As steadily increasing noise pollution impacts every day life, efforts to control it have assumed increasing importance. This has allowed nonwovens to grow in the acoustics market, where today’s nonwovens producers report success for acoustic nonwovens in automotives, buildings, furniture and other applications. Offering high performing sound absorbing and sound blocking traits, nonwovens offer flexibility, cost-effectiveness and lightweight characteristics.

“Dalco, as do our competitors, sees the market in acoustical nonwovens as growing,” says Gale Shipley, Automotive sales manager of needlepunch manufacturer Dalco Nonwovens.

As part of this growth, Shipley’s company is seeing machinery upgrades, to maximize efficiencies and enhancements, as well as new machine orders occurring. “In addition, Dalco characterizes the market as evolving with our customers desiring even greater sound absorption properties that most current technologies cannot provide alone. We see that having the ability to marry different technologies is what will be needed for this evolution to continue.”

Dalco manufactures specialty needlepunch nonwovens for acoustic enhancement in the automotive, flooring, construction, and office panel industries. In automotive, it customizes underbody shields, wheel well liners, trunk parts and carpet sound absorption layers to mitigate sound propagation from outside the cabin to in and from inside the cabin out. In the flooring sector, the company designs nonwovens to be utilized under carpet/tiles and in construction, Dalco’s products enhance sound absorption in the drywall area as well as in ceiling tiles. Its office panel nonwovens not only provide the acoustical properties for office cubicles but also have the ability to be molded into unique shapes.

In the acoustics market, Dalco’s needlepunch nonwovens primarily compete with foam products and spunbond/meltblown products. “Unlike foams and SMMS products, however, fibrous nonwoven products can be engineered for not only the acoustical properties but for rigidity, tensile/elongation needs, moldability and durability by simply changing the blend formula and weight. In some cases, Dalco’s needlepunch polyester nonwovens can be recycled back into fiber, which most foam composites cannot,” Shipley explains.

Frank Heislitz, CEO of Freudenberg Performance Materials, says his company’s acoustic solutions are competing with reinforced plastic, injection molded materials, foam, EVO or foil. “Nonwovens are lighter than other materials and they provide very high acoustic absorption, which gets even more important in e-mobility,” he says.

Another important aspect for customers, he adds, is that nonwovens are easy to handle allowing efficient assembly. 

There are three main factors driving growth for acoustic nonwovens from Freudenberg’s point of view. First is e-mobility. Good sound absorption in vehicles increases the comfort for the driver and has a high priority for electric cars because electrical drive trains cause less noise than combustion engines and because other noise sources in different frequency ranges become more important, according to Heislitz.

Secondly, fuel economy and efficiency requirements are driven by regulations dealing with issues such as CO2 reduction in the European Union, Corporate Average Fuel Economy standards (CAFE) in the U.S., or various fuel economy regulations in Asia. Nonwovens are helping to achieve these goals.

Finally, nonwovens offer an improved driving experience for the end-customer. “Good sound absorption in vehicles increases the comfort for the driver. Feeling comfortable in a car does not only depend on sophisticated features, but also on the unconscious perception of sensory impressions,” Dr. Heislitz explains. “There is a growing demand for creative and individualized car interiors, [and] the car is being used more and more as a mobile office in which good sound absorption is essential.”

Main applications for Freudenberg in the acoustic market are acoustic pads, microfilament materials based on Evolon technology and underbody shields.

Freudenberg’s lightweight acoustic pads provide outstanding sound absorption inside the vehicle and are cost efficient. They can be used for door panels, headliners, trunk areas and wheelhouses, among other areas. Meanwhile, the company’s Evolon microfilament technology can provide superior sound absorption inside cars. Since the material is made of microfilaments that are up to 100 times thinner than a human hair, significantly lower weight and therefore reduced fuel consumption can be achieved. Evolon is being used in interior trims, dashboards, hoods and car mats.

In other areas of the car, a nonwoven composite that utilizes Freudenberg technology is incorporated into molded underbody shields and wheel liners. This new multi-layer composite offers improved durability, abrasion, acoustical performance, temperature resistance and tear properties, all while offering a 15-40% weight savings compared to current product offerings, Dr. Heislitz says. “The construction is 100% recyclable and can be utilized in a closed loop system.”

For its part, Lydall, a global manufacturer of specialty engineered materials, offers acoustic nonwoven products that are often designed to perform the function of two or three other traditional materials with one engineered solution. According to the company, they can be tailored to provide high quality aesthetics, stiffness, durability, chemical resistance, and even designed to meet the latest fire protection standards. In many cases Lydall’s engineered nonwoven products can achieve the system level needs of its customers with simpler, more cost effective designs over traditional acoustic materials that often require structural support, protective layers, and aesthetic coverings, the company says.

Lydall’s range of acoustic absorbing and sound blocking constructions are primarily supplied to the automotive, building construction and industrial markets. The fact that its nonwoven acoustic materials offer high absorption properties at a low mass versus traditional materials allows its customers to improve system performance while also reducing weight and managing system cost.

One of the factors helping drive growth for acoustic nonwovens, from Lydall’s point of view, is that consumers value the benefits of well-designed acoustic systems and continue to demand improved levels of noise control in many areas of their lives. Noise levels inside cars, offices, homes and even public buildings become more important as the use of audio systems such as hands free calling and voice control products continues to expand. Because of this trend, Lydall anticipates growing opportunities for engineering acoustic solutions in the automotive and transportation markets as well as the commercial and residential building construction markets.

New Applications
As nonwovens continue to replace other materials in the acoustic market, they’re also being used in new applications.

From Sandler’s perspective, applications in room design and interior acoustics are a relatively new field of use and new product designs continuously emerge in this market. The company is working with customers in these markets, designing new product solutions together and incorporating its fibercomfort nonwovens into its partner’s acoustic products. “Our customers enhance our nonwovens with print motifs; lamination; flocking, for instance to create a roughcast look; or even with coatings made of natural materials such as hay or cornflowers to create individual designs. In this way, the textile materials help create an original look for every room,” says Gerhard Klier, Sandler’s sales director of Technical Products.

Sandler continues to see room designs become more spacious in private homes and office buildings, where more open-plan floor layouts are being designed. Because of this, acoustic room elements have become vital in ensuring a quiet, pleasant atmosphere despite the hustle and bustle of everyday life, thus partitions, acoustically efficient wall decoration and acoustic furniture are in high demand, according to the company. “The market is growing and nonwovens commend themselves to these applications,” Klier says.

As the world population grows, Dalco’s Shipley is seeing expanded usage for acoustical nonwovens in construction and flooring for large apartment complexes and theater rooms, as well as in mobile office panels. “At this time, the imagination of the design engineers is the window of the future,” she says.

While automotives has continued to be a major market for acoustic nonwovens, companies continue to see more nonwovens being utilized throughout the vehicle. Shipley attributes this to the material’s cost-effectiveness while maintaining similar aesthetics and acoustical parameters. “A great example of this is the large growth of dilour nonwoven carpets and floor mats once strictly supplied by tufted carpet,” she points out.

Freudenberg’s CEO agrees that acoustic nonwovens are being found in other areas of automobiles. In addition to traditional applications in the automotive interior such as the dashboard, door panel, trunk-liners and headliners, Dr. Heislitz sees a trend towards nonwovens solutions in the exterior of a car like underbody shields, wheel-arch liners and in the engine compartment.

For Turkish nonwovens producer Siteks, the oldest company within the Hassan Group, demand for acoustic materials is increasing in many markets in order to gain more comfort. These include sea-air-ground transportation as well as public areas—cinemas, sport halls, offices, hospitals, schools, restaurants and mechanical rooms.

“The possibilities of having various thickness, weight and easy recipe options [allows] nonwovens to gain more and more market share in acoustic markets every passing day,” says Ahmet Ilhan, export manager, Siteks.

Siteks’ acoustic nonwoven felts are utilized in the automotive, construction and white goods sectors.

In the automotive industry in particular, Ilhan says lightweight and sustainable products are very important nowadays. For this reason, the company has developed natural fiber reinforced thermoplastic felts and glass fiber reinforced thermoplastic felts for door panels, load floors, headliners, and other areas.

Siteks also recently developed a self-exhausting thermal bonded insulation felt. In the production of this new product, cotton fibers from recycled denim and thermoplastic fibers are used, and there are no chemical binders, resins or any irritant materials in the product. Because of its self-exhausting properties, Ilhan says the product is a safe alternative choice for thermal and acoustic insulation.

A Greener Profile
As companies continue to comply with new environmental regulations in specific markets, such as automotives, and also look to reduce their overall environmental footprints, nonwovens are helping them achieve these goals.

“There is a more and more growing awareness of environmental issues that fosters a sustainable use of resources,” says Freudenberg’s Dr. Heislitz.

Freudenberg’s nonwovens are helping address this trend by reducing weight and thus improving fuel economy of cars; fostering environmentally friendly production processes by enabling customers to recycle waste; with the use of latex and binder-free chemical products; and increasing the share of post-consumer recycling.

Many of Lydall’s acoustic products utilize post consumer and post industrial waste streams as one of its primary raw materials. This allows the company to minimize the environmental impact of its products and helps to reduce the environmental impact of polymer waste streams from other industries. These strategies allow Lydall to offer competitive costs to its customers while also helping them meet the growing demands for environmental sustainability from their customers and end users, the company says.

Dalco’s Shipley says the company will always offer customers products that can be 100% recyclable. For instance, its specialty needlepunch nonwovens in polyester blends can be recycled back into fiber. “This recycling further aides the NA regenerated fiber manufacturers to minimize huge price fluctuations,” she notes.

On the other hand, other blends offered by Dalco can be incinerated or manufactured into airlaid shoddy to avoid dumping into landfills.

According to Sandler’s Klier, as environmental awareness and sustainability considerations concern all areas of our lives by now, insulation solutions made from natural materials are in high demand and consumers are looking for sustainable building solutions. “Insulation materials made from wood, cellulose or even reed are – figuratively speaking – en vogue,” he says. “However, nonwovens demonstrate that synthetic materials can provide just as much sustainability. Being made from 100% polyester, Sandler fibercomfort nonwovens are fully recyclable even after decades of use. The nonwovens are also partially made from recycled fibers themselves, supporting closed material cycles and contributing to the conservation of resources.”

Moreover, particularly in construction, fibercomfort’s heat-insulating properties help lower the need for heating in the building. “In this way, the nonwovens contribute to reducing energy consumption,” he concludes.