JP2004336962A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint of which a water swollen fiber or liquid absorbing resin is rare to drop off the base material of nonwoven fabric, and which is reused even after used once to swell by absorbing water. <P>SOLUTION: The pipe joint comprises a joint body 3 for connecting the end of a pipe body. A resin base fiber 9 which is to be a base material, a water swollen fiber 10 in which a high melting-point water swollen resin material is fiberized, and a binder 11, are used and processed for nonwoven fabric. The base fiber 9 and the water swollen fiber 10 are combined by the binder 11 which is melted by the heat at the process to form a water stop layer 4. The water stop layer 4 is integrated with the surface facing the pipe body of a joint body 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint that connects pipes that are buried underground to protect electric wires and cables.
[0002]
[Prior art]
Generally, the pipes for protecting electric wires or cables and the pipe joints for connecting the pipes described above are buried in the ground, and in particular, the pipes and the pipe joints have a reliable and sufficient waterproof structure. Water structure is required.
[0003]
Conventionally, various pipe joints have already been invented in response to such demands.
That is, the pipe joint has a center tube at the center, and a short tube portion is rotatably connected to one side and the other side of the center tube, and the short tube portion on one side has a trapezoidal spiral. An uneven strip was integrally formed, and a spiral uneven strip having a semicircular cross section was integrally formed on the other short tube portion, and a water-tight sealing fiber sheet was fused and integrated on the inner peripheral surfaces of both short tube portions. There is a pipe joint with a watertight sealing sheet (see Patent Document 1).
As disclosed in this conventional publication, as shown in FIG. 8A, the above-mentioned water-tightly sealing fiber sheet 80 is made of a water-swelling resin material 81 in a powdery state and contained in fibers 82 or Since the fibers 82 are adhered and held on the outer peripheral surface, the bonding force between the water-swellable powdery resin material 81 and the fibers 82 is low, and as shown in FIG. When the resin material 81 (so-called water-expandable resin powder particles) expands by absorbing water, the resin powder particles 81 are separated from the fibers 82 and fall off. There was a problem that it could not be used and was of a so-called disposable type. In the drawing, reference numeral 83 denotes a joint main body.
[0004]
On the other hand, when the water-blocking layer is formed by a mold, a highly water-absorbent resin is formed into a nonwoven fabric in a fibrous state and mixed or held (see Patent Document 2), or a water-absorbent fiber nonwoven fabric is used as a water-blocking material ( Patent Document 3), but since it is merely about making the superabsorbent resin fibrous, the bonding strength of the fibrous superabsorbent resin to the base material of the nonwoven fabric is insufficient, and after the first use, It was difficult to reuse.
[0005]
[Patent Document 1]
Japanese Utility Model Publication No. 7-52467 (utility model registration No. 2133706)
[Patent Document 2]
JP 2002-33086 A [Patent Document 3]
JP-A-2003-74770.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a pipe joint in which a water-swelling fiber or a liquid water-absorbent resin hardly falls off from a nonwoven base material, and can be reused even if the pipe joint has been subjected to water-swelling expansion once used. I do.
[0007]
[Means for Solving the Problems]
A pipe joint according to the present invention is a pipe joint provided with a joint body for connecting ends of a pipe body, wherein a resin base fiber serving as a base and water in which a high-melting-point water-swelling resin material is fiberized are used. Expanded fibers and processed into a non-woven fabric using a binder, forming a water-stop layer in which the base fibers and the water-expanded fibers are bonded with a binder that is melted by the heat generated during the processing. The water blocking layer is integrated with the facing surface.
[0008]
The water-swelling fiber in which the high-melting-point water-swelling material having the above-mentioned structure is fibrillated does not melt due to heat at the time of processing. For example, Bel Oasis (registered trademark, product of Kanebo Gosen Co., Ltd.) may be used. As the binder, PET fiber or PE fiber may be used, and as the binder, a material which is melted by heat at the time of processing, such as low melting point PET, may be used.
[0009]
According to the above configuration, since the water-stop layer is formed by bonding the base fiber and the water-swelling fiber with a binder melted by heat during processing, the water-swellable fiber hardly falls off the nonwoven fabric base material, and Even when the expandable fiber absorbs water and expands, the water expandable fiber falls off very little.
[0010]
Further, since the above-mentioned water-expandable fiber shrinks to its original volume during drying, it can be reused even after the pipe joint has been used once.
[0011]
The pipe joint according to the present invention is also a pipe joint provided with a joint body continuing an end of a pipe body, in which a resin base fiber serving as a base and a low-melting water-swelling resin material are fiberized. The water-swelling fibers are processed into a nonwoven fabric using the water-swelling fibers, and the water-swelling fibers softened by heat during the processing form a water-stop layer bonded to the base fibers, and the water-stopping layer is formed on the surface of the joint body facing the tube. The water layer is integrated.
[0012]
The water-expandable fiber in which the low-melting-point water-expandable material having the above-mentioned structure is fiberized is softened by heat during processing. For example, Lanseal (registered trademark, product of Toyobo Co., Ltd.) may be used. PET fibers or PE fibers may be used as the material fibers.
[0013]
According to the above configuration, since the water-swelling fibers are bonded to the base fibers by the water-swelling fibers softened by heat during processing, the water-swelling fibers hardly fall off from the base material of the nonwoven fabric. Even when water is expanded by absorbing water, the water-swelling fibers fall off very little.
Further, since the above-mentioned water-expandable fiber shrinks to its original volume during drying, it can be reused even after the pipe joint has been used once.
[0014]
The pipe joint according to the present invention is further a pipe joint provided with a joint body for connecting an end portion of a pipe body, which is processed into a nonwoven fabric using a resin base fiber as a base material, and the nonwoven fabric absorbs liquid A water-stop layer impregnated with a water-soluble resin is formed, and the water-stop layer is integrated with a surface of the joint body facing the tube.
[0015]
PET fiber or PE fiber may be used as the base fiber having the above configuration, and Equos (trademark, product of Sunadd Co., Ltd.) may be used as the liquid water-absorbing resin.
[0016]
According to the above configuration, the water-stopping layer is impregnated with the liquid non-woven fabric made of the nonwoven fabric of the base fiber and the two are firmly bonded, so that the water-swelling fiber hardly falls off the nonwoven base material, Also, when the water-absorbent resin expands by absorbing water, the falling off of the water-absorbent resin is extremely small.
Moreover, since the above-mentioned water-absorbent resin shrinks to its original volume when dried, it can be reused even after the pipe joint has been used once.
[0017]
In one embodiment of the present invention, a clearance for water circulation is formed between the water-stop layer and the pipe during drying before and after water expansion.
The clearance of the above configuration may be set to an arbitrary value of 0.2 mm to 5.0 mm corresponding to the outer diameter of the tube.
[0018]
According to the above configuration, the clearance is formed between the water blocking layer and the pipe at both the time before the water expansion and the time of the drying after the water expansion, so that the operation of attaching and detaching the pipe joint is performed. It can be performed very smoothly and easily. In other words, the contact resistance between the water-stop layer and the pipe body is small at both the time of installation and removal of the pipe joint, and the falling off of the water-swelling fibers and liquid water-absorbing resin due to mechanical external force is further reduced, The reusability of the pipe joint is further improved.
In addition, since the water can satisfactorily penetrate into the water blocking layer due to the clearance, a good water stopping effect can be exerted by rapid expansion of the water blocking layer.
[0019]
【Example】
An embodiment of the present invention will be described below in detail with reference to the drawings.
The drawings show a pipe joint. In FIGS. 1 and 2, this pipe joint 1 has a waterproof layer 4 integrated over the entire inner peripheral surface of a synthetic resin or synthetic rubber joint body 3 having a continuous spiral uneven strip 2. One of the pipes 6 (so-called pipe) having the spiral ridges 5 and the other pipe 8 (so-called pipe) having the spiral ridges 7 are connected.
[0020]
That is, the pipe joint 1 is inserted and connected to the pipe 6 until the other end 1A of the pipe joint 1 coincides with the end 6A of one pipe 6, and then the end 6A of the pipe 6 and the other end are connected. After the end 8A of the pipe 8 matches or substantially matches, the screwed pipe joint 1 is unscrewed by about half the screwed amount, and the other end of the pipe joint 1 is inserted into the pipe 8 and connected. As shown in FIG. 3, both pipes 6, 8 are connected by the pipe joint 1.
[0021]
As shown in FIG. 3, between the water-stop layer 4 integrated with the inner peripheral surface of the joint main body 3 of the pipe joint 1 and the outer peripheral surfaces of the pipe bodies 6, 8, the water-stop layer 4 allows water to flow. A clearance C (a so-called water passage) for water circulation (for water intrusion) is formed before the water is expanded by absorbing water and before drying (water release) after the water expansion.
[0022]
These pipes 6, 8 and the pipe joint 1 are buried underground with electric wires, cables, etc. inserted through the pipes 6, 8, and when the water-stop layer 4 absorbs water. As shown in FIG. 4 from the state shown in FIG. 3, the water-stopping layer 4, particularly the portions on both ends of the pipe joint 1, expands, and the water-absorbing expansion causes the water-stopping layer 4 to connect the joint body 3 and each pipe. By sealing between the outer peripheral surfaces of the bodies 6 and 8 in a liquid-tight manner, a reliable water stopping effect is exhibited.
[0023]
FIG. 5 is an enlarged view showing the detailed structure of the water blocking layer 4. First, about 10 to 25 wt% of a base fiber 9 made of a resin such as PET which is a base material of the nonwoven fabric and a high melting point water-swelling resin material are used. About 70-90 wt% of the fibrillated water-swelling fiber 10 (a fiber that expands when absorbing water and releases moisture when the surrounding humidity is low) and a binder 11 (specifically, a binder resin) such as low melting point PET that is about 2- 15 wt%, and these are almost evenly mixed to form a nonwoven fabric (nonwoven fabric forming step).
[0024]
Here, as the above-mentioned water-swelling fiber 10, a softening point is a product of Bell Oasis (registered trademark, Kanebo Synthetic Fibers Co., Ltd.) having a softening point of about 170 ° C. (Highly water-absorbing and highly moisture-absorbing fibers formed into fibers). Also, a binder having a low melting point of about 120 ° C. is used as the binder 11.
[0025]
Next, the flat non-woven fabric is formed into a cylindrical shape, and the cylindrical non-woven fabric is applied to an inner mold (more specifically, an inner mold having a plurality of divided structures and a shape surface forming a spiral uneven strip). An outer mold having a half-split structure (specifically, an outer mold having a shape surface forming a spiral uneven strip) is arranged, and a joint body 3 is formed between the inner surface of the outer mold and the outer peripheral surface of the nonwoven fabric. When the synthetic resin or synthetic rubber of the above is filled, the outer mold is closed and heated and pressurized at a molding temperature of about 150 to 180 ° C., the binder 11 is melted by the heat during the processing, and FIG. 2), the base fiber 9 and the water-swelling fiber 10 are firmly bonded by the molten binder 11 (the bonding step by the binder), and the water-stop layer 4 is integrated with the joint body 3. (Integrating step), the pipe joint 1 shown in FIG. 1 is obtained after the mold is separated.
[0026]
The water-swelling fibers 10 in the above-mentioned water-stop layer 4 expand radially when absorbing water to be in the state shown in FIG. 5B and exhibit a water-stopping effect. Since the water-swelling fibers 10 are strongly bonded to the base fibers 9, the water-swelling fibers 10 fall off very little.
[0027]
As described above, the pipe joint according to the embodiment shown in FIGS. 1 to 5 is a pipe joint 1 including the joint body 3 that connects the ends of the pipes 6 and 8, and includes a resin-made base material as a base material. The non-woven fabric is processed using the material fiber 9, the water-swelling fiber 10 in which the high-melting-point water-swelling resin material is fiberized, and the binder 11, and the base fiber 9 is expanded by the binder 11 melted by heat during the processing. A structure in which the water-stop layer 4 is formed by bonding the fibers 10 to each other, and the water-stop layer 4 is integrated with a surface (in this embodiment, an inner peripheral surface) of the joint body 3 facing the pipes 6 and 8. It is.
[0028]
According to this configuration, in addition to the entanglement of the fibers 9, 10, the water-stopping layer 4 has the binder 11 melted by the heat during processing, and the base fiber 9 and the water-swelling fiber 10 are bonded together. In the past, the water-swelling fibers 10 hardly fall off from the base material of the nonwoven fabric, and even when the water-swelling fibers 10 expand by absorbing water, the shedding of the water-swelling fibers 10 is extremely small.
[0029]
Further, since the above-mentioned water-swelling fiber 10 shrinks to its original volume during drying, it can be reused even after the pipe joint 1 has been used once. In addition, since the water-swelling fibers 10 are almost uniformly present in the water-stop layer 4, an appropriate water-stop effect can be ensured.
[0030]
Further, a clearance C for water circulation is formed between the water blocking layer 4 and the pipes 6 and 8 before and after the water expansion.
According to this configuration, the clearance C is formed between the water blocking layer 4 and the pipes 6 and 8 both before and after the water expansion and at the time of drying after the water expansion. Mounting and removal operations can be performed extremely smoothly and easily. In other words, the contact resistance between the water-stop layer 4 and the pipes 6, 8 is small both when the pipe joint 1 is attached and detached, so that the detachment of the water-expandable fiber 10 due to mechanical external force is further reduced. Thus, the reusability (repeated use performance) of the pipe joint 1 is further improved.
[0031]
In addition, since the water can satisfactorily enter the water blocking layer 4 due to the clearance C, a good water stopping effect can be exerted by rapid expansion of the water blocking layer 4.
It is needless to say that the pipe joint 1 can be detached against the fitting force of the waterproof layer 4 even during the water absorption expansion.
[0032]
FIG. 6 is an enlarged view showing another embodiment of the water blocking layer 4. First, a resin base fiber 9 such as PET as a base material of a nonwoven fabric and a low-melting water-swelling resin material are fiberized. And water-expandable fibers 12 (fibers that expand when absorbing water and release moisture when the ambient humidity is low) and mix them almost equally to form a nonwoven fabric (nonwoven fabric forming step).
Here, Lanseal (registered trademark, product of Toyobo Co., Ltd.) having a softening point of about 120 ° C. is used as the above-mentioned water-swelling fiber 12.
[0033]
Next, the flat non-woven fabric is formed into a cylindrical shape, and the cylindrical non-woven fabric is applied to an inner mold (more specifically, an inner mold having a plurality of divided structures and a shape surface forming a spiral uneven strip). An outer mold having a half-split structure (specifically, an outer mold having a shape surface forming a spiral uneven strip) is arranged, and a joint body 3 is formed between the inner surface of the outer mold and the outer peripheral surface of the nonwoven fabric. The synthetic resin or synthetic rubber is filled, the outer mold is closed, heated and pressurized at a molding temperature of about 150 to 180 ° C., and the water at the time of this processing causes the water-expandable fiber 12 to be expanded as shown in FIG. 6 (b), the softened water-expandable fiber 12 becomes the water-blocking layer 4 which is firmly bonded (bonding step) to the base fiber 9 over a wide area. Since the water blocking layer 4 is integrated with the joint body 3 (integrating step), the pipe joint shown in FIG. 1.
[0034]
The water-swelling fibers 12 in the above-mentioned water-stop layer 4 expand radially at the time of water supply, and reach the state shown in FIG. That is, the swollen fibers 12 follow the surface to be stopped and stop water. At this time, since the water-swelling fibers 12 are softened by the heat during the above-described processing and are firmly bonded to the base fibers 9 in a wide area, the falling-off of the water-swelling fibers 12 is extremely small.
[0035]
As described above, the pipe joint of the embodiment shown in FIG. 6 is a pipe joint 1 including the joint body 3 that connects the ends of the pipes 6 and 8, and includes a resin base fiber 9 serving as a base. And a low-melting water-swelling resin material, which is processed into a nonwoven fabric using the fiberized water-swelling fibers 12 (see FIG. 6A). 9 (see (b) of FIG. 6), the water-stopping layer 4 is formed, and the water-stopping layer 4 is integrated with the joint body 3 on the surface of the joint body 3 facing the pipes 6, 8. .
[0036]
According to this configuration, in addition to the entanglement of the fibers 9 and 12, the water-stopping layer 4 combines the water-expandable fibers 12 softened by heat during processing with the base fibers 9 as shown in FIG. Since the water-swelling fibers 12 hardly fall off from the nonwoven fabric base material before water absorption, and when the water-swelling fibers 12 expand by absorbing water as shown in FIG. The falling off of the water-expandable fibers 12 is extremely small.
Further, since the above-mentioned water-expandable fiber 12 shrinks to its original volume during drying, it can be reused even after the pipe joint 1 has been used once. In addition, since the water-swelling fibers 12 are almost uniformly present in the water-stop layer 4, an appropriate water-stop effect can be ensured.
[0037]
Further, a clearance C for water circulation is formed between the water blocking layer 4 and the pipes 6 and 8 before and after the water expansion.
According to this configuration, the clearance C is formed between the water blocking layer 4 and the pipes 6 and 8 both before and after the water expansion and at the time of drying after the water expansion. Mounting and removal operations can be performed extremely smoothly and easily. That is, the contact resistance between the water blocking layer 4 and the pipes 6 and 8 is small both when the pipe joint 1 is attached and detached, and the falling off of the water-expandable fibers 12 due to mechanical external force is further reduced. Thus, the reusability of the pipe joint 1 is further improved.
In addition, since the water can satisfactorily enter the water blocking layer 4 due to the clearance C, a good water stopping effect can be exerted by rapid expansion of the water blocking layer 4.
[0038]
FIG. 7 is an enlarged view showing another embodiment of the water blocking layer 4. First, a nonwoven fabric is formed using a base fiber 9 made of a resin such as PET as a base material of the nonwoven fabric (nonwoven fabric forming step).
Next, the nonwoven fabric is impregnated with the liquid water-absorbent resin 13 (impregnation step). Here, as the liquid water-absorbent resin 13, Equos (trademark, product of Sunadd Co., Ltd.) is used.
[0039]
Next, the flat nonwoven fabric is formed into a cylindrical shape, and the flat nonwoven fabric is applied to an inner mold (more specifically, an inner mold having a plurality of divided structures and having a shape surface forming a spiral uneven strip). An outer mold having a half-split structure (specifically, an outer mold having a shape surface forming a spiral uneven strip) is arranged, and a molten state in which the joint body 3 is formed between the inner surface of the outer mold and the outer peripheral surface of the nonwoven fabric. The outer mold is filled with a synthetic resin or a synthetic rubber, and the outer mold is heated and pressed at a molding temperature of about 150 to 180 ° C. to form the water blocking layer 4. Since the water blocking layer 4 is integrated with the joint body 3 (integrating step), the pipe joint 1 shown in FIG.
[0040]
The liquid water-absorbent resin 13 in the water-stop layer 4 expands when absorbing water and changes from the state of FIG. 7A to the state of FIG. 7B to exhibit the water-stopping effect. Since the water-absorbent resin 13 is firmly bonded to the base fiber 9 over a wide area by impregnation, the falling off of the liquid water-absorbent resin 13 is extremely small.
[0041]
As described above, the pipe joint of the embodiment shown in FIG. 7 is the pipe joint 1 including the joint body 3 that connects the ends of the pipes 6 and 8, and the resin base fiber 9 serving as the base. Is formed into a non-woven fabric, and the non-woven fabric is formed with a water-blocking layer 4 impregnated with a liquid water-absorbing resin 13. The water-blocking layer 4 is integrally formed on the surface of the joint body 3 facing the pipes 6, 8. It was made into.
[0042]
According to this configuration, the water-stopping layer 4 is formed by impregnating the nonwoven fabric made of the base fiber 9 with the liquid water-absorbing resin 13, and the two 9 and 13 are firmly bonded. When the water-absorbent resin 13 expands due to water absorption, the water-absorbent resin 13 is hardly dropped off from the base material of the nonwoven fabric.
Moreover, since the above-mentioned water-absorbent resin 13 shrinks to its original volume during drying, it can be reused even after the pipe joint 1 has been used once.
[0043]
Further, a clearance C for water circulation is formed between the water blocking layer 4 and the pipes 6 and 8 before and after the water expansion.
According to this configuration, the clearance C is formed between the water blocking layer 4 and the pipes 6 and 8 both before the water expansion and during the drying after the water expansion. Mounting and removal operations can be performed extremely smoothly and easily. That is, the contact resistance between the water blocking layer 4 and the pipes 6 and 8 is small both when the pipe joint 1 is attached and detached, so that the detachment of the liquid water absorbent resin 13 due to a mechanical external force is further reduced. Thus, the reusability of the pipe joint 1 is further improved.
In addition, since the water can satisfactorily enter the water blocking layer 4 due to the clearance C, a good water stopping effect can be exerted by rapid expansion of the water blocking layer 4.
[0044]
In the above embodiment, the liquid water-absorbent resin 13 was impregnated before the formation of the water-stop layer 4, but the liquid water-absorbent resin 13 may be applied before the formation of the water-stop layer 4. After the formation of the layer 4, the liquid water-absorbent resin 13 may be applied. In any case, it is desirable that the liquid water-absorbent resin 13 be impregnated or applied to the entire water-stopping layer 4 almost uniformly. Further, the above-mentioned water-expandable fibers 10, 12 processed into urethane foam may be integrally formed with the joint body 3 of the pipe joint 1 to be integrated.
[0045]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, there is an effect that the water-swelling fiber or the liquid water-absorbing resin hardly falls off from the base material of the nonwoven fabric, and the pipe joint which has been used once and expanded by water absorption can be reused.
[Brief description of the drawings]
FIG. 1 is a perspective view of a pipe joint of the present invention.
FIG. 2 is a perspective view of a pipe joint and a pipe body.
FIG. 3 is a sectional view showing a connection state of a pipe body by a pipe joint.
FIG. 4 is a sectional view when water is stopped.
FIG. 5A is an explanatory view showing a bonding state by a binder, and FIG. 5B is an explanatory view at the time of fiber expansion.
6A is an explanatory view of a base fiber and a water-swelling fiber, FIG. 6B is an explanatory view showing a bonding state by softening, and FIG.
FIG. 7A is an explanatory view showing a bonding state between the base fiber and the liquid water-absorbent resin, and FIG. 7B is an explanatory view when the water-absorbent resin is expanded.
FIG. 8A is an explanatory view showing a conventional water-blocking layer structure, and FIG. 8B is an explanatory view showing falling off of resin powder particles.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Pipe joint 3 ... Joint body 4 ... Waterproof layer 6, 8 ... Pipe 9 ... Base fiber 10, 12 ... Water-expandable fiber 11 ... Binder 13 ... Liquid water-absorbent resin C ... Clearance

Claims (4)

A pipe joint having a joint body for connecting ends of a pipe body,
A base fiber made of resin as a base material, a water-swelling fiber in which a high-melting-point water-swelling resin material is fiberized, and processed into a nonwoven fabric using a binder,
Form a water-stop layer in which the base fiber and the water-swelling fiber are combined with a binder melted by heat during processing,
A pipe joint in which the water-stop layer is integrated with a surface of the joint body facing the tube. A pipe joint having a joint body for connecting ends of a pipe body,
The base fiber made of resin as the base material and the low-melting water-swelling resin material are processed into a non-woven fabric using fiberized water-swelling fibers,
A pipe joint in which a water-swelling fiber softened by heat during processing forms a water-blocking layer bonded to a base fiber, and the water-blocking layer is integrated with a surface of the joint body facing the tube. A pipe joint having a joint body for connecting ends of a pipe body,
Processed into a non-woven fabric using a resin base fiber as the base material,
Forming a water-stop layer impregnated with the liquid water-absorbent resin on the nonwoven fabric,
A pipe joint in which the water-stop layer is integrated with a surface of the joint body facing the tube. The pipe joint according to any one of claims 1 to 3, wherein a clearance for water circulation is formed between the water blocking layer and the pipe body before and after the water expansion and during drying.

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