Optimization solution for EV-electric vehicle limit bars: A direct customer requested a transparent square bar to be used by end users to secure components within their vehicles and also to display interior trim. The limit bar required high transparency, a smooth surface, and square corners. Acrylic, with its over 92% transparency and wear resistance, immediately came to mind. However, we found PC—polycarbonate to be a more suitable material compared to acrylic. PC also offers high transparency, a simpler manufacturing process, excellent physical properties, and a lighter weight, which contributes to vehicle weight reduction. This combination of factors allows for better cost control.
Based on the customer's drawings, we used a plastic extrusion process to manufacture polycarbonate strips. A problem arose: a small number of bubbles in the stopper strips. While this would pass inspection according to the customer's standards, we felt there was a way to achieve a flawless product. Since the product primarily serves as an internal structural component, the material's properties could not be altered. We investigated the manufacturing process, and our engineers determined that the bubbles were caused by the product's small size, preventing the escape of internal gasses from the polycarbonate material during extrusion (commonly referred to in the industry as "air entrapment"). The only solution was to address the trapped gas. We designed a structure in the mold to allow the gas to escape, ultimately creating a hole in the center of the polycarbonate strip. We also had the end customer confirm whether the hole would affect assembly. The customer ultimately approved the solution, and the product was successfully mass-produced, with a formal material number assigned.
Although the product is an internal structural component, minor cosmetic defects do not significantly impact its performance. As a manufacturer with twenty years of experience in plastic molding, we must avoid end customers questioning the product quality management of the direct customer manufacturing due to appearance. Lanxin Company has strict production and quality inspection processes and we insist on value output.