JP2001021081A - Pipe for flexible joint made of ptef - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a pipe for a PTEF flexible joint, which can be simply processed in a job-site, and which has a high bonding strength at its one end. SOLUTION: A laminated sheet 1 composed of a PTEF sheet 1 and a glass cloth 1b is bonded at its both ends so as to make a cylindrical form to manufacture a pipe for a PTEF flexible joint. In this arrangement, both end parts 2a, 2b of the PTEF sheet 1a are bonded together by an adhesive 2c, and both laminated end parts 2d, 2e of the glass cloth 1b are sewn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved technique for realizing a flexible joint.

[0002]

2. Description of the Related Art Conventional PTFs for flexible joints
The method of manufacturing the E-made cylindrical body is as follows: at the manufacturing plant, peel off the end of the laminated sheet of the PTFE sheet and the inorganic fiber nonwoven fabric;
In this method, a heat-sealing sheet of PFA or FEP is sandwiched between the ends of the PTFE sheet and heat-sealed to bond the ends to form a cylindrical body. Alternatively, a method of applying a PTFE adhesive tape from above the end portions of the superposed PTFE sheets, or a method of sandwiching the adhesive tape between the PTFE sheets and molding into a cylindrical shape has been adopted.

[0003]

The above-mentioned conventional method of manufacturing a PTFE cylinder by heat fusion is often carried out in a factory, and the dimensions may not match when assembled on site.

[0004] When a large expansion joint or endless processing is originally required in a factory, a manufacturing facility must be brought to the site, and the above-mentioned conventional method has been expensive. In addition, these are processes requiring skill, and are performed by specialized processors, so that extra work is required.

[0005] The method using an adhesive tape is easy to work in the field, but has a problem that it is difficult to adhere due to the non-adhesiveness of the PTFE sheet, and has a disadvantage that the end portion is peeled off.

An object of the present invention is to remedy the above-mentioned drawbacks of the prior art, and to provide PTFE which is easy to work on site and has good adhesion.
An object of the present invention is to provide a flexible joint cylindrical body.

[0007]

According to a first aspect of the present invention, there is provided a flexible joint cylindrical body made of PTFE, wherein the laminate of the etched PTFE sheet and the inorganic fiber woven fabric is made of an inorganic fiber woven fabric. The gist is that the cloth is fixed at both ends with the cloth facing outward.

[0008] The invention of claim 2 is characterized in that, in the invention of claim 1, both ends of the PTFE sheet are adhered to each other, and the laminated end of the inorganic fiber woven fabric is locked.

According to a third aspect of the present invention, in the first aspect of the present invention, both ends of the PTFE sheet are overlapped and adhered in a palm-shape manner and are folded back, and the laminated end of the inorganic fiber woven fabric is locked. The point is that

According to a fourth aspect of the present invention, in the first aspect of the present invention, a PTFE sheet is provided at one end thereof with a holding portion made of one piece or two-fold etched PTFE pieces, and the PTFE sheet is provided at the holding portion. The gist of the present invention is that the other end is sandwiched and adhered, and the laminated end of the inorganic fiber woven fabric is locked.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a PTFE flexible joint cylinder of the present invention. In the figure, reference numeral 1 denotes a laminated sheet of an etched PTFE sheet 1a and an inorganic fiber woven fabric, for example, a glass cloth 1b;
Both ends are fixed. FIGS. 2 to 5 show the fixing structure at both ends.

In FIG. 2, ends 2a and 2b of a PTFE sheet 1a are adhered to each other by an adhesive 2c.
The laminated ends 2d and 2e of the glass cloth 1b are locked 2f.

In FIG. 3, both end portions 2a and 2b of the PTFE sheet 1a are overlapped with each other in a palm shape and bonded by an adhesive 2c to be folded, and the laminated ends 2d and 2e of the glass cloth 1b are locked by 2f. Have been.

In FIG. 4, at one end 2a of the PTFE sheet 1a, there is provided a sandwiching portion 4 composed of one etched PTFE piece 3 adhered to the end 2a by an adhesive 2c. The other end 2b of the PTFE sheet 1a is sandwiched between the sandwiching portions 4 and adhered by an adhesive 2c. The laminated ends 2d and 2e of the glass cloth 1b are locked by 2f.
Have been.

FIGS. 10, 11, and 12 show a state in which the PTFE flexible joint cylinder of FIG. 4 is incorporated in a pipe. 7, reference numeral 7 denotes a holding flange, 8 denotes a companion flange, and 9 denotes a PTFE flexible joint cylinder of FIG. FIG. 12 is an enlarged view showing details of a portion B in FIG.

In FIG. 5, the etched PT
An end portion 2a of the FE sheet 1a is provided with a sandwiching portion 6 made of a folded PTFE piece 5 adhered to the end portion 2a with an adhesive 2c, and the sandwiching portion 6 is provided with a PTFE sheet 1a.
The other end 2b of the glass cloth 1b is sandwiched and adhered by an adhesive 2c.
f.

In each of the above embodiments, the glass cloth 1b
Can be locked by a method of sewing the overlapped glass cloth or a method of locking with staples. Although the PTFE sheet 1a and the glass cloth 1b are preferably bonded, they need not necessarily be bonded.

Further, the etching process of the PTFE sheet is usually performed on the entire both surfaces of the sheet because it is immersed in an etching solution, but may be performed only at the end to be bonded. When the glass cloth is bonded to the PTFE sheet, the surface to be bonded needs to be etched. As the above-mentioned etching method, for example, there is a method of immersing a PTFE sheet in a dispersion obtained by dispersing metallic sodium powder in a solvent. In this method, the entire PTFE sheet is usually immersed, and the whole of both surfaces is etched.

FIGS. 6 to 9 show PTFE of the present invention, respectively.
A method for manufacturing a flexible joint cylindrical body, particularly a method for treating an end of the cylindrical body, will be described.

In the embodiment shown in FIG. 6, the PTFE sheet 1a has been subjected to a double-sided etching treatment, the ends 2a and 2b of the PTFE sheet 1a are adhered to each other with an adhesive 2c, and the laminated ends 2d and 2e of the glass cloth 1b. Lock 2f
I do. In this case, the PTFE sheet 1a and the glass cloth 1
When b is bonded, the bonding between the ends 2a, 2b, 2d, and 2e of the PTFE sheet 1a and the glass cloth 1b is peeled off, and then the bonding and locking of the ends are performed.

In the embodiment shown in FIG. 7, the PTFE sheet 1a has been subjected to a double-sided etching treatment, and both ends 2a and 2b of the PTFE sheet 1a are overlapped in a palm-shape manner and bonded and folded back with an adhesive 2c to form a glass cloth 1b. The laminated ends 2d and 2e are locked 2f. In this case, if the PTFE sheet 1a and the glass cloth 1b are bonded, P
TFE sheet 1a and ends 2a, 2 of glass cloth 1b
After the adhesive of b, 2d and 2e is peeled off, the above-mentioned ends are bonded and locked.

In the embodiment shown in FIG. 8, the PTFE sheet 1a has been subjected to a double-sided etching treatment, and a holding portion 6 made of one PTFE piece 3 is provided on one end 2a of the PTFE sheet 1a by bonding with an adhesive 2c. , P
The other end 2b of the TFE sheet 1a is sandwiched and bonded with an adhesive 2c, and the laminated ends 2d and 2e of the glass cloth 1b are locked 2f. In this case, if the PTFE sheet 1a and the glass cloth 1b are bonded, the PTFE sheet 1a
After the adhesive between the end portions 2a, 2b, 2d, and 2e of the glass cloth 1b is peeled off, the above-mentioned end portions are bonded and locked.

In the embodiment shown in FIG. 9, the PTFE sheet 1a has been subjected to a double-sided etching process, and a folded PTFE piece 5 is provided on one end 2a of the PTFE sheet 1a by bonding with an adhesive 2c. 6, the other end 2b of the PTFE sheet 1a is sandwiched and bonded with an adhesive 2c,
The laminated ends 2d and 2e of the glass cloth 1b are locked 2f. In this case, the PTFE sheet 1a and the glass cloth 1b
Are bonded, the PTFE sheet 1a and the ends 2a, 2b, 2d, 2e of the glass cloth 1b are bonded and locked.

[0024]

As described above, according to the present invention, P
When manufacturing TFE flexible joint cylinders,
Etching at least the end of the PTFE sheet,
Since the bonding method is employed, work on site is easy, and the adhesiveness is good. Furthermore, the inorganic fiber woven fabric is
The lamination and locking are performed on the bonding end of the TFE sheet, so that the bonding strength is further improved.

In particular, since the invention of claim 3 has a structure in which one end of the PTFE sheet is overlapped and folded back in a palm shape, it has a five-layer structure, and has high strength against tensile force and high sealing stability.

According to the fourth aspect of the present invention, since the sandwiching portion is provided, the bonding surfaces of the PTFE sheet are on both sides and the tensile strength is large, and the positioning at the construction site is easy and the construction is easy. Moreover, the sandwiching portion has three layers (FIGS. 4, 8, 11, 1).
2) or a four-layer structure (FIGS. 5 and 9), which is thinner than the five-layer structure of the invention of claim 2, and the difference in thickness from the non-connection part is smaller, so that the flange of the pipe to be connected is The swelling at the portion is reduced, and the sealing performance is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a cylindrical body of the present invention.

FIG. 2 is a schematic view showing an embodiment of an end structure of the cylindrical body.

FIG. 3 is a schematic view showing another embodiment of the end structure of the cylindrical body.

FIG. 4 is a schematic view showing still another embodiment of the end structure of the cylindrical body.

FIG. 5 is a schematic view showing still another embodiment of the end structure of the cylindrical body.

FIG. 6 is a schematic diagram illustrating one embodiment of the method of the present invention.

FIG. 7 is a schematic diagram showing another embodiment of the method of the present invention.

FIG. 8 is a schematic diagram showing still another embodiment of the method of the present invention.

FIG. 9 is a schematic diagram showing still another embodiment of the method of the present invention.

10 is an axial sectional view showing a state in which the PTFE flexible joint cylinder shown in FIG. 4 of the present invention is incorporated in a pipe.

FIG. 11 is a view taken in the direction of arrows AA in FIG. 10;

FIG. 12 is an enlarged view showing details of a portion B in FIG. 11;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laminated sheet 1a PTFE sheet 1b glass cloth 2 end 2a, 2b end of PTFE sheet 2c adhesive 2d, 2e end of glass cloth 3,5 PTFE piece 4,6 sandwiching section 7 holding flange 8 companion flange 9 PTFE Flexible joint cylinder

Claims (4)

[Claims] 1. A flexible joint cylindrical body, wherein a laminate of an etched PTFE sheet and an inorganic fiber woven fabric is fixed at both ends thereof with the inorganic fiber woven fabric outside. 2. The flexible joint cylinder according to claim 1, wherein both ends of the PTFE sheet are adhered to each other, and a laminated end of the inorganic fiber woven fabric is locked. 3. The flexible sheet according to claim 1, wherein both ends of the PTFE sheet are overlapped in a palm-shape manner, bonded and folded, and a laminated end of the inorganic fiber woven fabric is locked. Tube for joint. 4. One piece or 2 pieces at one end of the PTFE sheet
A sandwich portion made of a folded PTFE piece is provided, and the other end portion of the PTFE sheet is sandwiched and adhered to the sandwich portion, and a laminated end portion of the inorganic fiber woven fabric is locked. The flexible joint cylinder according to claim 1, wherein: