After several years of development, the production capacity of my country's polyester filament geotextile has achieved rapid development, and its equipment level, process technology, and product quality are basically in line with international standards. Polypropylene filament geotextile is still a technological gap in my country.

The industry generally believes that the physical properties of polyester are better than polypropylene. Its stability, heat resistance and aging resistance are better than polypropylene. In fact, polypropylene chips can also be made into polypropylene fiber with compact structure and superior performance through multiple drafts through reasonable process flow, appropriate equipment configuration and processing conditions, and under the conditions of advanced equipment and technical processing. The polypropylene filament geotextile made by net laying, needle punching and consolidation has improved uniformity and strength of the fabric, and all indicators reach the standard of polyester geotextile. Especially when the weight is more than 100g/m2 (industrial geotextiles are mostly more than 200g/m2), the advantages are more obvious. In the case of needle-punching consolidation, because polyester filaments cannot be fully consolidated like polypropylene filaments, polypropylene filaments can form a compact three-dimensional structure after needle-punching, with obvious strength and uniformity Better than polyester filament. On the other hand, polypropylene fiber must be treated with anti-ultraviolet rays to meet the requirements of long-term exposure. However, geotextiles are generally not exposed to the sun or air, and the material is not required to have too high resistance to sunlight. Instead, higher requirements are placed on its corrosion resistance and anti-aging properties. Polypropylene has strong acid and alkali resistance, which is superior to polyester in this respect. It can be used in various geological conditions and environments, such as anti-leakage and anti-corrosion treatment in landfills. For this reason, our country needs a large amount of imported polypropylene geotextile every year.

It is understood that as early as the national "Seventh Five-Year Plan" period, the former Ministry of Textile Industry organized scientific research. Later, due to various reasons, this project was eventually shelved and industrial production was not realized. After more than 20 years of development, my country's polypropylene filament geotextile equipment and products are still in a blank state. There are also many calls in the industry, but the results have been diminished. According to the investigation of the Spunbond Branch, there are a few domestic companies in China, such as Shaoxing Lida Non-woven Fabric Co., Ltd. and Dalian Huayang Chemical Fiber Technology Co., Ltd., which are actively developing. Shaoxing Lida Company aimed at the market gap of my country's polypropylene filament geotextile equipment and products, and independently designed and manufactured a domestic polypropylene filament geotextile production line. The production line has a width of 1.8 meters and is a production line in the pilot stage. Its technology and process are constantly improving. General Manager Shan Jinglian told us that through two years of hard work, Lida has made certain progress in the research and development and process exploration of polypropylene filament geotextiles. Currently, the spinning position has been expanded from 1 to 6 positions. Important breakthroughs have been made in the most difficult technical "bones"-the mixed drafting of polypropylene tows and reciprocating netting. "There is still one kilometer away from the victory of the Long March," Mr. Shan said.

He gave us a detailed introduction to the arduous journey of Lida's research and development of polypropylene filament geotextiles in recent years. "Many places are crossing the river by feeling the stones. There is no more information to learn from, no experience to learn, and many times they are thinking while doing it." Mr. Shan said, "It takes a lot of time, energy and money to invest. Many ideas require Experiments prove that sometimes, the plan has to be changed and the parts and molds have to be reprocessed." We saw that there was a fenced area in front of the polypropylene filament geotextile production line in the production workshop, which was the site office of Shan Jinglian. Sitting in front of the production line equipment, he told us, “Sometimes I just sit in front of the production line, drawing drawings and designing, and instruct employees to revise the plan on site”. It is understood that Lida has many innovations in the production line and product development of polypropylene filament geotextile. For example, for the cooling of the tow, the methods such as ice block cooling, surface cooler cooling, spraying and circulating air cooling have been used successively, and repeated experiments have been performed dozens of times. Another example is to solve the problem of tow winding around the roll, using spray, water spray, electronic air rod, hot rolling, adding antistatic masterbatch and other methods.

Shaoxing Lida Company is the research and development unit of my country's first polyester geotextile production line. Now, under the leadership of Mr. Shan, the company is working towards another higher goal-the polypropylene filament geotextile production line. Shan Jinglian told us that the purpose of the development of this domestic polypropylene geotextile production line is to fill the domestic gap, end the history of my country's single polyester geotextile, contribute to the development of the industry, and find new economic growth points for the enterprise. "On the basis of the current 1.8-meter line, it will be scaled up to a 6-meter production line and finally industrialized." Mr. Shan is full of confidence.

In fact, there are still many ways to go to truly overcome the technical difficulties of polypropylene filament geotextiles. Polypropylene filament processing technology, equipment manufacturing and many other places are different from polyester filament, and there are technical barriers in many aspects. This is also the reason why the polypropylene market geotextile cannot make a breakthrough so quickly. However, polypropylene has good monofilament strength, good hot-melt adhesion, and because of its low specific gravity, polypropylene with the same grammage has 45% more fibers than polyester (saving raw materials and reducing costs). Therefore, The development stamina and cost-effective advantages of polypropylene geotextile are very obvious.

my country has a lot of demand for polypropylene geotextiles in areas such as highway, railway roadbed paving, dam reinforcement, and hazardous material landfills, and there is a lot of room for market development. To realize the localization and industrialization of polypropylene filament geotextile as soon as possible is an urgent and important task for the spunbond nonwoven industry. Fortunately, we have seen the dawn, and it is not far from the advent of polypropylene filament spunbonded needle-punched geotextile.