Water-based damping coatings in conventional passenger coaches
Noise and vibration while a coach runs affect passenger comfort, and the cabin is an enclosed space, so harmful-substance content matters too.
Why water-based
Traditional organic-solvent damping coatings are based on organic solvents; water-based coatings use water as the base. A coach interior is an enclosed space, so the VOC and hazardous-substance status of a specific model should follow its current technical data sheet (TDS), safety data sheet (SDS) and test methods.
How it is applied and how it works
It is usually applied to the inner surface of the body by airless high-pressure spraying. The coating turns structure-borne noise travelling through the body into heat in the material itself, and after spraying the inner surface forms a closed layer that reduces outside noise passing inward.
Features and limits in the source material
The features listed include low VOC, low smoke toxicity and low smoke density; the actual figures follow the model's data and test reports. Water-based coatings cost relatively more to make and are harder to apply, and their long-term effect and durability still need observing and verifying.