4. FIG. 4 also more clearly shows the width 110 of the non-overlapping portion 112 of the lining material 104 described with reference to FIG. 3. FIG. 4 also shows the width 111 of the lining material 104 including the width of the overlapping portion 106 and the width 110 of the non-overlapping portion 112 shown in FIG. 1.

The width 110 of the non-overlapping portion 112 of the lining material 104 can be obtained from Equation 2 shown below.

In Equation 2, W refers to the width 110 of the non-overlapping portion 112 of the lining material 104, W _o refers to the width 111 of the lining material 104 including the width of the overlapping portion 106 and the width 110 of the non-overlapping portion 112, and a Refers to the overlap percentage of the lining material 104.

Fig. 4 also shows how the pressing roller 102 of Fig. 1 is arranged at an inclination angle α. 2 and 4, the inclination angle α is formed between the axis 204 orthogonal to the rotation axis 202 of the pressure roller 102 and the longitudinal axis 107 along the length of the tube 100.

5A shows an example of a cross-sectional view 500 of the lining material 104 along the line AA in FIG. 4 in the upper half of FIG. 5A and an example of a portion of the lining material 104 in the lower half of FIG. 5A Perspective view 509. The lining material 104 in the example of FIG. 5A has three layers, specifically, the top layer 502, the middle layer 504, and the bottom layer 506. Each layer may be a fluororesin film layer. The bottom layer 506 is adhered to the inner surface of the pipe 100. FIG. 5A shows the width 110 of the non-overlapping portion 112 of the lining material 104 described with reference to FIG. 4. FIG. 5A also shows the width 111 of the lining material 104 including the width of the overlap portion 106 described with reference to FIG. 4. The thickness of the non-overlapping portion 112 and the thickness of the overlapping portion 106 can be changed. In FIG. 5A, the non-overlapping portion 112 is composed of 3 layers forming the lining material 104, and the overlapping portion 106 is composed of 4 layers forming the lining material 104. Compared to the non-overlapping portion 112, the overlapped portion 106 has an additional layer formed by the extension (or extended portion) of the top layer 502 in the example of FIG. 5A. It should be understood that in other configurations, any one or more layers can be extended to form part of the overlap portion 106 to increase the thickness of the overlap portion 106. In this case, the thickness of the overlapping portion 106 is about one third or 33% of the thickness of the non-overlapping portion 112. In another configuration with 6 layers of lining material, when the overlapping portion 106 is composed of 12 layers, and the thickness of the non-overlapping portion 112 is 6 layers, the total overlapping thickness of the overlapping portion 106 is smaller than that of the non-overlapping portion 112. The thickness is 100% greater.

FIG. 5B shows another example of a cross-sectional view 510 of the lining material 104 along the line AA in FIG. 4 in the upper half of FIG. 5B and one of the parts of the lining material 104 in the lower half of FIG. 5B Example perspective view 519. In the example of FIG. 5B, the lining material 104 has two layers, specifically, the top layer 512 and the bottom layer 514. Each layer may be a fluororesin film layer. The bottom layer 514 is adhered to the inner surface of the pipe 100. FIG. 5B shows the width 110 of the non-overlapping portion 112 of the lining material 104 described with reference to FIG. 4. FIG. 5B also shows the width 111 of the lining material 104 including the width of the overlapping portion 106 described with reference to FIG. 4. In FIG. 5B, the non-overlapping portion 112 is composed of two layers of the lining material 104, and the overlapping portion 106 is composed of three layers of the lining material 104. Compared to the non-overlapping portion 112, the overlapped portion 106 has an additional layer formed by the extension (or extended portion) of the top layer 514 in the example of FIG. 5B. It should be understood that in other configurations, any one or more layers can be extended to form part of the overlap portion 106 to increase the thickness of the overlap portion 106. In this case, the thickness of the overlapping portion 106 is about half or 50% of the thickness of the non-overlapping portion 112. In another configuration with 4 layers of lining material, when the overlapping portion 106 is composed of 7 layers and the thickness of the non-overlapping portion 112 is 4 layers, the total overlapping thickness of the overlapping portion 106 is smaller than the thickness of the non-overlapping portion 112 75% larger.

FIG. 5C shows another example of a cross-sectional view 520 of the lining material 104 along the line AA in FIG. 4 in the upper half of FIG. 5C and one of the parts of the lining material 104 in the lower half of FIG. 5C Example perspective view 529. The lining material 104 in the example of FIG. 5C has two layers, specifically, the top layer 522 and the bottom layer 524. Each layer may be a fluororesin film layer. The bottom layer 524 is adhered to the inner surface of the pipe 100. FIG. 5C shows the width 110 of the non-overlapping portion 112 of the lining material 104 described with reference to FIG. 4. 5C also shows the width 111 of the lining material 104 including the width of the overlapping portion 106 described with reference to FIG. 4. In FIG. 5C, the non-overlapping portion 112 is composed of two layers of the lining material 104, and the overlapping portion 106 is composed of three layers of the lining material 104. Compared to the non-overlapping portion 112, the overlapped portion 106 has an additional layer formed by the extension (or extended portion) of the top layer 522 in the example of FIG. 5C. It should be understood that in other configurations, any one or more layers can be extended to form part of the overlap portion 106 to increase the thickness of the overlap portion 106. In this case, the thickness of the overlapping portion 106 is about half or 50% of the thickness of the non-overlapping portion 112. In another configuration with only one layer of lining material, when the overlapping portion 106 is composed of two layers and the thickness of the non-overlapping portion 112 is composed of only one layer, the total overlapping thickness of the overlapping portion 106 is lower than that of the non-overlapping portion The thickness of 112 is 100% larger.

FIG. 5D shows a perspective view of an example of a portion of the lining material 104 of FIG. 4. The lining material 104 of FIG. 5D has 5 layers and one of the 5 layers 532 extended to form a portion of the overlap portion 106 and the other four 534 of the 5 layers are not extended. Each layer may be a fluororesin film layer. In the case of using the lining material 104 of FIG. 5D, the overlapping portion 106 will have 6 layers forming the lining material 104 and the non-overlapping portion 112 will have 5 layers. Therefore, the total overlapping thickness of the overlapping portion 106 will be 20% greater than the thickness of the non-overlapping portion 112.

FIG. 5E shows a perspective view of an example of a portion of the lining material 104 of FIG. 4. The lining material 104 of FIG. 5E has three of the five layers and five layers 542 that are extended to form a portion of the overlap portion 106 and the other two of the five layers 544 are not extended. Each layer may be a fluororesin film layer. In the case of using the lining material 104 of FIG. 5E, the overlapping portion 106 will have 8 layers forming the lining material 104 and the non-overlapping portion 112 will have 5 layers. Therefore, the total overlapping thickness of the overlapping portion 106 will be 60% greater than the thickness of the non-overlapping portion 112.

From FIGS. 5A to 5E, it can be said that the thickness of the overlapping portion 106 and the thickness of the non-overlapping portion 112 are governed by the following equation 3.

In Equation 3, O is the percentage of the total overlapping thickness of the overlapping portion 106 that is greater than the thickness of the non-overlapping portion 112. E is the number of layers that are extended to form the overlapping portion 106 and L is the total number of layers that form the lining material 104. Each layer may be a fluororesin film layer or may be a layer of other suitable materials.

FIG. 5F shows an example in which the total overlapping thickness of the overlapping portion 106 can be smaller than the thickness of the non-overlapping portion 112.

Specifically, FIG. 5F shows an example of a cross-sectional view 550 of the lining material 104 along the line A-A in FIG. 4. The lining material 104 in the example of FIG. 5F has one layer. This layer can be a fluororesin film layer. This layer 104 is adhered to the inner surface of the pipe 100. In this example, the lining material 104 has two opposite edge portions. Each edge portion is tapered to form a triangular cross section having a tip as one of the terminal ends of the lining material 104. FIG. 5F shows the width 110 of the non-overlapping portion 112 of the lining material 104 described with reference to FIG. 4. FIG. 5F also shows the width 111 of the lining material 104 including the width of the overlap portion 106 described with reference to FIG. 4. The thickness of the non-overlapping portion 112 and the thickness of the overlapping portion 106 can be changed by adjusting the distance between adjacent layers of the lining material 104 to be adhered to the inner surface of the pipe 100. In FIG. 5F, it is worth noting that the non-overlapping portion 112 is composed of one layer of the lining material 104, and the overlapping portion 106 is composed of less than one layer of the lining material 104. In this case, the thickness of the overlapping portion 106 is smaller than the thickness of the non-overlapping portion 112.

FIG. 5G shows an example in which there may be overlap of the lining material 104 at the edge portion, but the overlapped portion 106 and the non-overlapped portion 112 are still the same thickness.

Specifically, FIG. 5G shows an example of a cross-sectional view 560 of the lining material 104 along the line AA in FIG. 4 in the upper half of FIG. 5G and shows the lining material 104 in the lower half of FIG. 5G A perspective view 569 of an example of part. In the example of FIG. 5G, the lining material 104 has 4 layers, specifically, the top layer 562, the two middle layers 564 and 566, and the bottom layer 568. Each layer may be a fluororesin film layer. The bottom layer 568 is adhered to the inner surface of the pipe 100. The four layers are arranged in a staggered manner, so that two opposite step edge portions are formed in the lining material 104. FIG. 5G shows the width 110 of the non-overlapping portion 112 of the lining material 104 described with reference to FIG. 4. FIG. 5G also shows the width 111 of the lining material 104 including the width of the overlapping portion 106 described with reference to FIG. 4. The thickness of the non-overlapping portion 112 and the thickness of the overlapping portion 106 can be changed by adjusting the distance between adjacent layers of the lining material 104 to be adhered to the inner surface of the pipe 100. In the example of FIG. 5G, the opposite step edge portions of the lining material 104 are arranged to correspond to or flush with each other, so that the non-overlapping portion 112 is composed of 4 layers constituting the lining material 104 and the overlapping portion 106 is also formed by The lining material 104 is composed of 4 layers. In this case, the thickness of the overlapping portion 106 is the same as the thickness of the non-overlapping portion 112.

FIG. 6 shows an example of the apparatus and method for distributing two or more fluororesin films to form the lining material 104 described with reference to the previous figures. In FIG. 6, the first distributor 121 distributes a layer of fluororesin film 123 and the second distributor 122 distributes a layer of fluororesin film 124. Although a fluororesin film is described, it should be understood that a film made of other suitable materials can also be used to form the lining material 104. There are guide rollers 125 downstream of the first and second distributors 121 and 122 for guiding the layers of fluororesin films 123 and 124 to a pair of guide rollers 126. Correspondingly, more distributors and guide rollers can be added to the setup of FIG. 6 to form the lining material 104 with more than two layers. The pair of guide rollers 126 place the fluororesin films 123 and 124 in contact with each other. After passing through the guide roller 126, the fluororesin films 123 and 124 form a multilayer film 127 that will constitute the lining material 104. In this example, the individual fluororesin films 123 and 124 in the multilayer film 127 are not permanently attached to each other, but are stacked adjacent to each other.

There are a plurality of guide rollers 128 further downstream of the pair of guide rollers 126. The guide roller 128 is used to guide the multilayer film 127 so that the multilayer film 127 is placed between the two pressing rollers 129 and 130. The multilayer film 127 is then fed between the pressing roller 103 of FIG. 1 and the inner surface of the tube 100 shown in FIG. 1 to coat the inner surface of the tube 100 with the multilayer film 127. When heat is applied to the multilayer film 127 during the manufacturing process to spirally coat the lining material 104 on the inner surface of the pipe 100, the layers of the multilayer film 127 will adhere to each other, and one of the layers facing the inner surface of the pipe 100 will Adhere to the inner surface of the pipe 100.

The setting of FIG. 6 can be used to obtain the thickness of the overlapping portion 106 as described with reference to the previous figure in a range of more than 0% to 100% compared to the thickness of the non-overlapping portion 112 as described with reference to the previous figure. However, the setting must be adjusted so that the distributed layer or layers will be placed in contact with each other in a manner that will provide the extension required to form the portion of the overlap 106. If the layers all start with the same width, the excess edges of the layers on one side will need to be trimmed so that only one side of the layers has the extension required to form the portion of the overlap 106.

Fig. 7 shows a method for guiding the multilayer film 127 of Fig. 6 from the pressing rollers 129 and 130 of Fig. 6 to the guide roller 131 before feeding, so that the multilayer film 127 is placed between the pressing roller 103 of Fig. 1 and the pipe 100 of Fig. 1 An example of the arrangement between the inner surfaces. Fig. 7 is a perspective view of the pipe 100 from one end, so that the circumference of the pipe 100 (in this case, a circle) can be seen. Preferably, the guide roller 131 includes an adjustable joint (such as an adjustable universal joint or a ball joint) configured to adjust the feeding angle of the multilayer film 127 between the pressing roller 103 and the inner surface of the pipe 100. In this example, the feeding angle of the multilayer film 127 between the pressing roller 103 and the inner surface of the pipe 100 is the same as the inclination angle α described with reference to FIGS. 2 to 4.

Fig. 8A shows an example of a cross-sectional side view of the arrangement of Fig. 6; The pipe 100 is a cross-sectional view to show the rollers in the pipe. The component symbols of the same components appearing in FIG. 6 are reused in FIG. 8A. The arrangement of FIG. 8A guides the films 123 and 124 distributed from two respective distributors 121 and 122 to a position between a pair of guide rollers 126 to form a multilayer film 127. The distributors 121 and 122 are mounted to a mounting block 805 that can be attached to a fixed position (which can be a wall surface). The distributor 122 is located above the distributor 121. The multilayer film 127 formed between the pair of guide rollers 126 is further fed to the tapered roller 802. The tapered roller 802 is an additional feature not shown in the setup of FIG. 6. The arrangement of FIG. 8A also does not have the guide roller 128 shown in FIG. 6. The tapered roller 802 turns the multilayer film 127 toward the position between the pair of guide rollers 129 and 130 at an appropriate angle. Thereafter, the multilayer film 127 is further guided between the pressing roller 103 and the inner surface of the pipe 100 to be spirally coated on the inner surface of the pipe 100. The pressing roller 102 that operates in conjunction with the pressing roller 103 to press the multilayer film 127 on the inner surface of the pipe 100 is positioned on the outer surface of the pipe 100 opposite to the inner surface of the pipe 100. The distributors 121 and 122 are fixed to the supporting structure 803 so as to avoid unnecessary movement that would affect the distribution.

Fig. 8B shows a top view of the arrangement of Fig. 8A which is arranged so that the dispenser 122 and the pressure roller 102 can be seen. The tube 100 is deliberately drawn in perspective to show the roller 129 and the multilayer film 127 positioned in the tube. In Fig. 8B, the rotation axis 202 of the pressure roller 102, the axis 204 orthogonal to the rotation axis 202 of the pressure roller 102, and the longitudinal axis 107 along the length of the tube 100 are drawn for illustration. It should be understood that the rotation axis 202 of the pressure roller 102 is parallel to the rotation axis of the pressure roller 103, so the two pressure rollers 102 and 103 work together to provide the spiral coating of the lining material 104.

8A and 8B, the tapered roller 802 is mounted to a shaft, so that the tapered roller 802 can rotate around the longitudinal axis of the shaft 804. The shaft 804 has two opposite ends respectively mounted to a pair of elongated support members 806 extending from the mounting block 805. The tapered roller 802 is set so that the multilayer film 127 is turned between the pressure roller 103 and the inner surface of the pipe 100 at an appropriate angle. In this example, the appropriate angle at which the multilayer film 127 is fed between the pressing roller 103 and the inner surface of the pipe 100 is the same as the inclination angle α described with reference to FIGS. 2 to 4.

FIG. 9 is a perspective view of the pipe 100 of FIG. 1 and further illustrates how the positions of the pressing rollers 102 and 103 of FIG. 1 can be fixed inside the pipe 100. The supporting device 900 is shown in FIG. 9. The supporting device 900 includes a pressing roller 103, a roller support 905, an extendable shaft 904, a roller support 906, another roller 907, a guide roller support 903, guide rollers 129 and 130, and a support shaft 902. The pressure roller 103 to be positioned in the pipe 100 is fixed to one end of the roller support 905. Specifically, the pressing roller 103 is rotatably mounted to the support 905 so that the pressing roller 103 is rotatable. The other end of the support 905 is attached to one end of the extendable shaft 904. The other end of the extendable shaft 904 is attached to the roller 907 through the roller support 906. The pressing roller 103 and the roller 907 are located at opposite ends of the supporting device 900 and are both set to exert pressure on the inner surface of the pipe 100. The extendable shaft 904 can be mechanically adjusted so that the supporting device 900 starts from the point where the pressure roller 103 exerts pressure on the inner surface of the pipe 100 and presses on the lining material 104 to the point where the opposing roller 907 touches the inner surface of the pipe 100. The length of the lining material 104 or the point on the inner surface of the pipe 100 matches the diameter of the pipe 100. The pressure roller 102 is installed on the outer side of the pipe 100 in such a way that it will contact the outer surface of the pipe 100 above the inner surface of the pipe 100 coated by the pressure roller 103, and moves in series with the pressure roller 103.

The extendable shaft 904 may include a biasing mechanism such as a spring to apply force to the pressing roller 103 and the roller 907 located at opposite ends of each other. The pressing roller 103 and the roller 907 then apply pressure to the lining material 104 on the inner surface of the pipe 100 or the inner surface of the pipe 100.

The guide roller support 903 extends orthogonally from the position of the extendable shaft 904 in the middle of the support device 900. The pressing rollers 129 and 130 are fixed to the guide roller support 903. The support shaft 902 extends from the end opposite to the direction in which the guide roller support 903 extends orthogonally to the position of the extendable shaft 904. The length of the support shaft 902 can be adjusted.

The supporting shaft 902 can extend a length longer than the length of the pipe 100 to a fixed position outside or outside the pipe 100 to fix the position of the supporting device 900. In the case where the pipe 100 moves and the pressure roller 103 remains fixed during the spiral coating, the supporting device 900 needs to be fixed in position.

In another configuration where the pipe 100 is held in the same position and the pressing roller 103 moves across the pipe 100, the support shaft 902 can be attached to an actuator (not shown in FIG. 9) to roll the support device 900 to the pipe. 100 different positions coated within.

In another example, where the pressing roller 103 can rotate around the circumference of the inner surface of the pipe 100, the extendable shaft 904 can be attached to a rotary actuator capable of rotating the support device 900, which in turn follows the circumference of the pipe 100 Rotate the pressing roller 103.

The support 905 and/or the extendable shaft 904 may be configured as a heating device for heating the pressure roller 103, which in turn heats the lining material 104. Alternatively, the pressing roller 102 may be one that is heated instead. In another configuration, both the pressure rollers 102 and 103 may be heated together by a heating device.

The distribution and/or guiding and feeding of the lining material 104 can be such that the lining material 104 will not be in contact with the setting except that the guide roller guides and feeds the lining material 104 to the position between the pressure roller 103 and the inner surface of the pipe 100. The contact method of the components or components is completely performed in the pipe 100. In other configurations, the distributors (such as 121 and 122) may be positioned outside the pipe 100, and the guide rollers as described in the text are tied inside the pipe 100. It is also possible that some guide rollers are tied outside and some guide rollers are tied inside the pipe 100. The configuration depends on how the guide roller is deployed to guide the lining material 104 to a position between the pressure roller 103 and the inner surface of the pipe 100.

In the specification and the scope of the patent application, unless the context clearly indicates otherwise, the term "comprises" has the non-exclusive meaning of the word, which means "at least includes" rather than "consisting only of" The meaning of exclusivity in. The same applies to the corresponding grammatical changes of other forms of the word (such as "including", "containing", etc.).

Although the present invention has been described in this disclosure in conjunction with many specific examples and implementations, the present invention should not be so limited, but can cover various obvious modifications and equivalent configurations that fall within the scope of the appended application. Although the features of the present invention are expressed in specific combinations in the scope of the patent application, it is covered that these features can be arranged in any combination and order.

100‧‧‧Pipe fitting

102‧‧‧Press roller

103‧‧‧Press roller

104‧‧‧Inner Lining Material

105‧‧‧Distributor

106‧‧‧Overlapping part

Claims (16)

A method for coating the inner surface of a pipe, the method comprising: a) applying a lining material spirally over the length of the pipe to the inner surface of the pipe; and b) heating the pressurized lining material to Make the lining material adhere to the inner surface of the pipe as a coating, where a) and b) are carried out at the same time. The method of claim 1, wherein the lining material is an elongated strip and the method comprises: applying the lining material spirally over the length of the pipe to the inner surface of the pipe to make the elongated strip A part of the edge of the thing overlaps. Such as the method of claim 2, the method comprising: the total overlapping thickness of the overlapping part of the lining material is 20% to 100% larger than the thickness of the non-overlapping part of the lining material. The method according to any one of claims 1 to 3, wherein the lining material comprises one or more fluororesin films. The method according to any one of claims 1 to 3, wherein the lining material is a viscous material containing carboxyl functional groups. The method according to any one of claims 1 to 3, wherein the thickness of the lining material is between 100 μm and 500 μm. The method according to any one of claims 1 to 3, wherein the pressurized lining material is heated to a temperature between 60°C lower than the melting point of the lining material and 10°C higher than the melting point of the lining material Between the temperature. Such as the method of any one of claims 1 to 3, wherein the pressure of the lining material is At least two pressure rollers are used, one of which presses the lining material on the inner surface of the pipe, and the other presses the outer surface of the pipe opposite to the inner surface of the pipe. The method of claim 8, wherein the heating of the pressed lining material is performed by heating at least one of the pressing rollers. The method of claim 8, wherein the axis system orthogonal to the rotation axis of each pressing roller is at an inclination angle with respect to the longitudinal axis along the length of the pipe. The method of claim 10, wherein the inclination angle is provided by using a tapered roller to turn the dispensed lining material at the inclination angle toward a pressing roller that presses the lining material on the inner surface of the pipe. The method of claim 8, wherein the pressing roller that presses the lining material on the inner surface of the pipe is connected to the first end of the supporting device in the pipe, and is opposite to the first end of the supporting device The second end of the supporting device includes a roller for contacting the lining material that covers the inner surface of the pipe or the inner surface of the pipe. The method according to any one of claims 1 to 3, the method comprising: rotating the pipe and moving the pipe in a direction along the length of the pipe while the lining material is being pressed. A pipe fitting having a coating applied by any one of claims 1 to 13 on the inner surface of the pipe fitting, the coating being spirally adhered to the inner surface of the pipe fitting along the length of the pipe fitting The lining material. The pipe according to claim 14, wherein the lining material is an elongated strip and a part of the edge of the elongated strip overlaps with each other over the length of the pipe. Such as the pipe of claim 15, wherein the total thickness of the overlapping part of the lining material is 20% to 100% greater than the thickness of the non-overlapping part of the lining material.

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