Thermoplastic piece e.g. reinforcing flap, welding method for airbag of motor vehicle, involves modifying surface state of face of one of pieces to present rough surface state that increases abrasion capacity of pieces

摘要

The method involves pressing faces (3, 5) of pieces e.g. reinforcing flap (1) and dashboard flap (2), one against other, and vibrating the pieces with respect to one another along a welding direction (D) during a friction phase for creating local warm at a place of a junction between the faces. Vibration between the pieces is stopped and paused until materials of the pieces are integrated to form a solid connection between the pieces. A surface state of the face (3) of the piece (1) is modified to present a rough surface state that increases abrasion capacity. An independent claim is also included for an airbag comprising a reinforcing flap carrying a hinge system for permitting the airbag to be deployed at a dashboard flap.