TW425345B - Method for making improved geogrids - Google Patents

Abstract

An improved method for manufacturing polymeric geogrids is disclosed. The method includes the steps of: (a) co-spinning at least one high-melting point filament yarn with a plurality of low-melting point staple fibers to from a composite yarn, the low-melting point staple fiber has a melting point that is at least 10 to 20 DEG C lower than the melting point of the high-melting point filament yarn; (b) weaving the composite yarn to form a net-structured fabrics; (c) heating the net-structured fabrics to cause the low-melting point staple fiber to melt and wrap about the high-melting point filament yarn; and (d) cooling the net-structured to form a geogrid. One of the main advantages of this process is that it does not require the coating step (with molten PVC or asphalt), as do the prior art processes. Thus, the geogrids can be manufactured in a more cost- effective and environmentally compatible manner. The geogrid of the present invention also exhibits substantially increased junction strength as well retaining a greater portion of its ultimate strength at elongation.

Description

425345

Five 'invention description (1) The present invention relates to a method for manufacturing geogrid with better properties. In particular, .ηπ ^, the manufacturing method using industrial grids, which can be different from the method disclosed by the foundation, soil, and rock weaving, has many different advantages: '点: ΥΥ 果 果 灯' (2) can reduce Manufacturing cost, reducing or eliminating the problem of discarding waste; and (3) the mechanical properties of the geogrid produced, especially after elongation, it can maintain excellent strength. , ≫ Geogrid has been used in various civil engineering and mining applications such as soil stabilization, reinfrcement, and other applications. Geogrids, as their names suggest, are in the form of two-dimensional space and can be either soft or hard. In general, soft geogrids include a grid-like structure (usually formed by weaving) made of high tensile strength filaments to provide high load support strength. The grid openings formed by their staggered stripes are usually rectangular or square, and the stripes are 90 ° to each other. The angles are aligned, however, other shapes and / or relative angles may be used. According to the size of the grid, the composition of the strips, and other combinations, the general commercial geogrids can also be called geocells, geonets, or geocomposits. . Tenax in Baltimore, Maryland, United States

Company is one of the companies that sells these products. The most common method for making soft geogrids includes five main steps: (1) combining several high-strength long-fiber yarns into thicker yarns, (2) combining the yarns of item (1) Warping; (3) Weaving with 425345 V. Description of the invention (2) Forming a two-dimensional network structure; (4) Impregnated with polyvinyl chloride (PVC) or asphalt; and (5) Drying / curing to Form the final grid. The purpose of impregnating with polyethylene or green is to bundle high-strength long-fiber yarns. The fiber bundles can be aggregated or covered by these substances, and these adhesive substances can also be used for protection. The step of impregnating with polyethylene gas or asphalt can also make the mesh structure have excellent properties such as UV resistance and acid and alkali resistance. · The inventors of the present invention discovered that the geogrid produced by the conventional method has many disadvantages. The main disadvantage is that because the fiber bundles (the so-called ^ ribs of the geogrid) are only covered by adhesive materials such as polyvinyl chloride (PVC) at the intersecting point, the individual fibers between them There is no adhesive substance, so its intertwined junction strength is very serious. This severely limits the application scope of geogrids for geotechnical engineering. Environmental pollution ^ 2 impregnating agents such as polyethylene gas, bitumen, etc. have the problems of easily causing the environment, being miscellaneous, and difficult to clean processing equipment. .η edit ί: Π5’091 ’247 No. 247 discloses a manufacturing method for earth-strengthening applications. The industrial grid is suitably coated. This fabric: ά = formed by plastic woven fabrics (East Hu); the surname 疋, a number of spaced weft bundles and a plurality of spaced warp yarns, and are located in 蝰. The 10Cking yarns are parallel to the weft yarns in the warp bundle. Thin and noisy yarn bundles are fixed by fixing the yarn bundles. A plurality of ϋΓ " extend between the bundle and the fixed yarn ' to fabricate the weft by weaving the weft bundle and the fixed yarn's yarns. Contain the fabric before it is crimped or stored after it leaves the loom.

Page 5 425345 V. Description of the invention (3) Immerse in the hot polygas vinyl bath towel, wipe the exposed Fang Mu A and dry it with a heater. In Patent No. 247, poly styrene, & ψ 土 # is impregnated with a woven fabric in accordance with a conventional method: 3ΐΙ B :! Dry / heat to form geogrid. Similarly, there are * adhesives * applied on the surface of the fiber bundle, and there is / and there is adhesion between individual fibers', so the joint strength is very poor. Pass ί: 2: = 5 ', 045’377 discloses a continuous fiber-reinforced compound i, a qualitative person, you and law. This grid structure is formed by combining continuous fiber-reinforced / tree: ί 11 strands (c_osite strands) with a similar compound ί: ί (or with simple unreinforced plastic strips). This transformation is based on the fact that the reinforcing strip is formed by prepreg, including reinforcing the fibers buried in plastic η :. The prepreg tape is passed from a supply roller into a die for being pulled through the die. In a separate path, the thermoplastic resin is' inside 'deposited on the tape ±' to provide a ::: cover in the second plastic layer. Then, the '胄 thermoplastic resin flows out to form a horizontal strip, thereby forming a web or grid structure. The method disclosed in the 377 patent is different from the conventional method in that the first method is to use glass fiber to strengthen the cost. Secondly, the geogrid produced by the transverse strips deposited on the machine-oriented strips is not a woven geogrid. It is a non-woven geogrid. Although the geogrid obtained in the 377 method provides some advantages, it also has some disadvantages. However, the 377 method still uses the same basic method as the conventional method, i.e., heating and melting the thermoplastic resin 'to provide a coating layer on the surface of the composite fiber. U.S. Patent No. 5, 1 99, 825 discloses a method for protecting people and long wall mining equipment during longwall shield recovery 425345. 5. Description of the invention (4) Manufacturing and containing of grid composite Polymer grids and geocomposites are homogenized by melting and extruding a polymer needle-rolled engineering fabric with thermal bonding fabrics that are melted and extruded with a polymer grid using an open source 'extruder. Of the melt. Polyvinyl geotextiles are bonded to the point where the strength of the joints produced by the process is insufficient. As described above, the joint strength required for individual fibers in a fiber bundle is conventionally known. Although it has already been verified, it has not been able to solve this problem in order to solve this problem, and it is required to invent an improved method. method. In this invention, a grid composite grid of a woven fabric is obtained by combining a continuous long fiber. This flame heat source may use one addition. In this method, ‘the use of a gear to facilitate the dual-shaft disclosed by Puli is used to solve the problem because the grid formed by the 825 pin rolling method is not a problem. The grid has *-and there are not many invention problems. Therefore, the groundwork grid is made so that the groundwork connects the polymer grids. Grid polyester, non-woven engineering fabrics or geothermal rollers as thermoplastic granules are important restrictions by means of the step-by-step process of the grid by melting and mixing the mixer, that is, per bonded substance, and therefore The lack of improved geotechnical grids necessitates the development of an improved applicability. At the same time, the manufacturing of grids must be environmentally friendly. In order to improve the strength of geogrids, US Patent No. 5,669,796 discloses a heat-bonded geogrid fabric with a woven or warp-weft grid. It is a two-component fiber, and each long fiber has a sheath portion and a core portion. The sheath is a bonded polyolefin material, including a polyolefin and

425345 V. Description of invention (5) (intrinsic viscosity) at 25. It is at least 0.8 9 deciliters / gram in O-phenol solvent at C. This bicomponent fiber with a heart sheath structure is spun using melt-extruding polymer (spinneret). Before reaching the spinning nozzle, melt the polymer (including Polyolefin, adhesive, and carbon black) filtration. The sheath polymer and the core polymer are sent into each channel of each spinning nozzle, and are extruded through the spinning nozzle to form a bicomponent fiber. Patent No. 796 The disclosed method improves the coverage of the core polymer by using the lip polymer. However, because the steps are very complicated, the manufacturing cost is very expensive. The object of the present invention is to develop an improvement in manufacturing a woven geogrid. Method 'It can be used in various civil engineering programs to provide the selective separation and stiffening effect of foundations, soils, rocks, earth, or other geotechnical materials. In particular, the main purpose of the present invention is to develop a manufacturing geogrid = Improved method, which can be used with various types of civil engineering plans, and the long-term mechanical strength is improved. The method disclosed by the present invention provides many different advantages: 1) It is easy to implement; (2) It can reduce the manufacturing cost and meet the environmental protection requirements; and (3) The geogrid produced has excellent properties, including excellent mechanical strength and low elongation. This One of the advantages of the method disclosed by the invention is that it greatly improves the mechanical strength of the geogrid after elongation, but it does not substantially increase the manufacturing cost. Most geogrids are applied as the earth, etc. The situation will be extended. Therefore, the ability to retain mechanical strength is a very important parameter in the nature of a five-person geogrid. Another major advantage of the method disclosed in the present invention is that it does not require the practice of 425345. V. Invention Note (6) The device and steps of plastic plastic (asphalt) are also due to the device and steps of Α 翌 & He and plastic on the geotextile. ^ &Quot; The method includes the treatment of very hot (generally 150 ° C) The step of melting and plasticizing 'therefore requires quite expensive equipment, and usually there is a rigorous environment. Furthermore, the unused thermoplastic resin or asphalt is a problem of heavy disposal, and it is often a troublesome environmental problem. 1 = revealed Another advantage of the method is 'most of the known methods', the synthetic component is covered on the yarn bundle, and the individual fibers have no different properties, especially the county name Lapu "The second station waiter is not superior: the method This can be achieved using a two-component fiber structure of the heart sheath type, which requires quite complicated steps, so the manufacturing cost is extremely high. However, in the research, the inventor of the present invention found that ^ a variety of two melting point long fibers and one or A variety of low-melting-point long-fiber people, forming composite fiber bundles, and then warping the composite structure, ',, σ 0 in a grid-like network structure can make high-melt-sensitivity, J, cross-woven into a Λ cover. However, this way The coverage is only linear and does not: The complete coverage of the covering fiber is obtained. The pass-through point is long. The method for manufacturing the geogrid disclosed in the present invention is a high-melting long fiber and one or more low-melting short ones. When co-spun becomes a composite yarn, you can get a very good result by using composite spinning in A, and then 425345 5. Invention Description (7) 2 The composite yarn is knitted into a grid Web of patterns 2 woven structure. The mesh type of this kind of fabric can be rectangular or square, and it has a grid. The second dimension: This mesh fabric is then heat treated to make the low-melting staple fiber a soft geogrid with excellent mechanical and chemical properties. ... to the composite yarn disclosed in the Ming including at least one high melting point long fiber, or a plurality of low'melting point short fibers. High-dazzle long fibers must have high strength, high modulus, and low strain rate, so they can provide the function of strengthening the weaving ground: grid. High-melting long fibers that can be used in the present invention include polyesters, such as polyethylene terephthalate (PET), polybutylene terephthalate = vinegar (PBT), etc .; polyamines, such as nylon 6, nylon 66 Etc .; glass fibers; fluorene vinyl alcohol fibers; carbon fibers; and aromatic polyamide fibers (aramid). In addition, the main purpose of low-dot fiber is to use it as a matrix or adhesive, and its strength is not a major consideration. Examples of the low-melting short fibers that can be used in the present invention include polyethylene, polypropylene, polyester copolymers, polyamides such as nylon, and the like. The low-melting short fiber is preferably selected so that the melting point f of the high-melting long fiber is less than 20% of the melting point of the low-melting short fiber. c. The low melting point short fiber can also be a polymer of the same type as the high melting point long fiber used. The important point is that the low melting point short fiber must have a lower melting point. The weight of the long-melting long fibers and low-dazzle short fibers contained in the composite sand is, for example, preferably 50 to 70% to 30 to 50%. The two types of fibers are recovered. f yarn is wound into a bobbin. This composite yarn can then be used for weaving. Since the yarn formed by the present invention belongs to machine-spun yarn (叩 仙 " yarns), it can be used in various types of knitting machines (such as sword belt loom)

Page 10 425345 V. Description of the invention (8) (upier 100m) or warp kniUing machines) is constructed with 2 required grids. Generally speaking, the size of the grid can be square as X20 or rectangular 20x30 fflm. After weaving, we can place the box after weaving or other heating, preferably at a temperature above the low melting point staple fiber ΪίΐΓ G ° C, to form the final industrial grid product. -Composite yarn 'The present invention does not require the conventional method. The method disclosed in the present invention eliminates the need for coating 6 and reduces the size of the production equipment and the cost of related equipment. More importantly, the present invention greatly reduces the processing time, and reduces the problem of ring dyeing. Furthermore, with the #J < matrix & π / inter-strength fibers (ie, high melting point long fibers) can be bonded (= formed by short fibers with low melting point), they are tightly bonded. ν # and the junction of the yarn can be optimized. Significant increase in the joint strength and overall strength of the grid: a brief description of the circle-enhancing method: Figure 1 shows a schematic diagram of the steps for forming a composition according to a conventional method.乂 Floating dimensional geotechnical grid Figure 2 shows a preferred embodiment according to the present invention @ 地 工 格 心 ㈣㈣. 4% synthetic fiber A cross-sectional photo of the composite yarn is shown, magnified 100 times. Times. Show-cross-section photo of the treated composite yarn, enlarged by 100. The present invention discloses-an improved method for manufacturing synthetic fiber-type ground guard grid

V. Description of the invention (9) method, the local grid can be used in combination with the foundation, Λ engineering composites to provide the method of choosing to leave the ground, or other ground exposure methods to provide many different exposures, without the need for additional equipment . Chu_. The method is simple and easy to implement, and meets environmental protection requirements. One can reduce the manufacturing time and the resulting grid. The grid has excellent cores: made by the method = whole; strength. As mentioned above, one of the advantages of this method is that the main strength given by Xishanyan can be retained without substantial increase in length. :::::: Required-thermoplastic Devices on geotextiles: steps: not immersed in the whiskers, and the conventional method includes the steps of processing non-II (the second two are all fused plastic or asphalt. Therefore, the "devices usually required by law" There is usually a highly dangerous working phase: expensive :: plastic resin or asphalt can cause serious loss :: troublesome environmental issues. Ya 1 疋 The method disclosed by the present invention can also make the composition (ie, low fiber) Effectively and tightly cover long fibers. Phase 2: The adhesive component can only cover long fiber bundles, which is the method of the conventional method of the present invention: Another-advantage. The adhesive fiber component is coated on the outside of individual composite yarns. The excellent properties of the geogrid obtained by the method disclosed in the present invention can be obtained, especially in terms of contact strength and retention of post-strength strength. The invention not only can produce excellent ground 425345

And it can be made under the condition of less cost and less environmental protection problems. 5. Invention Description (ίο) Industrial grid. In the method disclosed in the present invention ', firstly, at least one high-refining-point long fiber and at least one or a plurality of low-melting-point short fibers are formed into a composite yarn through composite spinning (MM). This composite yarn is then woven into a mesh with mesh openings. The mesh can be rectangular or square. The woven mesh structure is then heated to melt the low-melting short fibers and coat the high-melting long fibers. And surrounding. After cooling, a soft geogrid with excellent mechanical and chemical properties can be obtained. The composite yarn disclosed in the present invention preferably includes one or more high-melting long fibers and at least one or a plurality of low-melting short fibers. It is preferable that the weight ratio of the high-melting long fiber and the low-melting short fiber contained in the composite yarn is 50.7% to 30-50%. ^ The high-melting and low-melting fibers may be single-component fibers or low-melting fibers. It can be bi-component fiber. If bi-component fiber is used, it can be of sheath type (sheath / core) or side by side (high-melting-point long fiber to provide the reinforcing properties of woven geogrid, which must have high strength , High modulus and low strain rate. Among the high melting point long fibers that can be used in the present invention, good examples include polyesters such as polyethylene terephthalate (pET), polybutylene terephthalate (PBT) Etc; and Ammonium, such as nylon 6, nylon 66, glass fiber, polyvinyl alcohol fiber, carbon fiber, and aromatic polyamide fiber, which can be used as a reinforcing component. The main purpose of low melting point short fiber is The mixture is used to cover the reinforcing component (ie, high-melting long fibers), and its strength is not a major consideration. Good examples of low-melting short fibers that can be used in the present invention include polyethylene, polypropylene, polyester copolymers, Polyamide (such as 425345 V. Description of the invention (11) Ni # H and polyamine copolymer, etc. The best choice of low melting point short fiber is to make the melting point of high melting point long fiber at least higher than that of low melting point short fiber High 20 C 〇 'The high and low melting point fibers are composite-spun and warped. Before the warping, other processing steps can be performed. Then, the yarn bundle can be subjected to the weaving step. The yarn formed by the present invention belongs to machine spinning Yarn can be used in various types of knitting: loom (such as sword belt loom, warp knitting machine) to form the required grid structure. Preferably, the size of the grid is 20x20 or 20x30mm, etc. Use other sizes. After weaving, you can The woven product is heated at a temperature of 10 to more than the marriage point of the baked AM fiber to form a final geogrid product. # Method The main feature of the method is' The present invention does not need to be acquainted with high $ # I $ $ ^ Complex coating steps. The present invention uses a method that includes Ying to make the hair == composite yarn in the knitting process. This new size reduces the size of the production line, except for the impregnation equipment, and the reduction is that the disclosure of the present invention is related to others The cost of the device. The environmental pollution problem has been solved. • Saved :: Reduced the processing time and reduced the geogrid made by the method: In addition to the use, the method disclosed by the invention disclosed by the present invention has high strength and excellent performance. The excellent properties of this product are that the individual fibers and this ==== tightly, live and adhere to each other. This results in an excellent amplitude improvement between the contacts of the floor cooker produced. Due to the adhesion, the joint strength and overall strength of the grid are usually excellent. It also causes short fibers to be different from long fibers. Page 14 425345 ----- 5. Description of the invention (12) Refer to Figure 1. Fig. 1 Turtle red is also a step of forming a fiber-type geogrid: knowing the most common methods to form the holster 1 provided, and merging into =: Intent. The long-strength long fiber 2 is woven into a shape in a braiding machine 5; :: The grid ribs formed by re-bundling are processed through a few warping beams 4, which are composed of a fiber bath 6 and a press roller 7. 2: Pass the net-like structure through-impregnated exhaustion, π α, impregnated contact 6 includes an impregnated component (usually poly-containing, "formed into a protective layer" to cover the fiber bundle. Finally heating the warp = weaving: The structure is dried in an oven ", and is wound up by the take-up pro 9 to form a geotextile grid. ^ The figure shows a schematic diagram of the steps of forming a synthetic fiber plastic geotextile grid according to a preferred embodiment of the present invention. The composite yarn bobbin η is provided by a reel stand or a creel 10. The composite yarn is passed through a tension controller 12 and then woven in a knitting machine 13 to form a woven mesh structure, including a grid rib formed by the composite yarn. Unlike the first method in the conventional method, the woven mesh structure does not pass through the impregnation bath, but passes directly through the guide roller 14 into the oven 15, and the woven mesh structure is heated here. , And then cooled, coiled into a geogrid by the coiling device 16. The elimination of the immersion bath greatly simplifies the manufacturing method, reduces manufacturing costs (both equipment costs and operating costs), and improves the manufacturing environment, while Environmental protection issues Solved. Figure 3 shows a cross-section photomicrograph of the composite yarn. The core part includes polyester long fibers (PET). The sheath portion includes polypropylene short fibers. Figure 4 shows a cross-section photomicrograph of the composite yarn after heat treatment. In Figure 4, the composite yarn bundle (that is, the long-fiber yarn and the fused short fiber) is bonded together through the fused polypropylene short fiber. Page 15 425345 V. Description of the Invention (13) The following examples illustrate the present invention. The methods, features, and advantages are not intended to limit the scope of the present invention, and the scope of the present invention should be based on the scope of the attached patent application. Example 1 In this example, high-melting-point fibers use high-strength fibers. 2,000d / 192f polyethylene terephthalate (PET) long fibers (fiUmen1: yarns) 'Low-melting fibers are polypropylene staple fibers (stapie fibers) with a fiber denier of 2.5 and a nominal fiber length It is 2 English leaves. Two bundles of south-strength polyester long fibers are combined and then co-spinning with polypropylene staple fibers to form a composite yarn. This composite yarn is woven into a grid having a 20x2Omm grid. open The net-like structure. The knitted net-like structure is heated at 190 ° C for 2 minutes to melt low-dazzle short fibers to bond high-strength PET long fibers. After cooling, the net-like structure solidifies and forms a ground. Industrial grid. Table 1 shows the comparison of the relevant physical properties of the commercial industrial grid and the industrial grid of Example 1 of the present invention. Both geogrids in the table have the same specifications, that is, the nominal strength is 150. kN / m. η

Page 16 425345 V. Description of the invention (14) Table 1 Commercial geotechnical grid f Example 1 Weaving pattern 瑀 Weaving moth Specification 150 kN / m 150 kN / m Polymer type PET / PVC PET / PP Ultimate strength 168.9 kK / m 1640 kN / m Ultimate elongation Dong 15.21% 13.1% * Strength at 5% elongation 39.3 kN / m 60. 1 kN / m Ultimate elongation Dong 23.3% 36. 6% Contact strength 11.7 kQ 15.5 kQ The unit surface area weight (per square meter) 796.5 cr 502.7 q The comparison results in Table 1 clearly show that under the same specifications, the strength of the joints of the industrial grid of the present invention is increased by 32.5 compared with commercial products. %. And, just as important, the strength retention of the geogrid of the present invention at 5% elongation is 57% better than that of commercial products. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make changes and retouching without departing from the spirit and scope of the present invention. The scope of protection shall be determined by the scope of the attached patent application.

Page 17 Year η q

(Please read the precautions on the back before filling this page) 425345 V. Description of the invention (3) Component symbol description Figure 1 Bobbin 2—High-strength long fiber 3—Yarn 4 A warp knitting machine 6—Bath bath 7 —Rolling press 8 —Oven second figure 9 ~ Winding roll 10 ~ Yarn frame 11—Composite yarn bobbin 12—Tension controller 13—Knitting machine 14—Guide pro 15—Oven 16—Winding device (machine) or less Several examples are given to illustrate the methods, features, and advantages of the present invention, but are not intended to limit the scope of the present invention. The scope of the present invention should be based on the scope of the attached patent application. Example 1

T Printed by the Central Bureau of Standards, Ministry of Economic Affairs, Consumer Cooperatives. In this example, the high-melting-point fibers use high-strength 2,000d / 192f polyethylene terephthalate (PET) long fibers (filament yams). The melting point fibers are polypropylene staple fibers, with a fiber denier of 2.5, and a nominal fiber length of 2 inches. Three bundles of high-strength polyester long fibers are combined and then co-spinned with polypropylene staple fibers to form a composite yarn. This composite yarn was woven into a mesh structure having a 20 × 20 mm grid opening. The woven mesh structure was heated at 19 ° C for 2 minutes to dazzle low-melting short fibers to bond high-strength PET long fibers. After cooling, the mesh structure solidified and formed a geogrid. Table 1 A comparison of the relevant physical properties of the commercial geogrid and the geogrid of the embodiment of the present invention is shown. Both geogrids in the table have the same specifications, that is, the nominal strength is 150kN / m.-^ 89.8 .21 correction) (CNS) (\ ---

Claims (1)

6. Scope of patent application 6. Manufacturing method of geogrid, including the following steps, (a) at least one form of high-melting fiber with long weave and at least one form with short fiber The low-melting point fiber is synthesized into a long staple fiber composite yarn, and the melting point of the low-melting point fiber in C is at least lower than the melting point of the high-melting point fiber. (b) weaving the composite yarn into a grid-like fabric; (c) heating the grid-like fabric to melt the low-melting fiber to cover the high-melting fiber; and, (d) cooling the grid-like fabric To form a geogrid. 2. The method according to item 1 of the scope of patent application, wherein the melting point of the low melting point dimension is at least 20 lower than the melting point of the high melting point fiber. C is a method as described in item 1 of the scope of the patent application, wherein the composite yarn, long-melting long fibers and low-melting short fibers are made by composite spinning. The method as described in item 1 of the scope of patent application, wherein the high melting point ester. , Selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, glass fiber, aromatic polyamide (aramid) fiber, polyethylene fiber and carbon fiber. The method described in item 4 of the Nilon Dragon Range: wherein the polyamine fiber 6 is in the method described in ΐΓΠϊΠ1 ', wherein the low-melting point amine copolymer is a group. Attack Page 18 • The method as described in item 6 of the scope of patent application, wherein the polyether base is 425345 6. The scope of patent application is nylon 6 or nylon 66. 8. The method according to item 1 of the scope of patent application, wherein the low-melting fiber is a bicomponent fiber. 9. The method according to item 8 of the scope of the patent application, wherein the bicomponent fiber is a sheath / core fiber or a side by s i d e fiber. 10. The method according to item 1 of the scope of patent application, wherein the composite yarn includes 50 to 70 weight percent of the high melting point fiber and 30 to 50 weight percent of the low melting point fiber. 11. The method according to item 1 of the scope of patent application, wherein the melting point of the high-melting fiber is greater than 150 ° C. 1 2. The method according to item 1 of the scope of patent application, wherein the high-melting woven fabric and the low-melting point fiber are formed into the composite yarn by a co-spinning method. 13. —Manufacturing method of a kind of geotextile grid 'includes the following steps: (a) forming at least one first fiber in the form of long fibers and at least one second fiber in the form of short fibers to form a composite yarn by composite spinning, The melting point of the first fiber is greater than 150. C 'and the melting point of the second fiber is at least 10 lower than the melting point of the first fiber. C; K (b) weaving the composite yarn into a grid-like fabric; (c) heating the grid-like fabric to dissolve and cover the second fiber-the first fiber; and (d) cooling the grid Mesh fabric to form a geogrid. 14. The method according to item 13 of the scope of patent application, wherein the first No. 19 Bin 42534 5 ------ VI. The melting point of the patented fiber is lower than the melting point of the first fiber by 20 ° C 1 5. The method described in item 丨 3 of the patented scope The composite yarn includes a plurality of the first long fibers and a plurality of the second short fibers. 16. The method according to item 13 of the scope of patent application, wherein the composite yarn includes 50 to 70 weight percent of the first fiber and 30 to 50 weight percent of the second fiber. 17. —A synthetic fiber-type geogrid 'comprising a plurality of longitudinal and transverse staggered composite yarns, each of which includes a plurality of first fibers covered with a polymer adhesive resin in a spaced manner, · The synthetic fiber type geogrid is prepared by the following steps: (a) forming a composite yarn in a composite spinning manner by using a plurality of long fiber types of the first fiber and a plurality of short fiber types of the second fiber; Wherein the second fiber is made from the polymer adhesive resin, and the melting point of the first fiber is at least 10 times higher than the melting point of the second fiber. C; (b) weaving the composite yarn into a grid-like fabric; (c) heating the grid-like fabric to melt the second fiber to cover the first fiber; and (d) cooling the grid-like fabric Fabric to form a geogrid. 18. The geogrid as described in item 17 of the scope of the patent application, wherein the first fiber is selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyamide, glass fiber, aromatic The group consists of aramid fibers, polyethylene fibers and carbon fibers. 19. The geogrid as described in item 17 of the scope of patent application, wherein the second fiber is selected from the group consisting of polyethylene, polypropylene, polyester copolymer, polyamide Page 425 345 Page 21