What is the production process of fiberglass mat?

High-end fiberglass mat on the market are primarily produced using a wet-process matting technique, similar in principle to papermaking. Using alkali-free E-glass chopped fiberglass as raw material, randomly distributed fibers are bonded together with an adhesive to form a thin sheet of nonwoven fabric.

 

Complete Process Flow:

1. Glass Melting and Drawing (Upstream Raw Material Preparation): Raw materials such as quartz sand and boron-calcium minerals are fed into a furnace according to the formula and melted at a high temperature above 1200℃ to become E-grade alkali-free glass liquid. This liquid is then drawn through a perforator into continuous fiberglass filaments with a diameter of a few micrometers. The surface is sprayed with a silane sizing agent and wound into filament yarn bundles...

 

2. Fiber Chopped Short Fibers: The fiberglass filaments are chopped into 3-12mm short fibers. Fiber length and dispersion are controlled, and fuzzy fibers and large bundles are removed, serving as the main material for mat production.

 

3. Pulping and Dispersion: Chopped fibers are fed into a dispersing tank, where water, dispersants, defoamers, and other additives are added. The mixture is thoroughly stirred to completely disperse the fibers in the water, forming a low-concentration, uniform fiber suspension slurry. This slurry is then transferred to a storage tank for later use.

 

The slurry concentration is extremely low, typically only 0.015-0.03%, ensuring the fibers do not clump together and guaranteeing the uniformity of the felt surface.

 

4. Inclined Mesh Forming and Vacuum Dewatering: The slurry overflows evenly from the pre-mesh box onto a moving inclined mesh forming belt. Using gravity and a vacuum dewatering tank, water is drained through the belt, and fiberglasss randomly and disorderly deposit on the mesh surface, forming a wet felt blank. At this stage, the wet felt has a very high moisture content and almost no strength.

 

5. Pre-Dewatering: The wet felt blank is transferred to a felting machine and further dewatered using a vacuum suction box and press rollers, increasing the strength of the wet felt blank and facilitating subsequent sizing and conveying.

 

6. Applying Adhesive (Sizing): The organic adhesive emulsion is applied to the fiber intersections of the felt blank using impregnation or spraying methods. Excess adhesive is then removed by vacuum suction, precisely controlling the adhesive content. The adhesive determines the dry strength, water resistance, and temperature resistance of the thin felt, making it a key formulation point.

 

7. Drying and Curing: The felt blank enters a hot air oven, with segmented temperature control between 100-250℃. Moisture evaporates first, then the adhesive cross-links and cures, forming strong bonds at the fiber intersections.

 

Temperature control is crucial: excessively high temperatures cause the felt surface to yellow and become brittle; insufficient temperatures result in incomplete bonding, poor strength, and fiber shedding.

 

8. Cooling and Online Inspection: After exiting the oven, the felt is cooled. Online thickness gauges, weight meters, and defect detection cameras monitor product indicators in real time, providing feedback for adjustments to process parameters.

 

9. Slitting, Rolling, and Packaging: The felt is slit to the customer's required width, rolled into large rolls, inspected, and packaged for warehousing.

Dry Process (Ordinary Chopped Straight Strand Mat, distinct from thin mat)

 

Some thicker mats use the dry process: chopped strands are air-blown onto a conveyor belt, randomly laid out, and then adhesive is sprayed/spread, followed by drying and curing.

 

Dry-process mats have lower surface uniformity than wet-process mats and are mostly used for ordinary fiberglass reinforcement; thin mats, electronic mats, and waterproof base materials are mostly produced using the wet process.

 

Key Process Control Points

 

Fiber Dispersion: Eliminating fiber bundles and lumps directly determines the appearance of the mat surface;

Pulp Concentration, Wire Speed, and Vacuum Degree: Controlling basis weight uniformity;

Adhesive Application Amount: Affecting tensile strength, water resistance, and heat resistance;

Oven Temperature Profile: Preventing embrittlement and incomplete curing.