Noise is an essential factor that affects physical and mental health in our modern society and has been identified by the WHO as a significant environmental stressor. Porous sound absorption panels are used to reduce human exposure to noise, converting the energy of sound waves into heat through frictional effects.

The current state of the art involves petrochemically based (mostly polyester) absorption panels, which are manufactured using thermoplastic nonwovens in a molding process.

This publication presents a material and technology development for the production of biobased nonwoven semi-finished products that can be recycled (material recycling). Viscose fibers are used in lengths ranging from 38 mm to 60 mm in combination with polylactide bicomponent fibers of specified lengths. The iterative optimization of nonwoven fabrics (process parameters and raw material selection) is explained, investigating their influence on the resulting acoustic and mechanical properties. The relationship between the basis weight and porosity of the nonwoven fabrics and sound absorption is demonstrated. Furthermore, mechanical properties such as modulus of elasticity and strength, as well as the influencing factors of raw material selection and nonwoven fabric formulation, are discussed. The evaluated properties of the nonwoven fabrics are compared to the state of the art.

The usability of the newly developed nonwoven fabrics for industrial applications is demonstrated by their processing into sound absorption panels using a molding process. In a complex component test, sound absorption panels based on the novel biobased material are compared to established polyester-based variants and evaluated for sound absorption and transmission properties.