阅读说明：本技术 耐久性提高的纤维增强聚合物条带以及利用此的格状土工格栅 (Fiber reinforced polymer strip with improved durability and grid geogrid using same ) 是由 尹光重 权五赫 鲜于艺林 于 2021-01-19 设计创作，主要内容包括：本发明涉及一种耐久性提高的纤维增强聚合物条带,所述耐久性提高的纤维增强聚合物条带由以下构成：作为增强材料的多个纤维集合体；作为被覆材料的热塑性聚合物树脂；以及在所述增强材料的表面利用粉末粘合剂的粘合剂,其特征在于,在制造纤维增强聚合物条带时,在增强纤维周围涂布粉末粘合剂,使其与被覆在所述增强纤维的聚合物树脂的粘合力得到强化,从而提高自身的耐久性。(The present invention relates to a fiber reinforced polymer tape with improved durability, which is composed of: a plurality of fiber assemblies as a reinforcing material; a thermoplastic polymer resin as a coating material; and a binder using a powder binder on the surface of the reinforcing material, wherein the powder binder is applied around the reinforcing fibers to enhance the adhesion to the polymer resin coating the reinforcing fibers and improve the durability of the tape itself when the tape is manufactured.)

1. An enhanced durability fiber reinforced polymer tape comprised of:

a plurality of fiber assemblies as a reinforcing material;

a thermoplastic polymer resin as a coating material; and

and a bonding material using a powder adhesive on the surface of the reinforcing material.

2. The enhanced durability fiber reinforced polymer tape of claim 1,

the fiber assembly is 1 kind of fiber selected from the group consisting of polyester fiber, glass fiber, aramid fiber, carbon fiber, basalt fiber, stainless steel fiber, copper fiber, amorphous metal fiber and the like, or synthetic fiber synthesized by more than 2 kinds of fibers.

3. The enhanced durability fiber reinforced polymer tape of claim 1,

the thermoplastic polymer resin is 1 resin selected from the group consisting of polyolefin resin having a Melt Index (MI) of 1 to 35, polyethylene terephthalate having an Inherent Viscosity (IV) of 0.64 to 1.0, polyamide, polyacrylate, polyacrylonitrile, polycarbonate, polyvinyl chloride, polystyrene, and polybutadiene, or a mixed resin synthesized from 2 or more resins thereof, independently of each other.

4. The enhanced durability fiber reinforced polymer tape of claim 1,

the powder binder is obtained by powdering a dicarboxylic acid consisting of 60 to 90 mol% of terephthalic acid and 10 to 40 mol% of isophthalic acid and a low-melting copolyester resin resulting from copolymerization of a diol consisting of 60 to 100 mol% of ethylene glycol and 0 to 40 mol% of diethylene glycol,

a glass transition temperature (Tg) of 50 ℃ or higher, a hardness (Shore D) of 80 or higher, and a softening point of 80 to 140 ℃.

5. A lattice-like geogrid is characterized in that,

the fiber reinforced polymer tapes according to any one of claims 1-4 arranged in parallel in a plurality of warp and weft directions at predetermined intervals,

each of the plurality of warp fiber reinforced polymer strips including at least one of a 1 st contact point that crosses over any one of the weft fiber reinforced polymer strips and a 2 nd contact point that crosses under another one of the weft fiber reinforced polymer strips,

the contact points are formed by mutually welding and fixing the thermoplastic polymer resin of the warp-direction fiber reinforced polymer strips and the thermoplastic polymer resin of the weft-direction fiber reinforced polymer strips in the contact point areas.

Technical Field

The present invention relates to a fiber-reinforced polymer strip having improved durability and a lattice-type geogrid using the same, wherein a polyester-based powder adhesive is coated around a reinforcing polymer to reinforce the adhesion to a polymer resin coated on the reinforcing fiber, thereby improving durability of the fiber-reinforced polymer strip and improving the contact strength of the lattice-type geogrid using the fiber-reinforced polymer strip.

Background

The present invention relates to geogrids mainly used as reinforcing materials for civil engineering and a method for manufacturing the same.

Geogrids are used for wall reinforcement, slope reinforcement, foundation reinforcement and the like in civil engineering construction, and are required to have physical properties such as workability resistance, frictional properties, and shape stability in addition to high tensile strength, low tensile strain and creep deformation properties. Geogrids are classified into plastic geogrids and fabric geogrids according to the manufacturing method and material.

Plastic geogrids are manufactured by coaxially or biaxially stretching polymer sheets extruded through an extruder after punching the polymer sheets through rollers at regular intervals (refer to GB 19890020843); or by extruding a polymer resin in a strip shape to form a planar lattice of warp and weft strands and then bonding them by laser or frictional heat (see GB 2266540). However, plastic geogrids have a problem in that they undergo large creep deformation when a load is applied for a long period of time due to the characteristics of the material, and the stability of the reinforcing structure is lowered.

The fabric geogrid is manufactured by manufacturing lattice fibers by using high-strength fibers and then coating polyvinyl chloride, asphalt, acrylic acid, latex, rubber-based resin and the like. The fabric geogrid has excellent tensile strength and creep characteristics because of the use of high-strength fibers, but the geogrid is highly likely to be damaged depending on the state of soil during construction, and therefore, the workability resistance is reduced, the manufacturing process is complicated, and it is economically undesirable.

Further, WO 99/28563 discloses a method for manufacturing a geogrid in which fiber-reinforced polymer strips are bonded in a lattice form as warp strips and thermoplastic polymer resin strips are bonded in a lattice form as weft strips. It is described in this patent that for geogrids, during movement of the warp direction fiber reinforced polymer strips, thermoplastic polymer resin is extruded, inserted, formed into weft direction strips and bonded, and fiber reinforced polymer strips can be inserted in the weft direction strips. However, when fiber-reinforced polymer tapes are bonded by such a method, not only are the reinforcing fibers present in the polymer damaged and the physical properties lowered, but also the warp polymer tapes and the weft polymer tapes are not in a molten state, and therefore, complete bonding between the tapes is not formed. In addition, since the geogrid of the above patent is a planar structure, there is a problem in that frictional characteristics and shape stability against vertical load are not good.

In addition, in the conventional method for manufacturing fiber-reinforced polymer strips for geogrids, in supplying a thermoplastic polymer resin in a molten state as a covering material to a plurality of fiber assemblies as internal reinforcing materials, there is a possibility that the adhesive force is reduced by the kind of the reinforcing material, and there is a possibility that a problem occurs in the contact point strength of the lattice-shaped geogrid.

Disclosure of Invention

Problems to be solved by the invention

Accordingly, an object of the present invention is to solve the problems of the prior art and to provide a fiber-reinforced polymer strip for geogrids in which the adhesion between a reinforcing material and a covering material is enhanced.

In addition, the present invention provides a geogrid that has not only excellent construction resistance, frictional characteristics, and shape stability, but also high tensile strength and low tensile strain and creep deformation characteristics.

Means for solving the problems

In order to solve the above problems, the present invention provides a fiber reinforced polymer tape having improved durability, the fiber reinforced polymer tape comprising: a plurality of fiber assemblies as a reinforcing material; a thermoplastic polymer resin as a coating material; and a bonding material using a powder adhesive on a surface of the reinforcing material.

Further, the present invention provides a fiber-reinforced polymer tape having improved durability, wherein the fiber assembly of the present invention is 1 type of fiber selected from the group consisting of polyester fiber, glass fiber, aramid fiber, carbon fiber, basalt fiber, stainless steel fiber, copper fiber and amorphous metal fiber, or a synthetic fiber composed of 2 or more types of fibers.

Further, the present invention provides a fiber-reinforced polymer tape having improved durability, wherein the thermoplastic polymer resin of the present invention is 1 resin selected from the group consisting of polyolefin resins having a Melt Index (MI) of 1 to 35, polyethylene terephthalate (polyethylene terephthalate) having an Inherent Viscosity (IV) of 0.64 to 1.0, polyamides (polyamides), polyacrylates (polyacrylates), polyacrylonitrile (polyacrylonitrile), polycarbonates (polycarbonates), polyvinyl chloride (polyvinylehloride), polystyrene (polystyrene), and polybutadiene (polybutadiene), or a mixed resin in which 2 or more resins are mixed, independently of each other.

Further, the present invention provides a fiber-reinforced polymer tape having improved durability, wherein the powder binder is obtained by powdering a low-melting copolyester resin obtained by copolymerizing a dicarboxylic acid comprising 60 to 90 mol% of terephthalic acid and 10 to 40 mol% of isophthalic acid with a diol comprising 60 to 100 mol% of ethylene glycol and 0 to 40 mol% of diethylene glycol, and has a glass transition temperature of 50 ℃ or higher, a hardness (Shore D) of 80 or higher, and a softening point of 80 to 140 ℃.

In addition, there is provided a lattice-like geogrid, wherein the fiber reinforced polymer strips of the present invention are arranged in parallel in a plurality of warp directions and weft directions at predetermined intervals, each of the plurality of warp direction fiber reinforced polymer strips includes at least one or more of a 1 st contact point crossing any one of the weft direction fiber reinforced polymer strips on the upper side and a 2 nd contact point crossing another one of the weft direction fiber reinforced polymer strips on the lower side, the contact points being formed by fusion-fixing the thermoplastic polymer resins of the warp direction fiber reinforced polymer strips and the weft direction fiber reinforced polymer strips to each other at contact point areas.

Effects of the invention

The present invention is characterized in that, in the production of a fiber-reinforced polymer tape, a powder binder is applied around reinforcing fibers to enhance the adhesion to a polymer resin coating the reinforcing fibers, thereby improving the durability of the tape itself.

In the geogrid of the present invention, the warp-direction fiber-reinforced polymer strips and the weft-direction polymer strips are vertically crossed, and the crossing contact points are welded and fixed to each other, so that the frictional force with a reinforcing object material such as soil and the resistance to a vertical load are increased, thereby not only having excellent shape stability and workability resistance, but also having high tensile strength, low tensile strain and creep deformation characteristics due to the use of the fiber-reinforced polymer strips reinforced with fibers inside the polymer resin.

Drawings

The drawings in the present specification illustrate preferred embodiments of the present invention, which serve to further understand the technical ideas of the present invention together with the detailed description given below, and the present invention should not be construed as being limited to the contents shown in the drawings.

Fig. 1 is a plan view illustrating a geogrid according to a preferred embodiment of the present invention.

Fig. 2 is a partially enlarged perspective view illustrating a portion of a geogrid according to a preferred embodiment of the present invention partially enlarged.

Fig. 3 is a schematic view showing the structure of a manufacturing apparatus of a fiber reinforced polymer tape according to a preferred embodiment of the present invention.

Fig. 4 is a schematic view showing the structure of an extrusion part of a manufacturing apparatus of a fiber reinforced polymer strip according to a preferred embodiment of the present invention.

Fig. 5a and 5b are a plan view and a side view, respectively, illustrating a schematic structure of a geogrid manufacturing apparatus according to a preferred embodiment of the present invention.

Fig. 6 is a schematic perspective view illustrating the structure of a strip arranging member in the geogrid manufacturing apparatus according to the preferred embodiment of the present invention.

Fig. 7a to 7d are schematic side and plan views showing the structure of a fusion in the geogrid manufacturing apparatus according to the preferred embodiment of the present invention, fig. 7a and 7b are schematic views showing the structure of the 1 st fusion machine, and fig. 7c and 7d are schematic views showing the structure of the 2 nd fusion machine.

Fig. 8a to 8c are schematic side views illustrating a process of bending a fiber reinforced polymer strip with a strip aligning member according to a preferred embodiment of the present invention.

Fig. 9 is a flow chart illustrating a process of manufacturing a geogrid with fiber reinforced polymer strips according to a preferred embodiment of the present invention.

Fig. 10a to 10d are views illustrating the structure of a strip aligning member according to other preferred embodiments of the present invention and the shape of fiber reinforced polymer strips aligned therewith.

Fig. 11a to 11c are sectional views showing examples of various shapes of the fiber reinforced polymer tapes.

Fig. 12 is a view showing a lattice shape of a conventional geogrid.

Detailed Description

Preferred embodiments of the present invention are described in detail below. First, in describing the present invention, detailed descriptions of related known functions or configurations will be omitted so as not to obscure the gist of the present invention.

The terms "about", "substantially" and the like as used herein to indicate the degree of certainty that a numerical value or a numerical value close to the numerical value is used in a meaning of preventing the disclosure of the correct or absolute numerical value mentioned in order to facilitate the understanding of the present invention from being misused by an unscrupulous attacker when manufacturing and material tolerances inherent in the stated meaning are used.

The present invention relates to a fiber reinforced polymer tape with improved durability, consisting of: a plurality of fiber assemblies as a reinforcing material; a thermoplastic polymer resin as a coating material; and a bonding material using a powder adhesive on a surface of the reinforcing material.

Powder adhesives (hot melt adhesives) are nuisance-free hot melt adhesives which are applied and bonded to the surface of an adherend in a heated molten state without using water or solvents at all and then solidify upon cooling to bond them.

General hot melt adhesive powder adhesives are widely used for automobile parts and the like, and have a function of bonding substrates. The classes are olefins (olefins), amides and polyesters.

The powder binder of the present invention is preferably a polyester type obtained by powdering a low-melting copolyester resin obtained by copolymerizing a dicarboxylic acid comprising 60 to 90 mol% of terephthalic acid and 10 to 40 mol% of isophthalic acid with a diol comprising 60 to 100 mol% of ethylene glycol and 0 to 40 mol% of diethylene glycol, and has a glass transition temperature (Tg) of 50 ℃ or higher, a hardness (Shore D) of 80 or higher, and a softening point of 80 to 140 ℃.

The low melting point copolymerized polyester resin is copolymerized from dicarboxylic acid and diol, wherein the dicarboxylic acid may consist of 60 to 90 mol% of terephthalic acid and 10 to 40 mol% of isophthalic acid, and the diol may consist of 60 to 100 mol% of ethylene glycol and 0 to 40 mol% of diethylene glycol.

For the terephthalic acid, ester-forming derivatives thereof or mixtures thereof may be used, and for the isophthalic acid, ester-forming derivatives thereof or mixtures thereof may be used.

In addition, it is preferable that the antimony-based catalyst is added in the polymerization step at 100-500ppm based on metallic antimony and the melt polymerization temperature is carried out in the range of 255-285 ℃. As the antimony catalyst, there are antimony oxide (ATO), Antimony Triethoxide (ATG), etc., and for the polymerization step, it can be carried out by adding a known polyester polycondensation catalyst. In addition to the above raw materials, various additives such as an oxidation stabilizer, a quencher, a color inhibitor and the like may be added.

The low melting copolymerized polyester resin prepared by the above method is solidified and cured at room temperature. Thereafter, the mixture was pulverized at room temperature by a pulverizer to obtain a powder.

Preferably, the adhesive polyester-based powder adhesive of the present invention has a softening point of 80 to 140 ℃, a glass transition temperature (Tg) of 50 ℃ or higher, a hardness (Shore D) of 80 or higher, a melt flow index of 5 to 40g/10 min, (190 ℃,2.16kg conditions) and a particle size of 50 to 1500. mu.m.

Here, if the melt flow index is less than 5g/10 min, it is difficult to expect high adhesive force due to poor flowability of the powder adhesive in the heating and melting step, and if the melt flow index exceeds 40g/10 min, the melted powder adhesive flows into the inside of the nonwoven fabric too much, and the adhesive force may be relatively lowered.

The softening point of the powder adhesive is 80-140 c, and the storage stability at high temperature is deteriorated at 80 c or less, while at 140c or more, an increase in process cost and substrate damage may be caused as the bonding temperature is increased and the process temperature is increased. When the glass transition temperature (Tg) is below 50 ℃, the high-temperature storage stability is poor and melting of the powder may occur during export transportation in summer. When the hardness (Shore D) is 80 or less, there is a problem that moldability becomes poor.

In addition, the particle size of the hot melt adhesive powder binder which can be pulverized at normal temperature of the invention is preferably 50 to 1500 μm. If the particle size is less than 50 μm, the amount of the powder binder to be absorbed by the fiber aggregate as a reinforcing material increases when the powder binder is dispersed, and if the particle size exceeds 1500 μm, it is difficult to uniformly disperse the powder binder, and melting by heating is not smooth, so that it is difficult to expect high adhesive force.

Geogrids using fiber reinforced polymer strips reinforced with fibers inside a polymer resin also have high tensile strength, low tensile strain and creep deformation characteristics, and improved construction resistance. In view of tensile strength and contact point strength of the geogrid and manufacturability, when the cross section of the fiber reinforced polymer strip is formed into a quadrangular shape, preferred adjustment ranges of the width and thickness thereof are 2mm to 30mm and 1mm to 10mm, more preferred adjustment ranges are 3mm to 20mm and 1.5mm to 5mm, respectively, and when the cross section of the fiber reinforced polymer strip is formed into a circular shape, preferred adjustment ranges of the diameter are 2mm to 20mm, more preferred adjustment ranges are 4mm to 15 mm.

As the thermoplastic polymer resin 110 constituting the fiber-reinforced polymer tapes 1,2, a mutually heat-weldable thermoplastic resin capable of sufficiently protecting the reinforcing fibers 100 from the outside is used, and for example, the following resins may be used alone or in combination: polyolefin-based resins having a Melt Index (MI) of 1 to 35, polyethylene terephthalate (polyethylene terephthalate) having an Inherent Viscosity (IV) of 0.64 to 1.0, polyamides (polyamides), polyacrylates (polyacrylates), polyacrylonitrile (polyacrylonitriles), polycarbonates (polycarbonates), polyvinyl chloride (polyvinylecloride), polystyrene (polystyrene), polybutadiene, and the like. In addition, any of the reinforcing fibers 100 constituting the fiber-reinforced polymer tapes 1,2 may be used as long as they are high-strength fibers having high tensile strength, low tensile strain and creep deformation characteristics, and for example, polyester fibers, glass fibers, aramid fibers, carbon fibers, basalt fibers, stainless steel fibers, copper fibers, amorphous metal fibers, or the like may be used alone or in combination of one or more kinds. In order to fully exert the function of the reinforcing fibers and to sufficiently protect the reinforcing fibers by the thermoplastic polymer resin, the total cross-sectional area of the fibers constituting the warp fiber-reinforced polymer tapes and the weft fiber-reinforced polymer tapes is preferably maintained at 20 to 80% of the entire cross-sectional area of the fiber-reinforced polymer tapes. When the total cross-sectional area of the reinforcing fibers is less than 20% of the total cross-sectional area of the fiber-reinforced polymer tape, it is difficult to sufficiently exhibit the reinforcing function of the reinforcing fibers, and when it exceeds 80%, the thickness of the polymer layer is too thin, so that the effect of bundling the reinforcing fibers by the polymer is reduced, the reinforcing fibers are not sufficiently protected, and the workability is lowered.

Fig. 1 is a plan view illustrating a geogrid according to a preferred embodiment of the present invention. Referring to fig. 1, the geogrid of the present invention has a lattice shape formed of a plurality of warp fiber reinforced polymer strips 1 arranged in parallel in warp direction at predetermined intervals and a plurality of weft fiber reinforced polymer strips 2 arranged in parallel in weft direction at predetermined intervals.

It will be understood by those skilled in the art that "warp" and "weft" as used in the present specification and claims refer to the 1 st and 2 nd directions, respectively, which are mutually intersecting. However, the warp direction and the weft direction according to the present invention are not limited to crossing each other at right angles, and the angle may be appropriately set within a range in which the geogrid can distribute load and can exert sufficient tensile force, as described later. In the present specification, the crossing point of the weft direction is described with reference to the warp direction, but this is a relative concept and can be applied similarly to the weft direction.

According to the invention, the warp fibre-reinforced polymer strips 1 and the weft fibre-reinforced polymer strips 2 cross one another in an alternating manner one above the other. Referring specifically to the enlarged partial perspective view of fig. 1, fig. 2, the warp direction fiber reinforced polymer tapes 1 form a 1 st contact point C by crossing any one 2a of the weft direction fiber reinforced polymer tapes 2 thereon₁While forming a 2 nd contact point C by crossing under it another weft fiber-reinforced polymer strip 2b adjacent thereto₂. In the method, if all the warp direction fiber reinforced polymer strips 1 and the weft direction fiber reinforced polymer strips 2 are in the contact point C at the 1 st point₁And the 2 nd contact point C₂Crossing each other in an alternating manner, the 1 st contact point C as in the embodiment shown in FIG. 1 is formed₁And the 2 nd contact point C₂The present inventors believe that the geogrid having a so-called "plain weave structure" which is alternately arranged exhibits the physical properties of the geogrid to the maximum extent.

According to another embodiment of the present invention, the warp-fiber-reinforced polymer strip 1 may include more than 2 consecutive contact points C at 1 st₁Or 2 nd contact point C₂In such a way that it crosses the weft fibre-reinforced polymer strip 2, such an embodiment being shown in fig. 10b as well as in fig. 10 d. That is, in the geogrids of these illustrated embodiments, the warp fiber reinforced polymer strip 1 is positioned at contact point C1₁Has 2 continuous second2 contact point C₂Or with 3 consecutive 2 nd contact points C₂In such a way as to cross the weft fibre-reinforced polymer strips 2.

As described above, the frictional force and the resistance to the vertical load between the geogrid formed by the warp-direction fiber-reinforced polymer strips 1 and the weft-direction polymer strips 2 crossing up and down and the reinforcing object material such as soil are increased, thereby greatly improving the shape stability and the construction resistance. The crossing angle of the plurality of warp direction fiber-reinforced polymer tapes and weft direction fiber-reinforced polymer tapes is preferably 80 ° to 100 °, and when the crossing angle is less than 80 ° or more than 100 °, the dispersion force and the stretching force against the vertical load are greatly reduced, and the fiber-reinforced polymer tapes cannot be used as a reinforcing material for civil engineering. The most preferred angle of intersection is 90.

The warp and weft fiber-reinforced polymer tapes 1,2 are each a structure in which reinforcing fibers are inserted inside a thermoplastic polymer resin, and fig. 11a to 11c show cross-sectional views of various fiber-reinforced polymer tapes. The various shapes can be obtained by changing the shape of the aggregation or dispersion of the plurality of fibers and the shape of the extrusion die of the thermoplastic polymer resin. For example, fiber-reinforced polymer tapes 1,2 (fig. 11a and 11b) can be produced by reinforcing the inside of a thermoplastic polymer resin 110 extruded with a square cross section with reinforcing fibers 100 of a plurality of fiber assemblies such as a square, oval, and circle, or by reinforcing the inside of a thermoplastic polymer resin 110 extruded with a circle cross section with reinforcing fibers 100 of a circle or oval fiber assembly to produce fiber-reinforced polymer tapes 1,2 (fig. 11c), and in addition, fiber-reinforced polymer tapes having various cross sectional shapes can be produced by various combinations.

The contact point C where the warp direction fiber reinforced polymer strip 1 and the weft direction fiber reinforced polymer strip 2 cross₁,C₂The thermoplastic polymer resins of (a) are fused to each other. Therefore, the warp-wise fiber reinforced polymer strips and the weft-wise polymer strips are mutually fixed when the geogrids are crossed up and down, so that the shape stability of the geogrid subjected to vertical load is maintained, and the construction resistance is improved.

In the geogrid of the present invention having the above-described structure, the plurality of warp fiber reinforced polymer strips arranged in parallel are preferably arranged at intervals of 10 to 100mm, more preferably at intervals of 20 to 80mm, based on the center line of each warp fiber reinforced polymer strip, and the plurality of weft fiber reinforced polymer strips arranged in parallel are also arranged at intervals of 10 to 100mm, more preferably at intervals of 20 to 80mm, based on the center line of each weft fiber reinforced polymer strip.

When the interval between the fiber-reinforced polymer strips is maintained in the above range, the soil is not separated and integrated, and the function as a reinforcing material is sufficiently exhibited. That is, when the interval between the fiber-reinforced polymer tapes is too large, the load applied to the structure cannot be dispersed, and thus the reinforcing function is lowered, and when the interval between the fiber-reinforced polymer tapes is too narrow, the separation of the upper and lower layers occurs, and the reinforcing function cannot be normally exhibited.

According to the geogrid of the present invention, the reinforcing strips are first manufactured by the fiber-reinforced strip manufacturing apparatus, and manufactured by the geogrid manufacturing apparatus using the manufactured fiber-reinforced strips. The following is a description in terms of respective steps.

Fiber reinforced tape fabrication

The general structure of a fiber-reinforced strip manufacturing apparatus according to a preferred embodiment of the present invention is shown in its functional form in fig. 3. Referring to fig. 3, the fiber-reinforced strip manufacturing apparatus of the present invention includes: an extrusion section 10 for melt-extruding the polymer resin 110 supplied through the hopper 11 to embed the reinforcing fibers 100 therein; and a cooling section 20 for cooling the extruded resin.

As shown in the detailed view of fig. 4, the extrusion part 10 includes: a crosshead die 12 for supplying a polymer resin 110 around the supplied reinforcing fibers 100 and coating the supplied reinforcing fibers 100 with the polymer resin 110, thereby forming fiber-reinforced polymer tapes; a guide holder 13 for providing a passage for supplying the reinforcing fiber 100 to the crosshead die 12, and for providing a vacuum state for removing air from the fiber 100; and a nozzle (Nipple)14 for setting a position of the supplied reinforcing fiber 100 and preventing a reverse flow thereof.

In the crosshead die 12, an extrusion passage 12a is formed along the feeding direction of the reinforcing fibers 100, and the extrusion passage 12a communicates with a resin supply passage 12b that supplies the polymer resin 110 stored in the hopper 11.

A fiber supply passage 13a for supplying the reinforcing fiber 100 is formed in the guide holder 13, and the guide holder 13 is coupled to the crosshead die 12 so that the fiber supply passage 13a is connected to the extrusion passage 12 a. Further, a vacuum drain pipe 13b for connection to a pumping member (15 of fig. 3) for making the periphery of the reinforcing fibers 100 supplied in the fiber supply path 13a in a vacuum state is coupled to the fiber supply path 13 a.

In the center of the nozzle 14, a nozzle hole 14a is formed along the longitudinal direction, and the nozzle 14 is provided such that the nozzle hole 14a is connected to the fiber supply path 13 a. The tip end of the nozzle 14 extends in the extrusion passage 12a of the crosshead die 12 to the vicinity of the point of connection with the resin supply passage 12 b. Accordingly, as described later, the reinforcing fibers 100 passing through and protruding out of the nozzle hole 14a are surrounded and coated by the polymer resin 110 supplied in a molten state through the resin supply passage 12 b.

The cooling part 20 includes a cooling tank 21 in which a refrigerant such as water is contained and a thermostat member 22 for maintaining the refrigerant at a certain temperature. The strip extruded from the extrusion part 10 is cooled by water while moving along the cooling groove 21, and the length of the cooling groove 21 can be appropriately adjusted according to the operation requirement.

In fig. 3, reference numeral 3 denotes a creel for stacking the reinforcing fibers 100, reference numeral 4 denotes a feeder for supplying the reinforcing fibers 100 to the extrusion section 10, and 4-1 denotes a powder adhesive supplier.

Reference numeral 5 is a winding member for drawing the extrusion-produced fiber-reinforced strip at a certain speed, and 6 is a winder for winding the strip at a certain length.

In the following, the operation of the tape manufacturing apparatus of the present invention having the above-described structure is observed, and the reinforcing fibers 100 first accumulated in the creel 3 are supplied to the extrusion section 10 through the feeder 4. Preferably, the feeding speed of the reinforcing fiber through the feeding machine 4 and the winding speed of the strip through the winding member 5 are kept in agreement, thereby maintaining a certain tension of the reinforcing fiber 100.

This is to prevent thermal shrinkage of the reinforcing fibers 100 occurring when they pass through the cross-head die 12, thereby allowing the geogrid to normally function as a civil engineering reinforcing material.

The powder adhesive supplier 4-1 is a component of the feeder 4, and spreads the polyester-based powder adhesive on the surface of the reinforcing material at normal temperature on the surface of the reinforcing fiber 100 before being supplied to the extrusion part 10. The reinforcing fibers 100 are fiber aggregates that are spread in all directions, up, down, left, and right, while maintaining a constant tension, in a state where the surface area is stretched most. At this time, the polyester-based powder adhesive adheres to the surface of the reinforcing fiber 100.

The reinforcing fibers 100 supplied to the extrusion part 10 enter the nozzle holes 14a of the nozzle 14 connected thereto through the fiber supply passage 13a of the guide holder 13. Subsequently, the fiber 100 discharged through the nozzle hole 14a passes through the extrusion passage 12a of the crosshead die 12.

At this time, the inside of the fiber supply path 13a of the guide shoe 13 is maintained in a vacuum state by the operation of the vacuum pump in the pumping member (13 of fig. 3), which is to prevent air bubbles from being trapped when the reinforcing fibers come into contact with the molten resin. If the bubbles are not removed, the bubbles expand or the surface of the compressed tape is broken, resulting in poor appearance of the tape and deterioration of the physical properties thereof. Further, the polymer resin layer becomes thinner in this portion as the bubbles expand, and there is a possibility that the reinforcing fibers are damaged even by a slight external impact during the application.

The reinforcing fibers 100 passing through the above-described nozzle 14 are surrounded by the molten polymer resin supplied through the resin supply passage 12b and exit the crosshead die 12.

Since the polyester-based powder adhesive spread on the surface of the reinforcing fiber 100 is melted by the heat of the melted polymer resin, the adhesion with the polymer resin as the covering material is increased. When the polyester-based powder is present on the surface of the reinforcing material, the adhesion of the powder is stronger than that when the molten polymer resin is directly contacted with the surface of the reinforcing material, and thus the bonding force between the reinforcing material and the coating material can be increased.

The nozzle 14 prevents the polymer resin 110 from flowing backward to the guide holder 13 side. In addition, by variously changing the sectional shape of the nozzle hole 14a, products having reinforcing fibers of various shapes shown in fig. 11a to 11c can be obtained.

Further, by changing the terminal cross-sectional shape of the extrusion passage 12a of the crosshead die 12, the profile of the ribbon can be changed.

The fiber-reinforced polymer strip leaving the crosshead die 12 is cooled by water from a cooling trough 21 of a cooling section 20. The fiber-reinforced strip thus cooled is wound on a winder 6 through a winding member 5 in a certain length.

According to the invention, the fiber-reinforced polymer tapes are manufactured with a rectangular cross-sectional shape with a width of 2-30mm, preferably 3-20mm and a thickness of 1-10mm, preferably 1.5-5mm, or a circular cross-section with a diameter of 2-20mm, preferably 4-15 mm. If the width or diameter of the strip is less than 2mm, it is difficult to manufacture a product having a minimum tension of 2 tons/m, the contact point adhesion is low, and if the width or diameter of the strip is more than 30mm or more than 20mm, the operation of arranging the manufactured product in a strip arranging device or winding the manufactured product on a reel in a certain length becomes difficult as described later.

Manufacture of geogrids

A process for manufacturing the geogrid according to the present invention using the manufactured fiber reinforced polymer strip will be described below. According to the manufacturing method described later, the geogrid can be produced at low cost and in large quantities.

According to the present invention, the fiber-reinforced polymer tapes 1 and 2 are arranged in the warp direction and the weft direction, respectively, and the arrangement form of the tapes is changed to diversify the lattice structure, thereby making it possible to more effectively exert the reinforcing property of the product.

Fig. 5a and 5b are schematic views illustrating the structure of the geogrid manufacturing apparatus according to the preferred embodiment of the present invention. Referring to the drawings, the geogrid manufacturing apparatus of the present invention includes a warp direction strip supply 30, a weft direction strip supply 40, a strip arrangement member 50, a welding portion 60, a winding member 70, and a winding machine 71.

The warp strip supply section 30 includes a warp bobbin creel 31 and a warp feeder 32, and the warp feeder 32 supplies the strip from the bobbin creel 31 to the strip aligning member 50. For example, the feeder 32 is constituted by a pair of rollers, and a polymer strip is inserted therebetween to be supplied. The warp creel 31 is loaded with warp fiber reinforced polymer strips 1, and a plurality of warp fiber reinforced polymer strips 1 are supplied side by side to the strip aligning member 50 by operating the warp feeder 32.

The strip arranging member 50 is a member for weaving a geogrid by alternately crossing warp and weft strips 1,2, and includes a pair of upper and lower plates 51 and 52 facing each other, as shown in fig. 6. At least one of the upper plate 51 and the lower plate 52 is moved up and down by a driving means not shown.

The mutually facing surfaces of the upper plate 51 and the lower plate 52 are provided with, for example, a 1 st bending member 80 and a 2 nd bending member 90 for pressing and bending the supplied warp fiber reinforced polymer tapes 1. The upper and lower plates 51 and 52 shown in fig. 6 are marked with hypothetical lattices, the intervals G between which are in accordance with the graduation marks of the manufactured geogrid. As will be described later, the intersections of the lattice each correspond to the intersections of the manufactured geogrid.

The bending members 80,90 are disposed at the intersections of the hypothetical lattice, in which case the 1 st bending member 80 and the 2 nd bending member 90 are alternately arranged in a staggered manner not facing each other, and the installation positions of the bending members are determined according to the 1 st contact point C of the manufactured geogrid₁And the 2 nd contact point C₂The position and number of the (c) are set. In this embodiment, as shown in fig. 1, the warp and weft fiber-reinforced polymer tapes 1,2 are regularly alternated up and down, having a so-called "plain weave structure", so that at this time, the 1 st bending member80 and 2 nd bending member 90 are also regularly arranged at the crossing points of one lattice.

The 1 st and 2 nd bending members 80,90 have warp support grooves 81,91 and weft through grooves 82, 92. As described later, the support grooves 81,91 are in contact with the warp fiber reinforced polymer tapes 1 supplied between the upper plate 51 and the lower plate 52 to prevent detachment at the time of pressurization, and the width of the support grooves 81,91 is formed to be wider than the width of the polymer tapes 1.

The through slots 82,92 correspond to the portions of the peaks and valleys of the warp fiber reinforced polymer strip 1 bent by the 1 st and 2 nd bending members 80,90, providing a passage for the weft fiber reinforced polymer strip 2 to pass through when the weft fiber reinforced polymer strip 2 is inserted. The width of the through-grooves 82,92 is therefore likewise greater than the width of the weft fibre-reinforced polymer strip 2.

In order to facilitate passage of the weft-wise fiber-reinforced polymer band 2 through the through grooves 82,92, the inclined surfaces 83,93 may be formed to be deeper than the depth of the support grooves 81,91, respectively, so that the ends of the inserted weft-wise polymer band 2 can be guided.

The weft tape supply 40 includes a weft creel 41 and a weft feeder 42, the weft feeder 42 supplying the tape from the creel 41 to the tape arrangement member 50. The bobbin creel 41 and the feeder 42 are configured to correspond to the warp-wise strip supply portion 30.

The fusion 60 is a device for bonding the contact points of the tapes arranged by the tape arrangement member 50 to each other, and is preferably composed of the 1 st and 2 nd fusion machines 61 and 62. According to the present invention, the tapes are bonded to each other by vibration in order to exhibit maximum strength without damaging the reinforcing fibers present inside the polymer resin.

The structure of the 1 st fusion splicer 61 is shown in FIG. 7 a. As shown, the fusion splicers 61 are opposed to each other, and include therebetween an upper clamp 63 and a lower clamp 64 that supply an arrangement of warp and weft fiber-reinforced polymer tapes 1, 2. A plurality of pairs of 1 st support frames 63a,64a facing each other are formed on facing surfaces of the upper jig 63 and the lower jig 64.

Similarly, the 2 nd fusion splicer 62 is constituted by an upper jig 65 and a lower jig 66 as shown in fig. 7c, and includes a plurality of 2 nd support frames 65a,66a formed by projecting the facing surfaces of the upper and lower jigs 65,66 so as to face each other.

According to the present invention, the positions of the 1 st support frames 63a,64a and the 2 nd support frames 65a,66a correspond to the positions of the mutual contact points of the warp and weft polymer tapes 1,2 arranged in the tape arrangement member 50, for example, as shown in fig. 7b and 7d, the 1 st support frames 63a,64a correspond to the 1 st contact point (C of fig. 1)₁) And the contact points are fused to each other, the 2 nd support frames 65a,66a therebetween correspond to the 2 nd contact point C₂And the contact points are fused to each other.

Preferably, the ends of the support frame are roughened so that they do not slip when in contact with the polymer strip. It should be understood that this structure is not limited to the present embodiment, and various modifications can be made to the structure capable of pressure-supporting the polymer strip.

The fusion splicer melts the polymer resin 110 surrounding the reinforcing fiber 100 in a short time by the relative vibration of the upper and lower clamps, thereby completing the bonding. For example, the 1 st support shelf 63a,64a of the 1 st fusion splicer 61 is at the 1 st contact point C of the polymer strip array₁Holding the lower clamp 64 in a fixed state and vibrating the upper clamp 63 in a direction perpendicular to the warp direction in a state of pressing the upper surface of the warp-wise polymer strip 1 and the lower surface of the weft-wise polymer strip 2 at positions, respectively, to make the 1 st contact point C₁The polymer resin of (a) is melt-bonded.

Similarly, the 2 nd supports 65a,66a of the 2 nd sealer 62 are at the 2 nd contact point C of the polymer strip array₂In a state of pressing the upper surface of the weft polymer tape 2 and the lower surface of the warp polymer tape 1, respectively, the upper jig 65 is held in a fixed state and the lower jig 66 is vibrated in a direction perpendicular to the warp directionMoving the 2 nd contact point C₂The polymer resin of (a) is melt-bonded.

Although the present embodiment illustrates the structure of the welding part 60 with a specific drawing, the present invention is not limited to this embodiment, and various means for melt-bonding the crossing warp and weft polymer tapes by inducing a mutual vibration motion therebetween are included in the technical idea of the present invention.

Next, a process of manufacturing the geogrid according to the present invention using the geogrid manufacturing apparatus having the same structure as described above will be described with reference to fig. 9.

First, the fiber reinforced polymer tapes manufactured in the previous tape manufacturing process are respectively mounted side by side with each other at the warp creel 31 of the warp tape supply 30 and the weft creel 41 of the weft tape supply 40 (step S300).

At this time, the interval between the fiber reinforced polymer tapes 1,2 mounted on the creels 31,41 is 10 to 100mm, preferably 20 to 80mm, with respect to the center line thereof. For example, 10-500 strips are supplied with the width of the final geogrid product taken as 1-5 m. If the distance between the strips is too large to be 100mm or more, the load applied to the structure cannot be dispersed, and therefore the reinforcing function is lowered, whereas if the distance between the strips is too small to be 10mm or less, the upper and lower layers of soil are separated, and the reinforcing function cannot be normally performed. When the interval between the polymer strips is maintained within the above range, the polymer strips are integrated without causing separation of soil, and can function as a reinforcing material.

Thereafter, the warp fiber reinforced polymer tapes 1 from the warp creel 31 are supplied side by side into the tape aligning member 50 by the warp feeders 32 (step S310). At this time, the upper plate 51 and the lower plate 52 of the strip aligning member 50 are maintained in a spaced state from each other, so that the warp-wise polymer strips 1 are introduced along the straight line connecting the guide grooves 81,91 of the 1 st bending member 80 and the 2 nd bending member 90. Preferably, after the supply of the warp fiber reinforced polymer strip 1 is finished, the warp fiber reinforced polymer strip 1 is cut at an appropriate length using a not-shown cutting member.

Then, in step S320, the warp fiber reinforced polymer strip 1 is press-bent. At this time, the nth warp fiber reinforced polymer strip (illustrated with a solid line) (refer to 1 of fig. 6)_n) And (n + 1) th warp fiber-reinforced polymer strip (illustrated by dashed lines) 1_n+1The bent state of (a) is shown in fig. 8a and 8b, respectively.

Referring to FIG. 8a, upper plate 51 and lower plate 52 are brought close to each other for the nth warp polymer strip 1_n1 st bending member 80 formed on the opposite surfaces thereof respectively at the time of pressing_nAnd 2 nd bending member 90_nContact and press the warp direction polymer strip 1_n. At this time, the bending members 80 are preferably passed through the 1 st and 2 nd bending members_n,90_nIn which a guide groove (refer to 81 and 91 of fig. 6) is formed so that the tape can be stably bent even in the pressing, thereby enabling the polymer tape to be stably bent without being separated. As a result of this bending, the first bending member 80 passes_nThe pressurized portions form valleys passing through the No. 2 bending member 90_nThe pressurized portion forms a mountain.

On the other hand, due to the pressurization is located at the second place_n+1Single location warp polymer strip 1_n+1When it comes to_n+1The 1 st and 2 nd bending members 80_n+1,90_n+1And the nth bending member 80_n,90_nAre arranged to be staggered with each other, so that, as shown in FIG. 8b, the appearance of the mountain and valley is similar to that of the nth stripe 1_nIn contrast to the opposite. I.e. passing through the 1 st bending member 80_n+1The pressed portion forms a valley passing through the No. 2 bending member 90_n+1The pressurized portion forms a mountain.

In fact, since the pressing of the upper plate 51 and the lower plate 52 occurs simultaneously, the respective bending states are as shown in fig. 8c, and the hills and valleys are staggered with each other and form a state opposite to each other.

As described above, the weft fiber-reinforced polymer tapes 2 are supplied by the weft tape supplying part 40 in a state where the bending of the warp polymer tapes 1 is proceeding (step S330). Specifically, the latitudinal polymer strip 2 is inserted through the latitudinal feeder 42 through the through slots 82,92 of the 1 st and 2 nd curved members 80,90, as also shown in fig. 8 c.

That is, the weft polymer tapes 2 are inserted into the n 1 st bending member 80_nN-th polymer strip 1 formed by pressing_nAnd by the (n + 1) th 2 nd bending member 90_n+1Pressure formed n +1 th polymeric strip 1_n+1In the space between the mountains. Alternatively, the weft polymer tapes 2 are inserted into the nth 2 nd bending member 90_nN-th polymer strip 1 formed by pressing_nAnd by the (n + 1) th 1 st bending member 80_n+1Pressure formed n +1 th polymeric strip 1_n+1In the space between the valleys. Although the weft fiber-reinforced polymer tapes 2 are inserted through the weft tape supply parts 40 disposed at one side of the tape arrangement member 50 in the present embodiment, the weft tape supply parts 40 may be disposed at both sides of the tape arrangement member 50, and weft tapes may be supplied from both sides at the same time.

As described above, in a state where the weft polymer tapes 2 are inserted and cut in an appropriate length is completed, the upper plate 51 and the lower plate 52 are separated from each other by a not-shown driving means, and the warp polymer tapes 1 and the weft polymer tapes 2 are "woven" in such a manner as to alternately cross each other up and down, as shown in fig. 1. At this time, the mountain portion of the warp polymer tapes 1 crosses the weft polymer tapes 2 to form the 1 st contact point C₁The valley portions of the warp direction polymer stripes 1 cross the weft direction polymer stripes 2 to form the 2 nd contact point C₂。

According to the present invention, various types of geogrids can be manufactured by changing the positions of the curved members 80,90 of the upper and lower plates 51, 52, examples of which are shown in fig. 10a to 10 d.

As shown in FIG. 10a, when 2 consecutive 1 st bending members 80 'are disposed between 2 nd bending members 90' along the warp direction on the facing surfaces of the upper plate 51 'and the lower plate 52', the warp and weft polymer tapes are arranged such that the 1 st contact point C is₁With two 2 nd contact points C in between₂As shown in fig. 10 b. That is, this case may beWhich is considered to be the insertion of 2 weft polymer strips in one valley (or mountain) of the warp polymer strips.

In addition, as shown in FIG. 10C, when 3 consecutive 1 st bending members 80 'are provided between the 2 nd bending members 90' on the facing surfaces of the upper plate 51 'and the lower plate 52', 1 warp polymer tapes 1 are aligned at the 1 st contact point C₁Has 32 nd contact points C₂As shown in fig. 10 d. That is, this case can be seen as inserting 3 weft polymer strips at 1 valley (or mountain) of the warp polymer strips.

Although in the present embodiment, the description has been made with respect to the nth warp polymer strip and the (n + 1) th warp polymer strip adjacent thereto, the same applies to any mutually different warp polymer strips which are not adjacent to each other.

The warp and weft polymer tapes 1,2 arranged in the manner described above are then transferred to the welding station 60 with the contact points C₁,C₂And (4) mutually welding. First, the upper and lower clamps 63, 64 of the 1 st fusion machine 61 shown in fig. 7a are brought close to each other, and the polymer tape array sandwiched therebetween is pressed. At this time, the 1 st contact point C of the polymer strip array is pressed and supported by the 1 st support frames 63a,64a formed on the facing surfaces of the upper and lower jigs 63, 64₁. More specifically, the support bracket 63a of the upper clamp 63 is in contact with the upper surface of the warp-wise polymer strip 1, and the support bracket 64a of the lower clamp 64 is in contact with the lower surface of the weft-wise polymer strip 2. At this time, since the ends of the supporting frames 63a,64a are treated with the rough surface, they can contact the surface of the polymer strip without sliding.

In this state, when the upper clamp 63 is vibrated, for example, left and right, at right angles to the longitudinal direction of the warp-wise polymer tape 1 in a state where the lower clamp 64 is fixed, the polymer resins 110 of the tapes are melted and bonded to each other at the first contact point C₁(step S340). At this time, in order to melt the polymer resin in a short time and to prevent the reinforcing fibers 100 therein from being damaged at the time of vibration welding, it is preferable to perform vibration motion at a vibration frequency of 60 to 300Hz and an amplitude of 0.3 to 1.8 mm.

As described above, the 1 st contact point C₁After the bonding is completed, the warp and weft polymer tape arrays are again transferred to the 2 nd fusion splicer 62, and the 2 nd contact point C is performed₁Vibration welding (step S350).

In the 2 nd fusion splicer 62, the 2 nd support frames 65a,66a of the upper jig 65 and the lower jig 66 contact the 2 nd contact point C of the arrangement of warp and weft polymer tapes₂That is, in this embodiment the support bracket 65a contacts the upper surface of the weft polymer strip 2 and the support bracket 66a contacts the lower surface of the warp polymer strip 1.

In this state, when the upper jig 65 is fixed and the lower jig 66 is vibrated at right angles to the longitudinal direction of the warp strips 1, for example, left and right, the adhesion is completed in the same manner as described above.

Although in the present specification and the drawings, it is exemplified and explained that the 1 st contact point C is individually performed₁And the 2 nd contact point C₂But it should be understood that the present invention is not limited to the above-described embodiment, and various modifications can be applied. For example, the 1 st contact point C may be bonded using 1 fusion bonding machine₁And the 2 nd contact point C₂At this time, the 1 st contact point C is firstly contacted₁The adhesive was applied while being wound around a winder, and then released and fed to a fusion splicer. At this time, the arrangement body is turned over and the upper and lower surfaces are transferred, and the 2 nd contact point C can be made₂Bonding of (3). Further, needless to say, the contact points of the polymer tapes may be bonded not by vibration melt bonding but by ultrasonic friction melt bonding or heat melt bonding.

As described above, the bonded geogrid is wound at a certain length on the winding machine 71 through the winding member 70. Preferably, for ease of use in the field, a length of 25-200m for the product of the fibre reinforced geogrid is suitable.

Although the description distinguishes the manufacture of fiber-reinforced polymer strips from the manufacture of geogrids, it is not to be understood that the process can be continuously constructed.

The present invention will be described in detail below with reference to examples. However, the embodiments according to the present invention may be modified into various forms, and thus the scope of the present invention is not to be construed as being limited to the embodiments described below. Embodiments of the present invention are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The physical properties of the geogrids according to the examples below were evaluated according to the criteria described later.

Broad tensile strength test: ASTMD 4595

A sample having a width of 20cm was fixed between upper and lower clamps of a deformation control type tensile testing machine, and was stretched at a rate of 10. + -. 3%/minute to measure the tensile strength and elongation at break by tensile deformation. When the glass fiber was used as a reinforcing fiber, the tensile strength (LASE 2%) was exhibited when the tensile strain was 2% by itself, and when the polyester high-strength yarn was used as a reinforcing fiber, the tensile strength (LASE 5%) was exhibited when the tensile strain was 5% by itself.

Creep test: ASTM D 5262

The creep test is used to evaluate the deformation behavior of the geogrid under a constant temperature condition (21 ± 2 ℃) under a continuous tensile load, thereby determining the tensile strength reduction coefficient caused by creep that needs to be considered in design. In this experiment, a load of 45% compared to the maximum tensile strength of the geogrid sample was applied to the sample, and the tensile strain after 1000 hours was measured.

Evaluation of workability resistance: ASTM D 5818

After treating the roadbed in the same way as when the actual building is constructed, a minimum of 10m is laid²The geogrid sample of (a) is compacted in the same manner as when an actual building is constructed after laying a fill material on the upper portion thereof. As a filling material, an aggregate having a size of at most 20mm was compacted at a thickness of 30cm, a geogrid sample was laid, and 30cm of the same filling material was laid on the upper portion of the geogrid sampleCompaction was performed 4 times back and forth using 10t capacity vibrating rolls.

After the compaction is finished, removing the compacted aggregate on the premise of not damaging the geogrid, extracting a geogrid sample, then carrying out a tensile test on the extracted sample, comparing the tensile strength with the tensile strength of the original sample, and calculating the strength reduction rate (%).

Shape stability test

After filling, laying and compacting by the same method as the evaluation of the workability, samples were taken out and the contact points of the warp and weft tapes were observed, and the contact points were evaluated as "poor" when the number of contact point separations was 20% or more, "normal" when 10-20% and "excellent" when 10% was less than full.

Evaluation of tensile test: GRI-GG5

Geogrids are laid in soil while filling the soil in soil tanks (soil boxes) with the length of 140cm, the width of 60cm and the height of 60 cm. At this point, the geogrid sample was attached to a stretching device through a 2.5cm slit (slit). Or, a rubber membrane is arranged on the upper part of the soil tank, and the uniform vertical load is pressurized into the soil tank through air pressure. Next, the vertical load was adjusted from 0.3kg/cm²Change to a maximum of 1.2kg/cm²And the tensile displacement speed was set to 0.1cm/min, the tensile displacement of the material when the maximum tensile force was applied was analyzed, and the interaction coefficient (Ci) indicating the frictional force between the geogrid and the soil was evaluated.

Peel strength

After preparing an oblique band having a length of 30cm, after fixing the weft band by using a jig as shown in the figure, the oblique band was fixed to an upper jig, and the upper jig was used upward at 50cm/min to measure the length of fiber shedding.

Example 1

A warp fiber-reinforced polymer tape having a cross section as illustrated in (c) of fig. 11b, a width of 8.4mm and a thickness of 2.3mm was manufactured by passing 3 equal parts of 48 polyester high-strength yarns having a fineness of 1000 denier through a nozzle having a circular cross section of 3 holes and a quadrangular die. In addition, a weft-direction reinforced polymer tape having the same cross section as the warp-direction fiber-reinforced polymer tape, a width of 6.3mm, and a thickness of 1.5mm was manufactured using 15 polyester high-strength yarns having a fineness of 1000 denier.

At this time, a polyester-based powder adhesive was supplied to the fiber surfaces of the reinforcing materials of the respective radial and latitudinal fiber-reinforced polymer tapes by a powder adhesive supplier to reach 1.5 wt% of the weight of the tapes. The powder adhesive had a softening point of 120 ℃, a Tg of 65 (. degree. C.), a melt flow index MI 16(g/10 min), a particle size of 350 (. mu.m), and a hardness (Shore D) of 80.

As the thermoplastic polymer resin, polypropylene having a melt index of 4 was used. The manufactured warp strips were then aligned in a strip aligning device such that the geogrid product width was 4m and the distance between the strip centers was 40mm, after which the weft strips were inserted at intervals of 40mm at 90 ° to the warp strips to form a lattice of a plain weave structure as shown in fig. 1. Then, after vibration welding of contact points formed by the warp tapes on the upper surfaces of the weft tapes at a frequency of 194Hz and an amplitude of 1.3mm in the first bonding device, the warp tapes were moved to the 2 nd bonding device, and vibration welding of contact points formed by the warp tapes on the lower surfaces of the weft tapes at a frequency of 194Hz and an amplitude of 1.3mm was performed to manufacture the geogrid. The number of ribs per unit length (r ibs/m), broad tensile strength (kN/m), LASE 5% (kN/m), tensile strain (%), creep deformation rate (%), strength reduction rate at construction (%) of the manufactured geogrid are shown in table 1, and the interaction coefficient at tension and shape stability are shown in table 2.

Example 2

A warp-fiber-reinforced polymer tape having a cross section as shown in (b) of fig. 11a, a width of 8.4mm and a thickness of 2.3mm was produced by passing 2 pieces of high-strength polyester yarn having a fineness of 24000 denier through a quadrangular cross-sectional nozzle having 2 holes and a quadrangular die.

At this time, a polyester-based powder adhesive was supplied to the fiber surfaces of the reinforcing materials of the respective radial and latitudinal fiber-reinforced polymer tapes by a powder adhesive supplier to reach 1.5 wt% of the weight of the tapes. The powder adhesive had a softening point of 120 ℃, a Tg of 65 (. degree. C.), a melt flow index MI of 16(g/10 min), a particle size of 350 (. mu.m), and a hardness (Shore D) of 80.

In addition, weft-direction reinforced polymer tapes having the same cross section as the warp-direction fiber-reinforced polymer tapes, 6.3mm in width and 1.5mm in thickness were manufactured using 2 polyester high-strength yarns having a fineness of 7500 deniers. Then, the strips were aligned and bonded in the same manner as in example 1, and a geogrid was manufactured. The number of ribs per unit length (ribs/m), tensile strength in width (kN/m), LASE 5% (kN/m), tensile strain (%), creep deformation rate (%) of the produced geogrid, and reduction rate (%) of strength at the time of construction are shown in table 1.

Comparative example 1

The conditions were the same as in example 1 except that the polyester-based powder adhesive was not provided on the surface of the reinforcing material when the weft fiber-reinforced polymer tapes were manufactured.

Comparative example 2

The conditions were the same as in example 1, except that the polyester-based powder adhesive was not provided on the surface of the reinforcing material when the radial fiber reinforced polymer tapes were manufactured.

Comparative example 3

The conditions were the same as in example 1 except that the polyester-based powder adhesive was not provided on the surface of the reinforcing material when the weft and warp fiber reinforced polymer tapes were manufactured.

[ TABLE 1 ]

[ TABLE 2 ]

	Stability of shape	Coefficient of interaction (Ci)
			Example 1	Is excellent in	0.96
Comparative example 3	Failure of the product	0.64

Referring to tables 1 to 2, the physical properties of the geogrids of the comparative example and the comparative example show the following differences.

The geogrids of examples 1,2 and the geogrids of comparative examples 1 to 3 have similar values in wide tensile strength (kN/m), LASE 5% (kN/m), tensile strain (%), creep deformation (%), strength reduction (%), but the fabric geogrids of examples show larger values in peel strength than the geogrids of comparative examples. The peel strength is a value for measuring a margin length required for connection with a face block during construction, and as the peel strength is higher, the required margin length can be shorter, thereby enabling economical construction. In addition, as a result of comparing the interaction coefficients (Ci) between soil and reinforcing material (table 2), the interaction coefficient (Ci) of the geogrid of example 1 was shown to be 0.96, and the interaction coefficient (Ci) of comparative example 3 was shown to be 0.84.

That is, the interaction coefficient of the geogrid according to example 1 is higher than that of the geogrid of comparative example 3. In this connection, the interaction coefficient when the geogrid is stretched is affected by the shape of the geogrid, and in the shape of the geogrid, the passive resistance member, that is, the member provided in the direction perpendicular to the direction in which the tensile force acts. In the experiment for the geogrid having the same width (60cm), the geogrid of comparative example 3 is the geogrid in which the length of the strips arranged in the direction perpendicular to the direction in which the tensile force acts is 60cm, whereas the geogrid of example 1 is longer than 60cm in actual length of the strips in the direction perpendicular to the direction in which the tensile force acts because the strips are arranged to intersect each other up and down to generate curvature. Therefore, the geogrid of the present invention has a larger contact area between the passive resistance member and the soil, and can exhibit more excellent reinforcement function, as compared with the geogrid of comparative example 3.