Problems with exterior trim components often emerge not during vehicle assembly, but afterward: rubber overmolding on grilles may peel or delaminate; mudguards can crack upon impact in cold weather; sealing strips may lose their resilience after prolonged compression, leading to air leaks or water ingress; and wiper blades might begin to chatter or make noise after just six months of use.
These issues translate into warranty and compensation costs, yet the root cause is almost always determined at the material selection stage.
▍Radiator Grilles: Precision Overmolding Requires Complete Filling and Strong Adhesion
Grilles feature thin walls, long flow paths, and intricate structures. If a material lacks sufficient flowability, it can result in incomplete filling (short shots) or flash. Furthermore, the high-temperature environment of the engine bay-combined with repeated thermal cycling-can cause soft rubber components to peel or delaminate, compromising both tactile quality and assembly precision.
KESUN EPK7090 (from the EPK series) offers an optimal balance of high flowability, heat resistance, and aging resistance. It features low odor, ensures complete mold filling, and provides stable bonding lines. It is well-suited for PP overmolding and structural exterior components, and is currently in stable mass production for several vehicle models.
▍Mudguards: The True Test is Resistance to Low-Temperature Brittleness
Mudguards are frequently subjected to impacts from gravel and exposure to mud and water. In cold regions, standard materials can easily become brittle and crack.
KESUN EG80BS (from the EG-S series) is engineered for extreme toughness and cold resistance; it remains crack-free even at -45°C. With exceptional impact resistance, it is suitable for diverse climatic conditions, including markets in northern regions and export destinations with cold climates.
▍Sealing Systems: Low Compression Set, Reliable Sealing, and Long-Lasting Elasticity
Sealing strips are subject to constant compression and bending. A loss of resilience-or "compression set"-inevitably leads to wind noise and water leaks.
The M1 series offers low compression set, consistent resilience, and excellent aging resistance. Combining strength with flexibility, these materials ensure long-term cabin quietness and effective waterproofing. They serve as a proven, high-performance alternative to imported materials.
▍Wiper Blades: Aging Resistance Is Fundamental-NVH Performance Is Equally Critical
A common issue during the production of wiper blade rubber strips is the formation of uneven particulate spots. Solutions include adjusting production speeds, enhancing screw shear, and optimizing material formulations.
Wiper blades are subjected to compression, friction, and environmental degradation (ozone and UV exposure). Over time, they harden, develop cracks, and eventually begin to chatter or produce abnormal noises.
The P1271-73AB series-a specialized material for wiper blades-offers excellent resistance to ozone and UV radiation. It features a matte finish and stable compression-set recovery. The material is ready-to-use via extrusion (requiring no vulcanization), helping to improve NVH (noise, vibration, and harshness) performance while protecting the internal metal components.
▍Beyond the Grade: Reliable Delivery Capabilities
1. KESUN is a nationally recognized high-tech enterprise with three major production bases and an annual capacity of approximately 100,000 tons. We ensure stable, large-scale delivery across a diverse range of material grades and customized solutions. Our operations strictly adhere to the IATF 16949 standard, and a Certificate of Analysis (COA) is provided for every batch.
2. In line with trends toward lightweight design and sustainability, we offer recycled material options complete with carbon footprint documentation. We also maintain compliance for food-contact and medical-grade applications, enabling use in even the most demanding environments.
3. We provide responsive, 24/7 technical support, rapid sampling for small-batch requirements, and end-to-end guidance from trial production through to full-scale manufacturing.
If your products are experiencing issues such as delamination (separation of the overmolded layer), low-temperature brittleness, loss of sealing resilience, or challenges regarding recycled material compliance and carbon footprint tracking, please leave a comment or send us a private message with your operating conditions and technical drawings. Our engineers at KESUN are ready to assist with grade selection, material strategy, and sample arrangements.
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