1.Types and production process of Geotextile:
Geosynthetics, as a new kind of geotechnical engineering material, can be made into various kinds of products with natural or artificial synthetic polymers (plastics, chemical fiber, synthetic rubber, etc.) as raw materials, which can be placed inside, on the surface or between layers of soil to strengthen (reinforce) or protect the soil.
The main types of geosynthetics include geotextiles, geogrids, geotextiles, geomembranes, geocell, bentonite pads (GCL), geopipes, and geotechnical foam.
At present, as an important variety of geotechnical materials, geotextile has been widely used in various fields of highway, railway, water conservancy, power, construction, seaport, mining, military industry, environmental protection and other projects.
1.1 Types of Geotextile:
Geotextile is a kind of permeable geosynthetic material, which is made of polymer fiber by hot pressing, needling, cementation and weaving, also known as geotextile, including weaving, nonwovens and other types.
Woven geotextiles include products produced by weaving (plain weaving, circular weaving), weaving (plain weaving, twill weaving), knitting (warp knitting, sewing) and other production processes.
Nonwoven geotextiles include products produced by mechanical reinforcement (needling method, water pricking method), chemical bonding (spraying method, impregnation method), thermal bonding (hot rolling method, hot air method) and other production processes.
In engineering application, geotextile can be used alone or combined with geogrid, geomembrane, geonet and other geosynthetics.
2.The Development of China Geotextile Industry :
The woven geotextile appeared in the 1960s, which is characterized by high strength, high cost, poor filter and drainage functions, and has limitations in engineering application.
The nonwoven geotextile began to be used in the engineering entity in the late 1960s in China. Although China’s nonwovens industry started late, its development speed is very fast.
2.1. The Archivement and Problems of China Geotextile Industry:
The high-performance raw materials give the products high strength and durability, and the advanced production technology gives the products good functions, which makes its application scope expand continuously.
Especially in the past 30 years, with the promotion of needled punched nonwovens geotextile and spunbonded nonwovens geotextile fabrics, the application field of nonwovens is more extensive than that of woven geotextiles, and it has developed rapidly. China has developed into a large nonwovens production country in the world, and gradually moves towards a strong production country.
From the perspective of geotextile production equipment, production technology and product quality, China’s Polyester geotextile has reached the world’s advanced level. However, as the main development direction of the industry, the production technology and products of high-strength and aging resistant geotextiles have not made a significant breakthrough in China.
2.2. Polypropylene Spunbond Geotextile Nonwoven Fabric in China and Other Countries:
In developed countries in Europe and America, high-strength polypropylene filament spunbond geotextile has accounted for 30% – 40% of the geotextile industry output, and even reached 50% in some countries. Overseas famous enterprises producing polypropylene spunbond geotextile include polyfelt company, which is located in Malaysia and affiliated to Dutch tencate company.
Compared with the developed countries, China’s high-strength polypropylene filament spunbond needle punched geotextile has lagged behind. In recent years, tiandingfeng nonwovens Co., Ltd. has successfully developed the production technology of high-strength coarse denier polypropylene spunbond needle punched nonwovens in cooperation with Italy’s fare (Farui) company, and has realized localization.
Its technical index has reached and exceeded the product index of polyfelt company, which has changed the situation of foreign monopoly of the technology and that almost all domestic filament spun-bond fabrics are PET Filament Nonwoven Geotextile. It ends the long history of China’s engineering application relying on imported polypropylene spunbonded needle punched geotextiles. It can be predicted that the geotextile market will continue to grow rapidly in the future, and polypropylene nonwoven geotextile will certainly become one of the trend directions of the development of China’s geotextile industry.