In the field of automobile manufacturing, car sealing strips undertake the core mission of isolating wind and rain and reducing noise, and directly affect the air tightness, ride comfort and energy efficiency of the whole vehicle. With the increasing diversification of vehicle model design, standardized car sealing strips are difficult to match complex body structures. Car sealing strip technology with customizable cross-sectional shapes is becoming a strategic solution for OEMs and parts suppliers to enhance product competitiveness.
The necessity of cross-sectional customization stems from the diversity of body structures. The geometric forms of areas such as body sheet metal joints, door and window rails, and sunroof edges vary greatly. For example, the streamlined waistline used by new energy vehicles to reduce wind resistance requires the car sealing strip to have a gradual curvature; the wide frameless doors of SUVs require special-shaped sealing lips with higher compression; and the extremely narrow gaps of laser-welded bodies require ultra-thin flat cross-sectional designs. If a fixed cross-sectional car sealing strip is forcibly installed, local stress concentration, sealing failure or abnormal noise problems will occur. Customized cross-sections can achieve millimeter-level fit with the body gap, reducing the risk of air leakage and water leakage by more than 70%.
Precise cross-sectional design can enable four core performances. First, the multi-cavity structure can resist 120km/h high-speed wind pressure and significantly improve air tightness. Secondly, the hollow velvet or composite variable cross-section design can absorb high-frequency vibrations in a targeted manner and effectively block tire noise and wind noise. For dynamic sealing areas such as doors and windows, the “main lip + auxiliary lip” structure can reduce friction loss and extend service life during repeated lifting and lowering of the glass. In addition, the hidden water guide groove design (commonly seen in roof sealing strips) can achieve rapid diversion of rainwater to prevent it from seeping into the cabin.
Achieving customized cross-sections requires a three-stage technical process. The first stage relies on 3D scanning and digital modeling: using a blue light scanner to obtain the body seam point cloud data, combined with CAE simulation to analyze the compression and rebound characteristics. The second stage is to conduct modular cross-section function design: the base bearing area uses high-hardness TPE or metal inserts to provide support; the dynamic sealing area uses EPDM/TPV composite rubber with a low friction coefficient; the decorative bonding area uses a colored skin treatment to match the body paint. The third stage adopts the micro-foam co-extrusion process: using multiple extruders to form a density gradient structure in one step, for example, the surface dense layer is anti-aging, and the internal microporous layer achieves a 15% weight reduction and improves the sound absorption effect.
In order to maximize the benefits of customization, it is recommended that the OEM provide key parameters simultaneously during the development stage of the new model: including the gap tolerance band of the key area of
We provide full-chain services from cross-section design, mold development to mass production, and have accumulated more than 120 successful car model cases. If you need customized solutions for the body sealing system, or submit 3D data to start free cross-section adaptation analysis, please feel free to contact us.
