In mine and tunnel operations, a wide variety of problems are often encountered, with water leakage being the most common. With the R&D and development of polymer materials, polyurethane two-component organic water-blocking materials have attracted more and more attention.

Working principle: The organic water blocking material is injected into the fractures of coalrock/ mass, and the consolidated matter generated by the reaction can effectively bond the broken rock mass into a whole and effectively block the water flow in the fracture.

Polyurethane water blocking products are two-component resin materials that are mixed by a special pump and react quickly to produce a product with certain strength, cohesion and deformation.

Features:

1. Rapid reaction, thickening and hardening;

2. Good adhesion, the resin generated by the reaction has a certain elasticity, which can be deformed with the rock formation to ensure a good plugging effect;

3. Good permeability, and the resulting resin is durable and strong.

Factors affecting the water blocking effect of water blocking materials:

First, the characteristics of the materials itself

1. Composition and proportion: for Polyurethane water-blocking materials, if the ratio of isocyanate group to hydroxyl group is improper, it will affect the cross-linking density of the cured material, and then affect the strength and toughness of the material, and reduce the water-blocking effect.

2. Reaction speed: too fast reaction speed may cause the material to be solidified before the gap is fully filled, and the water flow channel cannot be completely blocked; Slow reaction makes it difficult for the material to form under the erosion of groundwater currents.

 Second, construction factors

1. Injection pressure: Insufficient injection pressure will make the water plugging material unable to fully fill into the tiny cracks and pores of the mine, affecting the integrity of the plugging. However, excessive pressure can lead to material leakage, resulting in waste and affecting the effectiveness of the plugging.

2. Construction environment temperature: temperature has a great impact on the curing speed and performance of water blocking materials. When the temperature is too low, the material cures slower or may not even cure completely; Temperatures that are too high can cause the material to cure too quickly, causing internal structural defects.

 3. Geological conditions

1). Fracture size and shape: If the fracture is too large, the water-blocking material may be lost before it is fully cured; Fractures with complex shapes and many branches can make it difficult for the material to fill evenly, leaving a channel for water flow.

2). Groundwater conditions: too fast groundwater flow rate will have a scouring effect on the water blocking material, making it difficult for the material to solidify at the predetermined position; Chemical properties such as pH in water may also affect the curing reaction of the material.

Qichen is a manufacturer specializing in the production of Blended Polyols for Polyurethane rigid foam system and has been contributing to the development of polymer materials for water blocking in mines and tunnels.If you want to know more, please feel free to consult us.