The production process for sound-insulating felt generally involves steps such as compounding (mixing), calendering, curing, winding, and packaging. Its composition typically includes a base material, fillers, and additives. Base materials include asphalt, rubber, EPDM, PVC, and CPE; fillers include metal powder, quartz powder, and heavy calcium carbonate; and additives are used to enhance physical properties such as elasticity, tackiness, toughness, fire resistance, and tear strength.
One type of composite damping sound-insulating felt is composed of the following ingredients (by weight): 20–30 parts PVC, 6–16 parts nitrile rubber, 8–18 parts EPDM rubber, 30–80 parts halogenated butyl rubber, 15–25 parts barite powder, 6–10 parts quartz powder, 3–5 parts aluminum powder, 5–10 parts calcium carbonate powder, 10–15 parts fly ash, 1–9 parts flame retardant, 4–8 parts anti-aging agent, 2–6 parts defoamer, 5–15 parts acrylate, 2–10 parts plasticizer, and 1–5 parts vulcanizing agent.
The primary component of non-woven sound-insulating felt is cotton fiber. The manufacturing process begins by loosening the cotton fibers and adding phenolic resin or low-melting-point fibers. The mixture is carded into a fiber web, which is then layered to a predetermined thickness using a web-laying machine. Finally, heat is applied to melt the phenolic resin or low-melting-point fibers, thereby bonding the cotton fibers together to form the sound-insulating felt.