Abstract: The present application discloses a rear cover of a vehicle lamp having a valve structure and infrared radiation drying and air discharging function, which includes an end cover provided with a plurality of air vents, a connecting base for connecting with a vehicle lamp housing, and a membrane module for infrared radiation drying and air discharging. The end cover and the connecting base are assembled and connected to form the rear cover of the vehicle lamp. The membrane module is built in a cavity of the rear cover of the vehicle lamp. At least one valve is provided on a path of air circulation inside and outside the vehicle lamp housing through the rear cover of the vehicle lamp, and the at least one valve automatically opens and closes under impulse of air pressure difference.

Abstract: The present invention discloses a high sound absorption coefficient expanded PTFE composite fiber cotton, comprising a melt-blown high polymer fibrous layer and an expanded PTFE film layers or a modified film layer of expanded PTFE, the modified film layer of expanded PTFE is made by conducting modification treatment to a PTFE film; the high sound absorption efficiency expanded PTFE composite fiber cotton is made by combining the melt-blown high polymer fibrous layer and the expanded PTFE film layer or the modified film layer of expanded PTFE. Thus, the present invention with better full-frequency sound absorption capability and marked full-frequency sound absorption effect can be bound in a large area or filled on automobiles' engine hoods, body racks or the inner side face of automobile trunks to substantially absorb automobile noise; it has advantages such as chemical inertness, waterproof, dustproof, permeable filterability, long service life and weldability.

Abstract: The present invention discloses a high-sound-absorption composite material for a traffic sound barrier. The surface of a porous sound-absorption material layer is clad with a cladding layer in a sealing way, and the clad parts and joints are in sealed connection. The cladding layer is an expanded polytetrafluoroethylene microporous membrane or a modified membrane of the expanded polytetrafluoroethylene microporous membrane. A preparation method is disclosed, comprising the following steps of cutting the porous sound-absorption material; covering the surface of the porous sound-absorption material with the expanded polytetrafluoroethylene microporous membrane or the modified membrane of the expanded polytetrafluoroethylene microporous membrane; performing sealed connection on the clad parts and joints.