JP2001027365A - Underground buried object marker sheet and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a marker sheet in good productivity at a low cost. SOLUTION: This underground buried object marker sheet 10, having a base material consisting of a woven fabric 11 and a resin film 15 layered on this base material, is integrally formed with the base material and the resin film 15 thermally fused. Thermally fusing is easily and firmly generated by using a resin of mutually approximate melting point in bonding surfaces 11a, 15a of the woven fabric 11 and the resin film 15, the base material and the resin film 15 can be prevented from easily separating. As the woven fabric 11, by using a fabric obtained by weaving a three-layer structural tape formed with an outer layer consisting of resin having a melting point lower than resin forming a core layer in both surfaces of the core layer consisting of resin, or as the resin film 15, by using a film of two-layer structure layering two kinds of resin having a different melting point, a layer consisting of resin having a low melting point is provided so as to form the bonding surface 15a to the woven fabric 11, and strength can be given to the underground buried object marker sheet 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground buried object marking sheet which informs an operator of the presence of a buried object during ground excavation work by previously burying the object underground. It can be manufactured at high cost and high productivity.

[0002]

2. Description of the Related Art Gas pipes, water and sewer pipes buried underground,
When repairing various buried objects such as power lines and communication lines, or when burying new buried objects near existing buried objects, it is necessary to dig the ground again.
In such excavation work, the buried object may be damaged or damaged by an excavator such as a power shovel. Therefore, a strip-shaped buried object sign sheet is buried in the ground above the buried object, and this sign is used to call attention to an operator to prevent damage or breakage of the buried object.

[0003] As this kind of underground buried object marking sheet,
A laminate film consisting of a display film such as low-density polyethylene printed with the name of the object to be buried, words and marks to call attention, the time of burying, etc., and a woven fabric made by flat weaving flat yarn such as high-density polyethylene, A band-like sheet laminated through the center is mainly used. In addition, this sheet
The above-mentioned indications are printed directly on the surface of the woven fabric by providing a laminated layer colored according to the type of the underground buried object so that the type of the buried object can be easily recognized. There is also used one provided with a transparent laminate layer for protecting the film. In addition, a woven fabric having a cross-section of the process which is heat-sealed to increase the strength, and a laminate layer provided thereon (Japanese Patent Laid-Open No. 10-31446) is also used. As described above, in the production of a conventional underground object marking sheet, a step of extruding and laminating a molten resin is indispensable in order to form a laminate layer on a woven fabric serving as a base material.

[0004]

However, since extrusion lamination is a method in which a resin to be laminated is melted and laminated on a substrate, it is necessary to laminate many types of resin on the substrate, When the number is small, the productivity is poor and the cost is disadvantageous. Also, the equipment required for extrusion lamination is expensive, and a method that can be manufactured with less expensive equipment has been desired.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an underground object marker sheet which can be manufactured at low cost and with high productivity without using an extrusion lamination method.

[0006]

The underground object marking sheet of the present invention has a base material made of a woven fabric and a resin film laminated on the base material. It is characterized by being heat-sealed and integrated. The bonding surfaces of the woven fabric and the resin film are preferably made of resins having melting points close to each other. The woven fabric is preferably obtained by weaving a three-layer structure tape in which an outer layer made of a resin having a lower melting point than the resin forming the core layer is formed on both surfaces of the core layer made of the resin. . The resin film is a two-layered film in which two kinds of resins having different melting points are laminated, and it is preferable that a layer made of a resin having a lower melting point forms an adhesive surface with the woven fabric. The method of manufacturing an underground marker sheet of the present invention is a method of manufacturing an underground marker sheet having a base material made of a woven fabric and a resin film laminated on the base material. It is characterized by being thermally fused with a resin film and integrated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. Underground buried object marking sheet 10 shown in FIG.
Has a base material made of a woven fabric 11 and a resin film 15 laminated on the base material.
5 is heat-sealed and integrated. As shown in FIG. 2, the woven fabric 11 serving as a base material is formed by weaving a tape-like warp yarn 12a and a weft yarn 12b, and the warp yarn 12a and the weft yarn 12b are usually made of high-density polyethylene (HDPE).
Polypropylene (PP) or the like is used. The tape 12 used as the warp yarn 12a and the weft yarn 12b may have a single-layer structure made of one kind of resin or a multi-layer structure made of a plurality of kinds of resins, but the woven fabric 11 obtained by weaving the tape 12 And the resin film 15 are integrated by heat fusion, so that at least the adhesive surface 11a of the woven fabric 11 is formed of a resin having a melting point similar to that of the resin forming the adhesive surface 15a of the resin film 15, Preferably, the material is also selected.

As the multilayer tape 12, for example,
As shown in FIG. 3, the core layer 13 is formed on both sides of the resin core layer 13.
And a three-layer structure tape having an outer layer 14 formed of a resin having a lower melting point than the resin forming the resin. The woven fabric 11 woven using such a three-layer tape 12 has a three-layer structure having a resin having a lower melting point on the outside and a resin having a higher melting point than the outside at the center. Therefore, when the woven fabric 11 is heated and thermally fused with the resin film 15, the outer resin that comes into contact with the resin film 15 is
The resin is melted and strongly bonded to the resin film 15, but the central resin is not melted. Therefore, the woven fabric 11 has excellent heat-fusibility and strength. In addition, such 3
The outer layer 14 of the tape 12 has the same type on both sides even when the tape 12 is partially inverted and the front side and the back side are switched when weaving the woven fabric 11 by using the layer structure. , The low-melting-point resin is always disposed outside the woven fabric 11, so that the thermal fusion with the resin film 15 is not hindered. As the three-layered tape, HDPE having PP for the core layer 13 and HDPE for the outer layer 14 /
PP / HDPE tape, core layer 13 with HDPE, outer layer 14
LDPE / HDPE / LDPE tape having LDPE. These tapes 12 are obtained by forming a three-layer structure by a multilayer inflation method or the like, and then, if necessary, stretching.

As the resin film 15 to be laminated on the substrate made of the woven fabric 11, a resin film on which the name of an underground buried object, a word or a mark for calling attention, a burying time, etc. are usually used is used. Is done. Since the underground object marking sheet 10 is easily damaged by earth and sand when it is buried in the ground, such printing is performed inside the resin film 15, that is,
It is preferable to use a transparent film as the resin film 15, which is applied to the side of the adhesive surface 15 a with the woven fabric 11. This is preferable because the printing performed on the resin film 15 can be recognized through the transparent film and the printing can be protected.

For the resin film 15, a resin such as LDPE, linear low-density polyethylene (LLDPE), HDPE, or PP is used. The resin film 15 may have a single-layer structure made of one kind of resin or a multilayer structure made of a plurality of resins. However, since the resin film 15 is integrated with the woven fabric 11 as a base material by heat fusion, at least the Bonding surface 15a
It is preferable that the woven fabric 11 be made of a resin having a melting point close to that of the resin forming the bonding surface 11a. Thus, the bonding surface 11 of the woven fabric 11 and the resin film 15
When a and 15a are made of resins whose melting points are close to each other,
This is preferable because the thermal fusion between the woven fabric 11 and the resin film 15 becomes strong. The melting point difference between the resin forming the contact surface 11a of the woven fabric 11 and the resin forming the contact surface 15a of the resin film 15 is 3
5 ° C. or less, more preferably 20 ° C.
It is as follows. Furthermore, it is more preferable that the resin forming the contact surface 11a of the woven fabric 11 and the resin forming the contact surface 15a of the resin film 15 be the same type of resin.

When the resin film 15 has a multilayer structure, as shown in FIG. 4, a film having a two-layer structure composed of two kinds of resins having different melting points is preferable. The bonding surface 15a is formed of a resin having a similar melting point, and the outer layer 15b is formed of a resin having a higher melting point than the resin forming the bonding surface 15a. When the resin film 15 has such a two-layer structure, when the resin film 15 is heated and thermally fused to the woven fabric 11, the resin on the bonding surface 15a is melted and firmly thermally fused to the woven fabric 11. But the outer layer 15b
Resin does not melt. Therefore, the resin film 15 is excellent in heat sealability and has strength. For example, when the woven fabric 11 woven from HDPE / PP / HDPE tape is used as the base material, the resin film 15 is preferably a film in which the adhesive surface 15a is made of HDPE or LLDPE and the outer layer 15b is made of PP. LDPE
When the woven fabric 11 woven from the / HDPE / LDPE tape is used, the adhesive surface 15 is used as the resin film 15.
a is a film made of LDPE and the outer layer 15b is made of HDPE, or the adhesive surface 15a is LDPE and the outer layer 15b is LLDPE
Is preferred.

A base made of a woven fabric 11 and a resin film 15
As shown in FIG. 5, each is guided to a heat roll 20, heated and pressed by the heat roll, and thermally fused. At this time, the bonding surface 11 of the woven fabric 11 and the resin film 15 is so strongly bonded that the woven fabric 11 and the resin film 15 are thermally fused.
It is preferable that a and 15a are arranged so that they have resins whose melting points are close to each other. The temperature of the hot roll is woven cloth 1.
1 and the melting point of the resin used for the adhesive surfaces 11a and 15a of the resin film 15 are appropriately set.
00-130 ° C. For example, the woven fabric 11 is LDPE / H
It is woven from DPE / LDPE tape, and the adhesive surface 15a of the resin film 15 is LDPE and the outer layer 15
When b is LLDPE, the hot roll temperature is 105 to 11
5 ° C. In this case, the heat roll diameter is 300 mm
φ, the thermal fusion speed is about 20 m / min. The underground buried object marking sheet 10 manufactured by heat fusion in this way is
Usually, as shown in FIG.
It is formed so as to have the overlapping portion 16 at regular intervals. In the overlapping portion 16, the laminated layers are joined by fusion or sewing, and the shape is maintained. The underground object marking sheet 10 formed in such a shape is buried above the object together with various objects such as gas pipes, water and sewer pipes, power lines, and communication lines.

[0013] Such underground object marking sheet 10 is
Since the base material and the resin film 15 are characterized by being heat-sealed and integrated, they can be easily manufactured without the need for expensive extrusion lamination equipment.
In addition, since the heat fusion can be performed by a simple method using the heat roll 20, even when many kinds of resin films 15 are laminated on a base material or when the production amount is small, the production is efficiently performed. High productivity and low cost. The bonding surface 1 of the woven fabric 11 and the resin film 15
By using 1a and 15a as resins having melting points close to each other, the woven fabric 11 and the resin film 15 can be easily heat-sealed, and the heat-sealing becomes strong.
The base material and the resin film 15 are less likely to peel off when buried or excavated in the ground, resulting in the underground object marking sheet 10. Further, the woven fabric 11 is obtained by weaving a three-layer structure tape in which an outer layer 14 made of a resin having a lower melting point than the resin forming the core layer 13 is formed on both surfaces of a core layer 13 made of the resin. By doing so, it becomes possible to provide the woven fabric 11 with heat-fusibility with the resin film 15 and strength, and to obtain the underground buried object marking sheet 10 that is less likely to be damaged. Also,
The resin film 15 has a two-layer structure in which two kinds of resins having different melting points are laminated, and a layer made of a resin having a lower melting point forms an adhesive surface 15 a with the woven fabric 11. The film 15 can be imparted with the heat-fusibility with the woven fabric 11 and the strength, and becomes the underground buried object marking sheet 10 which is harder to break. Such a method of manufacturing the underground object marking sheet 10 is performed by heat-sealing and integrating the base material and the resin film 15, so that expensive equipment is not required and inexpensive materials such as the heat roll 20 are used. It can be easily manufactured with equipment, and even when laminating many kinds of resin films 15 on a base material or when the production amount is small, it is excellent in productivity and can be manufactured at low cost.

[0014]

As described above, the underground object marking sheet of the present invention can be easily manufactured without requiring expensive extrusion lamination equipment. In addition, when many kinds of resins are laminated on a base material or when the production amount is small, it can be efficiently produced, and the productivity is excellent.
Low cost. In addition, by making the bonding surfaces of the woven fabric and the resin film the resins whose melting points are close to each other,
The heat-sealing can be easily and firmly performed, and the underground object marker sheet is hard to peel off the base material and the resin film. Further, by weaving a three-layer structure tape in which an outer layer made of a resin having a lower melting point than the resin forming the core layer is formed on both surfaces of the core layer made of the resin, In addition, the woven fabric can be imparted with heat-fusibility with a resin film and strength, and can be a more easily damaged underground object marker sheet. Further, the resin film has a two-layer structure in which two types of resins having different melting points are laminated, and a layer made of a resin having a lower melting point forms an adhesive surface with a woven fabric. In addition, a heat-fusing property with a woven fabric and strength can be imparted, and the underground object marker sheet is more resistant to breakage. The method of manufacturing the underground object marker sheet of the present invention is performed by heat-sealing the base material and the resin film and integrating them, so that expensive equipment is not required, and it can be easily manufactured with inexpensive equipment. It is a low-cost manufacturing method with excellent productivity.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of an underground object marking sheet.

FIG. 2 is a perspective view of a woven fabric constituting the underground object marker sheet of FIG. 1;

FIG. 3 is a cross-sectional view showing one form of a tape constituting a woven fabric.

FIG. 4 is a cross-sectional view illustrating one embodiment of a resin film.

FIG. 5 is a schematic configuration diagram showing an example of a method for manufacturing a marker sheet underground.

FIG. 6 is a perspective view showing one form of an underground object marking sheet.

[Explanation of symbols]

10: Underground object marker sheet, 11: Woven cloth, 11a: Adhesive surface of woven cloth, 13: Core layer, 14: Outer layer, 15: Resin film, 15a: Adhesive surface of resin film

Claims (5)

[Claims] An underground object marking sheet having a base material made of a woven fabric and a resin film laminated on the base material, wherein the base material and the resin film are heat-sealed and integrated. Underground buried object sign sheet characterized by the following. 2. The underground object marking sheet according to claim 1, wherein the bonding surfaces of the woven fabric and the resin film are made of resins having melting points close to each other. 3. A woven fabric obtained by weaving a three-layer tape in which an outer layer made of a resin having a lower melting point than the resin forming the core layer is formed on both surfaces of a core layer made of the resin. The underground buried object marking sheet according to claim 1 or 2, wherein: 4. A resin film having a two-layer structure in which two kinds of resins having different melting points are laminated, wherein a layer made of a resin having a lower melting point forms an adhesive surface with a woven fabric. The underground buried object marking sheet according to any one of claims 1 to 3. 5. A method of manufacturing an underground object marking sheet having a base material made of a woven fabric and a resin film laminated on the base material, wherein the base material and the resin film are heat-fused. A method for producing an underground object marking sheet, which is integrated.