KR20000028000A - Composite geo-textile - Google Patents

Abstract

PURPOSE: A Geo-textile as a floor material for a reclaimed land is provided to have excellent dynamic physical property for being stable from acid, alkali, ultra violet rays, and temperature while being produced at low production cost. CONSTITUTION: A certain part of a Geo-textile exposed to ultra violet rays while loading waste is made of polyester non woven fabric layer containing carbon black. Herein, the weight of the polyester non woven fabric layer containing carbon black is lighter than polypropylene non woven fabric layer positioned under the polyester non woven fabric layer. The weight of the polyester non woven fabric layer containing carbon black is 150-400g/m2. The transformation by ultra violet rays of the polypropylene non woven fabric layer not containing carbon black is repressed by the polyester non woven fabric layer containing carbon black until completing the filling for repressing the deterioration of the physical property caused by the rise of temperature and the seepage water from wastes.

Description

Hybrid Geotextile

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to forge (hereinafter referred to as 'geotextile') used as flooring material in a landfill, and more particularly, to geotextiles in which polypropylene and polyester are combined.

Geotextile is one of the high-molecular materials for civil engineering. It is used as the flooring material of waste landfills to support the landfilled wastes and to drain leachate or sewage generated from wastes. For example, leachate generated during landfilling of food wastes becomes very acidic due to infiltration of rainwater, snow, etc., and in some cases alkaline. In addition, due to the decay of garbage, the exposure temperature is increased to about 80 ℃ in the summer when the temperature is high, and the longer the landfill period is exposed to ultraviolet rays, sunlight, and the like. Therefore, in the case of geotextiles applied to landfills, materials of good physical resistance to this exposure environment should be used.

In general, geotextiles are divided into woven geotextiles and nonwoven geotextiles.

Woven geotextiles are made of filament yarns or spun yarns that cross light and weft yarns at right angles. The basic tissue is divided into plain weave, twill weave, and runner weave yarns. Use it. Polyester and polypropylene fiber are used as a raw material of a fiber.

Non-woven geotextiles are formed by randomly arranging long fibers or short fibers and bonding them. For short fibers, needle punching process is used. Joining is done by punching or thermal fusion. In general, the constituent fibers form a disordered intertwined structure, excellent mechanical and hydraulic properties, and polypropylene and polyester fibers are mainly used.

Polypropylene-based nonwoven geotextiles are mainly manufactured by needle punching, which have stable properties to acids and alkalis, but cause brittleness when exposed to ultraviolet rays and sunlight, resulting in significant physical property degradation. When carbon black is mixed with polypropylene to improve stability to ultraviolet rays, the manufacturing process of the fiber is very difficult and the manufacturing cost is very high.

On the other hand, in the case of polyester, it is not difficult to produce fibers by mixing carbon black, and the polyester nonwoven fabric containing carbon black has better mechanical performance and stability against ultraviolet rays than polypropylene. Due to the molecular structure, when exposed to acid or alkali and high ambient temperature, it causes hydrolysis and decreases the tensile strength by almost 70%. In case of food waste, leachate shows strong acidity and heat generated by decay There is a problem in using in the landfill environment condition that causes an increase, and the manufacturing cost is high, it is uneconomical.

Accordingly, an object of the present invention is to provide a new geotextile having excellent mechanical properties as a flooring material of a landfill and not only being stable in acids, alkalis, ultraviolet rays, temperatures, etc., but also producing a low production cost.

In the research of the present inventors to solve the above problems, in the process of landfilling, intensive water resistance to ultraviolet rays is increased, and after the landfill is completed, the leachate and leachate are not affected by ultraviolet rays. If the physical properties can be prevented from being embrittled by temperature, the present invention has been completed by focusing on providing a geotextile in which the problems of the prior art as described above can be solved.

According to the present invention solving the above problems, there is provided a geotextile having a structure in which a carbon black-containing polyester nonwoven layer is laminated on a carbon black-free polypropylene nonwoven layer.

Hereinafter, the present invention will be described in more detail.

The geotextile of the present invention has a carbon black-containing polyester nonwoven layer in which portions exposed to ultraviolet rays when the garbage is loaded. Since the main purpose of such a carbon black-containing polyester nonwoven layer is to minimize physical embrittlement against ultraviolet rays until the completion of embedding, the weight is preferably lower than that of the polypropylene nonwoven layer to be placed thereunder. Typically, carbon black-containing polyester nonwovens have a strength retention of at least 70% / 500 hours. The weight of the carbon black-containing polyester nonwoven layer is suitably 150-400 g / m 2. If the weight of the polyester nonwoven layer is less than this, the geotextile's resistance to ultraviolet rays is somewhat insufficient, and if more, the economic disadvantage is more. However, this production cost problem will be solved by recycling the waste polyester.

On the other hand, the carbon black-free polypropylene nonwoven layer is prevented from being denatured by ultraviolet rays at least until the landfill is completed by the carbon black-containing polyester nonwoven layer deposited thereon. It acts to suppress the deterioration of physical properties. The preferred weight of the carbon black-free polypropylene nonwoven layer is 600-1,200 g / m 2.

The composite geotextile of the present invention may be prepared by compounding a polyester nonwoven fabric and a polypropylene nonwoven fabric prepared in separate processes by needle punching, or may be manufactured by needle punching in a web state. The latter of the two methods is preferable because the weight can be kept constant.

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited by the following examples.

Evaluation of the stability of the ultraviolet irradiation of the geotextile prepared in the following Examples and Comparative Examples was performed by the following method.

※ Evaluation of UV Stability of Geotextiles:

-Assess the modification of geotextiles exposed to UV and water according to ASTM D 4355.

Light source: Xenon arc (Type BH)

-Water and UV irradiation cycle: 18 minutes after 102 minutes of UV irradiation

External filter: borosilicate

Illumination time: 500 hours

-Black panel temperature: 63 ± 3 ℃

-Interpretation of results: Tensile strength in the length and width directions before and after UV dimming for 500 hours is measured, and the difference is calculated as a percentage and expressed as strength retention.

Example 1

The web was made from industrial polyester (PET) short fibers blended with carbon black, and the web was made from polypropylene (PP) short fibers without carbon black. These webs were needle punched to form a composite geotextile in which a 300 g / m 2 polyester nonwoven layer was formed on the upper layer and a 700 g / m 2 polypropylene nonwoven layer was formed on the lower layer. Evaluation of the stability of the prepared geotextiles to ultraviolet rays was performed. The results are shown in Table 1 below.

Example 2

The same procedure as in Example 1 was repeated except that the weight of the polyester nonwoven fabric layer was 1200 g / m 2 on the upper layer and the weight of the polypropylene nonwoven fabric layer was 1,000 g / m 2 on the lower layer. The measurement results are shown in Table 1 below.

Comparative Example 1

The weight of the polyester nonwoven layer was 1,000 g / m 2, and the same procedure as in Example 1 was repeated except that the polypropylene nonwoven layer was not constituted. The measurement results are shown in Table 1 below.

Comparative Example 2

The weight of the polypropylene nonwoven layer was 1,000 g / m 2, and the same procedure as in Example 1 was repeated except that the polyester nonwoven layer was not constituted. The measurement results are shown in Table 1 below.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 PET / PP weight ratio 300/700 200/1000 1000/0 0/1000 Tensile strength (㎏f) Before ultraviolet irradiation Longitudinal direction 260.97 296.70 179.95 250.75 Width direction 324.30 420.70 240.15 397.95 After ultraviolet irradiation Longitudinal direction 217.65 286.90 200.01 186.90 Width direction 275.30 337.75 238.50 193.90 Strength retention rate (%) Longitudinal direction 83.4 96.7 88.8 75.5 Width direction 84.9 80.3 93.0 49.7

As can be seen from the above examples and comparative examples, the composite geotextile according to the present invention is excellent in UV stability, stability against acid and alkali under high temperature conditions, and is produced because of high ratio of inexpensive polypropylene. There are advantages such as low cost.

Claims (2)

A geotextile, wherein the composite geotextile has a structure in which a carbon black-containing polyester nonwoven layer is laminated on a carbon black-free polypropylene nonwoven layer. The composite geotextile of claim 1, wherein the weight of the carbon black-free polypropylene nonwoven layer is 600-1,200 g / m 2, and the weight of the carbon black-containing polyester nonwoven layer is 150-400 g / m 2. style.