700gsm PP Polypropylene Nonwoven Geotextile High Strength For Isolation Layer

Ballastless Track Railway Project 700gsm PP Polypropylene Nonwoven Geotextile With CE certificate

Geotextiles are permeable geosynthetic materials made by needling or weaving synthetic fibers. Geotextile is one of the new geosynthetic materials, and the finished product is cloth. Geotextile has excellent filtration, drainage, isolation, reinforcement, protection, with light weight, high tensile strength, good permeability, high temperature resistance, freezing resistance, aging resistance and corrosion resistance.

Using ultra-high-strength polypropylene staple fiber or ES fiber as the main raw material, it is produced by non-woven technology and has the functions of isolation, reinforcement, protection, filtration, drainage, and buffering.
Product specifications: PP100~PP1200, width 2m~6m., length according to user requirements.

Polypropylene geotextile is a key technical material in ballastless track railway projects.

Its application is mainly reflected in the following core areas and technical characteristics:

I. Key Application Scenarios

1. Sliding layer function

Used between CRTS slab track and beam surface, two layers of geotextiles sandwich a layer of HDPE geomembrane (i.e. "two-textile and one-membrane" structure) can reduce the longitudinal stress caused by temperature changes and train loads, prevent deformation of track structure, and extend service life.

2. Isolation layer function

Layed between self-compacting concrete and foundation plate to avoid differences in expansion coefficients, wear and moisture migration caused by direct contact between different materials. For example, 700g/㎡ high-strength polypropylene geotextile is required in CRTSⅢ slab track to meet the China Railway Corporation's "Geotextile for Isolation Layer of High-speed Railway CRTSⅢ Slab Track" standard.

3. Drainage and protection

Polypropylene geotextile has good hydrophobicity and can effectively drain moisture in the track structure, while filtering fine particles to prevent loss and improve roadbed stability. In addition, its acid and alkali resistance can resist corrosion in alkaline environments of concrete and protect the track structure for a long time.

‌Material property requirements

1. Mechanical properties

• Tensile strength: longitudinal/transverse breaking strength ≥11kN/m (CRTSⅡ type lower geotextile has higher requirements).
• Burst strength: ≥4.3kN (700g/㎡ specification).
• Friction coefficient: ≤0.35 to reduce wear and extend life.

2. Durability

• Acid and alkali resistance, mildew resistance: polypropylene fiber has excellent chemical stability and is suitable for long-term exposure to concrete alkaline environment.
• Design life: 700g/㎡ polypropylene geotextile can meet the service requirements of high-speed rail for more than 70 years.

3. Construction adaptability

• Flexible specifications: single roll length ≥32m, width 2.5-2.9m, easy to lay on site.
• Thickness control: the thickness of the lower geotextile is 3.0-3.5mm, and the upper layer is 1.8-2.2mm, which can meet the needs of different structural layers.

Yixing Shenzhou Partial Typical engineering cases for PP Nonwoven Geotextile used in Railway project

1. Suiyu Railway Test Section

Our country used geosynthetics in ballastless track for the first time, verifying the feasibility of polypropylene geotextile in the sliding layer.

2. Beijing-Shanghai High-speed Railway and Wuhan-Guangzhou High-speed Railway

CRTSⅠ/Ⅱ type slab track is widely used, and polypropylene geotextile is used as the key material of the isolation layer and sliding layer.

3. Zhengzhou-Xuzhou Passenger Dedicated Line

CRTSⅢ type track slab was used on a large scale for the first time, with 700g/㎡ high-strength polypropylene geotextile, marking the maturity of domestic production technology.

I   Technical standards and innovation

· Standardized production: China Railway Corporation has set clear indicators such as 700g/㎡ unit area mass and elastic recovery rate to promote the unification of material performance.

· Process innovation: The mechanical properties are uniformed by adjusting the thickness through hot pressing rollers and transverse stretching shaping process.