Basalt is a volcanic extrusive rock and one of the most widely existing and distributed minerals on Earth. The continuous fiber produced from it represents a qualitative leap in fiber quality compared to ordinary rock wool.

Its high elastic modulus, high thermal stability, and excellent acid and alkali resistance have led to its widespread application.

1. Advantages of basalt fiber wet-laid nonwoven fabric

1.1 Good Tensile Strength and Reinforcement Effect

Basalt fiber wet-laid nonwoven fabric can retain its strength for 1200 hours under the action of water at 70°C, whereas ordinary glass fiber loses its strength in less than 200 hours. Its tensile strength can increase by 30% at temperatures of 100–250°C, while ordinary glass fiber decreases by 23%.

1.2 Excellent Corrosion Resistance and Chemical Stability

Basalt fiber wet-laid nonwoven fabricexhibits unique chemical stability in alkaline solutions and has better acid resistance than ECR glass fiber, offering significant acid and alkali resistance at a much lower cost.

1.3 Good Insulation Properties

The dielectric loss tangent of basalt fiber wet-laid nonwoven fabricis similar to that of glass fiber. Basalt fiber treated with specialized sizing agents has a dielectric loss tangent 50% lower than ordinary glass fiber.

1.4 High-Temperature Resistance and Low-Temperature Thermal Stability

Basalt fiber wet-laid nonwoven fabricheat resistance is close to that of high-temperature quartz glass fiber. At 400°C, it retains 85% of its original breaking strength; at 600°C, it retains 80%. Under the same conditions, mineral wool retains only 50%–60% of its original strength, while glass wool is completely destroyed.

1.5 Excellent Elastic Modulus

The elastic modulus of basalt fiber is similar to that of expensive S-glass fiber, with comparable strength. It demonstrates good weaving performance for fabrics weighing 150–210 g/m². It can replace S-glass and other glass fibers in manufacturing insulation products and composites, hard armor, and various GFRP products.

2.Preparation Process of Basalt Fiber Wet-Layer Nonwoven Fabric:

2.1 Raw Materials and Pretreatment: 

Select short basalt fibers wet-laid nonwoven fabric of a certain length (generally 3–12 mm). Due to their smooth surface and tendency to agglomerate, dispersants (such as polyacrylamide, surfactants, etc.) need to be added, sometimes along with a small amount of binder (latex, starch, or water-soluble resin). Use high-speed stirring or pulping equipment to fully disperse the fibers in water, forming a stable and uniform suspension slurry.

2.2 Basalt Fiber Wet-Laid Nonwoven Wet Forming: 

Feed the fiber slurry into a wet forming system similar to a paper machine (such as a wire or cylinder former). In a flowing water medium, the fibers randomly deposit on the surface of the forming wire, forming a uniform fiber web. This step requires high slurry concentration (usually 0.1%–0.5%) and flow field stability to ensure uniform areal density.

2.3 Dewatering and Pressing: 

The initially formed wet fiber web has a high moisture content. Water is gradually removed through gravity dewatering, vacuum filtration, and mechanical pressing to improve the contact density between fibers, providing a foundation for subsequent consolidation. 

2.4 Consolidation and Drying：

The consolidation method is selected based on product performance requirements: chemical bonding and hot-press consolidation.

2.5 Finishing

This includes hot-pressing, surface treatment (such as impregnation with functional coatings), cutting, and winding to improve mechanical properties, temperature resistance, or specific functions (such as filtration and insulation).

3.Basalt fiber wet-laid nonwoven fabric Process Characteristics

This method achieves highly uniform fiber distribution and controllable pore structure, making it suitable for preparing thin materials; however, it requires advanced dispersion technology and equipment, resulting in slightly higher production costs compared to dry methods.