JPH0132770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a laminated resin pipe.

When making fiber-reinforced polyester resin tubes, a cylinder with at least one end open is rotated around the tube axis to supply fibers and hardenable resin onto the tube wall, which is then applied to the tube. A non-foamed fiber-containing resin was pressed against the wall surface to form a cylindrical shape on the wall surface of the tube, and this was cured to obtain a resin tube. In this case, several layers of fiber-reinforced polyester resin were stacked together to form a single resin tube.

In this way, when the resin was made of the same type of resin, a resin tube was made by layering the resin layers many times, but it was also possible to make a resin tube by layering layers of different types of resin. Nothing was done. This is because different resins have different coefficients of thermal expansion, and it was thought that having different coefficients of thermal expansion would cause delamination during use.

Therefore, when providing a layer of foam made of different types of synthetic resin around a synthetic resin pipe, up until now, a foam board of different types of synthetic resin that has already been foamed has been brought into contact with or placed around the synthetic resin pipe. It was rolled up and glued. However, in such a method, it is difficult to contact or wind the foam board, and it also takes time to complete the adhesion, so it is not possible to efficiently produce a laminated resin pipe.

The inventor noticed that urethane resin has foaming properties and also exhibits strong adhesive strength to various resins, especially polyester resins. and,
I learned that if the foaming power of urethane resin is used for adhesion to other resins, strong laminated pipes can be obtained. However, it has been found that when a layer of polyester resin is directly provided on the urethane resin foamed in this way, the layer of polyester resin is not so strongly adhered to the urethane resin. However, it has been found that when the skin of the urethane resin foamed in this manner is peeled off and a layer of polyester resin is provided on top of the skin, both layers are firmly adhered to each other. This invention was made based on such knowledge.

In this invention, a cylinder with at least one end open is rotated around the cylinder axis, fibers and a curable resin are supplied onto the cylinder wall, and the fibers and the curable resin are pressed against the cylinder wall, so that the non-foamed fiber-containing material is placed on the wall surface. forming a cylindrical layer of resin, then spraying or casting a curable foamable urethane resin thereon to foam cure, cutting at least a portion of the free surface of the foam, The present invention relates to a method for manufacturing a laminated resin pipe, characterized in that fibers and a curable resin are supplied and pressed onto a foam surface including a foamed surface to form a cylindrical layer of non-foamed fiber-containing resin.

In the method of the invention, a tube with at least one end open is rotatable about the axis of the tube, and materials for forming the tube are supplied onto the wall of the tube. This requires a tube and a device to rotate it. An example of such a device is shown in FIGS. 1-4.

FIG. 1 is a perspective view showing an example of a device for rotationally moving a cylinder in the method of this invention. In FIG. 1, a cylinder 1 is supported by a plurality of rolls 3 attached to a truck 2 and is rotatable around the cylinder axis, and the truck 2 is supported by a plurality of rolls 3 attached to a truck 2.
By moving above, it is possible to move in the direction of the cylinder axis. Reference numeral 5 denotes an arm bar, which is fixed on the support column 6. The arm bar 5 has a resin and fiber supply tool 7 in a part thereof, and the supply tool 7 can move in and out of the cylinder 1 together with the arm bar 5. Therefore, the resin and fibers supplied from the supply tool 7 can adhere to the entire inner wall surface of the cylinder 1. In this way, the desired resin tube is formed inside the cylinder 1.

FIG. 2 is a perspective view of another device for rotating a cylinder. In FIG. 1, the cylinder 1 was placed on a trolley 2 and was movable in the axial direction, but in FIG.
Instead of the cylinder 1 being placed on a stand 8 and unable to move in the axial direction, the column 6 is placed on a cart 9, and the arm bar 5 and the supply tool 7 are movable in the axial direction of the cylinder 1. ing. There is no difference in other respects.

FIG. 3 is a partially cutaway elevational view of yet another apparatus for rotationally moving a cylinder. In FIG. 3, numerals 1 to 7 correspond to the same numbers in FIG. The apparatus shown in FIG. 3 shows a case in which resin or fibers are supplied onto the outer wall surface of the cylinder 1 to form a resin tube on the outside of the cylinder 1. To be more specific, rail 4
is fixed on the arm bar 5, so that the trolley 2 can move on the arm bar 5. Further, a cart 2 is inserted into the cylinder 1, and the cylinder is rotatably supported by the rolls 3 with the inside visible. As a result, the cylinder 1 is rotatable and movable in the axial direction. The supply tool 7 is attached to the outside of the cylinder 1. Note that 10 indicates a resin layer formed on the cylinder 1.

FIG. 4 is a partially cutaway elevational view showing yet another device for rotating the cylinder. This device is
As in FIG. 3, a resin layer is formed on the outside of the cylinder 1. In Figure 4, roll 3 is arm bar 5.
Since the cylinder 1 cannot be moved in the direction of the cylinder axis, the supply tool 7 can move on the rod 11 instead.

Using the apparatus shown in FIG. 1, the process of manufacturing the resin layer is performed as shown in FIG. First, a mold release agent is applied onto the inner surface of the cylinder 1, and a glass fiber mat 12 is supplied thereon from a supply tool (not shown), so that the glass fiber mat is uniformly brought into contact with the inner surface of the cylinder 1. Next, a curable polyester resin 13 is further cast on the mat 12 to uniformly impregnate the glass fibers. If necessary, press this impregnation against the cylinder wall. In this state, the polyester resin is cured. In this way, a layer of polyester resin containing glass fibers is formed along the inner surface of the cylinder 1 into a cylindrical shape.

After the polyester resin layer 13 is formed, a curable urethane resin 15 is sprayed onto it from the supply tool 7. This spraying may be performed after the polyester resin is cured, but may also be sprayed before the completion of curing. Spraying is carried out with care so that the urethane resin is dispersed as evenly as possible over the entire surface of the polyester resin. Paper 16 is placed on top of the sprayed urethane resin 15 to cover the surface, and the paper is pressed down.
Adjust the urethane resin layer below to have an even thickness. Alternatively, press the urethane resin with a pressure roll to prevent the surface from becoming uneven.

Since urethane resin contains a curing agent, it begins to harden after being sprayed, and at the same time foams. When foaming to increase its volume, the urethane resin adheres to the polyester resin, but especially when paper 16 or a pressure roll is present on the surface, the foaming pressure is directed against the polyester resin layer 13, so the urethane resin adheres to the polyester resin. The resin firmly adheres to the polyester resin layer 13. In this way, the foamed layer of urethane resin 15 is firmly adhered to the polyester resin layer 13, and a durable laminated tube is formed.

After foaming the urethane resin, at least a portion of the inner surface of the urethane resin is cut. It is desirable that this cutting be performed on the protruding portion of the inner surface. This is because even though urethane resin is sprayed or cast uniformly, the surface is slightly uneven due to foaming, so cutting the protruding parts will smooth out the surface. This is because when the fibers and curable resin are placed on top, the fibers and curable resin can easily form a smooth inner surface. Moreover, the outer skin of the urethane resin is peeled off by this cutting.

Cutting can be performed using various tools such as a knife, a rotary cutting machine, and a heating wire. For example, as shown in FIG. 6, the protruding portion of the urethane resin 15 can be cut by fixing the knife 17 and rotating the cylinder 1. Further, instead of the knife 17, a nichrome wire may be fixed and an electric current passed through the wire to heat the nichrome wire to melt and cut the protruding portion of the urethane resin. Furthermore, as shown in a partially cutaway and enlarged view of FIG. 7, a cutting machine 18 equipped with a rotary blade is brought into contact with the inner surface of the urethane resin 15, and while the cylinder 1 is rotated, fine pieces generated by cutting are removed. It is also possible to cut while drawing the material using a vacuum.

Although it is desirable that the entire inner surface of the urethane resin 15 be cut, it is also possible to cut only the protruding parts and leave the depressed parts uncut.

Fibers and curable resin are further supplied and brought into contact with the surface of the urethane foam 15, including the surface newly created by cutting. This supply and contact are performed in the same manner as in the formation of the polyester resin layer 13 described above. That is, a mat of glass fiber is supplied from a supply tool (not shown), and after it is brought into uniform contact with the urethane foam 15, a curable polyester resin is cast or sprayed on top of the urethane foam 15 to form a glass fiber mat. A layer of polyester resin containing fibers is formed into a cylindrical shape.

In the method of this invention, the generation of the resin layer as described above, particularly the generation and cutting of the urethane resin foam layer, are performed while rotating the cylinder 1 around the cylinder axis.
Since this can be carried out while moving in the direction of the cylinder axis, it is possible to easily obtain a laminated pipe of uniform quality and a desired length. In addition, in the laminated tube thus obtained, the foam layer of urethane resin in the middle is firmly adhered to the non-foamed fiber-containing resin layers on both sides, resulting in a laminated tube that is difficult to peel off. It will be done. This is because the urethane resin is applied in a fluid state to one fiber-containing resin layer and foamed, resulting in strong adhesion, while the other fiber-containing resin layer is coated with at least the surface after curing. This is because the other curable resin enters and hardens where a portion is cut and the bubbles are exposed, resulting in a strong bond. In addition, in this laminated pipe,
Since there are layers of non-foamed fiber-containing resin on both sides, it is strong and heat resistant, and because there is a foamed resin layer in the middle, it is relatively lightweight and has good thermal insulation. Become. The inventive method thus provides various advantages.

Although the case where the method of this invention is implemented using the apparatus shown in FIG. 1 has been described above, the case where the method of this invention is implemented using the apparatus shown in FIG. 2 is also the same.
This is because the device shown in FIG. 1 and the device shown in FIG. 2 differ only in whether the cylinder moves or the supply tool moves, but they are the same in that they both move relative to each other.

The apparatus shown in FIGS. 3 and 4 is otherwise similar to that shown in FIGS. 1 and 2, except that the resin is formed on the outside of the cylinder. However, the difference is that when the resin is formed on the outside of the cylinder, the resin contracts as it hardens, making it difficult to remove the molded resin tube from the cylinder. Therefore, it is desirable to separate the cylinder into at least two parts and remove it from the resin pipe.
That is, as shown in FIG. 8, the cylinder 1 is made up of half cylinders 21 and 22, one joint 23 is used as a hinge, a wedge 24 is inserted into the other joint, and they are fixed with bolts 25, so that they can be assembled and separated. When removing the resin tube from the cylinder, it is desirable to disassemble the cylinder.

The tube is not limited to a cylinder, and may be one tapered toward one end. Further, the cross section is not limited to a circle, but may be polygonal, that is, a square tube. In the case of a rectangular tube, it is preferable to attach a ring with a circular cross section only to the portion in contact with the roll 3 to ensure smooth rotation around the tube axis.

The rotational speed of the cylinder is appropriately determined depending on the size of its inner diameter or outer diameter. For example, the diameter is 2 to 3 m.
In the case of a cylinder of size , it is desirable that the rotation speed be 1 revolution every 10 to 30 seconds.

The fibers are not limited to glass fibers, and natural fibers or synthetic fibers can be used. Furthermore, the fibers may be planar or filamentous. Taking glass fiber as an example,
It may be a chopped strand, a tape, a mat, or a woven fabric. In the case of thread, it is sufficient to spread it evenly over the cylinder 1, but in the case of tape or mat, care must be taken to ensure that the joint or overlapping part is even with the other parts.

Unsaturated polyester is suitable as the non-foamed curable resin, but various other curable resins can also be used. For example, epoxy resin, phenol resin, etc. can also be used.

Urethane resin is used as the foamable curable resin. Urethane resin foams in a short time,
This is especially selected for use because it has completely cured and has strong adhesive strength. The urethane resin can be applied on the non-foamed resin layer by not only spraying but also casting.

Since the urethane resin has a low viscosity immediately after being sprayed or cast, large irregularities will not occur on the surface even if it is left as it is. However, the viscosity rises rapidly within a short period of time, about a few tens of seconds, and at the same time foams and increases in volume, so slight irregularities may become enlarged, resulting in large irregularities. Therefore, a paper, film, plate, or roll is placed on the surface of this resin to prevent the surface from having too large irregularities. When this is done, the paper, film, or board attached to the surface is forcibly removed, and the skin is peeled off, exposing air bubbles, and cutting may not be necessary. However, even in such cases it is still desirable to cut.

When a layer made of fibers and curable resin is formed on the urethane resin 15, a roll may be used as shown in FIG. 9 to smooth the inner surface. FIG. 9 shows a cross section of the cylinder 1.
FIG. 9 shows a structure in which a non-foamed polyester resin layer 13 containing fibers is formed on the inner surface of a cylinder 1, a urethane resin layer 15 is formed on the inner surface, and a non-foamed polyester resin layer containing fibers is further formed on the inner surface. 19, rolls 27 and 28 hanging from the arm bar 5 are provided inside the arm bar 5, and an endless belt 29 is stretched over the rolls 27 and 28.
9 is shown moving along the inner surface while holding it down. At this time, it is preferable that the belt 29 be made of a material coated with fluororesin and coated with a release agent such as silicone resin to prevent the polyester resin from adhering.

When making a laminated pipe with the above-mentioned sanderch structure,
After foaming and curing of the urethane resin is completed,
When applying a non-foamed curable resin thereon, it is preferable to apply the resin to the outside of the cylinder. This is because the non-foamed resin layer attached to the surface contracts as the curing progresses and exhibits sufficient adhesive strength to the urethane resin.

In short, according to the method of this invention, laminated tubes can be easily obtained continuously. Moreover, since the inner layer and outer layer of the obtained laminated tube are made of a non-foamed curable resin reinforced with fibers, it has high heat resistance and high mechanical strength. in addition,
Since the middle layer of the laminated tube is made of foamed urethane resin, it is lightweight and has good heat insulation properties.
In addition, in the manufacturing process, the foaming power of the urethane resin was used to press the non-foamed resin layer, so both resins adhered firmly. Furthermore, since the skin of the foamed urethane resin was cut, the foaming power of the urethane resin was used to press the non-foamed resin layer. Since the other non-foamed resin is infiltrated and solidified, both resins are firmly adhered to each other, so that a laminated tube without any risk of peeling can be obtained. The method of this invention thus provides various advantages.

The large laminated tubes obtained in this way, with a diameter of several meters, can be used for the side walls of heat-insulating containers and tanks, and the walls of basements to prevent condensation.

[Brief explanation of drawings]

1 to 4 are perspective views or partially cut away elevational views showing an example of a device used for rotating a cylinder in the method of the present invention. FIG. 5 is a partially cutaway perspective view showing a state in which the method of the invention is carried out using the apparatus shown in FIG. 1. FIGS. 6 and 7 are cross-sectional views showing one step of the method of this invention. FIG. 8 is a cross-sectional view of a cylinder that can be used in the method of this invention. FIG. 9 is a cross-sectional view of a cylinder in another step of the method of the invention.

Claims (1)

[Claims] 1 Rotate a cylinder with at least one end open around the cylinder axis, supply fibers and curable resin onto the cylinder wall, and press it against the cylinder wall to form a cylinder of non-foamed fiber-containing resin on the wall surface. forming a foam layer, then spraying or casting a curable foamable urethane resin thereon to foam and cure, cutting at least a portion of the free surface of the foam, and cutting the surface created by cutting. A method for manufacturing a laminated resin pipe, which comprises supplying and pressing fibers and a curable resin onto a surface of a foam containing the foam to form a cylindrical layer of non-foamed fiber-containing resin.