Sound absorbing material e.g. melamine resin foam, for e.g. carriage wall of rail vehicle, has surface with portion coated with flame retardant powder or sprinkled with retardant solution, where material is covered by sound transparent film

摘要

The material has a surface including a portion that is coated with a flame retardant powder (2) or that is sprinkled with a flame retardant solution, where the material is covered by a sound transparent film (3). The flame retardant powder is stirred with an adhesive. A layer (1) that is formed from the flame retardant powder is arranged between the film and the material. The flame retardant powder or the flame retardant solution is applied on an outer side of the film.