Filament nonwoven geotextile production process and materials
Filament nonwoven geotextile is a high-performance geotextile. It has good mechanical properties, water permeability, durability and environmental protection characteristics through a specific production process and the selection of high-quality fiber raw materials. Therefore, it has been widely used in civil engineering, transportation infrastructure, environmental protection engineering and other fields. The production process and material selection of filament nonwoven geotextile directly determine the performance and application effect of its products. This article will discuss in detail the production process, common materials, application fields and advantages and disadvantages of filament nonwoven geotextile.
- Overview of filament nonwoven geotextile
Filament nonwoven geotextile is a geotextile formed by long fibers through non-woven processes (such as needle punching, thermal bonding, chemical bonding, etc.). Long fibers have higher strength and better stability than short fibers, so filament nonwoven geotextiles are usually used in engineering projects that require high bearing capacity and long-term stability. It is mainly used in isolation, reinforcement, drainage and protection projects, which can effectively improve the stability of the soil and the safety of the project.
- Production process of filament non-woven geotextile
The production process of filament non-woven geotextile usually includes the following main steps:
2.1 Spinning process
The production of filament non-woven geotextile starts with the selection of raw materials, usually using synthetic fiber materials such as polyester (PET) and polypropylene (PP). First, these polymer raw materials are selected to be made into filament fibers through the melt spinning process. The characteristic of filament fibers is that they are longer than short fibers, so they can form a more stable fiber mesh structure in the geotextile and improve the mechanical properties of the geotextile.
Melt spinning: The polymer is heated to a molten state, and the molten polymer fibers are extruded through a spinneret to form continuous filaments.
Fiber finishing: The filament fibers after spinning need to be cleaned, cut and sorted to ensure the uniformity of the fibers and the stability of their performance.
2.2 Fiber laying and web formation
After the fibers are finished, they need to be laid into a web through different web forming processes. Common web-forming methods include:
Dry web-forming: The fibers are blown onto the mesh frame of the web-forming machine through air flow to form a loose fiber web. Dry web-forming is simple and environmentally friendly, but the fiber bonding is poor.
Wet web-forming: The fibers are suspended in an aqueous solution and the fiber web is formed by water flow. It is suitable for some geotextiles that require a particularly fine and uniform mesh structure.
Needle-punching: The fibers are interwoven with each other and formed into a solid fiber web through the puncture of a series of needles using a needle-punching machine. This method is often used to improve the strength and stability of geotextiles.
2.3 Fiber interweaving and bonding
After the fibers are webbed, the strength and stability of the geotextile need to be further improved by interweaving or bonding. Common interweaving and bonding methods include:
Needle reinforcement: The long fibers are punctured into a web by a needle-punching machine, and the strength of the fabric is improved by the interweaving of the fibers. Needle punching can make the filament non-woven fabric tighter and maintain a certain degree of water permeability. It is usually used in projects that require high strength and durability of geotextiles.
Thermal bonding: The fibers are bonded at high temperatures by hot pressing or hot air heating to form a strong mesh structure. The advantages of this method are energy saving and improved production efficiency.
Chemical bonding: Use adhesives to bond the fibers together to form a strong geotextile. Chemical bonding is usually used in projects with low requirements for water permeability or geotextiles that need to enhance anti-corrosion functions.
2.4 Post-treatment and finishing
The produced filament non-woven geotextiles also need to undergo a series of post-treatment processes, including:
Forming treatment: The geotextile is kept in a stable shape through high-temperature shaping treatment to prevent it from deformation.
Coating treatment: Sometimes, in order to improve the anti-ultraviolet and corrosion resistance of the geotextile, a protective coating such as a fluoride coating is applied to the surface.
Cutting and packaging: According to the size required by the customer, the filament non-woven geotextile will be cut into the required size, then packaged and ready for shipment.
- Material of filament non-woven geotextile
The material of filament non-woven geotextile is generally made of high molecular polymers such as polyester (PET) and polypropylene (PP). The selection of these materials directly affects the performance of geotextile.
3.1 Polyester fiber (PET)
Polyester fiber (Polyester) is one of the most commonly used raw materials in PET filament non-woven geotextile. It has good tensile strength, corrosion resistance, UV resistance and heat resistance. The advantage of polyester fiber is that it has a long service life and is suitable for use in various environments, especially in infrastructure fields such as civil engineering, transportation, dams, etc.
Advantages:
- Good mechanical properties and can withstand large external forces.
- High strength, good durability, and adaptable to harsh environments.
- Strong UV resistance, suitable for long-term outdoor use.
3.2 Polypropylene fiber (PP)
Polypropylene (Polypropylene) fiber is another commonly used raw material for PP filament non-woven geotextile. Polypropylene has a lighter weight and better chemical stability, and is widely used in some occasions with lower requirements or light engineering.
Advantages:
- Compared with polyester fiber, polypropylene fiber is cheaper and suitable for large-scale use.
- It has good resistance to chemical corrosion.
- It is light and easy to transport and construct.
3.3 Other materials
In addition to polyester, polypropylene and nylon, other materials such as aramid and glass fiber can also be used in the production of filament non-woven geotextiles. These materials are generally used in special projects, such as projects that require special resistance to high temperature, corrosion or impact.
- Application fields of filament non-woven geotextiles
Filament non-woven geotextiles are widely used in many fields, especially in civil engineering, environmental protection, water conservancy, transportation and other construction projects, playing an important role.
4.1 Civil engineering
In civil engineering, filament non-woven geotextiles are mainly used for foundation reinforcement, roadbed stabilization, foundation isolation and other functions. It can effectively isolate different soil layers, prevent soil from mixing with each other, and maintain the stability of the structure.
4.2 Traffic Engineering
In traffic engineering such as highways, railways, and airports, filament non-woven geotextiles are often used for foundation treatment, road reinforcement, and drainage. It can enhance the strength of the roadbed, prevent soil settlement and slippage, and ensure the safety and long-term use of transportation facilities.
4.3 Environmental Engineering
In environmental engineering such as landfills and sewage treatment, filament non-woven geotextiles have anti-seepage and isolation effects, which can prevent the spread of harmful substances and protect groundwater sources and the surrounding environment. It can also be used as a filter layer or drainage