Closures weatherstrips with variable cross sections 2018-36-0152
Closures systems performance is a trade-off between NVH (Noise, Vibration and Harshness) and DCE (Door Closing Efforts) requirements. Dynamic sealing performance and sheet metal rigidity are the key contributors for a stable system. The seals actuate like a spring on the system. Higher seal load is good for NVH performance, adding more dumping to the system, but it will negatively affect DCE, as it will demand additional energy to close the system. Nominal seal load must be defined to achieve a balance between these attributes. This study is about dynamic sealing profiles with variable seal load, which provides tunable solutions to address the trade-off between NVH and DCE on the side doors or rear closures.
Dynamic sealing weatherstrips are made of sponge EPDM extruded profiles with a specified load, defined by its CLD (Compression Load Deflection), which is given by the cross section design. While standard extrusion process produces a single cross section profile, a new extrusion technology provides the possibility of varying the profile cross section along the extrusion, thus the possibility to have different CLDs along the length of door perimeter.
This technology can assist on the issues that demand quick solutions on vibrations and load relieves, providing good results for these critical attributes. Timing and costs are very attractive as well on the small car segments.