JP2002348753A - Protecting material and underground pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protecting material having high impact strength, excellent in flexibility and good at productivity and capable of being thinned, and to provide an underground pipe excellent in impact strength. SOLUTION: This protecting material comprises a woven cloth 2 obtained by weaving a polyolefin flat yarn as warps 11 and wefts 12, wherein the woven cloth is twill weave and beaten density of the warps 11 and/or the wefts 12 of the woven cloth 2 is 5-50 yarns/inch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective material for protecting a buried pipe or the like buried underground and a buried pipe wound with the protective material.

[0002]

2. Description of the Related Art Buried pipes such as gas pipes buried underground are:
Damage may be caused by excavation tools and the like in digging work in road construction and construction work. In particular, since the gas pipe uses polyethylene, polyvinyl chloride, or the like as its material, it is easily damaged, and it is necessary to prevent the above-described accident. In order to prevent such an accident, the buried pipe is protected by a protective material wound around its outer peripheral surface.

FIG. 7 shows an example of a conventional protective material. The protective material 30 has a protective material main body 32 in which two woven fabrics 31 are stacked and laminated, and a display sheet 33 disposed on one surface of the protective material main body 32. Are sewn in the longitudinal direction with sewing threads 34 to be integrated.

As shown in FIG. 8, the protective material main body 32 is made of a 2000 denier synthetic resin flat yarn 35.
Is woven into a woven fabric by plain weaving so that the driving density of the warp yarn is 17 yarns / inch and the driving density of the weft yarn is 14 yarns / inch, and two woven fabrics are stacked and sewn.

[0005] The display sheet 33 has a 1000 denier flat yarn on the printed surface of the display film on which the name of the object to be buried, words for calling attention, etc. are printed, and the number of vertical and horizontal yarns is 10 / inch. It is obtained by laminating and bonding a woven cloth woven in such a manner.

Further, as another example of the protective material body,
A 3000 denier synthetic resin flat yarn is woven with a ridge weave shown in the organization chart of FIG. 9 so that the driving density of the warp yarn is 30 yarns / inch and the driving density of the weft yarn is 18 yarns / inch. And those that have been mentioned. FIG.
, The white portion is a portion where the warp yarn is floating above the weft yarn, and the black portion is a portion where the warp yarn is sinking below the weft yarn.

[0007]

When the woven fabric used for the protective material body 32 is a plain weave or a ridge weave, the warp yarn and the weft yarn have a high binding force and the yarn is fixed. for that reason,
When a hit by a drilling tool or the like is applied to the protective material 30, the impact of the hit cannot be released by the movement of the thread,
Since the impact is applied to the yarn without being dispersed, the yarn is easily cut.

Further, the protective material body 3 in which two woven fabrics 31 are stacked
When manufacturing No. 2, since a step of laminating the woven fabric 31 is required, productivity was poor. In addition, the protective material 30 is thick and bulky because the woven fabric is laminated, and there is a problem that the workability at the time of winding around the buried pipe is poor. In particular,
Plain weave and row weave fabrics had a high binding force of warp yarns and weft yarns and were poor in flexibility, so their workability was considerably poor.

Accordingly, an object of the present invention is to provide a protective material which has high impact strength, high flexibility, good productivity, can be made thinner, and a buried pipe excellent in impact resistance. .

[0010]

The protective material of the present invention has a woven fabric obtained by weaving a polyolefin flat yarn into a warp yarn and a weft yarn, and the structure of the woven fabric is an oblique weave. And the driving density of the warp yarn and / or weft yarn of the woven fabric is 5 to 50 yarns / inch. The fineness of the flat yarn is 200 to 10
Desirably, it is 000 denier.

It is preferable that the oblique weave is an angled oblique. Further, it is desirable that the polyolefin is a polypropylene having a melt flow rate of 1.0 g / 10 minutes or less. The buried pipe of the present invention is characterized in that the protective material of the present invention is wound.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 is a diagram showing an example of the protective material of the present invention. This protective material 1 has one woven cloth 2 and a display sheet 3 arranged on one side of the woven cloth 2. The woven cloth 2 and the display sheet 3 are sewn with sewing threads 4 in the longitudinal direction. And joined.

As shown in FIG. 2, the woven fabric 2 is composed of a polyolefin flat yarn warp yarn 11 and a weft yarn 12.
Are woven. As shown in the organization diagram of FIG. 3, the organization of the 3/3 oblique weave rising to the right and the organization of the 3/3 oblique weave rising to the left were continuously and alternately formed, as shown in the organization diagram of FIG. The oblique line is a mountain-shaped oblique structure having a mountain-shaped pattern. Here, the oblique weave is an organization generally called a twill weave.

The driving density of the warp yarn 11 of the woven fabric 2 is 5
The number is preferably 50 to 50 / inch, more preferably 10 to 40 / inch. The driving density of the weft yarn 12 is preferably 5 to 50 yarns / inch, and more preferably 15 to 40 yarns / inch. In the present invention, the texture is a cross-woven weave, and the warp yarn 1
As shown in FIG. 2, by increasing the driving density of the woven fabric 1, the warp yarns 11 having the increased density are gathered and the warp yarns 11 are lifted up. The cloth 2 has a thickness.

If the driving density of the warp yarns 11 is less than 5 yarns / inch, the warp yarns 11 will not be sufficiently gathered and gathered, and it will be difficult for the woven fabric 2 to have thickness and irregularities. If it exceeds 50 yarns / inch, knitting may be difficult. When the driving density of the weft yarn 12 is less than 5 yarns / inch, the gap between the flat yarns becomes large, and the protection may be insufficient. If it exceeds 50 yarns / inch, knitting may be difficult.

The interval between the peaks and valleys of the angled angled pattern (cycle of the angled angled pattern) is preferably 3 to 8 warp yarns, and most preferably 6 as shown in the figure. If the period of the angled angle is two or less, the spacing between the threads becomes narrow, so that the handling of the warp yarns at the time of weaving deteriorates, and the weaving property deteriorates. If the number is nine or more, the yarn is largely displaced and a gap is easily opened between the yarns. Also,
The dispersibility of the impact due to the oblique angle is reduced.

As a loom used for weaving the woven fabric 2, a conventional loom such as a looser loom, a rapier loom, and a water jet loom can be used.

The fineness of the flat yarn is 200 to 100
00 denier, preferably 500 to 7
More preferably, it is 000 denier. When the fineness of the flat yarn is less than 200 denier, the width of the flat yarn is insufficient, and the warp yarns 11 cannot be sufficiently gathered, so that the thickness and unevenness of the woven fabric 2 are not easily formed. If it exceeds 10,000 denier, weaving may be difficult.

The flat yarn has a width of 2 mm to 1 mm.
A range of 5 mm is preferred. Flat yarn width 2m
If it is less than m, the warp yarn 11 will not be sufficiently gathered and gathered,
It is difficult for the woven fabric 2 to have thickness and irregularities. If it exceeds 15 mm, weaving may be difficult.

The flat yarn is produced by melt-extruding a polyolefin by a known extrusion molding method such as an inflation method to form a film, slitting the film, and then stretching the film.

The polyolefin is not particularly limited. For example, high-density polyethylene, polypropylene and the like can be used. Among them, polypropylene is preferably used because of its excellent impact resistance. Also, J
If the melt flow rate of polypropylene measured according to IS K 6758 is 1.0 g / 10 minutes or less, the impact resistance is further improved.

In the polyolefin, if necessary, rubber components such as ethylene-propylene rubber; inorganic fillers such as calcium carbonate, silica, titanium oxide, talc, mica, barium sulfate and alumina; lubricants; coloring agents such as pigments Etc. may be added.

The strength of the flat yarn can be adjusted by the draw ratio. The strength can be increased by increasing the stretching ratio, but if the stretching ratio is too high, the film tends to be easily broken. The draw ratio during flat yarn production is preferably 7 to 10 times.

From the viewpoint of productivity, production cost, and weight reduction, the display sheet 3 is printed on a printing surface of a display film made of low-density polyethylene or the like on which the name of an embedded object, a word calling attention, etc. are printed. It is preferable to laminate a low-density polyethylene or the like colored with a pigment or the like to protect and identify the type of the buried pipe.

The joining between the woven fabric 2 and the display sheet 3 is as follows.
It is not limited to the sewing machine shown in the illustrated example.
It can be performed by high frequency, adhesive, heat welding, or the like.
Alternatively, the woven fabric 2 and low-density polyethylene colored with a pigment or the like may be directly bonded by sand lamination with the printing surface of the display film facing inward.

In the protective material 1, the texture of the woven fabric 2 is oblique weave and the driving density of the warp yarns 11 is increased, so that the warp yarns 11 having the increased density are gathered. As the warp yarn 11 rises, clear irregularities appear on the surface of the woven fabric 2, and the woven fabric 2 becomes thicker.
Easy to absorb shock. In addition, the structure of the oblique weave has a low binding force of the yarn and the yarn is easy to move, so that the impact is easily released.
With these, the impact strength of the protective material 1 is dramatically improved.

Further, since the oblique weave is a mountain-shaped oblique, the oblique lines are bent in a zigzag manner, and the oblique lines are not straight, so that the yarn is greatly displaced even when a hit with a drilling tool or the like is applied. There is no gap between the thread and the thread. Also,
The staggered zigzag lines make the impact even easier to disperse.

Further, since the structure of the woven fabric 2 is oblique weave,
High flexibility and excellent workability for buried pipes.
Further, since such a woven fabric 2 has a high impact strength, the protective material 1 can have a sufficient impact strength with one sheet, and the thickness can be reduced. Further, there is no need to stack two or more sheets and sew them as in the related art, so that productivity is high.

The woven fabric according to the present invention has a 3/3 oblique weave structure that rises to the right and 3
It is not limited to the woven fabric 2 of the Yamagata oblique weave, in which the structure of the / 3 oblique weave is continuous; Yamagata oblique weave; Yamagata oblique weave consisting of 4/4 oblique weave rising rightward and 4/4 oblique weave rising leftward; 5/5 oblique weave rising right And a 5/5 oblique weaving texture that is continuous to the left; a 3/2 oblique weaving organization that rises to the right and a 3/2 oblique weaving organization that rises to the left. Continuous sloping woven fabric of angled bunches;
3 Yamagata oblique weave fabric with continuous 3 oblique weave; 3/4 oblique weave up right and 3/4 oblique weave over left It may be a 4/3 oblique weaving structure that rises to the right and a mountain-shaped oblique weaving fabric that has a continuous 4/3 oblique weaving structure that rises to the left.

However, when the number of yarns to be floated is gradually increased as in the case of 4/4 inclined weaving and 5/5 inclined weaving, there is an advantage that the driving density is easily increased, but the binding force of the yarn is too low. The thread easily shifts greatly, and the tip of the drilling tool or the like may reach the buried pipe or the like. Also, when the number of yarns to be floated is reduced as in the case of 2/2 slanted weave, the driving density becomes low and the impact strength may be insufficient. Therefore, as the woven fabric in the present invention, the structure of the 3/3 oblique weave, which rises to the right, and the 3/3 which rises to the left,
A triangular woven fabric having a continuous triangular woven structure is preferably used.

Further, the woven fabric in the present invention may be any woven fabric of oblique weave, and is not limited to the woven fabric of angled oblique in the illustrated example. If the woven fabric is oblique weave and the driving density of the warp yarn and / or the weft yarn is 5 to 50 yarns / inch, the woven fabric can have thickness and unevenness.

Further, the woven fabric in the present invention is not limited to a single woven fabric as in the illustrated example, but may be a multiple woven fabric of two or more woven fabrics. However, for woven fabrics with more than four layers,
Since weaving is difficult and productivity tends to deteriorate, the woven fabric in the present invention is preferably up to triple woven.
The woven fabric 2 in the illustrated example has a warp yarn driving density higher than that of the weft yarn. However, the woven fabric of the present invention has at least one of a warp yarn and a weft yarn with a driving density of 5%.
What is necessary is just to set it as the range of-50 pieces / inch, and it is not limited to this.

In the protective material of the present invention, a split yarn obtained by spreading a flat yarn on a warp yarn and / or a weft yarn of a woven fabric may be used. Here, the split yarn is obtained by spreading the flat yarn.Specifically, by passing the flat yarn over a needle blade roll having a large number of needles planted on the surface,
The mesh is formed by making countless discontinuous splits (splits) along the length of the flat yarn. Split yarns are easier to weave because they are more flexible than unspread flat yarns. Also, split yarns are
Since the width can be made narrower than the unspread flat yarn, weaving can be performed even if the driving density is increased.

The protective material using such a split yarn can be set at a higher density of the woven fabric as compared with a case where a flat yarn that is not opened for both the warp yarn and the weft yarn is used. As a result, the impact strength of the protective material can be further improved. However, when the split yarn is used for the warp yarn, it becomes difficult to insert the weft yarn into the mouth formed by the vertical movement of the warp yarn by the heald during weaving, and it becomes difficult to weave the woven fabric. Is preferably used only for the weft thread.

Next, a buried pipe around which the protective material of the present invention is wound will be described. FIG. 4 is a diagram showing an example of the buried pipe of the present invention. The buried pipe includes a buried PE (polyethylene) pipe 20, a protective material 1 wound around the PE pipe 20 with the display sheet 3 facing outward, and a fixing member 1 for fixing the protective material 1 to the PE pipe 20. And a binding band 21 wound on the protective material 1.

The buried pipe is buried underground dug about 15 cm, for example, as shown in FIG. In such a buried pipe, since the protective material 1 having the woven fabric 2 having high impact strength is wound, the buried pipe is excellent in impact resistance against the impact of a drilling tool.

[0037]

The present invention will be described below in detail with reference to examples. The measurement method in this example was performed using the following method. (Implant density of woven fabric) The number of implants between 25.4 cm was measured using a metal straight scale at each of one position in the longitudinal direction and the width direction of the woven fabric, and this was implanted for 2.54 cm (1 inch). It was converted to density.

(Direct Impact Shock Destruction Degree) The PE pipe 20 was fixed on the iron plate 22 of the direct impact test device shown in FIG.
The protective material 1 was set on the PE pipe 20. Support bracket 2
4 and a mass of 3.5 supported by the deflection preventing roll 25
The cutting edge 27 for the direct hit test of the cutting edge fixing jig 26 of kg is placed in a direction perpendicular to the pipe axis and directly above the PE pipe 20, and the weight 28 having a mass of 3 kg is fixed from the position of 0.5 m in height to the cutting edge fixing jig. 26 was dropped. After the fall, the depth of the flaw on the surface of the PE tube 20 was measured, and the degree of destruction (%) was calculated from the ratio of the depth of the flaw to the thickness of the PE tube 20. The direct impact test was repeated 10 times, the degree of direct impact destruction of the warp yarn and the weft yarn was obtained for each, and the impact resistance of the protective material was evaluated from the average value and the maximum value of the degree of direct impact destruction of the PE pipe 20.

(Shear Impact Destruction Degree) The PE tube 20 was fixed on the iron plate 22 of the shear test device shown in FIG.
The protective material 1 was set on the PE pipe 20. Support bracket 2
4 and a mass of 3.5 supported by the deflection preventing roll 25
The cutting edge 29 for the shear test of the cutting edge fixing jig 26 of kg is arranged in the direction perpendicular to the pipe axis and obliquely above the PE pipe 20, and the weight 28 having a mass of 3 kg is fixed from the position of 0.75 m in height. The jig 26 was dropped. After falling, PE pipe 2
The scratch depth of the surface 0 was measured, and the degree of destruction (%) was calculated from the ratio of the depth of the scratch to the thickness of the PE tube 20. The shear test was repeated 10 times, and the degree of shear impact destruction of the warp yarn and the weft yarn was determined for each, and the impact resistance of the protective material was evaluated from the average value and the maximum value of the degree of shear impact destruction of the PE pipe 20.

Example 1 A flat yarn made of polypropylene (PP) having a melt flow rate (MFR) of 0.5 g / 10 min as a warp yarn and a weft yarn (fineness: 300)
0 denier) and the driving density of the warp yarn is 30 /
A woven cloth having an inch and a weft thread implantation density of 18 yarns / inch was woven and used as a protective material. This woven fabric is a Yamagata oblique woven fabric in which a 3/3 oblique weave texture rising to the right and a 3/3 oblique weave texture rising to the left alternately continue for every six warp yarns. The degree of direct impact and shear impact of the PE pipe 20 when this protective material was used was measured.
The weaving adequacy during weaving was evaluated. Table 1 shows the results.

(Comparative Example 1) M as warp yarn and weft yarn
A plain woven cloth having a warp yarn driving density of 17 yarns / inch and a weft yarn driving density of 14 yarns / inch using flat yarn made of PP having a FR of 0.5 g / 10 min (fineness: 2000 denier). Weaved. Two woven fabrics were piled up and joined by sewing to form a protective material. The degree of direct impact damage and the degree of shear impact fracture of the PE pipe 20 using this protective material were measured, and the weaving adequacy during weaving was evaluated. Table 1 shows the results.

(Comparative Example 2) M as warp yarn and weft yarn
FIG. 9 shows that a flat yarn made of PP having a FR of 0.5 g / 10 min (fineness: 3000 denier) is used, and the driving density of the warp yarn is 28 yarns / inch and the driving density of the weft yarn is 18 yarns / inch. The woven cloth of the row weave shown was woven and used as a protective material. The degree of direct impact damage and the degree of shear impact fracture of the PE pipe 20 using this protective material were measured, and the weaving adequacy during weaving was evaluated. Table 1 shows the results.

[0043]

[Table 1]

[0044]

As described above, the protective material of the present invention has a woven fabric obtained by weaving a polyolefin flat yarn into a warp yarn and a weft yarn, and the structure of the woven fabric is oblique. It is woven, and the driving density of the warp yarn and / or weft yarn of the woven fabric is 5 to 50 yarns / inch. Therefore, the impact strength is high, the flexibility is high, the productivity is good, and the thickness is thin. Is possible. Further, if the fineness of the flat yarn is 200 to 10,000 denier,
Impact strength is further improved, and further thinning is possible.

If the oblique weave is a Yamagata oblique,
Impact strength is further improved, and further thinning is possible. If the polyolefin is a polypropylene having a melt flow rate of 1.0 g / 10 minutes or less, the impact strength is further improved and the thickness can be further reduced.
Further, the buried pipe of the present invention has excellent impact resistance since the protective material of the present invention is wound thereon.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a protective material of the present invention.

FIG. 2 is a perspective view showing an example of a woven fabric used for the protective material of the present invention.

FIG. 3 is an organization diagram showing an example of a woven fabric used for the protective material of the present invention.

FIG. 4 is a schematic view showing an example of a buried pipe of the present invention and an example of its use.

FIG. 5 is a configuration diagram showing a direct impact test device used for measuring the degree of direct impact impact destruction.

FIG. 6 is a configuration diagram showing a shear test apparatus used for measuring the degree of shear impact fracture.

FIG. 7 is a perspective view showing an example of a conventional protective material.

FIG. 8 is a perspective view showing an example of a woven fabric used for a conventional protective material.

FIG. 9 is an organization diagram showing another example of a woven fabric used for a conventional protective material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protective material 2 Woven cloth 11 Warp yarn 12 Weft yarn 20 PE pipe

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Haga 4-1 Nihonbashi Kobunacho, Chuo-ku, Tokyo F-term in Heisei Polymer Co., Ltd. (reference) 3H024 AA04 AB07 AC01 4L048 AA15 AA34 AB11 AB28 BA01 BA02 CA01 CA12 CA15 DA30 DA41

Claims (5)

[Claims] 1. A woven fabric obtained by weaving a polyolefin flat yarn into a warp yarn and a weft yarn, wherein the structure of the woven fabric is oblique weave, and the warp yarn and / or A protective material characterized in that the weft driving density is 5 to 50 yarns / inch. 2. The fineness of the flat yarn is 200 to 200.
2. The protective material according to claim 1, wherein the protective material is 10,000 denier. 3. The protective material according to claim 1, wherein the oblique weave is an angled oblique. 4. The protective material according to claim 1, wherein the polyolefin is a polypropylene having a melt flow rate of 1.0 g / 10 minutes or less. 5. A buried pipe in which the protective material according to claim 1 is wound.