KR100536737B1 - A plastic matter having grid form and method for producing the same - Google Patents

Abstract

The present invention relates to a lattice-shaped plastic structure used for geogrids, fences, light shielding films and the like, and a method of manufacturing the same. The lattice-shaped plastic structure of the present invention is disposed in parallel in the radial direction at a predetermined interval, a plurality of slopes in which the high melting point fibers are reinforced in the resin formed by melting the low melting point thermoplastic fibers; And a plurality of weft yarns arranged in parallel in a direction upward at a predetermined interval and having a high melting point fiber reinforced in a resin formed by melting low melting point thermoplastic fibers. The intersecting contact regions are fixed by melting the low melting thermoplastic fibers of the warp yarn and the low melting thermoplastic fibers of the weft yarn. The lattice-shaped plastic structure according to the present invention is not only excellent in physical properties such as elongation, but also can be manufactured by a simple method, and thus economical.

Description

A plastic matter having grid form and method for producing the same

The present invention relates to a lattice-shaped plastic structure used for geogrids, fences, light shielding films and the like, and a method of manufacturing the same.

The grid-like plastic structure is used as a fence, a light shielding film, etc. in addition to the geogrid used for retaining wall reinforcement, slope reinforcement, ground reinforcement, etc. in civil engineering.

Grid-like plastic structures typically require high tensile strength, low tensile strain and creep deformation characteristics, as well as properties such as construction resistance, friction characteristics, and shape stability. In general, a method of manufacturing a lattice plastic structure is a method of injecting or extruding a plastic, punching holes at predetermined intervals, and then stretching the film in one or two axes. The lattice-like plastic structure using the injected plastic is inferior in tensile strength and difficult to manufacture in a continuous process, and is restricted in shape in size and shape. In addition, a technique for producing rigid plastic geogrids as lattice plastic structures using extruded plastics (see GB2266540, USP4374798, EP0374365A, GB2256164A) is known, which is extruded from high-density polyethylene or polypropylene and perforated at regular intervals. Next, it is made through the process of overlapping the plastic stretched in the transverse direction of the machine together with the uniaxial or biaxial stretching process. The rigid plastic geogrid made in this way is excellent in friction, drawing, chemical resistance and weather resistance, but when a load of 10 tons or more is added, there is a problem that the stability is lowered due to the high elongation in the inclined direction.

Textile geogrids used complementarily or competitively with plastic geogrids are made by weaving lattice-shaped fabrics using high-strength fibers and then coating them with polyvinylchloride, bitumen, acrylic, latex, and rubber-based resins. The textile geogrid manufactured in this way is excellent in tensile strength and creep characteristics because of the use of high strength fibers, but the friction resistance is poor, and the manufacturing process is complicated and economically undesirable.

On the other hand, WO 99/28563 discloses a method for producing a geogrid bonded in a lattice form using a fiber reinforced polymer strip as a radial strip and a thermoplastic polymer resin strip as an upward strip. In the above-mentioned patent, the geogrid is described as extruded and inserted thermoplastic polymer resin while the radial fiber-reinforced polymer strip is moving to bond while forming the upward strip, and the fiber-reinforced polymer strip can be inserted into the upward strip. have. However, when the fiber reinforced polymer strips are bonded in this manner, the reinforcing fibers present in the polymer are damaged and the physical properties thereof are degraded. Full adhesion is not achieved.

Therefore, the technical problem to be achieved by the present invention is to solve the problems of the prior art, to provide a lattice-shaped plastic structure having high economical properties such as elongation, and can be manufactured by a simple method.

In addition, another technical problem to be achieved by the present invention is to provide a manufacturing method capable of producing a large amount of the above-described lattice-shaped plastic structure at low cost.

In order to solve the above technical problem, the present invention is arranged in parallel in the radial direction at a predetermined interval, a plurality of inclination in which the high melting point fibers are reinforced inside the resin formed by melting the low melting point thermoplastic fibers; And a plurality of weft yarns arranged in parallel in a direction upward at a predetermined interval and having a high melting point fiber reinforced in a resin formed by melting low melting point thermoplastic fibers. Intersecting contact regions provide a lattice-like plastic structure in which a resin formed by melting inclined low melting thermoplastic fibers and a low melting thermoplastic fiber of the weft yarn are fused together and fixed.

In the plastic structure of the present invention, preferred combinations (A, B) of the low melting thermoplastic fibers (A) and the high melting fibers (B) constituting the warp and weft yarns are (polyolefin fibers, polyester fibers) and (polyolefin fibers). , Polyamide fibers), (polyolefin fibers, carbon fibers), (polyolefin fibers, cotton spun fibers), (polyolefin fibers, glass fibers) and the like.

The above-described lattice-shaped plastic structure comprises the steps of: (a) combining the low-melting thermoplastic fibers and the high-melting fibers to prepare a conjugated twisted composite fiber; (b) weaving or knitting into a lattice-shaped plastic structure such that the conjugated twisted conjugate fibers cross each other as warp and weft yarns, respectively; (c) the warp and weft yarns constituting the lattice-like plastic structure so that the low-melting thermoplastic fibers can be melted to cover the high-melting fiber and at the same time the contact areas where the warp and weft intersect are fused and fixed together. Heat-treating at a temperature higher than the melting point of the low melting point thermoplastic resin and lower than the melting point of the high melting point fiber while maintaining the tension; And (d) cooling the heat-treated plastic structure to a temperature lower than the melting point of the low melting thermoplastic resin.

In addition, the above-described lattice-shaped plastic structure comprises the steps of: (a) preparing a covering composite fiber covered with a low melting thermoplastic fiber on the surface of the high melting point fiber; (b) weaving or knitting into a lattice-shaped plastic structure such that the covering composite fibers intersect each other as warp and weft yarns, respectively; (c) the warp and weft yarns constituting the lattice-like plastic structure so that the low-melting thermoplastic fibers can be melted to cover the high-melting fiber and at the same time the contact areas where the warp and weft intersect are fused and fixed together. Heat-treating at a temperature higher than the melting point of the low melting point thermoplastic resin and lower than the melting point of the high melting point fiber while maintaining the tension; And (d) cooling the heat-treated plastic structure to a temperature lower than the melting point of the low melting thermoplastic resin.

Thus prepared, the lattice-shaped plastic structure according to the present invention is not only excellent in physical properties such as elongation, but also can be manufactured by a simple method, and thus economical.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

1 is a plan view showing a grid-shaped plastic structure according to an embodiment of the present invention. Referring to FIG. 1, the plastic structure 10 of the present invention includes a plurality of warp yarns 1 arranged in parallel in the radial direction at predetermined intervals, and a plurality of weft yarns 2 arranged in parallel in the upward direction at predetermined intervals. Has a lattice shape.

As used herein, the term "radial direction" and "upward direction" may be understood by those of ordinary skill in the art to mean a first direction and a second direction that cross each other. . However, according to the present invention, the radial direction and the upper direction are not limited to crossing at right angles to each other, and as described below, the angle is appropriately set within the range in which the plastic structure can distribute the load and exhibit sufficient pull force. Can be. In addition, although the description of the intersection point for the upward direction with respect to the radial direction in the present specification, this should be interpreted to be equally applicable to the upward direction as a relative concept.

According to the present invention, the warp yarns and the weft yarns 2 and 1 have a structure in which fibers 4a and 4b having high melting points are reinforced inside resins 3a and 3b formed by melting thermoplastic fibers having low melting points, respectively. As used herein and in the claims, the term 'low melting point thermoplastic fiber' refers to fibers having a lower melting point than 'high melting point fibers'. 'High melting fiber' is not only a thermoplastic fiber having a higher melting point than a 'low melting point thermoplastic fiber', but also a fiber which is decomposed before melting, and means a fiber whose decomposition temperature is higher than the melting point of the 'low melting point thermoplastic fiber'. Melting point The melting point when the fiber is a fiber which decomposes before melting means a decomposition temperature. In addition, the term 'fiber' used in the present specification and claims is not only manufactured in the form of yarn by extrusion spinning thermoplastic resin, but also injected into a film form to produce it in the form of yarn, or by spinning short fibers It is meant to include things made in the form of yarn. Such low melting thermoplastic fibers and high melting fibers include polyester fibers, nylon fibers, polyethylene fibers, polypropylene fibers, acrylic fibers, polyvinyl chloride fibers, ABS fibers, polystyrene fibers, and the like. You can choose to combine them properly, for example, Preferred combinations (A, B) of the low melting thermoplastic fibers (A) and the high melting fibers (B) include (polyolefin fibers, polyester fibers), (polyolefin fibers, polyamide fibers), (polyolefin fibers, carbon fibers), ( Polyolefin fibers, cotton spun fibers), (polyolefin fibers, glass fibers) and the like.

2 is a cross-sectional view of the plastic structure 10 of the present invention shown in FIG. Referring to FIG. 2, the contact areas where the warp yarn 2 and the weft yarn 1 intersect each other forming the plastic structure are formed of the resin 3b and the weft yarn 1 formed by melting the low melting thermoplastic fibers of the warp yarn 2. The resins 3a formed by melting low melting point thermoplastic fibers are fused together. Accordingly, since the crossed warp yarns and the weft yarns are fixed to each other, the shape stability of the plastic structure with respect to the vertical load is maintained, thereby improving the construction resistance.

The plastic structure of the present invention may be manufactured in the form of a lattice in which all the weft yarns 1 are located on the top surface of the warp yarn 2, or vice versa, as shown in FIG. 3a to 3c, the warp and weft yarns may be manufactured to cross up and down in various forms such as plain weave or twill weave. Further, in the plastic structure of the present invention, the cross-sectional shape of the high melting point fiber is preferably circular, but can be changed by changing the shape of a plurality of fibers and the shape of the extrusion die of the resin.

As described above, the warp yarn and the weft yarn in which the inside of the resin formed by melting the low melting point thermoplastic fiber is reinforced with the fiber exhibit high tensile strength, low tensile strain and creep deformation characteristics, and construction resistance is improved. The total cross sectional area of the high melting point fibers constituting the warp or weft yarn is the warp or weft total cross sectional area in order to fully exhibit the function of the reinforcing high melting point fiber and to sufficiently protect the reinforcing fiber by the resin formed by melting the low melting point thermoplastic fiber. It is preferable to keep at 5 to 85% of the ratio.

The plastic structure according to the present invention described above can be manufactured according to the following method.

First, the low melting thermoplastic fiber 5 and the high melting point fiber 4c are twisted together to prepare a composite twisted yarn 20 (see FIG. 4A). Alternatively, a covering composite fiber 30 may be prepared in which the low melting thermoplastic fiber 6 is covered on the surface 4d of the high melting point fiber instead of the twisted composite fiber 20 (see FIG. 4B). Ply twisted composite fiber can be prepared using a conventional weaving machine and a twisting machine or a twisted yarn, and the covering composite fiber can also be easily prepared using a conventional covering yarn.

Subsequently, the interwoven yarn or covering composite fiber is interwoven with each other as warp and weft yarns, respectively, to weave or knit the lattice-like plastic structure. Weaving or knitting may also be used conventionally used looms or knitting machines, the shape of the weaving or knitting may have a variety of modifications in addition to the form shown in Figures 1, 3a to 3c.

Then, the heat treatment is performed at a temperature higher than the melting point of the low melting point thermoplastic resin and lower than the melting point (or decomposition temperature) of the high melting point fiber while keeping the warp and the weft forming the lattice-shaped plastic structure in a tensioned state. Accordingly, the low melting thermoplastic fibers forming the warp and weft are melted to cover the high melting point fiber, and at the same time, the contact areas where the warp and the weft cross are fused and fixed together. That is, with the application of heat, first, heat shrinkage of the low-melting thermoplastic fiber occurs, and the high-melting fiber becomes a loop, followed by melting of the low-melting thermoplastic fiber. Since the warp and weft yarns are kept in a tense state (by grip or pin type fixing mechanism or winding tension), the high melting point fibers are linearly laid out so that the low melting point thermoplastic fibers are melted and formed in the center of the resin. The contact areas where the warp and weft yarns cross each other are fused with molten resin (formed by melting low melting point thermoplastic fibers) present on the outer surface of each of the warp and weft yarns.

Finally, when the heat-treated plastic structure is cooled to a temperature lower than the melting point of the low melting point thermoplastic resin, the molten low melting point thermoplastic resin solidifies to fix the warp yarn contact regions.

In the above-described method for producing a plastic structure, the low melting point thermoplastic fiber that is twisted or covered with the high melting point fiber is sufficiently reinforced by the resin formed by melting the low melting point thermoplastic fiber while fully exerting the function of the reinforced high melting point fiber. In order to be protected, it is preferable to adjust the twisted yarn or covering ratio such that the total cross sectional area of the high melting point fibers constituting the warp or weft yarn is maintained at 5 to 85% of the total cross sectional area of the warp or weft yarn.

Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present invention can be modified in many different forms, the scope of the present invention should not be construed as limited to the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

Hereinafter, the physical properties of the lattice-shaped plastic structure prepared according to Examples and Comparative Examples were measured by the following measuring method.

* Weight per unit area: ASTM D 5261

* Wide tensile strength: ASTM D 4595

* Single rib strength: GRI Test Method GG1

* Contact Strength: GRI GG2

* Limit creep strength: ASTM D 5262

* Long-term Design Strength: GRI Test Method GG4

<Example 1>

According to the manufacturing method of the present invention, a 3,000-denier high-strength polyester filament yarn and 15000denier polypropylene yarn were twisted together and woven into a lattice shape of FIG. 1. During weaving, the rib spacing was 22 mm and weaved with two theodolites per rib. After weaving, the fabric was heat-set for 20 seconds by passing the heater channel at 150 degrees to 160 degrees.

The number of ribs per unit area, weight per unit area, wide tensile strength, single rib strength, contact strength, limit creep strength, and long-term design strength of the manufactured composite geogrid are shown in Table 1.

<Example 2>

In accordance with the manufacturing method of the present invention, 3,000 denier high-strength polyester filament yarn was covered with 3000 denier polypropylene yarn to weave in the lattice shape of FIG. 1, when weaving, the rib spacing was 22 mm and the two weft yarns per rib were woven. It was. After weaving, the fabric was heat-set for 20 seconds by passing the heater channel at 150 ~ 160 degrees.

The number of ribs per unit area, weight per unit area, wide tensile strength, single rib strength, contact strength, limit creep strength, and long-term design strength of the manufactured composite geogrid are shown in Table 1.

<Comparative Example 1>

The sheet was prepared by extrusion using a polyolefin-based resin, and then a rigid geogrid (Tenax Co., Ltd.) prepared by drilling a hole at predetermined intervals and stretching in one or two axes was purchased.

The number of ribs per unit area of rigid geogrid, weight per unit area, wide tensile strength, single rib strength, contact strength, limit creep strength, and long-term design strength are shown in Table 1.

<Comparative Example 2>

The lattice-shaped soft geogrid of FIG. 1 was manufactured by a method of manufacturing a conventional soft geogrid coated with a polyvinyl chloride resin after weaving a lattice-shaped fabric using 3,000 denier high-strength polyester filament yarns.

The number of ribs per unit area, weight per unit area, wide tensile strength, contact strength, limit creep strength, and long-term design strength of the manufactured flexible geogrids are measured and shown in Table 1.

division Number of ribs per unit area Weight per unit area (g / m ² ) Wide tensile strength (kN / m) Single rib strength (kN / m) Contact strength (kN / m) Limit creep strength (kN / m) Long term design strength (kN / m) Example 1 40 410 18.8 0.75 48.4 43.2 24.2 Example 2 40 430 19.1 0.80 49.1 44.1 24.4 Comparative Example 1 27 360 13.8 0.51 43.6 35.4 14.3 Comparative Example 2 40 330 24 0.48 21.3 41.7 20.1

As described above, the lattice-shaped plastic structure according to the present invention is not only excellent in physical properties such as elongation but also excellent in economic efficiency, and thus may be usefully used as a plastic plate-like structure such as geogrid, fence, light shielding film, and filter. In addition, the plastic structure of the present invention can be easily and easily manufactured using existing looms, twisted yarns, heat treatment machines, etc., thereby reducing the cost of preparing production facilities.

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to

1 is a plan view showing a grid-shaped plastic structure according to an embodiment of the present invention.

2 is a cross-sectional view of the plastic structure of FIG.

3a to 3c are modified examples of the lattice-shaped plastic structure according to the present invention.

Figures 4a to 4b are schematic diagrams showing the composite twisted fiber and the covering composite fiber respectively used in the manufacturing method according to the present invention.

Claims (6)

A plurality of inclinations disposed in parallel in the radial direction at predetermined intervals and having a high melting point fiber reinforced in the resin formed by melting the low melting point thermoplastic fiber; And A lattice-shaped plastic structure formed of a plurality of weft yarns disposed in parallel in a direction upward at a predetermined interval and having high melting point fibers reinforced in a resin formed by melting low melting point thermoplastic fibers, The contact region where the warp and weft cross each other is a lattice-shaped plastic structure in which a resin formed by melting a low melting point thermoplastic fiber and a low melting thermoplastic fiber of the weft are fused together and fixed. The combination (A, B) of the low melting thermoplastic fiber (A) and the high melting point fiber (B) comprises (polyolefin fiber, polyester fiber), (polyolefin fiber, polyamide fiber), (polyolefin fiber). , Carbon fiber), (polyolefin fiber, cotton spun fiber) and (polyolefin fiber, glass fiber) any one selected from the group consisting of a lattice-shaped plastic structure. The lattice-shaped plastic structure according to claim 1, wherein the total cross sectional area of the high melting point fibers constituting the warp or weft yarn is 5 to 80% of the total cross sectional area of the warp or weft yarn. (A) a step of plying the low-melting thermoplastic fibers and high melting point fibers to prepare a conjugated twisted fiber; (b) weaving or knitting into a lattice-shaped plastic structure such that the conjugated twisted conjugate fibers cross each other as warp and weft yarns, respectively; (c) the warp and weft yarns constituting the lattice-like plastic structure so that the low-melting thermoplastic fibers can be melted to cover the high-melting fiber and at the same time the contact areas where the warp and weft intersect are fused and fixed together. Heat-treating at a temperature higher than the melting point of the low melting point thermoplastic resin and lower than the melting point of the high melting point fiber while maintaining the tension; And (d) cooling the heat-treated plastic structure to a temperature lower than the melting point of the low-melting thermoplastic resin. (a) preparing a covering composite fiber having a low melting thermoplastic fiber covered on a surface of the high melting point fiber; (b) weaving or knitting into a lattice-shaped plastic structure such that the covering composite fibers intersect each other as warp and weft yarns, respectively; (c) the warp and weft yarns constituting the lattice-like plastic structure so that the low-melting thermoplastic fibers can be melted to cover the high-melting fiber and at the same time the contact areas where the warp and weft intersect are fused and fixed together. Heat-treating at a temperature higher than the melting point of the low melting point thermoplastic resin and lower than the melting point of the high melting point fiber while maintaining the tension; And (d) cooling the heat-treated plastic structure to a temperature lower than the melting point of the low-melting thermoplastic resin. The combination (A, B) of the low melting point thermoplastic fiber (A) and the high melting point fiber (B) comprises (polyolefin fiber, polyester fiber), (polyolefin fiber, polyamide fiber). A method for producing a lattice-shaped plastic structure according to claim 1, which is any one selected from the group consisting of (polyolefin fibers, carbon fibers), (polyolefin fibers, cotton spun fibers) and (polyolefin fibers, glass fibers).